Genotype by Trait Relations between Yield and some Morphological Traits of Coconut (Cocos nucifera L.) Hybrid Varieties Based on GT Biplot

Abstract

The objective of this study was to evaluate the coconut hybrid varieties based on Genotype by Traits (GT) biplot to examine its usefulness in visualizing coconut trait relationship and its application in genotypes comparison. The experimental design was a randomized complete block design with two replications; each block consisted of 5 plots with a total of eight palms per plot while the remaining palms were used as guard rows. This experiment was conducted at the Main Research Station of the Nigerian Institute for Oil Palm Research (NIFOR), Benin City, Edo State, Nigeria. The materials for the present study consisted of 5 hybrid varieties of Coconut palm. Data on individual palms were recorded on seven quantitative traits: thickness of petiole (TP), number of fronds (NFD), number of leaflets (NL), number of fruits per palm (NF), number of bunches per palm (NB), width of leaflet (WL) and circumference of the stem 20 cm from the soil level (CF).The GT biplot analysis revealed close associations among the studied traits. The two axes explained 90.4% of the total variation among the cultivars due to the various traits measured thus reflecting the accuracy of inter-relationships among the measured characters. Correlation coefficient between the studied traits showed that there is a strong positive relationship between number of fruit and number of bunches. These two traits were however negatively correlated with other traits except number of fronds. Based on the Auto Find QTL function of GGE biplot, bunch yield and width of leaflets were identified as traits suiTable for indirect selection for nut yield improvement. H4 was identified as an ideal genotype as it combines several good traits in its genetic composition and thus could serve as a good genetic raw material from which better cultivars, synthetic varieties and pure lines can be developed. H1 was the best in terms of nut and bunch yields, indicating that it can be used as parents in the development of hybrid varieties and populations that are outstanding in these traits.