scholarly journals Combining Ability and Gene Action Controlling Grain Yield and Its Related Traits in Bread Wheat under Heat Stress and Normal Conditions

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1450
Author(s):  
Mohamed M. Kamara ◽  
Khaled M. Ibrahim ◽  
Elsayed Mansour ◽  
Ahmed M. S. Kheir ◽  
Mousa O. Germoush ◽  
...  

High temperature is a major environmental stress that devastatingly affects wheat production. Thenceforth, developing heat-tolerant and high-yielding wheat genotypes has become more critical to sustaining wheat production particularly under abrupt climate change and fast-growing global population. The present study aimed to evaluate parental genotypes and their cross combinations under normal and heat stress conditions, exploring their diversity based on dehydration-responsive element-binding 2 gene (DREB, stress tolerance gene in response to abiotic stress) in parental genotypes, and determining gene action controlling yield traits through half-diallel analysis. Six diverse bread wheat genotypes (local and exotic) and their 15 F1 hybrids were evaluated at two different locations under timely and late sowing dates. Sowing date, location, genotype, and their interactions significantly impacted the studied traits; days to heading, chlorophyll content, plant height, grain yield, and its attributes. Cluster analysis classified the parents and their crosses into four groups varying from heat-tolerant to heat-sensitive based on heat tolerance indices. The parental genotypes P2 and P4 were identified as an excellent source of beneficial alleles for earliness and high yielding under heat stress. This was corroborated by DNA sequence analysis of DREB transcription factors. They were the highest homologies for dehydrin gene sequence with heat-tolerant wheat species. The hybrid combinations of P1 × P5, P1 × P6, P2 × P4, and P3 × P5 were detected to be good specific combiners for grain yield and its attributes under heat stress conditions. These designated genotypes could be used in wheat breeding for developing heat-tolerant and climate-resilient cultivars. The non-additive genetic variances were preponderant over additive genetic variances for grain yield and most traits under both sowing dates. The narrow-sense heritability ranged from low to moderate for most traits. Strong positive associations were detected between grain yield and each of chlorophyll content, plant height, number of grains/spike, and thousand-grain weights, which suggest their importance for indirect selection under heat stress, especially in early generations, due to the effortlessness of their measurement.

2020 ◽  
Vol 12 (2) ◽  
pp. 107-113
Author(s):  
İ. Öztürk

Abstract. The purpose of the study was to assess the relationships between physiological parameters and grain yield of different bread wheat genotypes. In the present research a total of 25 bread wheat genotypes were tested during the 2016-2017 seasons under rainfed conditions. The experiment was conducted in a randomized complete blocks design with four replications. Grain yield, days of heading, plant height, biomass (NDVI) from GS25 up to GS85 growth stage, chlorophyll content (SPAD) during the heading stage, canopy temperature (CT) at GS60 and GS75 growth stages, and glaucousness were investigated. The results of variance analyses showed that there were significant differences (p<0.01) among genotypes for yield. The mean grain yield was 7948 kg ha-1 and yield ranged from 7033 kg ha-1 to 8759 kg ha-1, the highest grain yield performed by TE6744-16 line. According to the results, significant differences among cultivars in terms of plant height, days of heading, biomass, chlorophyll content, canopy temperature, glaucousness were found. TE6627-6 line had the highest chlorophyll content and also, chlorophyll content positively affected grain yield. Canopy temperature is generally related to yield under drought stress condition in bread wheat. In the study early maturing (days of heading) genotypes had lower canopy temperature. An increase in biomass after the heading phase has positively affected grain yield. In the study, no correlation was found between grain yield and biomass at GS25 and GS45 growth phase. There was a negative correlation between glaucousness with biomass at GS60, GS75 and GS85 growth phase. These results showed that physiological parameters such as biomass (at GS75 and GS85), canopy temperature (at GS60 and GS75), and chlorophyll content (at GS60), and glaucousness could be used for selection parameters under rainfed conditions for yield in bread wheat.


2021 ◽  
Vol 64 (3) ◽  
pp. 274-282
Author(s):  
Wajid Ali Jatoi ◽  
Abdul Basit Abbasi ◽  
Shahnaz Memon ◽  
Raza Ali Rind ◽  
Zulifquar Ali Abbasi

In the scenario of increasing global warming, heat stress received more importance. Un- fortunately, Pakistan is also in the line of most heat affected countries of the world. In this regard, wheat being a most important staple edible crop of Pakistan is highly affected by heat stress. For combating this situation, a study was carried-out on ten bread wheat genotypes viz. Moomal, Mehran, Imdad-05, Anmol- 91, Benazir, TJ-83, SKD-1, TD-1, Abadgar and Hamal at the Experimental Field, Department of Plant Breeding and Genetics, Sindh Agriculture University, Tandojam. The experiment was laid-out in a randomized complete block design (factorial arrangement) with three replications during Rabi season, 2016-17 in order to assess the response of wheat genotypes to terminal heat stress tolerance. Wheat genotypes were evaluated in two sowing dates viz., on 24th November as a normal planting and late planting on 31th December, 2016 considered as heat stress condition. The analysis of variance revealed significant differences among the genotypes under both sowing dates indicating suitability of the experiment to improve bread wheat genotypes for heat tolerance. Reductions in various traits were observed in late planting which indicated visible effects of heat stress on agro-economic traits. On an average plant height (cm), tillers/plant, spike length (cm), spikelets/spike, grains/spike, 1000-grain weight (g) and grain yield/plant (g) were declined by -4.63, -2.49, -3.04, -4.35, -16.29, -14.08 and -9.09 units respectively under the heat stress conditions, while the wheat genotypes like TJ-83, SKD-1 and Mehran showed minimum reductions under heat stress conditions for various traits suggesting their heat tolerance, nonetheless cultivars Moomal and Benazir expressed maximum declines under heat stress expressing their susceptibility to heat stress conditions. The remaining genotypes were found as moderately heat stress tolerant.  


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.


Author(s):  
Elfadil Mohamed Elbashier ◽  
Elfadil Mohammed Eltayeb Elbashier ◽  
Siddig Esa Idris2 ◽  
Wuletaw Tadesse ◽  
Izzat S.A. Tahir ◽  
...  

PurposeThe purpose of this paper was to study the genetic variability, heritability, heat tolerance indices and phenotypic and genotypic correlation studies for traits of 250 elite International Center for Agricultural Research in the Dry Areas (ICARDA) bread wheat genotypes under high temperature in Wad Medani, Center in Sudan.Design/methodology/approachBread wheat is an important food on a global level and is used in the form of different products. High temperature associated with climate change is considered to be a detrimental stress in the future on world wheat production. A total of 10,250 bread wheat genotypes selected from different advanced yield trials introduction from ICARDA and three checks including were grown in two sowing dates (SODs) (1st and 2nd) 1st SOD heat stress and 2nd SOD non-stress at the Gezira Research Farm, of the Agricultural Research Corporation, Wad Medani, Sudan.FindingsAn alpha lattice design with two replications was used to assess the presence of phenotypic and genotypic variations of different traits, indices for heat stress and heat tolerance for 20 top genotypes and phenotypic and genotypic correlations. Analysis of variance revealed significant differences among genotypes for all the characters. A wide range, 944-4,016 kg/ha in the first SOD and 1,192-5,120 kg/ha in the second SOD, was found in grain yield. The average yield on the first SOD is less than that of the secondnd SOD by 717.7 kg/ha, as the maximum and minimum temperatures were reduced by 3ºC each in the second SOD when compared to the first SOD of the critical stage of crop growth shown.Research limitations/implicationsSimilar wide ranges were found in all morpho-physiological traits studied. High heritability in a broad sense was estimated for days to heading and maturity. Moderate heritability estimates found for grain yield ranged from 44 to 63.6 per cent, biomass ranged from 37.8 to 49.1 per cent and canopy temperature (CT) after heading ranged from 44.2 to 48 per cent for the first and secondnd SODs. The top 20 genotypes are better than the better check in the two sowing dates and seven genotypes (248, 139, 143, 27, 67, 192 and 152) were produced high grain yield under both 1st SOD and 2nd SOD.Practical implicationsThe same genotypes in addition to Imam (check) showed smaller tolerance (TOL) values, indicating that these genotypes had a smaller yield reduction under heat-stressed conditions and that they showed a higher heat stress susceptibility index (SSI). A smaller TOL and a higher SSI are favored. Both phenotypic and genotypic correlations of grain yield were positively and significantly correlated with biomass, harvest index, number of spikes/m2, number of seeds/spike and days to heading and maturity in both SODs and negatively and significantly correlated with canopy temperature before and after heading in both SODs.Originality/valueGenetic variations, heritability, heat tolerance indices and correlation studies for traits of bread wheat genotypes under high temperature


2017 ◽  
Vol 9 (3) ◽  
pp. 1338-1342
Author(s):  
Amarjeet Kumar ◽  
Swati Swati ◽  
N. K. Singh ◽  
Birendra Prasad ◽  
Anil Kumar

To estimate the level of heat tolerance for different genotypes of bread wheat with respect to morphological characters under studied grains/ spike, grain weight/spike, grain filling duration (duration between the anthesis stage and the physiological maturity), 1000-kernel weight and grain yield/plant for yield. Physiological traits like relative injury (RI %), chlorophyll content, canopy temperature depression (CTD), were used in present investigation to contribute toward capability of plants to tolerate heat stress of the yield contributing traits during heat stress.The findings of present investigation had clearly explained that influences of environments on morpho physiological characters i.e. grain yield per plant (14886.15) and its attributing traits i.e. spike length (459.7), tillers per plant (622.34), spikelets per spike (278.1), 1000 kernel weight (13262.39), grain weight per spike (177.89) and number of grains per spike (2898.44) in wheat were highly significant and positive. Among the parent and their crosses had handsome amount of variations across the environment. The results of interaction for environments with parents, lines, testers and their crosses with respect to morpho physiological characters in wheat was found significant for some characters while variation was absent for other characters studied. Physiological traits like relative injury per cent, chlorophyll content and CTD were vital parameters to quantify the degree of heat stress to develop tolerant genotypes which is urgent and present need under changing climate scenario.


2021 ◽  
Vol 13 (5) ◽  
pp. 2972
Author(s):  
Muhammad Waheed Riaz ◽  
Liu Yang ◽  
Muhammad Irfan Yousaf ◽  
Abdul Sami ◽  
Xu Dong Mei ◽  
...  

Heat stress is one of the major threats to wheat production in many wheat-growing areas of the world as it causes severe yield loss at the reproductive stage. In the current study, 28 crosses were developed using 11 parental lines, including 7 female lines and 4 male testers following line × tester matting design in 2018–2019. Twenty-eight crosses along with their 11 parental lines were sown in a randomized complete block design in triplicate under optimal and heat stress conditions. Fifteen different morpho-physiological and grain quality parameters were recorded at different growth stages. Analysis of variance illustrated the presence of highly significant differences among wheat genotypes for all traits under both optimal and heat stress conditions. The results of combining ability unveiled the predominant role of non-additive gene action in the inheritance of almost all the studied traits under both conditions. Among parents, 3 parental lines WL-27, WT-39, and WL-57 showed good combining ability under both normal and heat stress conditions. Among crosses, WL-8 × WT-17, WL-37 × WT-17, WL-7 × WT-39, and WL-37 × WT-39 portrayed the highest specific combining ability effects for grain yield and its related traits under optimal as well as heat stress conditions. Biplot and cluster analysis confirmed the results of general and specific combining ability by showing that these wheat crosses belonged to a highly productive and heat tolerant cluster. Correlation analysis revealed a significantly positive correlation of grain yield with net photosynthetic rate, thousand-grain rate, and the number of grains per spike. The designated parental lines and their crosses were selected for future breeding programs in the development of heat resilient, climate-smart wheat genotypes.


2020 ◽  
Vol 12 (4) ◽  
pp. 301-311
Author(s):  
G. Gerema ◽  
D. Lule ◽  
F. Lemessa ◽  
T. Mekonnen

Abstract. The present study was conducted to assess the nature and magnitude of genetic variability and traits association of bread wheat genotypes for yield and related traits. A total of 180 genotypes were evaluated in alpha lattice design with three replications in 2017/18 cropping season. Data for 10 quantitative traits were collected and subjected to analysis of variance. The result from the analysis of variance revealed highly significant variability observed among genotypes for all traits studied. Phenotypic coefficient of variation (PCV) is superior over genotypic coefficient of variation (GCV) for most traits but narrow variations were found between PCV and GCV for most of the traits. Heritability in broad sense and genetic advance as percent of the mean (GA%) were relatively higher for Kernels per spike and grain filling period. Grain yield showed positive and highly significant (p≤0.01) association with number of tillers, kernel per spike and plant height both on genotypic and phenotypic levels.The path coefficient analysis showed that spike length, plant height and kernels per spike had positive direct effect on grain yield on both genotypic and phenotypic levels. Divergence analysis (D2) grouped the total test germplasm into 10 clusters. Among those, clusters IV and IX showed the highest genetic distance and thus the possibility to develop segregating populations upon the crossing of widely related genotypes in those clusters. The results could help researches to utilize the most promising wheat genotypes of this study in future breeding programmes for enhancing desirable traits.


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