Genetic diversity among south Indian tea germplasm ( Camellia sinensis, C. assamica and C. assamica spp. lasiocalyx) using AFLP markers

Abstract

Amplified Fragment Length DNA Polymorphism (AFLP) analysis of 49 tea cultivars from south India produced a total number of 1555 unambiguous polymorphic amplified DNA fragments. The dendrogram derived by unweighted pair group method with arithmetic mean algorithm (UPGMA) analysis and the PCO plot drawn using principal component analysis revealed that all these tea cultivars could be clearly distinguished into three distinct groups viz., Assam, China and Cambod as well as an intermediate. Among the populations characterized, the Chinary type showed a maximum diversity index of 0.612 and the minimum of 0.285 was observed within the Assam type. Genetic distance was maximum (0.946), between Assam and Cambod and minimum (0.852) between Assam and China. More than 90% similarity as observed between the cultivars UPASI-22 and UPASI-23. Affinity of each cultivar towards the populations was determined using the similarity index. Analysis and comparison of AFLP fragments revealed distinct segregation of all the cultivars into their respective groups, except UPASI-18 and UPASI-24. Studies on diversity assessment of south Indian tea cultivars using AFLP fingerprinting revealed that the present day commonly grown south Indian tea germplasm has narrow genetic diversity (<37.76) among the cultivars necessitating a sustained effort to preserve tea germplasm resources and the development of superior varietal material through wide genetic crosses.