Assessment of Genetic Diversity of Local Coffee Populations in Southwestern Saudi Arabia Using SRAP Markers

مقال فى مجلة

2023

تم النشر فى: https://doi.org/10.3390/agronomy13020302

Abstract: Coffea arabica, a member of the Rubiaceae family, is the most commercially important species

of the genus Coffea. It has been grown on the mountain terraces of southwestern Saudi Arabia for

centuries. At present, the species is subject to increased genetic erosion due to the abandonment of

many gardens by their owners and the increasingly dry climate. The current study was carried out to

determine the genetic diversity of 56 local coffee accessions collected from the southern regions of

Saudi Arabia using 30 sequence-related amplified polymorphism (SRAP) markers. Six SRAP markers

showed polymorphism among the 56 accessions. A total of 1125 bands, with an average of 187.5, was

produced from all six SRAP primers. The polymorphic information content (PIC) ranged from 74.8 to

97.7, with an average of 91.4 for all studied SRAP markers. The high polymorphism percentage seen

in this study, along with the high number of alleles produced and the high PIC values of the primers

used, demonstrate that the SRAP approach was an effective molecular technique for assessing genetic

diversity in the studied populations. The structural analysis showed a sharp peak, with no ambiguity,

demonstrating the highest delta K value at K = 3 and K = 6, and the coffee accessions could be

grouped into three and six main populations, respectively. The PCoA, cluster analysis, and structural

population analysis results suggest considerable genetic diversity among coffee populations growing

on the southwestern mountain terraces of Saudi Arabia. The 56 accessions were segregated into five

groups, mostly according to geographic distribution. The accessions from the southern districts of

Jazan region mostly clustered in groups 2 and 4, while the accessions from the northern districts

of Al-Baha and Assir regions formed separate groups. Based on these analyses, accessions KSA1R,

KSA6R, KSA21, KSA25, KSA37, KSA38, KSA42, KSA59, KSA60, KSA62, and KSA63 were the most

divergent. The genotypes should be conserved for use in coffee-breeding programs to improve the

agronomic value of the crop, broaden the genetic base of C. arabica in Saudi Arabia and increase

environmental resilience. Additional molecular and functional genomics studies are necessary to

further elucidate how this germplasm has evolved and enhance the value of local Arabica coffee

diversity in the Kingdom.