Phenotyping of RIL Population Derived from Heat Tolerant and Susceptible Parents for Grain Yield and its Components in Wheat Under Terminal Heat Stress Bhusal Nabin1, Sarial A K2, Saharan R P1, Munjal Renu1, Meena B K3, Sareen Sindhu3,* 1Department of Plant Breeding & Genetics, CCS Haryana Agricultural University, Hisar, 125004, Haryana 2Department of Plant Breeding & Genetics, CCS Haryana Agricultural University, College of Agriculture, campus Kaul, Kaithal, 136021, Haryana 3ICAR-Indian Institute of Wheat and Barley Research, Karnal, 132001, Haryana *email: sareen9@hotmail.com
Online published on 2 January, 2017. Abstract Terminal heat stress is a problem of 40% temperate wheat environments covering 36 million ha (m. ha) area worldwide andaround 13.5 m ha in India. Phenotyping for various genetic parameters for grain yield and its components especially under stress condition is mandatory tobreed varieties adaptable to such adverse environments. In present study 251 recombinant inbred lines (RILs) of wheat derived from a cross between HD 2808 (tolerant) x HUW 510 (susceptible) were phenotyped along with their parents under normal and stress (terminal heat) conditions during 2013–14 and 2014–15 rabi season in a randomized block design with plot size 3(1x 0.23)m2. Seed rate was kept at 100 kg ha−. The minimum and maximum temperature under late sown condition was higher than timely sown exhibiting considerable amount of heat stress. Data were recorded for grain yield (GY), 1000 grains weight (TGW), grain filling duration (GFD), grain filling rate (GFR), grain numbers/main spike (GNS) and grains weight/main spike (GWS). Analysis of variance revealed significant differences amongst RILs under timely and late sown conditions during 2013–14 and 2015–16 crop seasons for all the traits studied. Combined analysis of variance over years and conditions exhibited significant g x e interaction. The mean of RILs for all traits was within the parental range. The magnitude of PCV was higher than GCV over the years and conditions for all traits studied. High heritability coupled with high genetic advance for GY, GFR, GNS and GWS under all environments revealed the additive gene effects with least environment influence on traits. The additivity is a function of homozygosity while non-additivity reflects hetrozygosity in the RIL population studied. The traits for which a mapping population has been fixed could be utilized for QTLs mapping and transgressive segregants analysis. For segregating traits population could be advanced further to attain homozygosity. Top Keywords Wheat, Heat stress, RILs, Phenotyping, Heritability, Genetic advance, Variability. Top |