Assessment of Genetic Diversity of Promising Castor Been (Ricinus communis L.) Genotypes in Nigeria

Abstract

Castor oil plant (Ricinus communis L.) is an important oil crop with little research attention in Nigeria. In the present research, extent of genetic diversity among 20 Nigerian castor genotypes was determined using morphological descriptors and molecular markers. The genotypes were laid out on a randomized complete block design with three replicated plots. Molecular genotyping of the genotypes was carried out using genomic Simple Sequence Repeats (SSR). The genotypes revealed high divergence in seed colour, seed shape, seed mottle, seed caruncle and seed sizes. Seedling establishment varied from 70.18% (in Acc. 006) to 93.25% (Acc. 001) with average mean of 81.53%. Raceme length ranged from 15.90 cm to 29.54 cm with population mean of 20.80 cm. The highest seed yield (1222.98 kg/ha) was recorded in Acc. 001 and the least (611.46 kg/ha) was observed in Acc. 006. Seed oil content varied between 32.15% in Acc. 042 and 54.03% in Acc. 006. Agglomerative cluster dendrogram constructed from morphological data showed random distribution of the genotypes into three cluster groups irrespective of the sources/collection points. The genetic diversity based on SSR Marker Analysis revealed high average expected heterozygosity (0.74), Polymorphic information content (0.68), Nei’s gene diversity index (0.72) and Shannon's Information index (1.43). The dendrogram constructed from molecular data grouped the twenty genotypes into three groups at coefficient of 0.34. From these findings, it showed that the twenty genotypes evaluated are divergent in nature and they could serve as good genetic material for castor breeding in Nigeria.

Diversity Assessment by Molecular Barcoding and Seed Morphology in Ricinus communis L.

“…This could be attributed to an increased levels of total phenolics that magnitude seed adaptation against hot climate habitat (23,25,26), or it may be adopted to increase seed persistence in the soil (27) (30). In accordance with the current finding Salihu and his coauthor on 2019 could not find a direct correlation between genetic diversity among 20 Nigerian castor genotypes and their geographical distribution (13). The genetic similarities of Ricinus accessions from different locations may be owed to the domestication and immigrants from each other, in addition to random mating within population (12).…”

“…Nowadays, several DNA-PCR based molecular markers are successfully prevailed for assessing genetic diversity in different plant species. Many DNA markers span genome-wide to constitute a framework for high-throughput analyses of genetic diversity in plants such as Random Amplified Polymorphic DNA (RAPD), Inter Simple Sequence Repeats (ISSR), Amplified Fragment Length Polymorphism (AFLP) and Single Nucleotide Polymorphisms (SNP) (1,(11)(12)(13)(14). Other DNA based markers span only a specific locus within conserved regions of the genome regarded as fingerprint.…”

Single Nucleotide Polymorphisms: A Modern Tool to Screen Plants for Desirable Traits

“…GBS is gradually leading a transition from population genetics to population genomics, so that high-throughput marker recognition in plant population is affordable. A lot of commercial crops have been studied using GBS to aid breeding processes in Rice [20][21][22], Maize [23][24][25], potato [26][27][28]. Although GBS was initially developed as a reduced-representation sequencing (RRS) approach using restriction enzymes to decrease genome complexity before sequencing [29][30][31][32].…”