Genetic dissection of morphological and fibre quality traits in cotton and identification of donors for drought

Abstract

newlineThe present investigation was taken up in a recombinant inbred population of cotton at advanced stage (F10) derived from the cross MCU 5 x TCH 1218 in order to identify genotypes with high performance in a specific location or stable performance over locations for yield, yield attributes and fibre quality traits. Also it was aimed to identify lines with drought tolerance and to understand the physiological, biochemical mechanisms associated with the trait. To achieve these objectives, 220 recombinant inbred lines, parents and check KC3 were evaluated across three locations viz., Coimbatore (LI or E1), Aruppukottai (LII or E2) and Veppanthattai (LIII or E3) in a randomized block design with two replications during Kharif and late Kharif 2018 and 14 agronomic and fibre quality traits were recorded. Genetic parameters for variability, heritability and correlation of traits were worked out. Later, the RILs were specifically selected for yield and quality traits and statistically analyzed using Additive Main Effects and Multiplicative Interaction model (AMMI) and graphical genotype by environment (GGE) biplot method for their general and specific adaptation and role of environments in expression of traits. From the rainfed crop raised at Aruppukottai, based on newline newline newline newlinephysiological parameters and single plant yield, stress tolerace indices were calculated and statistically analysed to shortlist a few genotypes for evaluation under artificial condition with induction of stress during flowering and assessment of physiological, biochemical and agronomic characters in control and stressed plots at 15 and 35 days after imposing stress treatment to identify genotypes with drought tolerance. newline Location-wise differences were observed in mean performance of RILs, parents and check for traits. The total number of genotypes that scored high in per se performance for yield and its contributing traits was highest (33 nos.) at Aruppukottai followed by Coimbatore (20 nos.) and Veppanthattai (30 nos.). RIL 132 scored fo