Proximate Compositions Evaluation and Variability among Cultivars of Date Palm (Phoenix dactylifera L.) in Nigeria

Abstract

Genetic variability among the fruits of 22 date palm cultivars was studied using 6 nutritional characters to enable us classify the available germplasm into distinct groups on the basis of their genetic diversity using their nutritional characteristics from proximate composition. The main date palm-growing areas of Nigeria were surveyed in 2011 with the objective of characterizing cultivars as to the quality and economic value of their fruits. Descriptive statistics and some multivariate analysis techniques were used to classify the 22 date palm cultivars. The genotypes based on studied traits were grouped into three clusters. Discriminant function analysis was used to confirm the accuracy of grouping that was produced by cluster analysis. Sugar and crude protein content were identified as important traits that could be used to differentiate the genotypes as revealed by both principal component and discriminant analysis. Genetic distance between Daushenga 1 and Saberari 2 exhibited the greatest dissimilarity followed by Daushenga 1 and Hausawa. Hence the use of these parents for hybridization should be given greater emphasis for the production of transgressive segregants with high nutritional potential. The level of variability observed suggested a high diversity among the cultivars. The result of the principal component analysis indicated that the contribution of the first three factors with Eigen value greater than one accounted for 73.03% of the total variation. The moderately high ash content shows that date palm fruit can effectively serve as a source of inorganic minerals and good adsorbent in the removal of metallic ions, odour, colours and other particulate matter from aqueous medium of water and waste water thus making date palm fruit an effective material precursor in water and waste water treatment among other uses. The high soluble carbohydrate content indeed gives an indication that it compares favourably with other fast energy giving food stuffs and thus it can be added to some food content as an additive .This work identified the existence of inherent variability in the local germplasm collections, and the traits that could be used to exploit the observed variability, eliciting important relationships among the traits in the process.