| Autor: |
Gurjar, M. S., Sagar, V., Bag, T. K., Singh, B. P., Sharma, S., Jeevalatha, A., Bakade, R. R., Singh, K. S. |
| Předmět: |
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| Zdroj: |
Journal of Plant Pathology; Mar2015, Vol. 97 Issue 1, p135-142, 8p |
| Abstrakt: |
Bacterial wilt or brown rot caused by Ralstonia solanacearum is one of the most damaging diseases of potato worldwide. Strains of R. solanacearum have conventionally been classified into five races (r) and six biovars (bvs). Based on variation of DNA sequences, R. solanacearum strains are now classified into four phylotypes that broadly reflect the ancestral relationships and geographical origin of the strains. These phylotypes can be further subdivided into sequevars based on phylogenetic analysis of the endoglucanase (egl) gene sequences. In the present study, bacterial wilt-infected potato plants/tubers were collected from various potato-growing regions of the East Khasi Hills and West Khasi Hills districts of Meghalaya (India) during summer and autumn of 2012 and 2013. A total of 114 bacterial isolates were recovered, whose identity was confirmed as R. solanacearum by PCR with the species-specific primers 759/760. Using the biovar (bv) classification scheme, 67 isolates (58.8%) were categorized as bv 2T, 41 (35.9%) as bv 2 and six as bv3 (5.3%). A phylotype-specific multiplex PCR assigned 67 (58.8%) isolates to phylotype IV (bv2T), 41 (35.9%) to phylotype II (bv2) and six (5.3%) to phylotype I (bv3). A phylogenetic analysis of partial sequences of the egl gene of all isolates clustered 59 phylotype IV (bv 2T) isolates closely to sequevar 8 (GenBank accession No. DQ657634). The remaining 8 phylotype IV (bv 2T) isolates did not cluster with any of the four sequevar, i.e. 8, 9, 10 and 11 that are defined with phylotype IV and formed a distinct sequevar group. All 41 phylotype II (bv 2) isolates clustered with sequevar 1 (EF371844); three phylotype I (bv 3) isolates with sequevar 30 (AB508598), and three phylotype I (bv 3) isolates with sequevar 47 (GU295014). This is the first study that demonstrates a considerable biovar and phylogenetic diversity among R. solanacearum that cause potato bacterial wilt in the Meghalaya state of India. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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