Morpholological and molecular characterization of grain amaranth germplasm under salinity condition

Abstract

newline Amaranth is one such crop, which has high potential to act as alternative food grain in most parts of the world and amaranth has wide adaptability and can be grown from temperate to tropical conditions. The experiment was conducted at Genetics and Plant Breeding research farm during the Rabi season of 2023-24 in Randomized Block Design, aimed to characterize the grain amaranth morphological traits, artificial screening for salinity stress was conducted at Soil Science and Agricultural Chemistry in Completely Randomized Design and molecular analysis was done at ICAR-NISST, Kushmaur, Mau. newlineTo characterize of 23 grain amaranth genotypes using morphological, physiological, and molecular markers. Field evaluations showed significant variability across all six morphological traits including days to 50% flowering, plant height, inflorescence length, lateral spikelet length, seed volume weight and seed yield with seed yield ranging from 141.66 to 382.55 g. Genotype SGA6 exhibited the highest seed yield, while PCA revealed that inflorescence and lateral spikelet lengths were major contributors to variability. Under artificial salinity stress (12 dSm-1 and 15 dSm-1) wide phenotypic variability was observed across 12 seedling traits. Shoot length ranged from 4.00 to 17.57 cm and shoot Naand#8314;/Kand#8314; ratio from 0.12 to 2.20 indicating diverse salinity responses. Genotypes such as SGA5, SGA17, and SGA19 showed superior biomass traits while SGA2 and SGA23 demonstrated efficient ionic homeostasis through lower Naand#8314;/Kand#8314; ratio suggesting better salt tolerance mechanisms. Correlation analyses under both conditions identified positive associations among key yield and physiological traits and PCA explained over 57% of total variation through the first three components. Cluster analysis grouped genotypes into three distinct clusters based on performance and stress response. Molecular marker analysis with 36 SSR primers identified two significant markers: AhySSR29093 associated with root traits and AhySSR43989 with shoot Naand#8314; and