Diversity assessment of small bitter gourd (Momordica charantia L. var muricata) genotypes based on phytochemical and quality traits using multivariate statistics

Momordica charantia var. muricata, being a small-fruited variant of the commercial large-fruited bitter gourd, has been exploited less with respect to its biochemical and antioxidant properties. However, given its immense potential as a crop rich in nutrients, a study was carried out at Central University of Tamil Nadu, Thiruvarur, to evaluate the variability and diversity of 10 genotypes of small bitter gourd based on phytochemical and nutrient quality. The genotypes were found to have significant (P≤0.05) variation for all the traits assessed in the study. Among the ten genotypes MCM-4 was found superior which recorded highest values for most of the traits viz. total phenol (79.57 mg GAE/g), total flavonoid (67.55 mg QE/g), total terpenoid content (2.49 mg/g), FRAP (44.618 mg/mL), DPPH activity (0.94 %), crude fat (2.43 %), ash content (9.23 %), crude protein (29.62 %), calcium (60.14 ppm), manganese (0.3 ppm) and zinc content (0.3 ppm). Antioxidant activity (both FRAP and DDPH) in the fruit showed a significantly strong positive relationship with the total terpenoid content, vitamin C, ash content, crude protein, calcium and manganese. The principal components found four independent components accounting for 88.93 % of the total variance among 10 genotypes. Among the first four principal components (PCs), PC1 had the highest variability (49.11 %), followed by PC2 (19.03 %), PC3 (11.86 %) and PC4 (8.92 %). Hierarchical cluster analysis grouped ten genotypes into four clusters. The genotype in cluster II recorded the highest cluster means for most traits under study except for the moisture content, magnesium, iron and copper. These genotypes from different clusters can further be selected as parents in the hybridisation program to get superior hybrids.