Simultaneous selection model based evaluation of arsenic tolerance in black gram (Vigna mungo L.) using morphological parameters

Abstract

The evaluation of black gram under arsenic stress is important to identify the arsenic-tolerant genotypes for cultivation in arsenic affected soil and for crop improvement programs. Thirty-two black gram genotypes were received from Indian Institute of Pulses Research (IIPR) Kanpur, India was grown in sand and exposed to three arsenic toxicity levels (control, 150 and 300 µM NaAsO2). Root length, root weight, shoot length, shoot weight and total biomass of plants were recorded in the vegetative stage.The plants were grown in pots (45×30×20 cm)following CRD during Kharif 2014 and experiment was performed in three replications.The morphological characters of almost all genotypes were significantly decreased with increased concentration of arsenic in supplied nutrients, shoot length; root length was less affected, whereas shoot weight, root weight and total biomass were much decreased under arsenic stress condition. Selection of genotypes according to simultaneous selection index model suggests that genotypes IPU 99-176, IPU 25, IPU 2K 99-224 and IPU 99-3 are much successfully able to tolerate arsenic toxicity. The arsenic tolerance capacity of UH 82-14 and UPU 8335 were decreased with increasing concentration of NaAsO2 as compared to other genotypes. The genotypes IPU 99-235, UPU 8335, UH 82-14, LBG 623 and IPU 99-115 has very less capacity to cope arsenic toxicity. The genotypes IPU 99-176 and IPU 25 are appropriate for cultivation in arsenic affected soil as well as these genotypes may be much useful for hybridization program to develop the arsenic-tolerant heterotic cultivars. The root biomass and shoot biomass should be improved to develop arsenic tolerance in black gram. The ranking of genotypes based on multiple morphological parameters has great advantage on conventional methods under abiotic stress.