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Journal of Plant Sciences

Heterologous expression of peroxidase genes has been shown to influence morphology
and stress responses of several crop plants but little is known about the effect
in woody species. In this study, a barley cell-wall peroxidase gene (prx8),
peviously shown to influence growth and stress tolerance in tobacco, was introduced
into the genome of apple (Malus domestica cv. Greensleeves) via Agrobacterium-mediated
transformation and the presence of the transgene confirmed by PCR and Southern
blot analysis. The transgenic plants had up to 4-fold higher levels of peroxidase
activity compared to wild type plants and exhibited faster growth and increased
xylem production. Leaf discs were incubated at high temperatures (44°C)
and electrolyte leakage measurements indicated enhanced tolerance against temperature
stress. This effect was confirmed when whole plants were subjected to heat stress
after 6 and 12 months growth in soil. These results indicate a link between
peroxidase activity levels and resistance to thermal stress, as well as biochemical
and physiological changes, in this woody plant. 2014/05/29 - 07:58

In order to study the effects of sowing dates on phenology and yield of coriander (Coriandrum sativum L.), an experiment was conducted during 2010-2012 based on a randomized complete block design with three replications in HRS, Mondouri, BCKV, India. Six sowing dates included 5th November (D1), 12th November (D2), 19th November (D3), 26th November (D4), 3rd December (D5) and 10th December (D6). The results showed that a delay in sowing from November 5 to December 10 decreased plant height, number of primary branches per plant, days to 50% germination, days to flower initiation, days to 50% flowering and days to fruit maturity significantly. The 5th November exhibited significant improvement in yield attributes namely numbers of umbels per plant (25.58), umbellets per umbel (6.85), seeds per umbel (30.55), test weight (12.61 g), seed weight per plant (6.85 g) and seed yield ha-1 (1098.33 kg ha-1). 2014/05/19 - 10:35

Okra (Abelmoschus esculentus (L.) Moench) is an economically important vegetable crop grown in different part of Ethiopia particular in south western part of the country. The objective of the study was to evaluate genetic diversity among Okra accessions based on quantitative morphological traits. Twenty five Okra accessions were planted in 2011/2012 at Gambella in randomized complete block design with three replications. Data on 20 quantitative traits were collected and subjected to various statistical analyses. The analysis of variance showed significant differences (p<0.01) among the accessions for all quantitative characters measured. Cluster and distance analysis of quantitative characters based on multivariate analysis pointed out the existence of five divergent groups. The maximum distance was observed between cluster II and I (2846) while the minimum was between I and III (213.64). Principal component analysis indicated that six principal components explained about 83% of the total variation. Differentiation of germplasm into different cluster was because of cumulative effect of number of characters. Accessions like GM7, GM9 and GH13 from Gambella collection and AS4 and AS11 from Assosa collection are recommended for the next breeding work as they are high yielder accessions compared to the others. The present study indicated a considerable amount of variability for the majority of the quantitative characters in Okra for exploitation. However, it is recommended that the experiment should be repeated at more location and years with more collections to confirm the obtained results. 2014/05/19 - 10:35

The field experiment was conducted during at the Teaching and Research Farm, Ladoke Akintola University of Technology, Ogbomoso, Nigeria. To evaluate the rate of Amaranth growth to different plant based mulching materials and their response to weed infestation. There were three plant materials incorporated into the soil which are tithonia, neem, gliricidia with four weed levels being weed free, weed once, weed twice. They were replicated three times making a total of thirty-six experimental plots. The experiment was laid out in a Randomized Complete Block Design (RCBD), data collected was subjected to Analysis of Variance (ANOVA) and means were separated using Duncan Multiple Range Test (DMRT) at 5% probability level. Results from the experiment showed that better growth and yield of amaranth was obtained in the weed free plot. Both duration of weed eradication and weed infestation had significant effect on plant height, stem girth and yield of amaranth. In general, all these parameters increase as the duration of weed amaranth competition decreased, while growth parameters increase with an increase in weed eradication. However, highest value was obtained from tithonia mulch plots and neem mulch produced the lowest value on plant height and yield while gliricidia mulch gave the lowest value of stem girth. 2014/05/19 - 10:35

Random amplified polymorphic DNA markers were used to determine the altitudinal
variation within and between Plagiochasma appendicualtum collected from
different altitude of Western Himalaya especially from Mussoorie region of India.
Findings of UPGMA cluster analysis and band frequency of all the nine accessions
were separated according to their altitudes supporting to their morphological
differences as well. Gene flow and spore dispersal plays an important role in
the polymorphism. Gene flow within P. appendiculatum growing on same
altitude is very high as compared to accessions collected from different gradient
of altitudes i.e., the genotypes collected from same altitude showing not so
much polymorphism compared to different altitude. It has been concluded that
the RAPD markers would be useful to characterize the altitudinal variation between
different accessions of P. appendiculatum and may be also valuable to
other bryophytes collected from various environmental condition. 2014/02/27 - 23:07

The availability of access to diverse genetic material is important to be successful
in any plant breeding effort. An investigation was undertaken to assess genetic
diversity of 24 known rice genotypes based on17 morpho-agronomic traits by using
multivariate analyses: hierarchical cluster and Principal Component (PC) analyses.
Cluster analysis separated the genotypes into two groups which are in contrast
for flowering, plant types, biomass, grain yield, seed width, seed length and
seed weight. The first three PCs explained 73.5% of the total variability. Days
to flowering, plant height, culm length, panicle length, biomass, seed length
and shape were the important traitsin differentiating the genotypes. The hierarchical
cluster and PC analyses were in agreement in grouping the genotypes. Parental
combinations from the two clusters with higher value of Euclidean distance could
be used for genetic improvement. Generally KOH1 is the most diverged genotype
from others. Thus crossing of this genotype with Azucena, CH1, KDML105 and SPR1
may result in heterotic expression in the F1 and substantial variability
in the subsequent segregating population. 2014/02/27 - 23:07

Numerical taxonomic study of eleven Combretum Loefl. species common
in southeastern Nigeria was carried out based on morphological and anatomical
characters. PAST software was used to calculate the Euclidean distances and
the coefficients were clustered by unweighted pair-group clustering method (UPGCM).
From the 107 characters employed in the numerical analysis, the species were
separated into two broad clusters (C1 represented by C. zenkeri and
C2-the remaining 10 species). The clustering further suggested that there were
groups within the genus hence C2 separated into two subgroups with C. glutinosum,
a lone sub-cluster and the other nine species, which separated into four other
sub-clusters. The similarity coefficient among the Combretum species
studied ranged from 4.69 between C. mooreanum and C. bracteatum
to 8.72 between C. glutinosum and C. zenkeri. Generally, results
obtained favour species arrangement and clustering based on phylogenetic relationship
as in C. mooreanum, C. bracteatum and C. platypterum and
habitat preference. The unknown species, Combretum sp.1 is more closely
related to C. bracteatum than any other species studied. However,
C. constrictum, C. dolichopetalum, C. glutinosum, C. hispidum,
C. paniculatum, C. platypterum, C. racemosum and C.
zenkeri have been confirmed as individual taxa based on previous classifications.
Though each Operational Taxonomic Unit (OTU) is confirmed species, we assert
that the closeness observed amongst the OTUs imply that introgression as a mechanism
of speciation in the wild, is at play in the genus. 2014/02/27 - 23:07

Rice is mostly grown in the Asian subcontinent and known by its good cooking
qualities. Its production is, however, often constrained by several biotic factors.
The present study may be useful for the development of resistant lines against
the blast disease possess high yielding capacity. Thirty nine Indica
rice genotypes were used to study the extent of genetic parameter and association
analysis for quantitative and qualitative traits. These genotypes were screened
against blast disease of rice by artificial inoculation in field. All quantitative
and qualitative traits exhibited highly significant difference (p<0.01) among
treatments, it indicates the adequate genetic variability among the genotypes
under study. Estimates of genotypic and phenotypic coefficient of variation
were high for filled grains per plant, total grains per plant, panicle initiation
and Grain Yield per Plant (GYPP). Heritability was high (>80%) for all the
characters except head rice recovery, hulling percentage and kernel breadth;
indicates the roles of additive gene action and a good scope of selection using
their phenotypic performance. GYPP showed strong positive association with yield
contributing traits while non-significant association with rest of the traits.
In blast screening, none of the varieties and F1 hybrids found highly
resistant. Among the parental lines, Anjali was resistant, HUR3022, Vandana,
HUR105 and BPT5204 were moderately resistant and six lines were moderately to
highly susceptible. Among the hybrids, only two hybrids (AnjalixBPT 5204 and
AnnadaxBPT 5204) were found resistant to rice blast disease. 2013/12/30 - 08:19

Vatica diospyroides Symington has two distinct commonly known subtypes:
The SS and LS forms distinguished by the color of petals and cotyledons. These
subtypes may also differ in their contents of the valuable products for human
health-therefore it is important to develop and share a reliable method of subtype
identification. The Random Amplified Polymorphic DNA (RAPD) technique was applied
with 3x and 5xCTAB (Cetyltrimethyl ammonium bromide) extraction procedures,
the concentrations of NaCl and DNA templates were varied and 10-mer random woody
primers were screened to find distinguishing genetic indicators. The best yields
of SS and LS DNA (412.8-578.4 μg g-1 FW) were found with phenol:
Chloroform: Isoamyl alcohol (25:24:1) followed by 5xCTAB buffer. Five effective
primers (OPU5, OPU8, OPU9, OPU14 and OPU15) gave a total of 18 DNA bands (200-2500
bp), when using 1.5 mM NaCl and 200 ng μL-1 DNA template in
PCR conditions. Of the bands, 12 were evidently polymorphic. The primer OPU9
produced 1 polymorphic band (220 bp) for LS and 1 monomorphism (at 500 bp).
With OPU15, a total of 4 bands were observed: The markers at 320, 480 and 520
bp specify the LS form, while at 900 bp the band is shared by both subtypes.
In conclusion, the V. diospyroides subtypes distinguished by different
color petals and cotyledons, are also genetically differentiated: The phenotypic
differences are not environmentally induced. These initial results encourage
pursuing genomics based phylogenetic analyses of V. diospyroides. 2013/12/30 - 08:19

This study determined whether in vitro storage of Khaya senegalensis
clones could delay their maturation and increase their capacity for adventitious
rooting. Forestry trees display the desired traits of high adventitious rooting,
rapid stem growth and long internodes when they are propagated from juvenile
rather than mature explants. In vitro storage has the potential to maintain
the juvenility of clones during the period of clonal field selection but there
is little empirical evidence to show that in vitro storage delays clonal
maturation. This study assessed the maturation of 20 clones that had been stored
for 12 months using two different methods: (1) as ex vitro stock plants
in the nursery; or (2) as shoots in vitro at 25°C. K. senegalensis
proved amenable to vegetative propagation, with high rooting percentages (76±4%)
and adventitious root numbers (5.2±0.4) from the cuttings of nursery-stored
stock plants. However, storing shoots in vitro for 12 months provided
higher rooting percentages (89±2%) and adventitious root numbers (6.3±0.5).
These results demonstrate that K. senegalensis clones did undergo significant
maturation in the nursery and that in vitro storage delayed their maturation.
In vitro storage is, therefore, an effective method for clonal archiving
that minimises investments in water, fertiliser, pesticide and space while providing
planting stock with the juvenile-phase characteristics required for forestry
plantations. 2013/09/11 - 13:11

Oman is located on southeast corner of the Arabian Peninsula and the whitefly
(Bemicia tabaci Genn) is a predominant pest responsible for vectoring
begomoviruses. Whiteflies were collected during 2011-2012 from various crops
grown in different regions of Oman for biotype and secondary symbiont identification.
Polymerase Chain Reaction (PCR) amplification with specific primers was used
for B. tabaci biotypes and secondary symbionts identification.
Only biotype B of B. tabaci was identified from whitefly population collected
from various crops in different regions of Oman. All B biotypes were found to
be infected with the secondary symbiont, Hamiltonella. The presence of
only biotype B strongly suggests that it is a well-adapted pest to a variety
of crops grown in different geographical regions of Oman. 2013/09/11 - 13:11

Alpha-amylase enzyme is the important member in physiological metabolism of high plant, especially during seed germination stage. The current study identified 19 amy1 genes from 19 hexaploid wheat (Triticum aestivum L.) accessions. The nucleotide and deduced amino acid sequences of amy1 genes were analyzed in detail, respectively. It showed that two main variation types were characterized due to the base substitution and/or indel mutations in genomic nucleotide sequences and the exon and intron domains were presented different variation degree. This study identified 8 clustered haplotypes from hexaploid wheat accessions through characterization of exon domains. The haplotype 8 was the major variation types and the others were low relative frequency. The haplotype 7 was a special kind of haplotypes among amy1 genes in wheat accession PI243793 because of the variation of amino acid sequences at 155-161 sites. These results would contribute to the understanding in functional aspects and efficient utilization of amy1 genes in hexaploid wheat cultivars. 2013/06/23 - 16:43

In order to exploit new genetic resources for the improving of starch quality
of common wheat, the genetic diversity of null alleles of Granule-bound starch
synthase I (waxy gene) was investigated by special PCR molecular markers
in Triticum L. The results indicated that there was relative abundant
genetic diversity of waxy alleles in all accessions. Accession AS2347,
AS2356, AS2317 and AS2308 with null allele at Waxy-B1 locus and AS2310
and AS2335 with null alleles at Waxy-A1 and Waxy-B1, were observed
in 81 landraces of Triticum turdigum L. from China. In 53 landraces of
Triticum aestivum L. from Sichuan, China, eight accessions at Waxy-A1,
Waxy-B1 and Waxy-D1 loci and accession AS1668 at Waxy-D1,
were observed null alleles. In 29 Triticum macha, Accession PI361862
and PI572911 at three Waxy loci, PI572913 at Waxy-B1 and Waxy-D1,
PI572910 at Waxy-A1 and Waxy-D1, PI 290507 at Waxy-B1 and
PI572906 at Waxy-D1, respectively, were observed null alleles. Seven
accessions with null alleles at Waxy-B1 locus was observed in 28 Triticum
sphaerococcum. Specially, the accessions of two regions, Anyue in Sichuan,
China and Georgia, had the high frequency of the mutations with null alleles
of waxy gene. Landraces of Triticum aestivum L. with the high
frequency of waxy wheat, could be considered as a unique genetic resource
for improving of waxy wheat. These result suggested that the special molecular
marker could be used reliably in evaluation of genetic resources and these mutations
also could be directly used in the improving of common wheat. 2013/06/23 - 16:43

Rice improvement for high yield is important to increase productivity of the crop. The success of breeding program depends on the choice of best parents and selection method. A research was conducted by applying Single Seed Decent (SSD) with Rapid Generation Advance (RGA) for speeding up the breeding cycle and to select elite line at F7 in 2012. A total of 271 recombinant inbred lines (RILs) were obtained in this program. Augmented design in RCBD with 3 replications was performed using standard check varieties (PTT1, CNT1, SPR60, RD31 and RD41). Three lines were observed with significantly higher yield than the best check variety, CNT1. However, only one line was significantly higher for number of filled seed per panicle than the best parent, CH1. All ten top-yielding lines had significantly higher filled seed per panicle than CNT1. Plant height of mostly the top-ten high-yielding lines ranged between 110 to 120 cm and days to 50% flowering all early more than KDML 105. Positive trangressive segregation was observed for 11 of the traits evaluated; however, the frequency was higher for plant height, days to 50% flowering and number of panicles. The result of correlation analysis revealed highly significant and positive correlation between yield and all the eleven traits under study. Stepwise regression analysis identified panicle weight, number of panicle, days to 50% flowering, seed-setting rate and flag leaf length as traits contributing for linear increase in yield. These traits could be considered as critical criteria for selecting high-yielding lines in rice breeding programs. 2013/06/23 - 16:43

The morphology (vegetative and floral) of Jatropha L. species (Jatropha curcas L., Jatropha gossypifolia L., Jatropha multifida L. and Jatropha podagrica Hook) in parts of the Niger Delta was investigated. The study aimed at establishing taxonomic affinities and differences between these species based on their leaves, inflorescences, flowers, fruits and seed characteristics. Visual observations, measurements and photographs of relevant organs of wild and ornamental collections of the four species were taken. Results obtained showed that the four species differ distinctively in leaf outline, leaf length, leaf base, margin and texture with the glandular leaf margin of J. gossypifolia and incised lobes of J. multifida being diagnostic and asserting their statuses as taxonomic species. Leaf length varied from 7.01±0.90 cm in J. gossypifolia to 24.75±1.18 cm in J. podagrica. The distinct yellowish-green flower colour of J. curcas distinguishes it from other species which possess different shades of red colour. Variation was observed in fruit shape (ellipsoid and tear-drop shapes) of J. curcas showing that intraspecific morphological or ecological types exist within this species. However, similarities were observed in leaf venation which is actinodromous and basal in all species and in floral arrangement which is cymose. These and other features confirm the relatedness of the species. 2013/02/20 - 03:43

Fenugreek (Trigonella foenum gracium L.) is a widely known medicinal semi-arid crop, cultivated worldwide. But this herb is susceptible to salt stress especially during the vegetative growth phases. In order to investigate selected physiological characteristics like germination stress, proline and chlorophyll content under salinity stress, 8 Omani fenugreek accessions were exposed to 0, 4, 6, 8, 10 dS m-1 NaCl for 8 days. All accessions showed salt tolerance at germination and seedling growth at low level of salinity. But germination was delayed as NaCl concentration increased and 10 dS m-1 NaCl showed very poor germination rate. The accessions were then transferred to pots under same salt concentration to analyze the proline and chlorophyll content. The presence of NaCl in soil significantly influenced both proline and chlorophyll content and they both correlated positively. 2013/02/20 - 03:43

Rockmelon is belongs to one of Cucurbitaceae family. It is widely cultivated for commercialization. In this experiment, three different rockmelon cultivars were selected to be studied. Seed morphology, plant growth yield and fruit quality of rockmelon cultivars (Glamour, Honeymoon and Champion) planted in coco peat were evaluated. Plant was irrigated through fertigation technique and grown under rain shelter. After five weeks, fruit was harvested and tested for ascorbic acid and Total Soluble Solid (TSS) content. Among all three cultivars studied, seed of rockmelon cv. Glamour measured with highest seed biomass (0.034 g). It also gave the best germination response (99%) with highest seedling height (12.14 cm) and widest leaf area (244.5 cm2). For fruit performance, cv. Honeymoon yielded fruit with highest fresh weight (2.24±0.04 kg) and widest diameter (54.86±0.586 cm). However, overall rockmelon cv. Champion remains as the best quality cultivar studied. The fruit measured with thickest mesocarp (37.23±1.60 mm) and contained with highest percentage of ascorbic acid (30.43%) and TSS (16%). As conclusion, all rockmelon cultivars tested have been successfully grown in coco peat and cv. Champion was the best cultivar to be planted as it gave the best fruit value. 2013/02/20 - 03:43

The present study was carried out to evaluate the antioxidant and antibacterial activity of methanolic leaf extract of Hippophae rhamnoides L. (Sea buckthorn, SBT) leaves under in vitro conditions. The chemical composition of the methanolic leaf extract was quantified in terms of total phenol and flavonoid contents. The Hippophae rhamnoides methanolic leaf extract exhibited potent antioxidant activity determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and then by 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), assays. The scavenging capacity by DPPH and ABTS of the extracts was found to increase with every unit increase of Hippophae rhamnoides leaf extracts reaching 68% at 30 μg mL-1 concentration. Further, the extract was evaluated for antibacterial activity against three human pathogenic bacteria E. coli, A. protophormial and M. luteus, however, it was maximum against E. coli. The study shows that the methanolic extract of Hippophae rhamnoides leaves have marked antioxidant and antibacterial activities. 2013/02/20 - 03:43

Commiphora mukul possesses a vast ethnomedical history and represents a phytochemical reservoir of heuristic medical value. It plays a very important role in all these processes as a key ingredient of the treatment procedures. C. mukul contains wide numbers of phytochemical constituents i.e., flavonoid, terpenes, phytosterols etc. which have different biological activities like antimicrobial, anti inflammatory, anti carcinogenic activity and various other important medicinal properties. There is a need to review this plant in order to provide scientific proof for its application in traditional medicine system. Guggulsterone is a main active substance in gugulipid, an extract of the C. mukul, used to treat a variety of disorders in humans, including dyslipidemia, obesity and inflammation. In this review an effort was made to update the information on its phytochemicals and pharmacological properties. 2012/09/01 - 16:42

Improved vegetative propagation methods are needed for eucalypt hybrids because demand for eucalypt hybrids is often greater than their seed supply and it can be difficult to produce adventitious roots on eucalypt cuttings. This study examined the timing of adventitious root formation in cuttings of two eucalypt hybrids, Corymbia torellianaxCorymbia citriodora and Eucalyptus pellitaxEucalyptus grandis and determined the effects of combining Indole-3-butyric Acid (IBA) with an ethylene inhibitor, 1-methylcyclopropene (MCP) or aminoethoxyvinylglycine (AVG), on rooting, defoliation and death of cuttings. Root initiation commenced within 14 days, well before the main phases of cutting defoliation and death. IBA often increased rooting percentage or the number of adventitious roots per rooted cutting. IBA also increased defoliation and death of Corymbia cuttings in one experiment, but AVG alleviated these effects and increased the percentage of cuttings that formed roots. The combined IBA and MCP or AVG treatments frequently increased cutting production and root system quality. Combining IBA (8 g kg-1) with MCP (400 nl L-1) or AVG (125 mg L-1) raised the number of Corymbia rooted cuttings by 83 and 206%, respectively and the number of Eucalyptus rooted cuttings by 46 and 110%, respectively. These Corymbia plants possessed 2.2 and 2.6 more adventitious roots and the Eucalyptus plants possessed 1.0 and 1.1 more adventitious roots, on average, than untreated cuttings. The rooting percentages obtained with optimal treatments (30-42 and 29-59% for Corymbia and Eucalyptus, respectively) allow hybrid deployment through clonal propagation. The combination of an auxin rooting hormone with an ethylene inhibitor is a novel and effective treatment for improving vegetative propagation of eucalypt hybrids. 2012/09/01 - 16:42

Local Hampton Roads Virginia (USA) folklore has intimated for almost forty years that a Quercus virginiana called “Old Pointe” tree which had been targeted by some City planners to be removed, had a historical connection to the “Emancipation oak” (i.e., a tree that is historically significant in the US because it's the physical location where slavery ended in the US). As we come to the 150 years of the end of the US Civil war this paper shows how modern research can be used to answer a historical ethnological question. The objective of this research was to evaluate the genetic similarity of a Hampton Roads Virginia Live oak (Quercus virginiana Mil. L.) to a historic Q. virginiana called the “Emancipation oak” using random amplified polymorphic DNA. Cluster analysis was used to describe patterns of genetic similarity. Six primers produced 86 bands and had average polymorphisms of 54%. Three Zelkova trees [Zelkova serrata (Thunb.) Makino] were used as an out-group. Analysis using UPGMA dendrogram divided the Quercus and Zelkova species into two distinct groups. A similarity matrix was computed with Jaccard coefficient among the five trees. The cophenetic correlation for the goodness-of-fit of the cluster analysis to the similarity matrix was 0.99. This study successfully demonstrates that RAPD markers can be used in estimating the extent of genetic relatedness of live oaks. 2012/09/01 - 16:42

To determine the involvement of seed born fungi in cotton seedlings damping-off, 39 isolates representing 13 species belonging to seven genera were isolated from seven cotton cultivars and tested on the same cultivars under greenhouse conditions. Obtained results showed that cotton seedling damping off was varied among cultivars as well as within the same cultivar. The occurrence of damping off was dependent upon cultivars responsibility and the virulence of isolate used. It was also found that some tested isolates i.e., Fusarium moniliforme isolate No. 11, Fusarium semitectum isolate No. 20, Macrophomina phaseolina isolate No. 25, Penicillium isolate No. 30 and all tested isolates of Rhizoctonia were capable of infecting all tested cultivars. Tested isolates of Macrophomina phaseolina were highly virulent against different cotton cultivars. 2012/07/11 - 22:16

To avoid fungicide risks, efficacy of Allium sativum was evaluated against corn grain rotting fungi. Mycotoxigenicity of tested fungi was also investigated using HPLC. All Aspergillus species were toxigenic except corn and popcorn isolates of Aspergillus clavatus as well as corn isolate of Aspergillus terreus. Highest Aflatoxin was produced by corn Aspergillus flavus and popcorn Aspergillus flavus var. columnaris. Meanwhile, three of eight Fusarium isolates were toxigenic and varied in the kind and amount of toxin produced. Although some Fusaria failed to produce any toxins, Popcorn isolate No. 8 of Fusarium subglutinans produced fumonisin, vomitoxin and zearalenone. Corn isolate of Penicillium funiculosum was produced more Patulin and less citreoviridin than corn isolate of P. oxalicum. Garlic juice was effectively inhibited the fungal growth at all concentrations used. All tested isolates were responded to garlic juice regardless of the concentration used. The most sensitive fungi to all garlic juice concentrations used were corn isolates of A. flavus and Penicillium oxalicum. They exhibited significant inhibitory effects of about 63.70 and 75.56%, respectively, at 1.25% concentration. Popcorn isolate of F. subglutinans was the most sensitive Fusaria to all concentrations used with maximum inhibition of about 81%. Efficacy of garlic juice against mycotoxin producing fungi suggests its possible use in minimizing the risk of mycotoxins as well as fungicides exposure. 2012/07/11 - 22:16

Plant architecture is governed by the action of meristems. During vegetative development, the shoot apical meristem is responsible for initiating all of the above-ground structures including the nodes, internodes, leaves, axillary meristems and the inflorescence. Five barley mutants with low-tiller have been found, currently including, low number of tillers1 (lnt1.a), absent lower laterals1 (als1), intermedium-b (int-b), uniculm2 (cul2.b), uniculm4 (cul4) and semi brachytic (uzu). Specifically, the cul2.b mutant failed to develop tillers, while the lnt1.a mutant can produce 1-4 tillers. Genetic analysis indicated that two mutant phenotypes were caused by two recessive genes cul2.b and lnt1.a, respectively. In this study, two F2 populations, 279 individuals derived from BowmanxGSHO 531 and 184 individuals derived from BowmanxGSHO 1984 were developed for mapping the cul2.b and lnt1.a genes using Simple Sequence Repeats (SSR) markers. F3 populations were created to identify genotypes of F2 individuals. Ultimately, cul2.b was located between SSR markers GBM1212 and Bmag 0613 on the long arm of chromosome 6H, with distances of 12.7 and 13.2 cm to the two markers, respectively. Another five SSR markers (GBM 1319, GBM 1423, Bmag 0807, Bmag 0378 and Bmag 0003) on chromosome 6H were also found around the cul2 gene, with distances of 19.6, 33.3, 34.1, 71.5 and 80 cm to the cul2.b gene. The lnt1.a gene was positioned 7.8 cm away from GBM 1043 on chromosome 3H. This study narrowed the block of tiller development gene in the cul2 and lnt1 mutant. It is a benefit for further map-based clone of the genes. 2012/07/11 - 22:16

Black pod disease caused by Phytophthora palmivora and Phytophthora megakarya is a serious constraint to cocoa (Theobroma cacao L.) yields in Ghana. To investigate the association between disease resistance and pod husk anatomical/histological traits, 8 cocoa genotypes were evaluated by leaf discs and detached pod inoculations and examination of anatomical factors. Width of vascular bundles, length of vascular bundles, epicarp thickness, distance between vascular bundles and epicarp, number of cells in epicarp and number of cells in mesocarp were negatively correlated with resistance to black pod disease. Number of vascular bundles and cell width were positively correlated with black pod disease resistance. Lower epicarp thickness and higher number of vascular bundles were observed in susceptible genotypes suggesting their porosity to Phytophthora species. The cells in epicarp and mesocarp were arranged more compactly in resistant than susceptible genotypes. Presence of extra thickness of phloem fiber and its gritty nature in resistance genotypes may act as strong mechanical barrier for penetration and absorption of sap from phloem. The cell walls of resistant genotypes stained deep red with phloroglucinol, a lignin specific stain, suggesting the presence of lignin. Principal components analysis showed that the first 2 components contribute to explain 98% of the total variation of anatomical traits. Number of cells in epicarp and number of vascular bundles were the major contributors to PC1 and PC2. The principal components, correlation coefficients, multiple and step-wise regressions indicated that number of vascular bundles, epicarp thickness, number of cells in epicarp and cell width were reliable histological traits and they could be used to screen and select for resistance to black pod disease of cocoa. 2012/06/06 - 18:18

The objective of the research was to determine the chemical compositions and antibacterial and antifungal activity of essential oils from 4 medicinal plants consist of Mentha piperita, Mentha spicata, Anethum graveolens and Foeniculum vulgare. Antibacterial and antifungal activity of these oils and their components were assayed against a variety of human pathogenic bacteria. Main components in Mentha piperita oil were menthol, limonene, 1,8-cineole, sabinene, menthyl acetate and menthone, in Mentha spicata oil carvone, menthol, limonene and menthone, in Anethum graveolens leaves oil α-phellandrene, Dill ether and β-phellandrene and in Foeniculum vulgare oil terpin-4-ol, t-anethole, fenchone and estragole. Present results showed that oils extracted from leaves of Anethum graveolens and Foeniculum vulgare plants did not show antibacterial or antifungal activities. Mentha piperita showed strong antibacterial and antifungal activities, however, lower than Mentha spicata. Carvone possessed the highest antibacterial and antifungal activity among the tested components. Essential oils of Mentha species possess great antibacterial and antifungal potential and could be used as natural preservatives and fungicides. 2012/06/06 - 18:18

Downy Mildew (Plasmopara viticola) is a well characterized plant pathogen which is known to infect a large number of grape cultivars (Vitis spp.). Downy mildew affects all parts of the plant, including leaves, shoots, buds, stems and fruit, leading to significant decreases in crop quality and on occasions complete loss of yield. This study investigates the ability of three bio-elicitors namely; Trichoderma harzianum, Streptomyces plicatus and Pseudomonas fluorescens to induce elevated levels of resistance in cv. Tifey cultivars in the face of P. viticola infection. In addition the study will explore some of the specific biochemical changes occurring within the plant in response to treatment with particular bio-elicitors with particular focus on changes in protein expression and levels of photosynthetic pigments. Enzyme activities such as peroxidise, polyphenoloxidase, chitinase and β-l, 3 glucanase were determined using spectroscopic methods, photosynthetic pigment level were determined in a similar manner. Protein expression patterns were analysed by polyacrylamide gel electrophoresis (SDS PAGE). The greatest reduction for disease severity was observed in response to treatment with T. harzianum at 1x10-6 spore mL-1 and followed by S. plicatus at 1x10-8 CFU mL-1. Both chlorophyll and carotene levels were increased in response to treatment with T. harzianum followed by P. fluorescens when compared to an infected untreated control. Significant diversity was observed in terms of enzyme activity depending on the type of elicitor employed. SDS PAGE analysis for grape seedlings showed considerable diversity in protein expression levels between biotic treatments. Pearson cluster analysis showed that protein expression patterns for treatments with S. plicatus and P. fluorescence treatment were highly similar (95.76%), T. harzianum (94.25%) clustered separately to S. plicatus and P. fluorescence indicating a possible differential response to fungal and bacterial elicitors. This study suggests that the use of bio-elicitors may provide an effective alternative to fungicides in the quest to control downy mildew disease in grapes. 2012/06/06 - 18:18

Short postharvest vase life is one of the most important problems on the cut flowers. Combinations of malic acid, salicylic acid, citric acid and sucrose were used as preservative mixture for cut carnations and their effect on regulation of senescence was examined. The study was conducted in a factorial arrangement, carried out in a complete randomized design. The factors were malic acid (0,100 and 150 mg L-1), salicylic acid (0, 1.5 and 3 mM), citric acid (0 and 150 mg L-1) and sucrose (0 and 3% w/v). The effects of treatments and their interaction on the total chlorophyll content, ACC-oxidase activity, anthocyanin leakage, membrane stability and malondialdehyde content of cut flowers of carnations (Dianthus caryophyllus L. cv. White) were investigated. 150 mg L-1 MA and 1.5 mM SA both caused significant decrease in anthocyanin leakage, ACO activity and MDA content compared to other levels (p≤0.05). Flower stems that were kept in water containing either 150 mg L-1 MA or 1.5 mM SA or their combinations; all had significantly increased vase life relative to the control treatment. MA application increased water uptake and decreased microbial growth as well. 2012/06/06 - 18:18

In order to improve the agricultural product, especially leguminous plants (Vicia faba L.) in sandy soils, we used bentonite to ameliorate their physical and chemicals properties. To evaluate the ecological advantage of this clay in these soils, an increasing amount of bentonite were added to the sandy soil, then the physical and chemical characteristics of the mixture were identified such as pH, EC (Electrical Conductivity), total calcareous, active calcareous, total phosphorus, organic carbon, organic matter, total nitrogen and exchange cations capacity. The drought causes a rise of salts in the rhizosphere particularly in arid and semi-arid regions. This work is an analysis of the response of the leguminous plant Vicia faba L. to increasing concentrations of bentonite and salt as well as to understand the variability of certain metabolic activities, mineral content and morpho-physiological behavior of the plant response to this abiotic stress. Results show that variability exists in physical and chemical characteristics and morphological growth of the plant according to the bentonite amount mixed in the sandy soil sample. 2012/03/08 - 17:51

Field experiments were conducted using fourteen rice genotypes during the main rainy seasons of 2009 and 2010 at three rainfed upland locations of Southwest Ethiopia to estimate the genetic variability, heritability and correlation coefficients of grain yield and yield contributing traits in upland rice. The experiments were laid down in a randomized complete block design with three replications. Highly significant (p<0.01) variation was obtained for days to 50% flowering, days to 85% maturity, plant height, panicle length, spikelets per panicle and thousand grains weight. Significant difference (p<0.05) were noted for panicles per plant, grains per panicle, total spikelet fertility and grain yield. Days to 50% flowering, plant height, grains per panicle, spikelets per panicle, thousand grains weight and grain yield showed relatively high GCV and PCV estimates. High heritability was obtained for plant height (92.17%), followed by 50% flowering (90.16%), thousand grains weight (83.17%), days to 85% maturity (82.45%), panicle length (79.25%) and spikelet per panicle (60.25%) which indicates high heritable portion of variation. High to medium estimates of heritability and genetic advance were obtained for plant height, days to 50% flowering, panicles per plant, spikelets per panicle, grains per panicle and thousand grains weight, indicating the roles of additive gene action and a good scope of selection using their phenotypic performance. Grains per panicle had maximum positive direct effect and highly significant (r = 0.906**) genotypic correlation coefficient with grain yield. The present study revealed that for increasing rice yield in upland ecology, a genotype should possess more number of grains per panicles, tillers per plant and panicle per plant, high spikelet fertility and large panicle size. 2012/03/08 - 17:51

Plants of Malva sylvestris L., were studied for morphological variations and anthocyanin production, malvidin and delphinidin with silver nitrate treatment. Effects of exogenous silver nitrate on anthocyanin accumulation have been examined. Foliar spray of 0.1 M silver nitrate for five consecutive days significantly increased the anthocyanin content showing distinct morphological variations with respect to plant height, plant biomass, leaf number and leaf mass. By traditional chilled acidified methanol the total anthocyanins were extracted and estimated by pH differential spectroscopic method. The anthocyanins were purified by C-18 Sep-pak column and further analyzed for different anthocyanins by Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) methods respectively. The evidence presented in this paper indicates that the enhanced anthocyanin production is related to different levels of oxidative stress induced by silver nitrate to the plant tissues. 2012/03/08 - 17:51

Aqueous and ethanol extracts of leaves (1000 ppm) of four important medicinal plant species, Aegle marmelos (Rutaceae), Albizia amara (Mimosoideae), Cassia auriculata (Caesalpinoideae) and Cissus quadrangularis (Vitaceae) has been tested individually and in combination for their antibacterial activity against Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi and Bacillus subtilis. Results showed higher antibacterial activity in combination of extracts of the medicinal plants studied. The aqueous leaf extracts of C. auriculata and ethanolic leaf extracts of C. quadrangularis showed 1.8 and 1.7 cm zone of inhibition (ZI), respectively against E. coli and B. subtilis while tested individually. Whereas, the combination of aqueous leaf extracts of C. auriculata +C. quadrangularis (1:1) showed 2.5 cm ZI against E. coli. Similarly, the highest antibacterial activity of 3.0 cm ZI was observed against B. cereus in combination of aqueous leaf extracts of all the four plants. This study clearly demonstrates the synergistic activity of plant extracts against different bacteria. 2012/03/08 - 17:51

For the purpose of studying the changes of free proline as one of the important metabolites in plants under drought stress, the seeds of two types of Haloxylon persicum and Haloxylon aphyllum were planted in vase. Then their resulting twigs were taken care for one year and after one month compatibility with greenhouse environment, they underwent drought stress operations. The study of changes of this osmolyte in the branchlet and roots of the twigs of these two types of haloxylons were programmed within the format of a Completely Randomized Design with two treatments of species and fifteen treatments of tension (avoiding irrigating the twigs). The two species of Haloxylon persicum and Haloxylon aphyllum and the levels of 0 (control), 2, 4 … and 28 days of no-irrigation were determined as treatments of the experiment. The free proline was measured by using Bates. method. The analysis of data was done through the method of two sides' variance analysis and averages were compared by using Duncan's test. The study of the data of branchlet showed that the impact of drought stress on the increase of the rate of proline in both types of haloxylons was meaningful with a 99% possibility, however, no meaningful changes was observed between these two species. The analysis of the data of the both species roots confirmed a very meaningful impact of the factor of tension and the meaningful impact of the factor of species on changes of free proline. The study of the impact of drought stress on changes of the quantity of total proline showed that the changes of this feature is in a full similarity with the changes of the proline of the root and following the same model. The increase of the rate of proline of branchlet, root and total proline was in agreement with tension intensity. 2012/01/02 - 23:16

The present investigation was carried out to access the suitability and reliability of ISSR analysis for inferring genetic diversity among chickpea genotypes. A total of six ISSR markers were used to study genetic diversity among 115 genotypes of chickpea. Out of six ISSR markers (GTGC)4 (GTG)5 and (TCC)5 were found to generate reproducible DNA fragments of size ranging from 0.15-3, 0.40-2.5 and 0.35-2 kb and yielded 2-9, 3-10 and 4-11 number of fragments, respectively. Clustering analysis separated all the genotypes into five genetically similar groups. The value of cophenetic correlation coefficient (r) is 0.91 which is considered as a good fit. The genetic similarity coefficient among 115 chickpea genotypes ranged from 0.01 to 0.90. These values indicated high genetic variability among chickpea cultivars and can be used efficiently for gene tagging and genome mapping of crosses to introgress the favourable traits such as high yield potential, disease and insect resistance into the cultivated genotypes. 2012/01/02 - 23:16

The existence of diverse morphotypes and the constantly expanding genome have made evolutionary assessment of members of the Solanum group difficult. The different patterns of seedling growth following germination provide a set of diagnostic tools for analysing the degree of relatedness among these species. Subsequently, species rate and percentage germination and the developmental patterns of seedlings to 10th leaf stage were assessed. In the control, the germination rate and percentages were 0.94 (85%) and 0.09 (80%) for Solanum gilo and S. melongena Golden, respectively. The latter species had a significant increase in rate of germination from 0.09 to 0.11 and 0.89, respectively in the control, 1% KMnO4 dilution and mechanical scarification while no significant increase was observed in all the concentrations of colchicine. The radicles emerged 4 days after soaking and cotyledons were fully spread 3-5 days after and subsequently dropped from 8 days of growth. The first three leaves were elliptic and pinnately veined, initiated in bud from 14 days of radicle growth and were shed after 12 days of growth. The 4th and subsequent leaves were initiated in buds from 18-20 days of radicle growth, revealed the net venation and lobbing of margins characteristic of members of the genus and their growth was indeterminate. The lateral buds were initiated in all seedlings and trichome hairs became prominent on the stems of S. scabrum subsp. scabrum from 54 days after radicle growth. The pattern of germination and seedling growth was remarkably similar for all the species. The seed shape, size and colour distinguished the eight species into individuals with ovoid or flattened-reniform seeds which may either be brown, yellow or pale yellow in colour. Flowers were bisexual with exerted styles while few were staminate or short styled with anthers loosely arranged around the styles. The species common ancestry and close evolutionary history were discussed. 2011/12/20 - 20:40

Legume-rhizobia symbiosis is a biological process which because of their crucial role in introduction of fixed nitrogen into both agricultural and natural systems has been extensively studied but the molecular mechanisms programmed in legumes such as perception of Nod factors, subsequent signal transduction and nodule organogenesis are still unknown, especially in common bean. In this study, responses of mitochondorial proteins of Phaseolus vulgaris L. root cells under early stages of interaction with Rhizobium etli was studied using shotgun proteomics technique in a time course manner. Three-day-old bean seedlings were infected by bacteria. At 0, 12, 24, 48 and 72 h after inoculation, the plant roots were collected, mitochondoria was purified and proteins were extracted and analyzed by mass spectrometry. Out of 15 proteins identified, up-regulated proteins were related to energy and disease and defence; whereas down-regulated proteins were related to protein synthesis and protein destination. These results provide an evidence to decrease in metabolism and signalling mechanism in root during early stages of symbiosis. 2011/12/20 - 20:40

A field experiment to evaluate Soil Organic Carbon (SOC) and maize grain yield under different soil amendments and cropping systems was conducted in 2006 and 2007 at the Soil Research Institute, Kwadaso, Kumasi. The experiment was a split plot with three replications. The main plot factor (cropping systems) consisted of continuous maize, maize/soybean intercropping and maize cowpea rotation systems, the sub-plot (amendments) comprised of Poultry Manure (PM) at 4 t ha-1, poultry manure+chemical fertilizer (PM+CF) at 2 t ha-1 (PM)+45-30-30 kg ha-1 (NPK 15-15-15), Chemical Fertilizer (CF) at 90-60-60 kg ha-1 NPK 15-15-15 and a control (no amendment). Soil samples were taken at 21 and 84 days after amendment (DAA). Generally, PM+CF produced the highest range of SOC (1.14-1.37%). The least (0.98-1.28%) was recorded on the control plots. Plots amended with chemical fertilizer alone or in combination with poultry manure out-yielded the control in maize grain yield. Positive correlations between SOC at 84 DAA and maize grain yield were recorded in the major (r = 0.70*) and minor (r = 0.89**) rainy seasons of 2006 which established crop yield a function of SOC at harvest. Land equivalent ratios of sole maize (maize grown under continuous maize system) and maize intercropped with soybean were <1 which suggested more efficient utilization of land resources with sole maize cropping than intercropping maize with soybean. 2011/12/20 - 20:40

Cassava (Manihot esculenta) is a major source of starch in tropical and subtropical countries. The genomic organization of the granule-bound starch synthase I (GBSS I) in cassava was examined to increase our knowledge of starch biosynthesis and facilitate the production of modified starches in cassava. Three partial genomic clones were generated and the sequence analysis revealed that they were identical at both nucleotide and amino acid levels. The insert in one of the clones, pOYE303-1 (accession no. HM038439), was 731 nucleotides long and encoded a partial protein of 124 amino acids with predicted molecular weight of 13.65 kDa and calculated 10.01 isoelectric point. HM038439 contained the first conserved domains of GBSS including the KTGG motif responsible for ADP-glucose binding site. Phylogenetic analysis revealed that cassava GBSS I belongs to dicot subgroup and is closely related to GBSS I of potato, sweet potato and buckthorn. In silico identification by nucleotide sequence alignment between genomic and cDNA sequences revealed three putative introns in GBSS I. The longest intron was 121 bp long and was located between nucleotide 595 and 716. The implications of these findings on starch biosynthesis and modification are discussed. 2011/12/20 - 20:40

Mycotoxins is a serious problem threatening human and animal health and detection is the most important steps to get rid of them. The impact of these mycotoxins on seed physiological characteristics as discoloration is important things that are related with seed quality as well as marketing. The fungal isolation was conducted from three cultivars of bean seeds (Giza3, Giza4 and Giza6) after dividing into groups depending on their color. Sixteen fungal species were associated with discolored bean seed samples. The Aflatoxin (AF), Alternariol (AOH) and Zearalenone (ZON) were determined using immunoaffinity columns and GC-MS. Aflatoxin was existed in all colored seeds while, the dark brown colored seeds contaminated with AF, AOH and ZON. The highest concentration was found in dark brown colored seeds followed by golden brown. However, Zearalenone (ZON) was detected only in the dark brown in high concentration (45 μg kg-1 seeds). AOH toxin excreted by both isolates of A. alternata ranged from 1.0 to 3.0 μg g-1. The highest level of AOH toxin has been detected after 14 days of incubation and then decreased. Whereas, the normal seeds contained the lowest concentration of Aflatoxin. The amount of Aflatoxin produced by A. parasiticus increased positively with increasing incubation time. The amount reached 200 (μg kg-1) after 35 days incubation. Nevertheless, this amount was decreased to 125 (μg kg-1) after some period when bean seeds simultaneously inoculated with A. alternata and A. parasiticus. In conclusion mycotoxins affect on the seed physiology, there is a direct relationship between the rate of mycotoxins (AF, AOH and ZON) contamination and the degree of discoloration. The presence of more than fungus together may result in lack of mycotoxins content. 2011/12/20 - 20:40

Rapid disappearing of many coastal and inland habitats in the State of Qatar, due to the enormous activities of constructions, would put wildlife at real risk; urging scientists for environment conservation. This study was aimed to document the morphological features and the ecophysiological aspects of four wild plant species, Aeluropus lagopoides, Sporobolus spicatus, Ochradenus baccatus and Tetraena qatarense. Analyses included physical and chemical properties of soils and organic and inorganic contents of these plants were carried out. Although these plants are considered as xerophytes as the data of soil water content have shown; they might have well adapted to saline environments, since they live in soils of high salinity levels. A. lagopoides, S. spicatus and T. qatarense were living in soils of ECe ranged between 45 to 50 dS m-1, between 107 to 128 dS m-1 and between 12 to 187 dS m-1 respectively. O. baccatus, on the other hand, proved to be a typical xerophyte plant since it was never found in saline soils and survived water deficit as low as 4-12% field capacity. Considerable variations were found in all parameters studied especially in the electrical conductivity of the saturated soil extracts (ECe). Also, these species showed great variation in the organic components especially proline, soluble sugars and nitrogen, photosynthetic pigments and major elements. The data of trace elements, however, did not indicate clear differences. Such efforts can be considered as a prerequisite for successful ecological restoration, encouraging the decision makers to implement plans for restoration of vegetation. 2011/12/03 - 19:04