scholarly journals Evaluation of some bread wheat genotypes popular in Saudi Arabia under drought stress

2019 ◽  
pp. 1892-1900
Author(s):  
Soleman M. Al Otayk ◽  
Abdulrahman A. AL Soqeer ◽  
Abd Elsalam M. Menshawy ◽  
Mohamed I. Motawei

Six bread wheat genotypes were evaluated in three separate irrigation regime experiments to compare the response of agronomic performance and to identify genotypes with high yield potential under drought stress. The first irrigation treatment (I3) was given normal water irrigation (about 7000 m3 ha-1, according to recommendation for Qassim Region). The second (I2) and third (I1) treatments were given 2/3 and 1/3 of water amount of the first treatment, respectively. Factorial experiments in randomized complete block design with three replications were conducted during 2009/2010 and 2010/2011 seasons in the arid environment of central region of Saudi Arabia. Measurements were taken on days to heading, plant height, number of spikes m-2, number of kernels spike-1, 1000-kernel weight and grain yield. The drought susceptibility index (DSI) and water utilization efficiency (WUE) were calculated. The results revealed that effect of irrigation regime was highly significant for all traits, except days to heading. All studied characters were significantly decreased by reducing the amount of irrigation water. Grain yield showed maximum sensitivity as affected by moisture-stress. Means over environments indicated the existence of sufficient genetic variability among the genotypes for all the characters studied. Giza 171 recorded the highest values for most yield characters, while genotype 'Sama' was the lowest for the most yield characters. Giza 171, Sakha 93 and IC-1 recorded highest grain yield and WUE, based on average over irrigation treatments. Giza 171, Sakha 93 and IC-2 can be considered as drought stress tolerant genotypes.

Author(s):  
Soleman M. Al-Otayk

The present study was carried out to evaluate agronomic traits and assessment of genetic variability of some wheat genotypes at Qassim region, Saudi Arabia', during 2010/11 and2011/12 seasons. Fourteen wheat genotypes including five bread wheat and nine durum wheat genotypes were evaluated in randomized complete block design with three replications. The genotypes were evaluated for ten different yield contributing characters viz., days to heading, days to maturity, grain filling period, grain filling rate, plant height, number of spikes m-2, kernels spike-1, 1000-kernel weight, grain yield and straw yield. The combined analysis of variance indicated the presence of significant differences between years for most characters. The genotypes exhibited significant variation for all the characters studied indicating considerable amount of variation among genotypes for each character. Maximum coefficient of variation was observed for number of spikes m-2 (17%), while minimum value was found for days to maturity. Four genotypes produced maximum grain yield and statistically similar, out of them two bread wheat genotypes (AC-3 and SD12) and the other two were durum wheat (AC-5 and BS-1). The genotypes AC-3, AC-5 and BS-1 had higher grain yield and stable in performance across seasons. The estimation of phenotypic coefficient of variation in all the traits studied was greater than those of the genotypic coefficient of variation. High heritability estimates (> 0.5) were observed for days to heading, days to maturity, and plant height, while the other characters recorded low to moderate heritability. The high GA % for plant height and days to heading (day) was accompanied by high heritability estimates, which indicated that heritability is mainly due to genetic variance. Comparatively high expected genetic advances were observed for grain yield components such as number of kernels spike-1 and 1000-kernel weight. Grain yield had the low heritability estimate with a relatively intermediate value for expected genetic advance. The results of principle component analysis (PCA) indicated that the superior durum wheat genotypes for grain yield in the two seasons (AC-5 and BS-1) are clustered in group II (Fig. 2). Also, the superior two bread wheat genotypes (AC-3 and SD12) were in group I. Therefore, it could be future breeding program to develop new high yielding genotypes in bread and durum wheat.


2004 ◽  
Vol 55 (11) ◽  
pp. 1139 ◽  
Author(s):  
Mario Gutiérrez-Rodríguez ◽  
Matthew Paul Reynolds ◽  
José Alberto Escalante-Estrada ◽  
María Teresa Rodríguez-González

Spectral reflectance (SR) indices [NDVI (R900 – R680/R900 + R680); GNDVI (R780 – R550/R780 + R550); and water index, WI (R900/R970)]; and 6 chlorophyll indices (R740/R720, NDI = R750 – R705/R750 + R705, R780 – R710/R780 – R680, R850 – R710/R850 – R680, mND = R750 – R705/R750 + R705 – 2R445, and mSR = R750 – R445/R705 – R445) were measured with a FieldSpec spectroradiometer (Analytical Spectral Devices, Boulder, CO) on bread wheat (Triticum aestivum L.) genotypes adapted to irrigated and drought conditions to establish their relationship with yield in field-grown plots. Bread wheat genotypes from the International Maize and Wheat Improvement Center (CIMMYT) were used for this study in 3 experiments: 8 genotypes in a trial representing historical progress in yield potential, and 3 pairs of near-isolines for Lr19, both of which were grown under well-watered conditions; and the third experiment included 20 drought tolerant advanced genotypes grown under moisture stress. These were grown during the 2000 and 2001 spring cycles in a temperate, high radiation environment in Obregón, NW México. The 9 SR indices were determined during grain filling along with canopy temperature depression (CTD), flag leaf photosynthetic rate, and chlorophyll estimates using a SPAD meter. The relationship of SR indices with grain yield and biomass fitted best with a linear model. NDVI and GNDVI showed positive relationships with grain yield and biomass under well-irrigated conditions (r = 0.35–0.92), whereas NDVI showed a stronger association with yield under drought conditions (r = 0.54). The 6 chlorophyll indices showed significant association with yield and biomass of wheat genotypes grown under well-irrigated conditions (r = 0.39–0.90). The association between chlorophyll indices and chlorophyll estimates was correlated (r = 0.38–0.92), as was the case for photosynthetic rate (r = 0.36–0.75). WI showed a significant relationship with grain yield in wheat genotypes grown under drought stress conditions (r = 0.60) as well as with grain yield and biomass under well-irrigated conditions (r = 0.52–0.91). The relationship between WI and CTD was significant (P ≤ 0.05) in both environments (r = 0.44–0.84). In conclusion, the SR showed potential for identifying higher-yielding genotypes in a breeding program under dry or irrigated conditions, as well as for estimating some physiological parameters.


2013 ◽  
Vol 26 (1) ◽  
pp. 01-10
Author(s):  
M. M. Rahman ◽  
J. Rahman ◽  
M. A. K. Azad ◽  
N. C. D. Barma ◽  
B. K. Biswash

Thirty local and exotic wheat genotypes were evaluated in alpha lattice design with three replications at the Regional Wheat Research Centre (RWRC), Bangladesh Agricultural Research Institute (BARI), Rajshahi during Rabi season of 2010-11. The main objective of this study was to identify the extent of genetic diversity for traits related to drought tolerance mechanism. Genotypes were grouped into five different clusters. Cluster V comprised with the maximum number of genotypes (eleven) followed by cluster III with six and IV with five genotypes. Inter-cluster distance was maximum between clusters I and II (15.03) indicated wide genetic diversity between the genotypes of these two clusters followed by the distance between cluster I and III (14.20). The highest inter genotypic distance (1.5566) was estimated between the genotypes G4 and G18 and the lowest (0.2240) between G13 and G14. Among the characters, early ground coverage, initial plant m-2, days to heading, peduncle length and chlorophyll content of flag leaf at 14 days after anthesis contributed the maximum for divergence in the genotypes investigated. It revealed that these parameters contributed more to grain yield under drought stress. Cluster I had the highest grain yield ha-1, spikes m-2, TDM and LAI at 86 DAS, CTgf, peduncle length and plant height. Cluster II exibitted the lowest days to heading, days to maturity, plant height, CTgf , chlorophyll content at 14 days after anthesis, LAI, TDM and spikes m-2 . Crosses between I and II, I and III, I and IV, III and V and II and V have greater chance to generate more heterotic F1s. Considering magnitude of genetic distance, contribution of different traits towards total divergence, magnitude of cluster means for different traits and performance the genotypes; G30, G6 and G28 of cluster I, G18 and G7 of cluster II and G25, G27 , G19, G2 and G1 of cluster V could be utilized as parents for future hybridization programme to improve drought-tolerant high yielding wheat crop.DOI: http://dx.doi.org/10.3329/bjpbg.v26i1.19977


2019 ◽  
Vol 7 ◽  
pp. 40-52
Author(s):  
Jawed Aslam Khyber ◽  
Faiza Soomro ◽  
Wahid Dino Sipio ◽  
Abdul Wahid Baloch ◽  
Jay Kumar Soothar ◽  
...  

The current study was planned to identify drought tolerant bread wheat genotypes based on physiological and yield traits. In this context, a set of 12 genotypes (Sarsabz, NIA-Sundar, NIA-Amber, Sassui, Khirman, Marvi-2000, NIA-Sarang, Kiran-95, NIA-Sunheri, Bhittai, Bathoor-08 and Tatara) were evaluated under normal and water stress conditions. Mean squares from analysis of variance exhibited that genotypes, treatments and genotype x treatment interaction showed significant differences (P<0.05) for majority of the studied traits, indicating that there is significant variations are existed for physio-yield traits; therefore these genotypes may be preferred for further breeding programs in respect to drought stress. Regarding reduction percentage of genotypes under drought stress against normal water conditions, the minimum reduction was observed in Bathoor-08 for spike length and flag leaf area, Kiran-95 for grain yield plant, NIA-Sundar for seed index, Marvi-2000 for relative water content, Sarsabz for grains spike, whereas maximum but desirable reduction of stomatal dimension and density was displayed by Sarsabz and Tatara under water stress conditions, respectively. On the basis of drought tolerant indices, the genotypes Kiran-95, NIA-Sundar and Sarsabz showed lower values for tolerance index (TOL), trait stability index (TSI) and stress susceptibility (SSI), nevertheless it is believed that lower values of these indices show the less reduction in yield and its related traits due to water stress conditions hence can be tagged as tolerant genotypes for drought. Correlation results revealed that MP, SSI, TOL and TSI indices were correlated with grain yield under two conditions and they can be the appropriate indices for screening wheat genotypes.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1646
Author(s):  
Hafiz Ghulam Muhu-Din Ahmed ◽  
Muhammad Nouman Iqbal ◽  
Muhammad Arslan Iqbal ◽  
Yawen Zeng ◽  
Aziz Ullah ◽  
...  

Genome-wide association study (GWAS) was performed for stomata- and yield-related attributes with high-density Illumina 90 K Infinium SNP (single nucleotide polymorphism) array in bread wheat to determine genetic potential of germplasm for scarce water resources with sustainable yield potential. Major yield and stomata attributes were phenotyped on a panel of Pakistani and foreign accessions grown in non-stressed and water shortage environments during two seasons. Highly significant variations were shown among accessions in both conditions for examined characteristics. Water shortage conditions reduced the overall wheat yield and strong positive correlation existed among stomatal frequency, leaf venation and grain yield per plant. Population structure analyses based on 90,000 SNP data classified the accessions into four sub-populations which indicated the presence of genetic variability. Marker-trait association (MTA) analyses revealed that 422 significant SNPs at p ≤ 10−3, after crossing the false discovery rate (FDR) <0.05 threshold, were linked with examined attributes. Pleiotropic loci (wsnp_Ex_c8913_14881924 and Tdurum_contig10598_304) were associated with flag leaf area (FLA), stomata size (SS), stomata frequency (SF), leaf venation (LV), number of grain per spike (NGS) and grain yield per plant (GYP), which were located on chromosome 4B and 6B at the positions 173.63cM and 229.64cM, respectively, under water shortage conditions. Pleotropic loci wsnp_Ex_c24167_33416760, wsnp_Ex_c5412_9564046 and Tdurum_contig81797_369 on chromosomes 7A, 2A and 4B at the positions 148.26cM, 261.05cM and 173.63cM, respectively, were significantly linked with stomata and yield indices such as FLA, SS, SF, LV, NGS and GYP under normal and water shortage conditions. The current experiment not only validated several MTAs for studied indices reported in other studies but also discovered novel MTAs significant under water shortage environments. Associated and significant SNPs will be useful in discovering novel genes underpinning water shortage tolerance in bread wheat for producing high-yielding and drought tolerant wheat varieties to fulfill the wheat demand for growing populations.


2000 ◽  
Vol 80 (4) ◽  
pp. 739-745 ◽  
Author(s):  
B. L. Duggan ◽  
D. R. Domitruk ◽  
D. B. Fowler

Crops produced in the semiarid environment of western Canada are subjected to variable and unpredictable periods of drought stress. The objective of this study was to determine the inter-relationships among yield components and grain yield of winter wheat (Triticum aestivum L) so that guidelines could be established for the production of cultivars with high yield potential and stability. Five hard red winter wheat genotypes were grown in 15 field trials conducted throughout Saskatchewan from 1989–1991. Although this study included genotypes with widely different yield potential and yield component arrangements, only small differences in grain yield occurred within trials under dryland conditions. High kernel number, through greater tillering, was shown to be an adaptation to low-stress conditions. The ability of winter wheat to produce large numbers of tillers was evident in the spring in all trials; however, this early season potential was not maintained due to extensive tiller die-back. Tiller die-back often meant that high yield potential genotypes became sink limiting with reduced ability to respond to subsequent improvements in growing season weather conditions. As tiller number increased under more favourable crop water conditions genetic limits in kernels spike−1 became more identified with yield potential. It is likely then, that tillering capacity per se is less important in winter wheat than the development of vigorous tillers with numerous large kernels spike−1. For example, the highest yielding genotype under dryland conditions was a breeding line, S86-808, which was able to maintain a greater sink capacity as a result of a higher number of larger kernels spike−1. It appears that without yield component compensation, a cultivar can be unresponsive to improved crop water conditions (stable) or it can have a high mean yield, but it cannot possess both characteristics. Key words: Triticum aestivum L., wheat, drought stress, kernel weight, kernel number, spike density, grain yield


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