Genetic diversity, association and principle component analyses for agronomical and quality traits in genomic selection training population of groundnut (Arachis hypogaea L.)

Groundnut (Arachis hypogaea L.) is the world's third important source of oil. A Genomic Selection Training Population (GSTP) comprising 340 genotypes was evaluated over four locations for two seasons to study genetic variability and association among agronomical and quality traits. GSTP exhibited significant variation among the genotypes. seasons and G x E interaction. Moderate to high magnitude of genotypic coefficient of variation and phenotypic coefficient of variation coupled with high heritability was observed for most quality traits. The first 7 components of PCA analysis contributed more than 75% cumulative variability. The training population grouped into three clusters in both the seasons. The number of pods/plant, pod and seed yield/plant were significantly and positively associated with each other, while test weight had negative association with number of pods/plant and had positive association with pod and seed yield during rainy season of 2015. The significant positive correlation was also observed between oil, linoleic acid and stearic acid; similarly, linoleic acid had positive association with stearic acid and palmitic acid. Significant negative correlation was observed between oil and protein content, oleic acid and linoleic acid content. The superior genotypes, namely, ICG 5221, ICGV 01393, ICGV 07220, ICGV 97120, ICGV 06420, ICG 9507, ICGV 06188 and ICGV 00440 were best performer for yield, yield components and nutritional quality traits while ICG 2381 and ICG 5221 recorded a better performance for oil content. The rainy season was found to have an advantage for vegetative, physiological growth, oil content, oleic and oleic to linoleic ratio while the post-rainy season led to forced pod filling and reduced maturity.