MSc

The field experiment entitled ‘Morphological and biochemical characterization of coconut (Cocos nucifera L.) germplasm was conducted at Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara during the period from 2004 to 2005. The objectives of the study include morphological and biochemical characterization of coconut germplasm available in the college farm and to asses the variability so as to identify the superior types. Based on previous years yield data, forty palms of twenty years old were selected randomly and subjected to cluster analysis for grouping the selected palms. Karl Pearson’s coefficient of correlation and path analysis were also carried out to study the degree of association of different characters.

In the present study, the palms under investigation showed high variability for all the 28 characters studied. The cluster analysis of the selected palms showed that C1 and C4 were placed distant by as compared to other clusters. Among the different morphological and biochemical characters studied, cluster C4 recorded superiority over other clusters with respect to yield and yield contributing characters like total nut yield (158 nuts palm-1 year-1), number of bunches produced (12), number of nuts bunch-1(19), stem and leaf characters like stem girth (87cm), number of leaves (37) and petiole length (121cm), followed by cluster C3 with respect to nut yield (129 nuts palm-1 year-1). The study also revealed that cluster C1 was inferior with respect to above characters such as total nut yield (30nuts palm-1 year-1), number bunches produced (6), number of nuts bunch-1(5.67), stem and leaf characters like stem girth(62cm), number of leaves (23) and petiole length (69cm). Cluster C4 included single palm (T22), C3 was comprised of five palms (T9, T10, T20, T21 and T32) and cluster C1 included single palm (T33).

Biochemical characters like leaf polyphenol content and APH enzyme activity were more in the cluster C6 during summer season (April, 2005). The activity of GOT enzyme at the onset of rainy season (June, 2005) was more in C4.

Characters like number of leaves on the crown showed highly significant positive correlation with nut yield, number of bunches produced year-1 and number of nuts bunch-1. Inflorescence characters like number of inflorescence produced palm-1year-1 showed highly significant positive correlation with nut yield and number of bunches palm-1. Bunch characters like number of bunches palm-1 year-1, length of bunch stalk and nuts bunch-1showed positive correlation with nut yield. Nut weight was positively correlated with copra content. However, the leaf polyphenol content was negatively correlated with nut yield.

Female flowers inflorescence-1, duration of female phase, bunch stalk length, petiole length and activities of GOT enzyme during onset of rainy season had recorded positive direct effects on nut yield revealing the role of these characters in selection. Number of female flowers spikelet-1 showed direct negative effect on nut yield and leaf polyphenol content had high negative indirect effect on nut yield through number of female flowers inflorescence-1.