Ecology, Environment and Conservation Paper

PHYSIOLOGICAL RESPONSES OF RESISTANT AND SUSCEPTIBLE GROUNDNUT (ARACHIS HYPOGAEA L.) GENOTYPES TO LATE LEAF SPOT

V.S. Shinde, K.S. Raghuwanshi and S.R. Zanjare

Abstract

Late leaf spot (LLS) disease caused by Phaeoisariopsis personata (Berk. and Curt.) Von Arx. is globally wide spread and is the most important foliar disease of groundnut (Arachis hypogaea L.). The research was performed to study the effect of late leaf spot on ten resistant genotypes of groundnut including two wild species viz., RHRG 6083, GPBD 4, KDG 128, ICG 11426, ICG 12672, ICG 13919, ICG 14475, ICGV 94118, ICGV 13160 (A. batizocoi) and ICGV 13165 (A. cardenasi) and two susceptible genotypes SB XI and JL 24 at AICRP on Groundnut, MPKV, Rahuri during 2013-14 and 2014-15. The late leaf spot disease caused significant alterations in physiological processes. The susceptible genotypes SB XI and JL 24 showed significant alterations i.e. lowered rate of photosynthesis, which reduced from 16.70 μ moles m-2 s-1 and 16.02 μ moles m-2 s-1 to 2.04 μ moles m-2 s-1 and 4.56 μ moles m-2 s-1 respectively at 30 DAI. The stomatalconductance also declined significantly in susceptible genotypes SB XI and JL 24 from 0.16 mol H2O m-2 s-1 to 0.11 mol H2O m-2 s-1 to 0.06 mol H2O m-2 s-1 and 0.03 mol H2O m-2 s-1 respectively, at 30 DAI while, the transpiration rate substantially increased in susceptible genotypes i.e. from 2.13 m moles m-2 s-1 and 2.29 m moles m-2 s-1 to 3.26 m moles m-2 s-1 and 3.56 m moles m-2 s-1 respectively, at 30 DAI with LLS pathogen. It was observed that resistant genotypes showed slight changes in photosynthesis, stomatal conductance and transpiration after challenge by LLS pathogen.