Integrated Approach for Screening Groundnut Genotypes and Unveiling Morphological and Biochemical Factors Associated with Resistance to Thrips, Scirtothrips dorsalis Hood

Thrips is an important sucking insect pest and are the major problem in the groundnut. The pressure from thrips is higher in the summer. One species of thrips i.e., Scirtothrips dorsalis Hood was reported in the present investigation. To minimize crop losses, it is important to efficiently manage thrips, Scirtothrips dorsalis Hood. Finding the source of resistance is one strategy to reduce yield losses. In the summers of 2020 and 2021, forty-four groundnut varieties were screened in the field to determine their resistance to thrips occurrence. Nineteen genotypes were chosen for additional research, including host preference and oviposition preference tests in greenhouse conditions and host plant resistance studies, based on preliminary screening studies conducted at the field level in 2020 and 2021. None of the genotypes were totally free from thrips damage. Nonetheless, three genotypes (Dh-256, RST-1-2020-12, and INS-1-2020-11) were classified as resistant. Ten genotypes were very vulnerable, 14 were susceptible, and 17 were somewhat resistant. The biochemical and morphological examination results showed that resistance against thrips was conferred by increased levels of phenols, tannins, trichome density, and leaf colour

Comparative Studies of Lepidopteran Pest Incidence on JL 24 and DH 256 Varieties of Groundnut

This experiment compares the incidence of lepidopteran pests under protected and unprotected groundnut cultivation at AICRP on Groundnut, MARS, Dharwad, Karnataka in the kharif season of 2021–2022. In order to protect the protected plot from pests, protection measures were implemented at 50 DAS using flubendiamide 20 WG @ 0.5g/l for leaf-eating caterpillars. Based on the crop's phenology, observations were made. Spodoptera litura, Thysanoplusia orichalcea, Helicoverpa armigera, and Maruca vitrata, were deemed to be the main pests, with the remaining pests being of less significance based on their population density and type of damage. When comparing unprotected JL-24 and DH-256 crop plots to protected plots, the majority of major and minor pests were infested during the vegetative to maturity stage, with maximum infestation occurring during the pod formation and pod filling stages of the crop. In comparison to unprotected plots, protected plots had the highest pod and haulm yields.

Not Available

Not AvailableMulti-environment testing at five locations for rust and late leaf spot (LLS) resistance with 41 introgressed lines (ILs) bred using marker-assisted backcross breeding in the genetic background Spanish-type groundnut varieties identified significant genotype, and genotype 9 environment interactions (GEI) for LLS disease resistance and yield parameters. Significant GEI effects suggest the need to identify location specific breeding lines to achieve gains in pod yield and LLS resistance. The observed variable LLS disease reaction among the ILs in part suggests influence of background genotype on the level of resistance. A breeding scheme with early generation selection using molecular markers followed by phenotyping for LLS, and multi-location testing of fixed breeding lines was optimized to enhance selection intensity and accuracy in groundnut breeding. The ILs, ICGVs 14431, 14436 and 14438 with pooled LLS score at 90 DAS of 3.5–3.7 were superior to respective recurrent parent for pod yield, with early maturing similar to recurrent parents. The pod yield advantage in ILs is attributed by more number of pods, besides resistance to LLS that contributes to better filling.Springe