Morpho Physiological Variability In Late Sown Mustard Genotypes Under Terminal Heat Tolerance

Abstract

The present investigation entitled Morpho-physiological variability in newlinelate sown mustard genotypes under terminal heat tolerance was conducted newlinein Randomised Block Design (RBD) with 12 new promising mustard genotypes newlineviz., Vardan, Ashirwad, NPJ-207, NPJ-208, RGN-403, PBR-417, DRMRIJ 16-3, newlineDRMR-2035, RRN-911, RH-1556, RGN-368 and BPR 541-4 widely differing in newlinetheir growth behaviour during two consecutive years (2017-18 and 2018-19). newlineStudy their genotypic variability for morphological, physiological, yield and its newlineattributes and correlation coefficient under late sown condition. Results revealed newlinethat growth in terms of plant height, biomass accumulation, branching behavior, newlineleaf area, growth parameters, physiological characters, phonological newlinedevelopment yield and its components varied significantly among tested mustard newlinegenotypes during both years of study under late sown conditions. Findings newlineindicated that mustard genotypes viz., DRMRIJ 16-3, RGN-403, and RH-1556 newlinerecorded higher value of total branches plant-1, leaf area (cm2), dry matter newlineaccumulation at harvest (g), leaf area index, chlorophyll content (SPAD), newlinechlorophyll stability index (CSI), net photosynthetic rate, Canopy temperature newlinedepression (CTD), Relative water content (RWC), lesser membrane injury index newline(MII)%, siliquae on different branches, number of seeds/siliqua, seed yield/plant, newlinebiological yield per plant, test weight, harvest index as compared to other newlinegenotypes under late sown condition and these genotypes also accumulated newlinehigher growing degree days (GDD), Helios thermal unit (HTU) from sowing to newline50% flowering and sowing to physiological maturity. RRN-911 and RGN-368 newlinewere found poor performer to terminal heat as these recorded the lowest values newlinefor most of studied parameters. Further, these genotypes took significantly lesser newlinedays for their phenological stages i.e., days to anthesis, 50% flowering and newlinephysiological maturity as compared to other genotypes evaluated under late newlinesowing stress. newline newline