Validation of Phenotypic Response of Black Gram (Vigna mungo (L.) Hepper) Genotypes for Salinity Tolerance at Seedling Stage under Hydroponics System

Abstract

Salinity is an important environmental constraint that adversely affects seed germination, seedling establishment, and subsequent growth of black gram (Vigna mungo (L.) Hepper). Identification of genotypes capable of maintaining satisfactory growth under saline conditions is therefore important for developing suitable breeding material for salt-affected environments. A hydroponic screening for salt tolerance in black gram at the seedling stage was conducted in the Plant Breeding and Genetics Laboratory at Adhiparasakthi Agricultural College, Kalavai, Ranipet, from March to July 2026. Seedling-stage screening is simple, rapid and efficient. The present investigation was carried out using seven black gram genotypes in a completely randomized design (CRD) with two replications. Observations were recorded for seven genotypes for salinity-tolerance traits, viz., germination percentage (%), root length (cm), shoot length (cm) and seedling vigour index, under different salinity levels imposed using NaCl (control and EC 4, 11 and 16 dS/m). Data were analyzed using R software version 4.6.0. Analysis of variance showed that genotype, salinity treatment and their interaction significantly affected germination, root length and shoot length. The black gram genotypes viz., VBN 8 and VBN 10 performed best for most of the characters. The black gram genotypes viz., PU 31 and T9 showed the poorest performance for germination percentage (%), root length (cm), shoot length (cm) and seedling vigour index at a salinity level of EC 16 dS/m. Increasing salinity stress adversely affected germination percentage (%), root length (cm), shoot length (cm) and seedling vigour index in all black gram genotypes. However, VBN 8 and VBN 10 consistently performed better under saline conditions, demonstrating greater salt tolerance. Hence, these genotypes can be used as checks for future screening and breeding programmes aimed at developing salinity-tolerant varieties of black gram.