Phenotypic and genotypic variability among exotic arabica coffee genotypes using morphological and molecular markers (SRAP)

Abstract

Coffea arabica is said to have low genetic variability, however more information is still needed about the extent of diversity present in the arabica coffee gene pool by evaluating existing genetic resources present in India. The study therefore was conducted to assess the phenotypic and genotypic variability in arabica coffee germplasm accessions. Significant variation was observed among coffee accessions for the traits studied indicating the presence of diversity. Out of 20 traits, per cent ‘A’ grade bean contributed maximum to the diversity (63.29 %). The 41 arabica coffee accessions were grouped into six clusters. The maximum intra-cluster and inter cluster distance (D² = 737.34) was revealed by cluster V (7 genotypes) and cluster II and VI (D² = 8544.21), respectively. Principle Component Analysis displayed 79.50% of variability. Observations on Coffee Leaf Rust disease incidence showed that mean disease severity infection was ranged from 1.34 to 32.67%. On the other hand, molecular analysis of 10 SRAP primers established high rate of polymorphism with an average PIC value of 0.74. The UPGMA clustering grouped arabica coffee genotypes into two major clusters. The similarity matrix coefficient was ranged from 0 to 94%. SRAP marker demonstrated high polymorphism rate can be utilized for future crop improvement program in coffee. Study established high phenotypic but low genetic diversity among the arabica coffee accessions based on morphological and molecular markers, respectively and identified high yielding, coffee leaf rust disease resistant accessions which showed possibility of developing improved varieties through breeding.