Comparison of different tolerance indices and PCA biplot analysis for assessment of salinity tolerance in lentil (Lens culinaris) genotypes

Abstract

Lentil is very important legume crop and affected by salinity stress. This study was planned to sort out the lentil germplasm for salinity tolerance. Four different salinity treatments were used (S0mM, S50mM, S100mM, S150mM) in hydroponic culture and root length (RL), shoot length (SL), root weight (RW), shoot weight (SW), total proteins contents (PC), a-amylase (A.A), total soluble sugars (TSS) sodium ions (Na+), potassium ions (K+) and sodium to potassium ratio (Na+/K+) were used as criteria for selection. Principle component analysis (PCA) based biplot, rank sum (RS) scores, integrated selection index (ISI) and integrated scoring (IS) were used as statistical analysis for sortation of lentil genotypes for salinity tolerance and to compare the results of different indices with each other and with PCA based biplot. Analysis of variance showed that genotypes, salinity treatments and their interactions for all subjected traits were significantly different from each other. PCA based biplot showed that Na+, Na+/K+, K+ and TSS under S0mM, RW, SW, RL, SL, K+, Na+/K+ and Na+ under S50mM, SL, SW, RL, RW, Na+, K+, Na+/K+ under S100mM, TSS, SL, RL, RW, Na+, K+, Na+/K+ under S150mM were most discriminating parameters for evaluation of lentil genotypes under respective salinity treatment. PCA biplot showed that Masoor 2002, NL20-3-3, NL9775, NARC11-2 and ILL5888 under S0mM; Masoor 2002, NL9775, ILL5888 and ILL6024 under S50mM; Masoor 2002, NL0196, NL20-3-3, NL9775 under S100mM; Masoor 2002, Masoor 2009, NL9775, NL0196, NL0188 and NL20-3-3 under S150mM were tolerant. Masoor 2002, NL 20-3-3, LN 0188, M93 and NL9775 were declared to be salt tolerant by RS, ISI and IS. Results of RS, ISI, IS and PCA Biplot were comparable and equally valid as these declared unanimously Masoor 2002, NL 20-3-3, LN 0188, M93 and NL9775 as salt tolerant at early growth stages. Genotypes NARC 11-4 and Marka 209 were relatively susceptible against salinity. These tolerant and susceptible lentil genotypes could be used as further evaluation against salinity on physiological and biochemical basis.