摘要
Coffee (Coffea arabica) is an economically important crop cultivated on the terraced slopes and narrow valleys of the mountains in the south-western Saudi Arabia. The objective of the study was to evaluate genetic diversity among nineteen coffee accessions collected from different coffee growing areas based on quantitative morphological and pomological traits. Data of 17 quantitative traits were collected and subjected to various statistical analyses. The analysis of variance showed significant differences (P < 0.05) among the accessions for the majority of quantitative traits measured. A principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to determine the nature and degree of divergence among accessions. PCA showed that four principal components explained about 85.62% of the total variation. Differentiation of germplasm into different clusters was because of cumulative effects of a number of characters. Cluster and distance analysis of quantitative traits revealed the existence of five different groups. The maximum distance was seen between clusters IV and V (76.4) while the minimum was seen between I and II (16.13). Accessions like KSA6 and KSA8 from Tallen valley and KSA10 and KSA11 from Hada and Shada valleys collection are recommenced for the next breeding work as they are high yielder accessions compared to the others. However, it is suggested to complete the present results by additional assessment of the in situ collection and variety trials. These results are of great interest for future breeding programs for this species.
Coffee (Coffea arabica) is an economically important crop cultivated on the terraced slopes and narrow valleys of the mountains in the south-western Saudi Arabia. The objective of the study was to evaluate genetic diversity among nineteen coffee accessions collected from different coffee growing areas based on quantitative morphological and pomological traits. Data of 17 quantitative traits were collected and subjected to various statistical analyses. The analysis of variance showed significant differences (P < 0.05) among the accessions for the majority of quantitative traits measured. A principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to determine the nature and degree of divergence among accessions. PCA showed that four principal components explained about 85.62% of the total variation. Differentiation of germplasm into different clusters was because of cumulative effects of a number of characters. Cluster and distance analysis of quantitative traits revealed the existence of five different groups. The maximum distance was seen between clusters IV and V (76.4) while the minimum was seen between I and II (16.13). Accessions like KSA6 and KSA8 from Tallen valley and KSA10 and KSA11 from Hada and Shada valleys collection are recommenced for the next breeding work as they are high yielder accessions compared to the others. However, it is suggested to complete the present results by additional assessment of the in situ collection and variety trials. These results are of great interest for future breeding programs for this species.
