Combining Ability of Drought-Tolerant Bread Wheat Genotypes for Agronomic and Physiological Traits

Agronomy

Zamalotshwa Goodness Thungo¹  Hussein Shimelis¹  Jacob Mashilo¹ 

[1] School of Agricultural, Earth and Environmental Science (SAEES), College of Agriculture, Engineering and Science (C.A.E.S.), Discipline of Crop Science, University of KwaZulu-Natal, Scottsville, Pietermaritzburg 3209, South Africa;

关键词: abiotic stress;    combining ability;    gene action;    wheat;    yield components;    yield gains;   

DOI  :  10.3390/agronomy12040862

来源: DOAJ

【 摘 要 】

A combining-ability analysis is key to select desirable parents and progenies with enhanced response to selection under water-limited environments. The objective of this study was to determine combining ability for agronomic and physiological traits among distantly related drought-tolerant bread wheat (Triticum aestivum L.) genotypes under well-watered (WW) and terminal-drought (TD) conditions to determine their genetic merit for breeding. Ten heat- and drought-tolerant wheat genotypes were crossed in a half-diallel mating design to generate 45 F₁s, which were evaluated under WW and TD moisture regimes in rainout shelter (RS) and greenhouse (GH) environments. The following agronomic traits were assessed: days to 50% maturity (DTM), plant height (PH), spike length (SL), number of productive tillers (TN), spikelets number per spike (SPS), number of grains per spike (GPS), grain yield (GY) and thousand-kernel weight (TKW); and physiological traits (stomatal conductance (SC) and chlorophyll content index (CCI)). Variances attributable to general combining ability (GCA) and specific combining ability (SCA) were significant (p < 0.05) for GY, DTM, PH, SL, SPS, GPS, TKW and CCI. The parental genotypes LM72, LM81 and LM95 with positive and significant GCA effects on GY were selected to make crosses to develop high-yielding wheat genotypes for water-limited environments. Crosses LM71 × LM02, LM71 × LM81, LM82 × LM02, LM82 × LM81, LM22 × LM100, LM22 × LM81 and LM95 × LM22 were selected with positive and significant SCA effects for GY. The selected parents and crosses are valuable genetic resources for breeding and genetic advancement.

【 授权许可】

Unknown