Abstract
To study genetic analysis of some physiological traits of drought stress in wheat using diallel techniques, an experiment was performed on ten bread wheat genotypes as parents and their 45 F1 hybrids in a randomized complete block design with three replicates under well-watered and drought stress conditions at the Research Farm of Faculty of Agriculture, Sohag University, Egypt during season of 2018/19. The results showed significant differences between the genotypes (G), Parents (P), F1 crosses, P vs. F1, GCA and SCA under well-watered and drought stress in the flag leaf area (FLA), flag leaf chlorophyll content (FLCC) and flag leaf temperature (FLT), except FLCC for F1 crosses exhibited insignificant differences. The significant differences were found in the interaction of SCA × Env., in all studied traits and GCA × Env., for FLT., indicating the involvement of both additive and dominance gene action in their inheritance. The most desirable heterotic effects were considered as the largest positive heterosis estimates for FLA and FLCC, and the lowest negative for FLT. The parent numbers P9, P8 and P3 were the best general combiner for FLA under normal irrigation and drought stress. While the parents P2, P7 and P9 were the best general combiner for FLCC, under normal irrigation and (P1, P2 and P3) under drought stress. Therefor the parents P1, P4 and P5 were the best general combiner for FLT under normal irrigation, also the P3, P4 and P5 were the best general combiner for FLT under drought stress conditions. Under normal irrigation and drought stress conditions as well as the combined data, the additive genetic components of variation (VA) in F1 ’s was much greater than dominance component (VD), as expressed by the (VA/VD) ratio which was more than unity for the FLA, and FLT under normal irrigation and their combined. This indicates that the additive gene effects in F1 crosses are more important than dominance and plays the major role in the inheritance of these studied traits.
Highlights
Wheat is the most important cereal crops in terms of area and production
The significant or highly significant differences were found among the 10 parents for studied traits traits under normal irrigation, drought stress and overall, two environments, the flag leaf area (FLA), flag leaf chlorophyll content (FLCC) and flag leaf temperature (FLT) under normal irrigation and drought stress showed highly significant differences between these parents (Table 2)
These results are harmony with those obtained by Esmail et al (2016), and Samah (2019), they revealed that highly significant differences among the genotypes for all characters indicating the presence of considerable variability among the bread wheat lines
Summary
Wheat is the most important cereal crops in terms of area and production. Its importance is derived from many properties and uses of its grain, which make it a staple food for more than one third of the world's population. Still there is a big gap between the consumption and local production (48%) Another challenge facing Egypt is the growth of its population that is expected to reach 170 million by 2050 (Boko et al, 2007). Carbon dioxide fixed after anthesis by the ear in wheat is ranged from 17 up to 30% of the grain weight, whereas in the absence of severe drought stress of wheat plant largely succeeds in grain development within the ear and the flag leaf area correlation with yield not by physiological activity and by the correlation in development of large flag leaves and large ears Flag leaf is an important contribution to grain yield, 1000-kernel weight, and grain number, compared to penultimate and antepenultimate leaves. The current investigation aimed to: (1) Study the effect of drought stress at anthesis stage on some physiological traits for F1 crosses and their parents. (2) Estimation of the general and specific combining ability effects and the genetic behavior of the parents and their crosses related to physiological traits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
