Variability and Correlation in Coconut Germplasm for Morphological and Fruit Characters

Coconut, an important perennial oilseed crop which provides food, oil, health drink (Tender nut water), medicine, fuel, etc., to the man kind and improve the lively hood of the farming people. According to Fisher [1] the continuous variation exhibited by quantitative traits with which the plant breeder includes heritable and nonheritable components. Variability always provides more possibility of selecting desired types [2]. Selection is effective only for variations which are heritable in nature. The choice of parents, depends upon variability and proper selection for the desirable characters. The larger the variability in the material more will be the scope for improvement. Nut characters are of prime importance in classifying coconut varieties. Studies on diversity of nut traits in coconut germplasm are meagre. This effort was made to document the diversity of morphology, nut and yield characters in coconut.

Twelve coconut genotypes viz., Kalpa Raksha, Aliyarnagar Tall, Kalpathatu, IND 057, IND 050, IND034, VPM3, Chandra Kalpa, IND 040, Kalpadhenu, CRP509 and CRP509 were received from CPCRI, Kasaragod and planted at Coconut Research Station, Veppankulam. The morphological characters viz., plant height, plant girth, number of functional leaves, petiole length, length of leaves, length of leaflet, breath of leaves and number of leaf lets (left and right) were taken periodically. The fruit/ nut characters viz., whole nut weight, dehusked nut weight, kernel thickness, kernel weight, shell weight, copra weight, nut length and nut breath and cumulative yield of each palm over period of nine years were recorded. Mean performance of these germplasm was analyzed. Variability and correlation studies were done for morphological and nut characters were studied using SAS, software version, 4.0.

The mean, range and variability for various morphological and nut characters were given in Tables 1 and 2. The mean performance among the germplasm were higher in VPM3 for length of petiole (1.36 m), no of leaflets (125 left, 123 right). IND 034 registered highest whole nut weight (1345.0 g), dehusked nut weight (850.5 g), kernel weight (400.0 g), shell weight (185.0 g), copra weight (203.0 g). Variability parameters indicated that high variability exists in kernel weight, copra weight, nut length and whole nut weight. Hence all the characters except nut breadth were good for further improvement through selection (Table 3).

Table 1: Mean and variability for morphological characters in coconut.

Table 2: Mean and variability for nut characters and yield in coconut.

Table 3: Correlation of nut characters in coconut.

Correlations analysis revealed significant and positive association between all the nut characters studied. Ganesamurthy et al. [3] reported the similar results in tall coconut varieties. Satyabalan and Mathew [4] also reported the same results in West Coast Tall coconut varities. So, selection based on one character will lead simultaneous improvement on other correlated characters also. The genotypes with desirable characters can be profitably exploited in coconut breeding programme. It can be concluded that a wide range of variability and significant differences between genotypes for various traits existed in the material studied. The results presented in this paper indicate that the germplasm of coconut were important genetic reservoir of variability.