Genetic Diversity Assessment Among Tall Coconut Palm

Abstract

The tall coconut (Cocos nucifera L.) has great socioeconomic importance in Brazil and was first introduced on the coast of the north-eastern region, where it has been exploited in a semi-extractivist manner. The goal of this study was to quantify the genetic divergence between accessions introduced and preserved at the International Coconut Genebank for Latin America and the Caribbean, estimate the efficiency of descriptors used in the discrimination of the accessions, and indicate the essential descriptors for the activities of characterisation and evaluation. The accessions used were: Polynesia Tall; Tonga Tall; West African Tall; Rennel Tall; Rotuma Tall; Vanuatu Tall; Malayan Tall and Brazilian Tall Praia-do-Forte. Thirty-five quantitative descriptors recommended for the species were used. Genetic divergence was estimated by the Mahalanobis’s generalised distance and the cluster analysis was performed using the unweighted pair group method with arithmetic mean (UPGMA). The relative importance of the descriptors was measured according to Singh and Jolliffe’s methods, and the variables were selected taking into consideration the matching information in the two methods, eliminating those that were discarded in the two procedures. The agronomic characteristics indicated that the first canonical variable explained 90.25% of total variance. The most efficient descriptors for detecting the genetic divergence were: fruit equatorial circumference; nut polar and equatorial circumference; quantity of liquid endosperm; total fruit weight; nut weight; stem height; girth of stem at 1,5m height; number of leaflets; and number of bunches. The most dissimilar accessions according to the agronomic characteristics were Rotuma Tall and West African Tall, which can be primarily indicated as genitors for the formation of segregating populations in breeding programmes.

Genetic divergence of native palms of Oenocarpus distichus considering biometric fruit variables

“…Additionally, the selection, based on any of the eight features, provides genetic advantages to differentiate individuals within the same population, due to the cross between genetically different individuals causing greater heterotrophic effect 21 . The variability between the genotypes can be attributed to the data quantitative nature, polygenic, controlled by many genes 13,22 and is important in ex situ genetic conservation, due to increasing the effective population size and reducing the mortality caused by inbreeding 23 . The efficiency of these biometric characteristics to distinguish genotypes from the family Arecaceae was confirmed with similar results for E .…”

“…These values should be considered in breeding and conservation programs for this palm 10 . Genetic variations in native populations are important to obtain parents to produce superior and divergent individuals for the interest characteristics in the F1 generation 22,25,26 . However, collection intensity may reduce fruit availability for frugivorous animals, compromising gene flow and genetic diversity in the forest fragment 27 .…”

“…distichus genotypes, as reported for Capsicum spp. Species 30 , Passiflora edulis Sims 31 and Cocos nucifera L. 22 .…”

“…distichus genotypes by geometric distances in scatter plots 34 , as reported for genetic divergence in C . nucifera 22 . The projection of dissimilarity measures in 2D projection representation and use of dendrograms are acceptable when the correlation value between measures of original distances and a graphics is higher than 0.9 and values of distortion and stress lower than 20% 35 .…”

Ethnobotanical study of the coconut palm in the Coastal Zone of Benin

“…Coconut palm, Cocos nucifera L. (2n = 2X = 32), the sole species of the genus Cocos, is a diploid perennial oilseed plant, belonging to the Arecaceae family (Batugal et al 2005). Coconut tree is the most widespread cultivated tree in the world and is found in all intertropical regions (Nayar, 2017;Sobral et al, 2018). Southeast Asia is coconut, and gender role in the value chain of coconut.…”