Assessment of Genetic Diversity for the Properties Related to the Quality of Hexaploid Bread Wheat (SeriM82 / Babax) under Drought Stress

In order to study the diversity of related characteristics of bakery quality in 167 bread wheat genotypes (SeriM82 / Babax), along with their parents, were evaluated based on two replications. The measured traits including protein content, zeolite sediment volume, bread volume, moisture content, grain hardness, water absorption, wet gluten, gluten index, gluten elasticity, Sodium dodecyl sulfate (SDS) sedimentation volume and quantitative trait of 1000 seed weight according to standards International. After analysis of variance, the data of the experiments and the comparison of the meanings were performed using multivariate methods, cluster analysis and factor analysis, genotyping grouping and the relationship between the variables (traits). The result of variance showed that genotype was significant for protein, bread volume, wet gluten, gluten index, sedimentation of sodium dodecyl sulfate and 1000 grain weight at 1% level. Factor analysis from 11 traits examined, 4 factors with 60% variance, the first factor with variance of 27.48% including traits of protein content, zeolite sediment volume, bread volume, moisture content and water absorption, the second factor with variance of 4.8% Includes wet gluten characteristics, gluten elasticity, SDS sedimentation volume, third factor with 10.16% variance, including seed hardness and gluten index, and fourth factor with variance of 9.85% of 1000 seed weight. The results of factor coefficient evaluation indicate the importance of protein content traits, zeolite sediment volume, bread volume, moisture content and water absorption in selection of suitable genotypes for drought conditions. Based on cluster analysis (intra-group variance algorithm), genotypes were divided into eight groups, the fifth group had high baking quality and could be used in breeding programs to improve the quality of baking.

Plant growth promoting rhizobacteria reduce aphid population and enhance the productivity of bread wheat

Abstract Plant growth promoting rhizobacteria increase plant growth and give protection against insect pests and pathogens. Due to the negative impact of chemical pesticides on environment, alternatives to these chemicals are needed. In this scenario, the biological methods of pest control offer an eco-friendly and an attractive option. In this study, the effect of two plant growth promoting rhizobacterial strains (Bacillus sp. strain 6 and Pseudomonas sp. strain 6K) on aphid population and wheat productivity was evaluated in an aphid susceptible (Pasban-90) and resistant (Inqlab-91) wheat cultivar. The seeds were inoculated with each PGPR strain, separately or the combination of both. The lowest aphid population (2.1 tiller1), and highest plant height (85.8 cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320 m2), straw yield (8.6 Mg ha1), and grain yield (4.8 Mg ha1) were achieved when seeds were inoculated with Bacillus sp. strain 6 + Pseudomonas sp. strain 6K. The grain yield of both varieties was enhanced by 35.538.9% with seed inoculation with both bacterial strains. Thus, the combine use of both PGPR strains viz. Bacillus sp. strain 6 + Pseudomonas sp. strain 6K offers an attractive option to reduce aphid population tied with better wheat productivity.

Plant growth promoting rhizobacteria reduce aphid population and enhance the productivity of bread wheat

Abstract Plant growth promoting rhizobacteria increase plant growth and give protection against insect pests and pathogens. Due to the negative impact of chemical pesticides on environment, alternatives to these chemicals are needed. In this scenario, the biological methods of pest control offer an eco-friendly and an attractive option. In this study, the effect of two plant growth promoting rhizobacterial strains (Bacillus sp. strain 6 and Pseudomonas sp. strain 6K) on aphid population and wheat productivity was evaluated in an aphid susceptible (Pasban-90) and resistant (Inqlab-91) wheat cultivar. The seeds were inoculated with each PGPR strain, separately or the combination of both. The lowest aphid population (2.1 tiller−1), and highest plant height (85.8 cm), number of spikelets per spike (18), grains per spike (44), productive tillers (320 m−2), straw yield (8.6 Mg ha−1), and grain yield (4.8 Mg ha−1) were achieved when seeds were inoculated with Bacillus sp. strain 6 + Pseudomonas sp. strain 6K. The grain yield of both varieties was enhanced by 35.5-38.9% with seed inoculation with both bacterial strains. Thus, the combine use of both PGPR strains viz. Bacillus sp. strain 6 + Pseudomonas sp. strain 6K offers an attractive option to reduce aphid population tied with better wheat productivity.

Heterobeltiosis in Wheat (Triticum aestivum L.) F1 Diallel Crosses under Contrasting Soil-N Conditions.

Breeding wheat cultivars with improved adaptation to low soil-N, has gained importance worldwide in order to decrease N fertilizer consumption and overcome the ecological and economic problems of the misuse of this fertilizer. Identification of wheat crosses that show useful heterosis (heterobeltiosis) is an important issue in breeding programs. The main objective of the present investigation was to estimate heterobeltiosis for nitrogen use efficiency and other studied traits of F1 diallel crosses among six wheat parents in order to identify the superior ones for future use in breeding programs. Genetic materials were evaluated at two seasons (2007/2008 and 2008/2009) in a split-plot design with randomized complete block arrangement, using three replications. Main plots were assigned to N levels (0 and 75 kg N/fed), while sub plots were devoted to genotypes. Data combined across the two seasons were presented. In general, low N caused a significant reduction in 9 out of 14 studied traits. These reductions were relatively high in magnitude for number of spikes/ plant (SPP) for parents (23.65%) and F1's (23.99%). On the contrary, low–N caused increases in the averages of nitrogen use efficiency (NUE) by 89.5 and 97.60% for parents and F1's, respectively. Averages of heterobeltiosis for all studied characters were either nonsignificant or significant but non favorable, except for plant height under both low and high N, NUPE under high N and GPS under low N. However, some crosses for each trait showed significant and favorable heterobeltiosis. Under low–N, the highest favorable and significant heterobeltiosis estimate was shown by L27 x Gem 7 for GYPP (14.94%), NUTE (44.81%) and GPS (25.82%), L25 x L26 for 100 GW (13.87%), L 25 x L 27 for SPP (12.53%), L 27 x Gem 9 for GPS (26.19%) and Gem 7 x Gem 9 for BYPP (28.99%).

Morphological and SSR Assessment of Putative Drought Tolerant M3 and F3 Families of Wheat (Triticum aestivum L.).

In an attempt to develop drought tolerant genotypes of bread wheat, two procedures, i.e., mutation and hybridization were used to induce new genetic variation. Selection for high grain yield/plant (GYPP) and other desirable traits was practiced in the M2 populations of 7 gamma irradiated genotypes and F2 populations of 15 diallel crosses among 6 genotypes of wheat under well watering (WW) and water stress (WS) conditions. Progenies of these selections (53 M3 and 109 F3 families) and their seven parents were evaluated in the field under WW and WS. Significant yield superiority of twelve families (7 M3 ’s and 5 F2 ’s) over their original and better parents, respectively under WS reached 74.71% (SF9). These putative drought tolerant families were assessed on the DNA level using SSR analysis. Fifteen SSR primers were used for PCR amplification of the genomic DNA of these 12 selections and their parents. The SSR analysis proved that the 12 families are genetically different from their 7 parents, with an average polymorphism of 86.67%. The genetic similarities (Gs) ranged from 30% to 88%. Both mutants SF3 and SF4 exhibited very low Gs (42 and 40%, respectively) with their common parent (Giza-168), indicating that gamma rays were very effective in changing the genetic background of Giza-168 towards high GYPP under WS conditions. SSR assay permitted the identification of seven unique bands (5 positive and 2 negative) for three drought tolerant wheat genotypes (SF3, SF4 and Aseel-5). These bands might be considered useful as markers associated with drought tolerance in bread wheat breeding programs.

Character Association and Heritability Analysis in Pakistani Elite Bread Wheat Cultivars.

An investigation was done on correlation and heritability analysis for 09 characters on 20 advance bread wheat cultivars which were grown in randomized complete block design with three replications during rabi, 2012-13. The trait grain yield per plant made positive and significant association with productive tillers per plant, spike length, spikelets per spike, grains per spike, seed index, total biomass and harvest index. Indicating a thorough selection for these traits will automatically improve seed yield in wheat because the five yield contributing traits are associated among themselves, selection in one of the traits will wholly result in the improvement of the other traits. Significant and negative correlation was revealed by plant height with productive tillers per plant, spike length, spikelets per spike and seed index, suggesting that dwarf wheat genotypes are by and large good yielders. High heritability estimates were observed for seed index, total biomass, grains per spike and plant height, indicating that these traits were predominantly controlled by additive gene effects and direct selection may be effective for these traits.

SSR- Based Genetic Diversity Assessment in Tetraploid and Hexaploid Wheat Populations.

Molecular analysis for a set of hexaploid (Triticum aestvium) and tetraploid (Triticum durum) wheat cultivars was investigated by applying 11 SSR primers set. The plant materials consisted of 45 genotypes 15 of which were Triticum aestivum and 30 of T. durum obtained from four different regions Egypt, Greece, Cyprus and Italy. PCR products were separated on a 6% denaturing polyacrylamide gel electrophoresis and produced a total of 3840 DNA fragments which were used for the molecular analysis. The estimated parameters computed by POPGENE (Version 1.32) within the two population indicated that the Nei’s genetic diversity (H) was 0.2827, and the Shannon's Information index (I) was 0.4533 with standard deviation ± 0.0699 and ± 0.0852 respectively. The analysis of population structure revealed that genetic diversity within populations (Hs=0.2761) represented 97.7% of the total genetic diversity (HT=0.2827). The proportion of the total genetic diversity that was attributed to the population differentiation was low (Gst=0.0233) within population. ANOSIM (ANalysis Of Similarities), results showed that R was equal to 0.9048 (P<0.0001) indicated that all the most similar samples of genotypes are within the same population. The wheat varieties from the four distinct regions were clustered according to SSR data into two main clusters, durum wheat varieties and bread wheat varieties, the principal coordinate analysis (PCOORDA) validated the results of the dendrogram. This study showed that the two populations still had moderate considerable level of genetic diversity and show little genetic differentiation among them. Understanding genetic variation within and between populations is essential for the establishment of an effective breeding program concerning the intraspecific and interspecific hybridization.

Stability of some quality traits in bread wheat (Triticum aestivum) genotypes.

This study was carried out in order to determine some quality traits such as thousand grain weight (TGW), hectoliter weight (HW), grain protein content (GPC), Zeleny sedimentation volume (ZSV) and stability of quality traits of 25 bread wheat genotypes. The experiment was conducted at seven environmental conditions during 2 growing periods (2003-2004 and 2004-2005) using randomized complete block design with four replicates. The ANOVA showed that out of the total sum of squares, 48.4, 28.0 and 23.6% for TGW, 71.4, 14.9 and 13.7% for HW, 54.4, 23.0 and 22.6% for GPC, 44.7, 41.7 and 13.6% for ZSV was attributable to E, G and G x E interaction effects, respectively. Thousand grain weight, hectoliter weight, grain protein content and Zeleny sedimentasyon volume of genotypes changed from 34.5 to 41.4 g, from 76.5 to 80.4 Kg, from 11.49 to 13.37% and from 22.1 to 46.0 ml, respectively. Seven stability parameters, covering a wide range of statistical approaches, were used so as to predict the genotypes. The study of genotypic stability showed that Bezostaya and advanced lines numbered 11 and 24 had high stability for quality traits and proved to be the best within the pool of the studied genotypes. Also, 8 and 17 numbered genotypes demonstrated high stability for TGW, HW, GPC and HW, GPC and ZSV, respectively.

Nonparametric stability methods for interpreting genotype by environment interaction of bread wheat genotypes (Triticum aestivum L. )

Evaluation of performance stability and high yield is essential for yield trials conducted in different environments. We determined the stability of 10 bread wheat (Triticum aestivum L.) genotypes (5 cultivars and 5 advanced lines) using nonparametric stability measures and compared nonparametric stability statistics across 19 environments in the Central Anatolian Region of Turkey. Experiments were setup in a randomized complete block design with four replications. Nonparametric stability measures revealed that AL-2, Karahan-99 and Altay-2000 were the most stable and well adapted genotypes across the 19 environments. In addition, it was concluded that graphs of mean grain yield (t ha-1) vs. nonparametric measures (Si(1), Si(2), S(3), Si(6) and sigma-gy) values and kr vs. sigma-r values could enhance visual efficiency of genotype selection based on genotype by environment interaction. Furthermore, high TOP values, Si(3) and Si(6) were associated with high grain yield, but the other nonparametric stability measures were not positively correlated with grain yield and instead characterized a static concept of stability. Choice of genotype for increased grain yield in bread wheat would, therefore, be expected to change yield stability by increasing the values of the Si(3), Si(6) and TOP nonparametric stability statistics.