Screening of Groundnut (Arachis hypogaea L.) Genotypes for Identification of Sources of Resistance against Leaf Spot Disease

Abstract

Background: Groundnut (Arachis hypogaea L.) is the fourth most important oil seed crop in the world. The early and late spots are a foliage disease more common and more destructive of groundnut which cause severe yield losses up to 70% and reduces the quality of the pod and fodder. Recent efforts have targeted on developing resistant source against leaf spot disease which are helpful for discarding the hazardous toxic chemical compounds used for controlling the disease. The current study aimed to identify the sources of resistance to leaf spot from the newly identified genotypes as well as from wild species and to study the way in which these were responding to the to the disease development. Methods: Seventy three groundnut genotypes were screened against late leaf spot disease under artificial epiphytotic conditions in field at AICRP on Groundnut, MPKV, Rahuri during kharif 2015-16. The observations of disease intensity and rate of infection were recorded. Result: Among the Seventy three groundnut genotypes, 10 genotypes showed resistant and 33 genotypes showed the moderately resistant reaction to leaf spot disease. The 25 entries showed the susceptible and 05 genotypes showed the highly susceptible reaction to the leaf spot disease. All the susceptible cultivars belong to A. hypogaea sub. sp. fastigiata var. fastigiata to as Spanish bunch. These 10 resistant genotypes of groundnut including two wild species viz., RHRG 6083, KDG 128, GPBD 4, ICGV 94118, ICGV 4983, ICG 12672, ICGV 13160 (A. batizocoi), ICGV 13165 (A. cardenasi), ICG 11426 and ICGV8193 were selected for intensive artificial screening under glasshouse conditions and also confirmed resistance. The resistant lines will be useful to develop introgression lines using marker-assisted backcrossing approach to improve foliar fungal disease resistance in popular groundnut varieties.

Genotype × Environment Interaction for Resistance to Early Leaf Spot of Groundnut Mini Core Collections in the Savannas of Nigeria

“…The variance component analysis revealed highly significant (p <0.0001) genotype and GEI effects for ELS and pod weight (kg ha -1 ) indicating that the genetic components and the GEI are more important in the reaction of groundnut genotypes against ELS and pod weight (Table 1). High variability in groundnut against ELS reaction has been previously reported (Shaibu et al, 2020;Zanjare et al, 2020). The significant G and GEI effects for resistance to ELS suggested the possibility of identifying resistant genotypes adapted specifically to a target environment and the need to deploy specifically adapted varieties in the future for more effective genetic control of ELS.…”

Validation of Groundnut (Arachis hypogaea L.) Mini-core Genotypes for Phenotypic Extremities along with LLS Resistance Through Genetic and Molecular Intervention

“…Two hundred and twenty groundnut genotypes received from ICRISAT, Hyderabad were evaluated for their late leaf spot resistance along with yield superiority through phenotypic and genotypic intervention. The phenotypic screening for LLS resistance was carried out in groundnut genotypes using Percent Disease Index (PDI) score (Subrahmanyam et al, 1995 andZanjare et al, 2023). The genetic diversity was assessed for two hundred and twenty four groundnut genotypes through the D 2 analysis and Principal Component Analysis (PCA) besides clustering of genotypes was also performed based on molecular data for late leaf spot resistance.…”