Assessment of the genetic diversity among oily spot (Xanthomonas axonopodis pv. punicae) pathogen of pomegranate by randomly amplified polymorphic DNA analysis

Abstract

Pomegranate (Punica granatum L.) is an important fruit crop of India and other subtropical countries. Bacterial blight caused by Xanthomonas axonopodis pv. Punicae is becoming a major threat in Maharashtra as well as other states of India. It causes yield losses up to the extent of 80 – 90 %. This study aims to the collection of 7 strains (X. axonopodis) and utilized for assessment of genetic diversity by using RAPD markers. Whereas 7 strains of X. axonopodis were differentiated and distinguished into seven major region representing Malegaon, Nampur, Satana, Khakurdi, Ramnagar, Rahuri and Nashik region. However the genetic similarity within 7strains of X. axonopodis was ranged between 72.72-100 %. Similarly the genetic relationship of strains X. axonopodis was also established and showed 72.72 %, 72.72 %, 72.72 % 92.30%, 94.11% and 100 % similarity with region of Malegaon, Nampur, Satana, Khakurdi, Ramnagar, Rahuri and Nashik region. Average polymorphism in strains of X. axanopodis based on RAPD analysis was 84.095 %. The combine data analysis by using UPGMA method also revealed the two distinct groups representing seven strains of X. axonopodis and in first group M1 and second group R4 and subgroup RH6, N2, NS7, S3, K5, these genotypes were present respectively. Considering predominance and economic loss caused by X. axonopodis pv. punicae in pomegranate, it is an essential to undertake preliminary work on characterization of this pathogen at the molecular level.