Inheritance of cellular thermotolerance in bread wheat

Abstract

Leaf membrane stability (LMS) and the tetrazolium triphenyl chloride (TTC) test, heat susceptibility index (HSI), heat response index (HRI) and grain yield were used to evaluate 20 diverse wheat genotypes under normal and heat stress conditions for 2 years. The varieties ÔSeriÕ and ÔRaj 3765Õ had a desirable combination of cellular thermotolerance (TTC and LMS), heat tolerance (HRI) and high grain yield potential under heat stress, while ÔWH 730Õ and ÔWH 533Õ were better in cellular thermotolerance and heat tolerance. The varieties ÔPBW 373Õ and ÔKauzÕ also performed better under heat stress in terms of grain yield and HSI/ HRI. The varieties ÔKanchanÕ, ÔPBW 373Õ, ÔNIAW 34Õ and ÔGW 173Õ were avoiders/escapers, ÔSeriÕ and ÔHUW 234Õ were tolerant to heat stress, while ÔWH 730Õ, ÔWH 533Õ, ÔNesserÕ, ÔRaj 3765Õ and ÔKauzÕ showed a combination of both. Correlation coefficients revealed that HRI was the most important trait, followed by TTC because the genotype having high HRI also had high grain yield and was better in mitochondrial viability and membrane stability under heat stress. Significance of GCA and SCA variances indicated the presence of both additive and dominant types of gene action. The use of the parents with high GCA effects, namely, ÔRaj 3765Õ and ÔWH 730Õ in a crossing programme for thermotolerance may provide desirable segregants through selection.

Membrane Thermal Stability at Different Developmental Stages of Spring Wheat Genotypes and Their Diallel Cross Populations

“…Another expression of membrane stability is leaf membrane stability (LMS). The genotypes having high cell viability had also high LMS and high grain yield under heat stress and LMS was significantly positively associated with heat response index (Dhanda and Munjal 2006). High temperatures at seedling growth decreased MTS in wheat (Efeoglu and Terzioglu 2007).…”

“…Both MTS and RI have been used by different researchers to evaluate heat stress Srivastava 2001, Dhanda andMunjal 2006). The high correlation between same growing stages showed that either MTS or RI measurement can be reliably used to determine electrolytic conductivity of wheat genotypes.…”

“…They observed transgressive segregation in F 5 progeny means of relative injury values determined by MTS tests, suggesting that the parents had different genes contributing to heat tolerance and that the trait is not simply inherited. Both additive and dominant types of gene action were reported at the genetic direction of MTS (Dhanda and Munjal 2006).…”

Cell membrane stability- an important criterion for selection of heat tolerant genotypes in wheat (Triticum aestivum L.)

“…There was also decline in biomass, grain filling duration (GFD) and 1000 grain weight (TGW) under late and very late sowing conditions due to terminal heat stress at anthesis and later stages (Kumari et al, 2013). Grain yield show low heritability (Blum, 1988), and influenced by environmental fluctuations, due to this grain yield cannot be directly used as sole selection criteria (Dhanda and Munjal, 2006). Cell membrane stability has a reasonable relationship to plant performance under heat stressed environments and has therefore been considered as a possible selection criterion for grain yield under heat stress (Blum et al, 2001).…”

“…It is difficult to bring progress for increasing grain number and yield components under heat stress condition as these are complex characters and largely influenced by environmental factors. Canopy temperature depression (Reynolds et al, 1998;Bahar et al, 2011;Shefazadeh et al, 2012), cell membrane stability Munjal, 2006 andBahar et al, 2011) and chlorophyll fluorescence (Moffatt et al, 1990;Sayed, 1992) have been used as physiological screening techniques for heat tolerance. Membrane leakage is reported as a measure of stress cellular damage (Fokar et al, 1998a).…”