Genetic diversity of the bacterial wilt pathogen Ralstonia solanacearum using a RAPD marker

Sayeda Nishat; Islam Hamim; M Ibrahim Khalil; Md Ayub Ali; Muhammed Ali Hossain; M Bahadur Meah; Md Rashidul Islam

doi:10.1016/j.crvi.2015.06.009

Genetic diversity of the bacterial wilt pathogen Ralstonia solanacearum using a RAPD marker

C R Biol. 2015 Nov;338(11):757-67. doi: 10.1016/j.crvi.2015.06.009. Epub 2015 Aug 21.

Authors

Sayeda Nishat¹, Islam Hamim¹, M Ibrahim Khalil², Md Ayub Ali¹, Muhammed Ali Hossain¹, M Bahadur Meah¹, Md Rashidul Islam³

Affiliations

¹ Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
² Plant Pathology Division, Bangladesh Institute of Nuclear Agriculture, Mymensingh, Bangladesh.
³ Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh. Electronic address: rasha740177@yahoo.com.

PMID: 26302834
DOI: 10.1016/j.crvi.2015.06.009

Abstract

Bacterial wilt caused by Ralstonia solanacearum is a destructive disease of many economically important crop species. A significant variation in wilt incidence and severity in eggplant and potato was observed among the growing areas surveyed. R. solanacearum isolates obtained both from eggplant and potato belong to biovar III, while isolates from eggplant belong to race 1 and isolates obtained from potato belong to race 3. Random amplified polymorphic DNA (RAPD) technique was used as a tool for assessing genetic variation and relationship among seven isolate groups of R. solanacearum viz., RsB-1, RsB-2, RsB-3, RsP-1, RsP-2, RsP-3 and RsP-4, consisting in a total of 28 isolates. Out of the RAPD markers used, amplification with four decamer primers produced 70 bands with sizes ranging from 100 to 1400 bp. Out of 70 bands, 68 bands (97.06%) were polymorphic and two bands (2.94%) were monomorphic amongst the seven R. solanacearum isolates group. The Unweighted Pair Group Method of Arithmetic Means (UPGMA) dendrogram constructed from Nei's genetic distance produced two main clusters of the seven isolates of R. solanacearum. The isolates RsB-1, RsB-2, RsB-3 and R-4 grouped in cluster І, while RsP-2, RsP-3 and RsP-4 grouped in cluster ІІ. The highest intra-variety similarity index (Si) was found in RsB-1 isolate (86.35%) and the lowest one in RsP-2 (56.59%). The results indicated that relatively higher and lower levels of genetic variation were found in RsP-3 and RsB-3, respectively. The coefficient of gene differentiation (G(st)) was 0.5487, reflecting the existence of a high level of genetic variations among seven isolates of R. solanacearum. Comparatively higher genetic distance (0.4293) and lower genetic identity (0.6510) were observed between RsB-2 and RsP-4 combinations. The lowest genetic distance (0.0357) and highest genetic identity (0.9650) were found in RsB-1 vs. RsB-2 pair. Thus, RAPD offers a potentially simple, rapid and reliable method to evaluate genetic diversity analysis in R. solanacearum.

Keywords: Bacterial wilt; Genetic diversity; R. solanacearum; RAPD.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Cluster Analysis
DNA Primers / genetics
DNA, Bacterial / genetics
Genetic Variation*
Plant Diseases / microbiology*
Ralstonia solanacearum / genetics*
Ralstonia solanacearum / isolation & purification
Ralstonia solanacearum / pathogenicity
Random Amplified Polymorphic DNA Technique*
Reproducibility of Results
Solanum / microbiology
Solanum melongena / microbiology

Substances

DNA Primers
DNA, Bacterial