Tolerant Wheat Genotypes Research Articles

Tolerance of wheat (Triticum aestivum) genotypes to root-lesion nematode (Pratylenchus thornei) in the subtropical grain region of eastern Australia

Practical and statistically sound methods are required to provide reliable assessments of the tolerance to P. thornei of large numbers of wheat genotypes for plant breeders’ selections and growers’ choice of cultivars to sow in the subtropical grain region of eastern Australia. We showed from six experiments that tolerance indices for wheat genotypes as ratios of grain yield from paired high and low P. thornei treatments were highly significantly related to grain yield on P. thornei infested field sites. We then applied factor analytic multi-environment trial (MET) analysis to 29 field experiments that tested 784 unique wheat genotypes for tolerance to P. thornei based on grain yield on infested sites. Tolerance to P. thornei was effectively modelled with three factors rotated to a principal components solution, which accounted for 84.0, 4.7 and 3.6% respectively of the genotype x experiment variance and covariance. We then validated the estimated best linear unbiased predictions based on these three components (PA(1 + 2 + 3)-eBLUPs) as a quantitative tolerance index to predict relative grain yield of wheat genotypes in independent experiments on P. thornei infested sites. The range of PA(1 + 2 + 3)-eBLUPS was subdivided into nine arithmetically equal subranges to provide nine ordinal alpha ratings from very intolerant to tolerant for growers’ sowing guides and to select nine genotypes as P. thornei tolerance checks in future experiments. There was a 60% loss of grain yield between genotypes in the very intolerant category compared with the tolerant category emphasising the need for continued characterisation of wheat for tolerance to P. thornei.

Evaluation of Diverse Wheat (Triticum aestivum) and Triticale (× Triticosecale) Genotypes for Low Phosphorus Stress Tolerance in Soil and Hydroponic Conditions

Identification of “donors” possessing superior traits to adapt to low phosphorus (P) soils is a primary requirement to develop efficient crop plants for sustainable agricultural production. Diverse wheat (Triticum aestivum L., 89) and triticale (×Triticosecale Wittmack, 15) genotypes were phenotyped in soil with low and sufficient P for two seasons and once in the hydroponic system. Principal component analysis of relative biomass and grain weight revealed four clusters each for wheat and triticale. In low P soil, genotypes in the efficient cluster showed lesser reduction in total biomass, grain weight, total P uptake, and harvest index (HI), and improved P acquisition efficiency (PAE) and P harvest index (PHI) as compared to the inefficient cluster. In hydroponics, reduction in total biomass was less while root biomass and PAE increased at low P in the efficient genotypes. Out of 22 (soil) and 38 (hydroponics) P-efficient wheat genotypes, nine were overlapping in both screens while in P-inefficient cluster, out of 23 (soil) and 5 (hydroponics), three were common. A few P-efficient genotypes identified were DL784-3, DBW 16, and GW 322 and triticale TREAT, whereas P inefficient were C306 and ABACUS PVR (triticale). The selections in hydroponics are likely to be relevant in the field as demonstrated by overlapping of genotypes in both the mediums. Genotypic variations in P efficiency were strongly associated with P utilization rather than P uptake.

Interrelationships among different grain characteristics of wheat grown under optimum and late sowning date conditions in the Eastern Indo-Gangetic plains of India

Wheat growth has been severely affected by increases in global temperature. The Eastern Indo-Gangetic Plains of India face similar constraints due to the traditional wheat–rice cropping system where wheat planting is often delayed leading to high temperature induced terminal heat stress. Grain characters like grain length, width, area along with starch synthesis are affected severely during heat stress. Considering the importance of grain traits, we screened the response of 55 wheat genotypes under terminal heat stress conditions to ten grain characteristics. We found that the means of all the grain traits were reduced in heat stress conditions. The effect of heat stress shows a significantly reduced grain width and perimeter, but the extent of damage is less on different grain starch characteristics e.g., grain starch area (GSA), grain starch length (GSL) and grain starch volume (GSV). Stepwise multiple regression analysis revealed that grain starch area and grain volume are the best predictors of yield under optimum sowing date conditions whereas, grain width is the best predictor under late sowing date conditions. Interrelationship studies among ten grain characters showed that the genotypes with higher levels of grain starch characteristics (GSA, GSL and GSV) in combination with the five grain size characters (grain length, grain width, grain perimeter, grain area, A/B-type starch granules) under late sowing date conditions should be promoted for the cultivation of wheat in heat stress prone areas. The present study identified and recommends some heat tolerant wheat genotypes in terms of higher yield and grain starch characteristics namely, CRPW-33, CRPW-17, CRPW-12, CRPW-126 and CRPW-21.

Characterization of wheat genotypes for drought tolerance and water use efficiency

ABSTRACT: The selection of wheat genotypes according to their drought tolerance is essential to off-season cultivation. The objective of this work was to characterize wheat genotypes through yield and components, morphological characteristics under water stress, and irrigated water use efficiency in the Cerrado region in Brazil. Genotypes were planted during the winters of 2016 and 2017 since there is no precipitation during this season and water levels can be measured. They were then submitted to four water regimes: WR1, WR2, WR3, and WR4, representing 100 %, 83 %, 50 %, and 30 % of evapotranspiration replacement. The following variables were evaluated: peduncle length (PL), number of ears m−2 (NE m−2), hectoliter weight (HW), thousand grain weight (TGW), drought resistance index (DRI), irrigated water use efficiency (IWUE) and yield. Most variables showed correlation with yield and can be a useful tool for breeding programs. PL and HW were best correlated with yield. BRS 264 (irrigated biotype) was productive in treatments receiving the greatest number of irrigation treatments. Given that WR1 registered the highest water level, it was not expected that the rainfed biotype (BR18) would show a higher yield than an irrigated biotype (BRS254). BRS404 (rainfed biotype) was the most productive under moderate stress treatment (WR3). Alianca (rainfed biotype) showed a higher yield under severe stress. Rainfed biotypes presented a higher DRI than the irrigated ones. These genotypes can be used as a reference in breeding programs under each water regime in which their performance was outstanding. None of the variables studied contributed to the selection of the most efficient wheat genotypes in the IWUE.

Development and validation of heat-responsive candidate gene and miRNA gene based SSR markers to analysis genetic diversity in wheat for heat tolerance breeding

Being a major staple food crop of the world, wheat provides nutritional food security to the global populations. Heat stress is a major abiotic stress that adversely affects wheat production throughout the world including Indo-Gangatic Plains (IGP) where four wheat growing countries viz., India, Bangladesh, Nepal and Pakistan produce 42% of the total wheat production. Therefore, identification of heat stress responsive molecular markers is imperative to marker assisted breeding programs. Information about trait specific gene based SSRs is available but there is lack of information on SSRs from non-coding regions. In the present study, we developed 177 heat-responsive gene-based SSRs (cg-SSR) and MIRgene-based SSR (miRNA-SSR) markers from wheat genome for assessing genetic diversity analysis of thirty- six contrasting wheat genotypes for heat tolerance. Of the 177 SSR loci, 144 yielded unambiguous and repeatable amplicons, however, thirty-seven were found polymorphic among the 36 wheat genotypes. The polymorphism information content (PIC) of primers used in this study ranged from 0.03-0.73, with a mean of 0.35. Number of alleles produced per primer varied from 2 to 6, with a mean of 2.58. The UPGMA dendrogram analysis grouped allwheat genotypes into four clusters. The markers developed in this study has potential application in the MAS based breeding programs for developing heat tolerant wheat cultivars and genetic diversity analysis of wheat germplasm. Identification of noncoding region based SSRs will be fruitful for identification of trait specific wheat germplasm.

Genotype Environment Interaction (G × E) of Heat Tolerant Wheat Genotypes over Locations and Years

Twenty heat tolerant wheat genotypes were evaluated in three heat stress environments of Bangladesh such as Wheat Research Center (WRC), Nashipur, Dinajpur, Regional Wheat Research Center, BARI, Gazipur, Regional Wheat Research Center, RARS, Jashore in 2015-2016. The experiments were conducted in RCBD with three replications in 2015-2016. The stability and response to change of location and sowing time of the genotypes were assessed through AMMI model and regression coefficient analysis on seven characters, viz. days to heading, days to maturity, plant height (cm), spikes m-2, grains spike-1, 1000-grain weight (g) and yield (kg·ha-1). Among the linear interactions, sowing time alone exerted the maximum sum of square (335,388,000.00**) and among the non-linear interactions, location × year paid the highest effect (7,676,490.00**), which was followed by year × location × sowing time interaction (3,956,500.00**). The highest grain yield (4475.3 kg·ha-1) was obtained from the genotype G13, followed by the genotypes G17 (4460.8 kg·ha-1) and G19 (4404.7 kg·ha-1). The genotype G8 had the smallest interaction effect, while the genotype G14 followed by G10 responded vigorously to amelioration. The genotypes G13, G18 and G19 showed averagely high yield and showed stability over the environmental modifications. The other two genotypes G20 and G12 exhibited great reduction of yield potential under unfavorable environment. The environment 121 proceeded by J121 and G131 appeared as favorable environments. The genotypes G13 and G19 produced high yield (kg·ha-1) in the favorable environments. The genotypes G16 and G18 high IPCa1 scores, indicated sensitive to mega-environmental changes. The best genotype with respect to environment was genotype G13. Genotypes G17 and G19 were best for site E1; genotypes G14, G16 and G18 were best for site E2.

Photosynthetic response of some Triticum cultivars to the combined influence of nanofertilizers and water deficit

The effects of water deficit modelling by polyethylene glycol (PEG), metal nanoparticles (NPs) and their combined action on water status, chlorophyll fluorescence and pigments composition in the leaves of three drought tolerant wheat genotypes – Triticum aestivum L. (Trypilska and Favorytka cultivars) and Triticum dicoccum Schrank. (cv. Holikovska), have been studied. Water deficit, induced by PEG, as well as the treatment with metal NPs (Cu, Fe, Mn, Zn) and their combined action, showed no effects on the maximal quantum yield of PSII photochemistry (Fv/Fm) in dark-adapted leaves of studied plants. However, water deficit decreased the efficiency of excitation energy capture by open PSII reaction centers (Fv′/Fm′) in light-adapted leaves of the Favorytka cultivar. The increase of chlorophyll fluorescence photochemical quenching (qP) and actual quantum yield of PSII electron transport (φPSII) levels, the decrease in non-photochemical quenching coefficient (qN) were observed in Favorytka and Holikovska cultivars under the combined action of water stress and NPs treatment. According to photosynthetic pigments composition, the NPs treatment of wheat plants, grown on medium with PEG, did not bear an additional pressure on the seedlings. However, the NPs treatment did not decrease the negative effect of the simulated water deficit of the cv. Favorytka seedlings.

Screening for heat tolerant genotypes in bread wheat (T. aestivum L.) using stress tolerance indices

Heat is a major stress that severely affects wheat productivity. The objective of the current study was estimating the effect of heat stress during the grain-filling stage for screening heat tolerant wheat genotypes by measuring six stress tolerance indices for grain yield and also measured the % of decline on other important traits. A set of 190 wheat genotypes along with four local checks were evaluated in two separate experiments, one under normal condition (timely sown) and the other under heat stress condition (late sown) in augmented block design at the research farm of Department of Genetics and Plant Breeding, C.C.S. University, Meerut (U.P) during rabi season of 2014-2015. The calculation of % declines revealed that there was a significant decline in the performance of traits under heat stress environment (late sown) in comparison to a normal environment (timely sown). Three traits, namely grain yield/plant, biological yield/plant and grain weight/ spike showed 57.15 %, 53.66 % and 47.73 % decline, respectively under heat stress environment indicating that above mentioned three traits are highly affected by heat stress. To evaluate the susceptible and tolerant genotypes for grain yield under heat stress environment, six stress tolerance indices viz. heat susceptibility index (HSI), mean productivity (MP), tolerance (TOL), stress tolerance index (STI), trait stability index (TSI) and trait index (TI) were calculated based on the grain yield under normal (timely sown) and stress (late sown) environments. The results of correlation between stress tolerance indices and grain yield in normal environment showed a significant positive relationship with MP (0.822**), STI (0.568**), TSI (0.316**), HSI (0.314**), TI (0.188*) and TOL (0.084). However, in stress environment, grain yield showed a significant positive correlation with TI (1.000**), STI (0.907**), MP (0.713**) and TOL (0.129) and negative correlation with HSI (-0.860**) and TSI (-0.808**). Based on the correlation analysis, we have selected four stress indices viz. HSI (heat susceptibility index), MP (mean productivity), STI (stress tolerance index) and TI (trait index) for their use in the selection of heat tolerant wheat genotypes. The results indicated that 9 genotypes (G51, G64, G71, G114, G119, G134, G139, G148 and G150) were heat tolerant and 12 genotypes (G1, G3, G7, G27, G38, G40, G77, G107, G136, G160, G171 and G187) were highly heat susceptible. The genotype G77 was the most heat sensitive genotype while genotype G119 and G139 showed a high yield under heat stress environment. Therefore, genotypes G119 and G139 were identified as a suitable genotype under late sowing environment and can be recommended for heat stress environment. Further, these two genotypes may be also employed in breeding programs aimed for developing heat tolerant varieties of wheat.

Heavy metal phyto-accretion, biochemical responses and non-carcinogenic human health risks of genetically diverse wheat genotypes cultivated with sewage of municipal origin

Current study explored the effects of municipal sewage (MS) irrigation on heavy metal phyto-accretion, biochemical responses and human health risks of diverse wheat genotypes along with recycled municipal sewage (RMS). Mean concentrations of PO4 3-, NO3 --N, chemical oxygen demand, biological oxygen demand, K, Co, Cu, Cd, Cr and Ni were found higher in MS than irrigation criteria. This led to significant increase in heavy metal contents in roots, stem and grains of MS irrigated wheat genotypes compared to RMS and control treatments. No adverse health risk effects for individual or multiple metals were recorded in RMS irrigated wheat genotypes on grounds of lowest heavy metal accumulation. Multivariate techniques i.e. principal component analyses (PCA) and hierarchical agglomerative cluster analyses (HACA) identified tolerant (inefficient metal accumulators) and sensitive (efficient metal accumulators) wheat genotypes in MS and RMS. Tolerant wheat genotypes showed lowest accumulation of heavy metals, efficient biochemical mechanisms to combat oxidative stress and lower health risks to adults/children. Cultivation of identified tolerant wheat genotypes is recommended in areas receiving municipal wastes to reduce human and environmental health risks. Moreover, genetic potential of identified tolerant wheat genotypes from MS and RMS can be utilized in breeding heavy metal tolerant wheat germplasm worldwide.

Assessment of terminal heat tolerance based on agro-morphological and stress selection indices in wheat

A study was conducted to quantify the effects of terminal heat stress on yield and component traits for two consecutive years under normal and late sown environments. Analysis of variance indicated significant differences among genotypes for most of the studied traits. Tiller/meter (T/M) and grain yield were the most affected traits (>30% reduction), whereas traits like grain filling rate (GFR), grain number per spike (GNPS) and thousand kernel weight (TKW) were less affected (<15%) under heat stress. The traits, viz. GFR, GNPS, TKW, T/M and spike weight, as well as the relative change in these traits exhibited positive and significant correlation with yield and yield stability index (YSI), while negative and significant correlation with heat susceptibility index (HSI) and kernel weight reduction percentage (KWR) under heat stress. Based on HSI, KWR, and YSI indices, genotypes WH 1021, NW 1014 and NW 2036 were identified as the heat tolerant, while HD 3086, HD 2967 and HD 3059 were identified to be highly productive under both normal and heat stress environments based on STI and mean yield across the environments. The above selected genotypes also showed high mean performance for GFR and TKW under heat stress and could be used for breeding wheat genotypes for heat tolerance.

Indices based on culm-leaf growth, spike-grain development and relative yield for identification of heat tolerant genotypes in triticale and wheat

Indices based on culm-leaf growth, spike-grain development and relative yield for identification of heat tolerant genotypes in triticale and wheat

Evaluation of some Bread Wheat Genotypes under Normal and Reduced Irrigations

The present study was conducted at Sakha Agricultural Research Station's Experimental Farm to evaluate six wheat genotypes during 2017/18 and 2018/19 wheat growing seasons under normal irrigation (five irrigations) and reduced irrigation (only one irrigation after the establishment). A randomised complete block design with nine replicates was the experimental design. Two stress tolerance indices were calculated to differentiate the high yielder and water deficit tolerant wheat genotypes. Results showed that the irrigation effect was highly significant for all studied characters, except for number of kernels spike-1. The mean values of all studied characters in the normal irrigation were higher than those recorded in the reduced irrigation, except for number of kernels spike-1 and 1000-kernel weight. There were a highly significant differences among genotypes for all the studied characters. The best cultivar was Misr 2 which recorded the highest values for grain filling rate, number of spikes m-2 and grain yield with a significant differences compared to the other studied genotypes. Two susceptible/tolerance indices indicated that the three genotypes namely Cham 4, Sakha 93 and Vorobey were identified as stress tolerant genotypes and the genotypes Cham 4 had the higher grain yield as well. Accordingly, it was recommended to be used in wheat breeding programs to transmit tolerance genes to the commercial cultivars for reduced irrigation.

Evaluation of drought tolerance indices for identification of drought tolerant and susceptible genotypes in wheat (Triticum aestivum L.)

This experiment was designed to identify the drought tolerant and susceptible genotypes in wheat genotypes collected from different wheat breeding centre of India. The experiment was conducted in alpha lattice design under stress and non-stress conditions to estimate the drought tolerance indices. Nine drought tolerance viz., Tolerance index (TOL), Mean productivity (MP), Harmonic mean (HM), Stress susceptibility index (SSI), Yield index (YI), Relative drought index (RDI), Grain yield per plant under potential condition (Yp ), Grain yield per plant under stress condition (Ys) were calculated. The indices were estimated based on grain yield under stress condition (Ys) and non-stress condition (Yp). These indices were subjected for analysis of variance, correlation coefficient analysis, cluster analysis. SSI is suggested as useful indicator for wheat breeding where the stress is severe; while MP, TOL and HM are suggested if the stress is less severe. Based on grain yield per plant twenty-one tolerant genotypes and eleven susceptible genotypes were identified. Identified tolerant and susceptible genotypes can be used for the development of mapping populations to identify QTLs for drought tolerance in wheat (Triticum aestivum L.).

Genetic relationship among selected heat and drought tolerant bread wheat genotypes using SSR markers, agronomic traits and grain protein content

ABSTRACT Assessing the genetic variation and relationships present in crop germplasm is a pre-requisite for parental selection and breeding. The objective of this study was to determine the genetic relationships present among selected heat and drought tolerant wheat genotypes using simple sequence repeat (SSR) markers, agronomic traits and grain quality parameters to select desirable parents for breeding. Twenty-four agronomically selected wheat genotypes sourced from the International Maize and Wheat Improvement Centre (CIMMYT)’s heat and drought tolerance nursery and four local check varieties were genotyped using 12 selected polymorphic SSR markers. The test genotypes were phenotyped using yield and yield-component traits, and grain protein content (GPC) under non-stressed (NS) and drought-stressed (DS) conditions. Expected heterozygosity mean value of 0.58 indicated moderate genetic diversity for breeding. The studied wheat genotypes were delineated into six genetic groups using cluster analysis. Significant genotypic differences were observed for agronomic traits and GPC under NS and DS conditions. Genetically unrelated breeding parents including LM02, LM13, LM23, LM41, LM44, LM71, LM73 and LM75 were selected for population development and breeding for enhanced grain yield and protein content under heat and drought-stressed environments.

Identification of suitable trait index for selection of heat tolerant wheat (Triticum aestivum) genotypes

Terminal heat stress is one of the major production constraints in wheat-producing areas of south-east Asia. The selection of genotypes based on grain yield per se is not effective under stress condition. In the present study 30 wheat (Triticum aestivum L.) genotypes were evaluated under normal and heat stress conditions during 2016-17 and 2017-18 to determine the suitable trait index for selection of genotypes under non-stress and heat stress environments and identification of heat tolerant genotypes. The observation was recorded for 13 morphological, biochemical and physiological traits. The index based on seven characters like grain yield, days to heading, biological yield, green fodder yield, dry matter content, catalase and peroxidase was most suitable with the genetic gain of 4856.09% and the genetic advancement of 33.09 in normal condition and the index based on five characters comprising days to heading, biological yield, number of tillers, catalase and peroxidase was most suitable with an expected genetic gain of 20101.32% and genetic advance of 35.09. The genotypes RAJ 3765, BRW 3794, HD 2643, SW 129, DBW 14, SW 160, BRW 3759, BRW 3762 and BRW 3800 were identified as moderately tolerant considering selection index score and heat susceptibility index. These genotypes may be promoted for cultivation under late sown conditions and used as parents for the development of genotypes tolerant to terminal heat stress.

Thermal imaging and multivariate techniques for characterizing and screening wheat genotypes under water stress condition

The present study was undertaken to understand the combined impact of thermal imaging and multivariate techniques to characterize and screen different wheat genotypes under water stress condition. Ten wheat genotypes namely HD-2987, HDR-77, PBW-343, PBW-175, HD-2967, HD-2781, HD-2985, HD-3043, C-306 and PBW-502 were grown under two irrigation conditions (I and Io corresponding to IW/CPE ratio of 1.0 and 0.4, respectively). The water stress conditions in wheat genotypes were characterized thermo-graphically using canopy temperature-based stress indices, namely crop water stress index (CWSI), stomatal conductance index (IG) and stomatal resistance index (CSI3). Simultaneously, plant biophysical parameters like normalised difference vegetation index (NDVI), leaf area index (LAI), transpiration, stomatal conductance, photosynthesis, were measured at peak vegetative stage along with yield and its attributes (panicle number, tiller number, 1000 seed weight, crop yield, total dry matter, harvest index) were observed. These parameters were analyzed using multivariate techniques namely principal component analysis (PCA), hierarchical cluster analysis (HCA) and discriminant analysis (DA) to develop a new index called normalized water stress tolerance index (NWSTI), to group wheat genotypes depending on their ability to tolerate water stress. Based on these multivariate analysis, wheat genotypes were classified as tolerant (C-306, HD-3043, HD-3987 HD-3985 and HD-2781), moderately tolerant (HDR-77, PBW-175 and PBW-502) and sensitive (HD-2967, PBW-343) to water stress with NWSTI score of >0.66, 0.33–0.66 and <0.33, respectively. Structural matrix from DA analysis showed that biophysical parameters like stomatal conductance, harvest index, photosynthesis, transpiration, NDVI and panicle number have significant (p < 0.001) role in discriminating wheat genotypes into three different groups of water stress tolerance. Distinct location of group centroid in the canonical distribution function further signifies (p < 0.001) the truthfulness of the HCA based dendrogram prepared using the normalized values of crop biophysical parameters. A significantly higher correlation (R2 , p < 0.001) between NWSTI and the thermal image-based stress indices (that characterize the instantaneous crop condition for the ten wheat genotypes), prove the usefulness of NWSTI as a stress index. In future, the newly developed water stress index NWSTI, may play a potential role in the screening and selection of drought tolerant wheat genotypes.

Morpho-physiological character association studies of seedling traits in ten wheat (Triticum aestivum L.) genotypes under osmotic stress conditions

In the past, many environmental stress especially water stress, negatively influenced the productivity and production of wheat (Triticum aestivum L.), one of the most important cereal crop in the world. Breeding current high yielding water stress tolerant wheat genotypes is a research priority specifically for these regions where climate change is predicted to result in more water stress conditions. A strategy that evaluates genotypes for physiological responses to water stress at earlier growth stages may be more targeted to water stress. Therefore, present investigation, ten wheat genotypes were screened following a completely randomized design under controlled condition. Different concentrations of PEG-6000 were used to induce osmotic stress at the germination growth stage. The analysis of variance indicated that significant differences among treatments for all seedling traits. All genotypes also differed significantly in germination percentage, shoot and root length, fresh and dry weight of shoot and root. Significant treatment interaction revealed that genotypes responded variably to osmotic stress treatments; hence provided better opportunity to select a water stress tolerant genotype at seedling growth stages. Data revealed a decreasing trend in values for all traits with the increasing concentration of PEG-6000. The relative minimum decrease over average due to osmotic stress was 9.04 percent in seed germination, 20.58 percent in shoot length, 9.01 percent in root length, 10.04 percent in shoot fresh weight, 3.30 percent in shoot dry weight, 11.57 percent in root fresh weight and 11.01 percent in root dry weight. However, relative decrease of individual genotype for various seedling traits might be more meaningful which indicated that genotype AKAW-5017 showed minimum reduction in root length, fresh root weight, dry root weight, fresh shoot weight and dry shoot weight while the minimum decline of seed germination and shoot length observed in AKAW- 3717. However, AKAW-4842, AKAW- 4907, and AKAW-4926 gave almost equally lower reduction for seed germination, root length, and shoot length and were consider as water stress tolerant. Correlation coefficient studies revealed considerable and positive correlation among seedling traits. The result indicated that increase in one trait may cause a simultaneous an increase in other traits; hence, selection for any of these seedling attributes will lead to developing water stress tolerant wheat genotypes.

Screening of wheat genotypes for drought tolerance using a combination of morphological and biochemical traits

Screening of wheat genotypes for drought tolerance using a combination of morphological and biochemical traits

Assessment of wheat (Triticum aestivum L.) genotypes for high temperature stress tolerance using physico-chemical analysis

Assessment of wheat (Triticum aestivum L.) genotypes for high temperature stress tolerance using physico-chemical analysis

Proteomic analysis of wheat contrasting genotypes reveals the interplay between primary metabolic and regulatory pathways in anthers under drought stress

Reproductive stage is very sensitive to various forms of environmental stresses such as drought stress. The proteomic analysis of anther during pollen development in response to drought stress was performed using a label-free quantitative shotgun proteomic technique to define the underlying molecular principles in two contrasting wheat genotypes Shiraz (susceptible) and D-10 (tolerant). Drought stress resulted in around two-fold decline in seed setting capacity and pollen viability in the Shiraz genotype compared to D-10. A Partial Least Square Discriminant Analysis (PLS-DA) of proteomic data revealed the abundance of 131 differentially abundant proteins significantly contributing in separation of drought tolerant and susceptible genotypes under normal and stress conditions. Proteins involved in cellular respiration, carbohydrate metabolism, RNA metabolism, and vesicle trafficking showed completely different responses in two genotypes. These proteins may maintain hexose pool and energy level and control regulation of transcription and transport. Furthermore, different members of functional groups such as protein biosynthesis and degradation, chromatin organization, and cytoskeleton dynamics were differentially abundant in response to stress in both genotypes which suggest their function in both genotypes to maintain minimum pollen viability/ fertility under drought stress. In conclusion, our findings revealed various metabolic and regulatory pathways underlying survival strategies required for pollen fertility and viability. SignificanceDrought caused by global climate change decreases cereal grain productivity worldwide. Yield losses due to water stress have been reported for major small grain cereal including wheat. Our findings highlighted the importance of key proteins in wheat adaptation to drought stress at reproductive stage. The obtained data showed that differentially abundant proteins in drought tolerant wheat genotype was remarkably associated with cellular respiration, carbohydrate metabolism, RNA metabolism, and vesicle trafficking. These results revealed fundamental data to elucidate the complexity of pollen fertility and viability under drought stress condition in wheat.