MSc

Morpho-physiological diversity assessment of Garcinia gummi-gutta (L.) Robs. germplasm of hermaphrodite trees of National Bureau of Plant Genetic Resources, Regional Station (NBPGR), Vellanikkara and two local accession was carried out at College of Forestry, Vellanikkara. The objective of this study was to explore the variability in terms of vegetative, flower, fruit, seed characters, biochemical characters of fruits and seed butter in the 32 entries of G. gummi-gutta.
Study indicated presence of conical, dome and pyramidal canopy shape with most trees having conical shape crowns in G. gummi-gutta. Horizontal, erect and drooping branching pattern was observed among the entries, with drooping branches predominating. Wide variation in tree height and height of first branch from base and GBH was observed. High correlation was observed between tree height and height of first branch.
Leaf characters such as leaf length, breadth and leaf area had considerable variation among the accessions. Flower characters study revealed the presence of cream, yellow and pinkish red colour petals. Petal length, petal breadth, pedicel length and weight of flowers too varied among the entries. Petal length and breadth were correlated.
The fruit characters such as fruit weight, rind weight, fruit yield had wide variation (CV of 27.59%, 46.7% and 30.75% respectively). The yield varied from 70 to 980 fruits per trees. Seed characters like seed length, breadth, seed weight and germination differed among the accessions. Significant correlation was noticed between fruit weight and rind weight, number of fruits per tree and tree height.
The study on primary metabolites content in fruits showed considerable variation in terms of carbohydrate, protein, crude fat and reducing sugar. Among them reducing sugar showed low variation with CV of 3.19 percent. Secondary metabolites in fruits like phenolics and flavonoids content too varied among the accessions. Phenol content varied from 900 mg/100 g to 1200 mg/100 g. The fruits of various accessions differed in terms of mineral content like Ca, Na, K, P, K and Mg. The vitamins such as vitamin B1, B2, B12, C, A and E showed low variation among the accessions in the present study. The vitamin C varied from 16.69 to 27 mg/100 g. The correlation between biochemical characters of G. gummi-gutta indicated the presence of significant, positive correlation between Na and flavonoids, Na and Mg, Na and phenol, K and crude fat, phenol and flavonoids. Path analysis for fruit yield indicated that number of fruits per tree and fruit weight had high, positive and direct effects on fruit yield. Path analysis indicated that rind weight had high, positive and direct effect on rind yield.
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Melting point and colour of seed butter varied among the accessions. Biochemical characters of butter such as saponification value, acid value and iodine value had lower extent of variation.
The PCA analysis on morphological feature indicated that the first two PC’s could explain 37.4 percent of the variation. The first component was composed of fruit weight, rind weight, and pedicel length and leaf breadth. The second component was influenced by petal length, tree height and height of first branch. The PCA analysis on biochemical feature indicated first two PCs with Eigen values >1 could explain the 34.9 percent of the variation. The first component was mainly composed of vitamin B1, vitamin B2, vitamin B12 and vitamin C. The second components were strongly associated with iodine value, vitamin A, phenol and vitamin E.
The present investigation related to variation in morphological and biochemical parameters in G. gummi-gutta indicated considerable variation among the accessions. Trees could be grouped into five clusters based on these characters using cluster analysis. Thus, there is a possibility of taking up hybridisation work using the present germplasm for improving the yield and nutritional value of this important tree crop of Kerala.