Genotype by Trait (GT) Biplot Analysis for Multi-trait Evaluation and Selection in Sesame (Sesamum indicum) Genotypes
C. Anjana
Department of Genetics and Plant Breeding, SVAC, ANGRAU, Tirupati, India.
N. Sabitha *
SVAC, ANGRAU, Tirupati, 517502, India.
D. Bharathi
RARS, Tirupati, India.
B. Ramana Murthy
Department of Statistics and Computer Applications, S.V. Agricultural College, Tirupati ANGRAU, Andhra Pradesh, 517502, India.
Rajan Isha Pearl
Department of Genetics and Plant Breeding, Agricultural College, ANGRAU, Bapatla, 522101, India.
*Author to whom correspondence should be addressed.
Abstract
Multi-trait evaluation of genotypes is a cornerstone of modern plant breeding, and graphical analytical tools such as the Genotype by Trait (GT) biplot have become indispensable for simultaneously interpreting complex genotype–trait relationships. In the present investigation, GT biplot analysis was employed to evaluate 45 sesame genotypes during Rabi 2025–26 across 14 yield and yield-attributing traits. The two principal components, PC1 (24.52%) and PC2 (18.45%), collectively accounted for 42.97% of the total variation. The which-won-where polygon view of the GT biplot delineated nine sectors with vertex genotypes TPTS-83, TPTS-94, TPTS-152, TPTS-66, TPTS-144, TPTS-45, TPTS-69, RMT-586 and RMT-631 exhibiting superior performance for their respective trait clusters. TPTS-66 was associated with days to 50 per cent flowering, days to maturity, plant height, first capsule height, specific leaf area and oil content, whereas TPTS-69 and RMT-586 were associated with branching traits, number of capsules per plant, capsule length, thousand-seed weight, harvest index and seed yield per plant. The vector view of the GT biplot revealed significant positive associations of seed yield per plant with harvest index, 1000-seed weight, number of primary and secondary branches, number of capsules per plant, SPAD chlorophyll meter reading (SCMR) and capsule length. The genotype TPTS-45 was identified as the ideal genotype, with JCS-3993, TPTS-144, VS-21-008, TPTS-244, TPTS-69 and VS-20-001 ranking as the most desirable. The discriminativeness versus representativeness analysis highlighted seed yield per plant, number of capsules per plant, number of primary and secondary branches, plant height and first capsule axis height as the most informative and reliable traits for genotype selection. These findings provide a robust framework for multi-trait-based selection and hybridisation in sesame breeding programmes aimed at developing high-yielding, early-maturing cultivars with improved oil content.
Keywords: Sesame, GT biplot, multi-trait evaluation, vertex genotypes, trait association, ideal genotype, discriminativeness, representativeness