Genetic Analysis of Some Agronomic Traits in Two Bread Wheat Crosses under Heat Stress Conditions.

Abstract

The present investigation aimed to determine genetic parameters and type of gene action controlling some agronomic traits of the two bread wheat crosses, Shandawel 1 × Gemmeiza 11 and Misr 1 × Giza 168 under normal 20 th Nov. and heat stress 20 th Dec. conditions, using six populations model (P 1 , P 2 , F 1 , F 2 , B C1 and B C2). Scaling test indicated the presence of non-allelic interactions for all studied traits except number of spikes/plant in cross 2 under normal conditions, number of grains/spike in cross1 under favorable conditions and in cross 2 under heat stress and grain yield/plant in cross 1 under normal conditions. The relative importance of additive and dominance effects varied for traits and crosses under normal and heat stress conditions. Dominance effects were generally greater than additive, except for days to heading in cross 2 under heat stress, plant height under normal conditions in cross 2 and biological yield in cross 1 under heat stress and in cross 2 under normal conditions, indicating that dominant genes playing major role in inheritance of these beside the additive one. Dominance × dominance gene interaction was higher in magnitude than additive × additive and additive × dominance in most traits, indicating that these traits greatly affected by dominance and non-allelic interactions. Therefore, it is advisable to delay selection to later generations with increased homozygosity. Positive highly significant heterosis over better parent values were observed for all studied traits, except for plant height in cross 2 under both sowing dates, number of grains/spike in cross 1 under heat stress and in cross 2 under both environments. Broad sense and narrow sense heritability and genetic advance ranged from moderate to high in most cases. Based on these results, these two crosses could be selected to produce high yielding lines under heat stress conditions.

Estimation of some genetic parameters using six populations mean analysis in three faba bean crosses exposed to natural infection of foliar diseases

“…The significance of additive (a) and dominance (d) components indicated that, both additive and dominance gene effects were important in the inheritance of these traits and selecting desirable traits may be practiced in the early generations but it would be effective in the late ones. Similar trend of results was obtained by Ashrei et al, (2013), El-Refaey andAbd El-Razek (2013), Abo Mostafa et al, (2014) and Abd El-Hamid and Ghareeb (2018).…”

Inheritance of Drought Tolerance Using Six Populations Model in Two Bread Wheat Crosses

“…Therefore, the advancement of any plant breeding program is reliant upon the presence of genetic variability. Whereas, the efficiency of selection and expression of heterosis likewise depend on the magnitude of genetic variability in the plant population (Singh & Narayanan, 1993;Singh & Chaudhary, 1999;Farshadfar et al, 2001Farshadfar et al, , 2008aAmin, 2013;Abd El-Rady, 2018).…”

Esteimats of the Genetic Parameters for Yield and its Attributes of Wheat under Optimum and Late Sowing Dates

“…This condition causes great losses of yield due to high temperature during grain filling period. (Hamam, 2014;Raza et al, 2018;Abd El-Rady, 2018;Abdallah et al, 2019 andKoubisy 2019), had confirmed the damaging effect of heat on wheat.…”