Genetic Diversity and the Impact of Geographical Location on the Relationships Between Phoenix dactylifera L. Germplasms Grown in Saudi Arabia

Abstract

Phoenix dactylifera L. is an important crop in the Middle East and North Africa. Date palm diversity faces risks including salinity and lack of rain. It is important to understand the genetic diversity of these germplasms. The objectives of this study were to investigate the degree of dissimilarity and to examine the impact of location on the genetic relationship between local cultivars in Saudi Arabia. The current study included 91 famous date palm accessions and a group of non-famous cultivars, collected from three main regions that are important in date palm cultivation in Saudi Arabia, and twenty-four nuclear microsatellite loci were tested. High polymorphism content was detected in some loci, making it possible to identify and distinguish strains using four markers. Examination of the genetic variation between local date palm germplasms showed a wide range of genetic dissimilarity (0-0.950). For the neighbor-joining algorithm tree, structural analysis and discrimination analysis for principal component, local genotypes can be classified within three main clusters. Cultivars of some regions were grouped according to their geographical location. The results of this study will be useful for those interested in strain identification, classification and conservation as well for those interested in improving fruit production.

Genetic diversity and population structure of date palms (Phoenix dactylifera L.) in Ethiopia using microsatellite markers

“…Generally, the structure result had shown shared ancestry between unknown date palm genotypes and known date palm cultivars that were early introduced. The admixture result of the present study at K = 3 is in agreement with those reported by [ 39 , 40 , 43 ]. Similarly, [ 44 ] revealed three differentiated date palm memberships at K = 3 using different SSR as well as four date palm groups at K = 4 using SNPs.…”

“…This result was also supported with results in PCoA and population STRUCTURE analysis (i.e., intermixing distributions of genotypes on principal component axis and admixture structures were observed). The present result of PCoA showed certain match with the previous studies reported by [24,41], contrary to the report by [38][39][40]42]. According to the model-based clustering for genetic structure of date palm individuals, three genetically distinctive subpopulations were presented that were not formed in line with their collection places.…”

“…In this study, number of alleles/ locus varied from 5 to 16 and maximum number of alleles (16) was amplified by MdPCIR085 and MdPCIR093 loci. According to [ 3 ], a maximum number of alleles (11) was detected by MdPCIR050; ranging between 4 and 11, whereas [ 40 ] reported a number of alleles ranging from 6 to 15 per locus and maximum (15) number of alleles amplified by primer MdPCIR015. The current study showed high genetic diversity among Ethiopian date palm populations may be due to high heterozygosity ( > 0.72).…”

“…Due to this reason, DAPC mostly assigned individuals to single clusters [ 34 ]. DAPC was suggested as an alternative method to identify and describe clusters of genetically related individuals by analysing complex genetic data and detecting admixed individuals by determining the probability that each individual belonged to each cluster [ 40 , 45 ].…”

Genetic diversity of sugar palm (Arenga pinnata) derived from nine regions in Indonesia based on SSR markers

“…Among the nine sugar palm populations in this study, the populations of Lebak, Tasikmalaya, and Brebes had low heterozygosity based on Ho values that were smaller than the values (Table 2). Long-term crossing with individuals from outside the population and the process of adaptation to the environment can affect heterozygosity levels (Aljuhani 2016). In the populations of Lebak, Tasikmalaya, and Brebes, it is suspected that the incidence rate of crossings with individuals from outside the population is shallow, and environmental changes have not very successfully stimulated the response of significant adaptations of individuals in the population, thus not giving rise to new alleles.…”