In vitro screening of chickpea genotypes for drought related traits using PEG 6000

Abstract

Chickpea is adversely affected by drought stress at all the growth stages including germination and seedling emergence thereby seedling establishment. An in vitro screening method was used to screen the genotypes for drought tolerance using polyethylene glycol (PEG) 6000. Six drought related seedling traits viz. germination percentage, shoot length (cm), root length (cm), shoot-root ratio, number of secondary roots and relative water content were studied in fifteen genotypes including thirteen MAGIC lines and two varieties JG 11 and HC 5. PEG solutions of 3%, 5% and 7% were used to induce different levels of water stress to compare with control (0%). Analysis of variance revealed significant variability among genotypes, different levels of PEG as well as between genotypes and stress levels. In general a decrease in the mean values under subsequent water induced stress was observed as compared to control in all the six traits under study with few exceptions like root length and shoot root ratio. The root of few genotypes viz. M 31, JG 11, HC 5, M 30 and M 27 increased with increase in stress level. Similarly, shoot root ratio also increased in two genotypes namely M 37 and M 32. Considering complex and quantitative nature of drought tolerance, drought related traits were assigned rank score given to each genotype in order of showing increase or minimum decrease in that seedling trait at control and 7% PEG induced stress levels. Total sum of scores over six seedling parameters revealed that JG 11 was most drought tolerant among all fifteen genotypes under study with total score of seventy six, followed by HC 5 whereas M33 was the most susceptible genotype for drought tolerance.