Genetic diversity of ‘Candidatus Liberibacter asiaticus’ in Iran based on SSR markers

Paper ID : 1952-24IPPC (R3)

¹Department of Plant Protection, Hormozgan Agricultural Organization

²Department of Plant Pathology, College of Agronomy Sciences, Sari Agricultural and Natural Resources University, Sari, IRAN

³Plant Protection Research Department, Fars Agricultural and Natural Resources Research and Education Center, Agricultural Research Education and Extension Organization (AREEO), Zarghan, Iran

⁴Plant Protection Research Department, Hormozgan Agricultural and Natural Resources Research and Education Center, Agricultural Research Education and Extension Organization (AREEO), Bandar Abbas, Iran

⁵Department of Plant Protection, College of Agriculture, Shiraz University, Shiraz, Iran

Citrus huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (CLas), Ca L. africanus (CLaf), and Ca. L. americanus (CLam) is the most devastating disease affecting the citrus industry worldwide. In this study, the genetic diversity of 36 CLas isolates collected from south of Iran was investigated using eight pairs of simple-sequence repeats (SSRs) primers. CLas isolates consisted of 16 isolates from Hormozgan province in four main populations (Siahoo, HajiAbad, Minab, Rudan), six isolates from Sistan and Baluchestan in two main poulations (Sarbaz and Nikshahr), six isolates from Kerman in two main populations (Jiroft and VakilAbad) and eight isolates from Fars in two main populations (Darab and Jahrom). Polymorphisms of SSR markers were determined using 3% agarose gel electrophoresis. A matrix similarity based on zero and one were prapared and the cluster analysis was performed based on Jaccard similarity coefficient and unweighted pair group method with arithmetic mean (UPGMA) using NTsys 2.02 software. Totally, 26 alleles were identified with 8 primer pairs. The number of alleles for each locus ranged from one to five alleles and the mean for all markers (total loci) was 3.25. The highest polymorphism information content (0.7) was related to LasSSR-C-f / r primer pair and the lowest was observed in LasSSR-077-f / r primer pair (0.17). The mean content of polymorphism information in eight primers was 0.51. Cluster analysis based on genetic similarity was performed using Jaccard, Dice and simple similarity coefficients and Jaccard similarity coefficient with coefficient of 0.6989 was selected for cluster analysis. Cluster analysis of CLas isolates based on Jaccard similarity coefficient and UPGMA algorithm in NTsys 2.02 software showed that CLas isolates were divided into 16 distinct groups (A1-A16). Sarbaz and Nikshahr (SS15, SN26) from Sistan and Baluchestan province were located in a separate group. Most isolates in Kerman and Fars provinces formed separate groups individually or with together. To our knowledge, based on the results of UPGMA cluster analysis, studied isolates were somewhat separable based on geographical location and origin.

Greening; Simple-sequence repeats; SSR; huanglongbing