Genetic variability, morphological diversity, and antioxidant potential in gynoecious Coccinia accessions: implications for breeding and biofortification

Abstract

This study investigates genetic variability, morphological diversity, and biochemical traits in gynoecious Coccinia accessions using multivariate analysis. ANOVA revealed significant variation across key traits, with vine length (VL) ranging from 243.0 to 532.2 cm (CV = 10.15%), internode length (IL) from 6.15 to 9.7 cm, and leaf length (LL) from 6.52 to 8.76 cm. Fruit-related traits, including fruit diameter (FD) (1.72-4.76 cm), fruit length (FL) (3.74-8.16 cm), and average fruit weight (AFW) (11.88-30.42 g), showed significant variability (p < 0.01). Reproductive traits such as the number of female flowers per plant (NFFP) ranged from 828 to 1824 (CV = 12.08%), highlighting strong selection potential. Biochemical attributes exhibited considerable variation, with ascorbic acid (AsA) content between 18.52 and 53.68 mg/100 g and total soluble solids (TSS) from 0.9 to 3.4%. Antioxidant-related traits, including total phenolics (TPL: 13.66-24.95 mg GAE/100 g), total flavonoids (TFL: 5.42-12.16 mg CE/100 g), and ferric reducing antioxidant power (FRAPL: 20.49-46.62 µmol TE/g), indicated high bioactive potential. Strong positive correlations between yield traits (e.g., AFW and fruit yield per hectare, FYH, r > 0.9), were found by correlation analysis, and both trade-offs and synergies were seen between biochemical and morphological variables. Principal Component Analysis (PCA) highlighted genotype-specific trait relationships and explained 50.8% of the total variation. Cluster and network analyses further illustrated genetic diversity, with Thar Dipti (CHESIG-7) and Thar Sadabahar (CHESIG-2) emerging as genetically distinct accessions. These findings provide valuable insights for breeding strategies aimed at improving yield, antioxidant content, and fruit quality in Coccinia accessions.

Keywords: Coccinia grandis; Antioxidants; Biochemical traits; Correlation PCA; Genetic variability; Yield traits.

Fig. 1

Collection sites of coccinia gynoecious accessions

Fig. 2

Morphological variability in fruits among coccinia gynoecious accessions during 2022 to 2024 (A) CHESIG-1: Round oblong, continuous strips; (B) CHESIG-2: Round oblong, discontinuous stripes; (C) CHESIG-3: Round, continuous stripes; (D) CHESIG-4: Oblong, discontinuous stripes; (E) CHESIG-5: Oblong, discontinuous stripes; (F) CHESIG-6: Round oblong, discontinuous stripes; (G) CHESIG-7: Round oblong, stripless; (H) CHESIG-8: Shouldered oblong, continuous stripes; (I) CHESIG-9: Spindle shape, discontinuous stripes; (J) CHESIG-10: Pear shape, sparse stripes

Fig. 3

Male and female flower of coccinia

Fig. 4

The distribution box plots represent the distribution of morphological, yield, and biochemical traits in Coccinia gynoecious accessions based on their mean values

Fig. 5

Graphical representation of correlation matrix for growth, yield and quality traits in ivy gourd gynoecious accessions

Fig. 6

Correlation Plot of 25 Morphological, Yield, and Biochemical Traits in 10 Coccinia Gynoecious Accessions

Fig. 7

Transformed heatmap of 25 Morphological, Yield, and Biochemical Traits in 10 Coccinia Gynoecious Accessions

Fig. 8

The network graph of 25 Morphological, Yield, and Biochemical Traits in 10 Coccinia Gynoecious Accessions provides insights of the relationships among traits, highlighting their interactions in terms of positive (blue lines) and negative (red lines) correlations

Fig. 9

The Principal Component Analysis (PCA)-biplot displays the multivariate relationships among various traits and the accessions analysed

Fig. 10

The dendrogram shows the clustering of various Coccinia gynoecious accessions

Fig. 11

The MDS plot represents the spatial distribution of genotypes based on their pairwise dissimilarities in accessions

Fig. 12

The relative contribution of traits to genotype difference is highlighted by the variable relevance ranking plot