Identification of elite breeding lines in linseed (Linum usitatissimum L.) through best linear unbiased prediction insights

Linseed or flaxseed (Linum usitatissimum L., 2n = 30, x = 15) is an annual herb belonging to the family Linaceae and tribe Lineae. It bears blue or white flowers and produces small, flat seeds ranging in colour from golden yellow to reddish brown, with a crisp texture and nutty flavour. The present investigation was conducted during the rabi season of 2021–2022 under the All India Coordinated Research Project (AICRP) on Linseed at Regional Research and Technology Transfer Station (RRTTS), Odisha University of Agriculture and Technology (OUAT), Keonjhar, Odisha, India. The experimental material comprised eight advanced breeding lines (F8 generation) and three check varieties. The experiment was laid out in a randomized block design (RBD) with three replications. Data on seed yield and other agro-morphological traits were used to estimate genetic variability, heritability, genetic advance (GA) and trait correlations. Analysis of variance (ANOVA) revealed highly significant variation among the studied traits. Low to high genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were recorded for the advanced breeding lines. The highest GCV and PCV values were recorded for number of basal branches (NBB) per plant (14.66 % and 29.87 %), number of capsules per plant (NCP) (23.16 % and 23.91 %) and seed yield (SY) (17.99 % and 20.02 %). The highest broad-sense heritability was observed for plant height (PH) (0.97), days to maturity (DM) (0.96) and number of seeds per capsule (NSC) (0.93), whereas the lowest broad-sense heritability was recorded for NBB per plant (0.24). High heritability coupled with high GA as a percentage of mean was observed for NCP and SY, indicating the predominance of additive gene action for these traits. The highest significant positive correlation was observed between test weight (TW) and SY (0.67), followed by number of top branches and TW (0.45). Therefore, the results of the present investigation revealed the existence of substantial variability for SY and other agronomical traits, which can be exploited in future breeding programmes for the superior varieties.