Abstract

For integrated management of wilt disease, foolproof knowledge about the genetic diversity among the prevalent isolates is very important. One hundred (100) isolates of Fusarium oxysporum f. sp. lentis, causing agent of vascular wilt in lentil were collected from different agro-climatic regions of India. Finally, fifteen distinct F. oxysporum f. sp. lentis isolates were selected for molecular characterization by three molecular markers. Twenty randomly amplified polymorphic DNA (RAPD)primers produced a total of 105 reproducible bands, out of which 81 (77.14%) were polymorphic and 24 (22.85%) were monomorphic. Nine simple sequence repeats (SSR) primer pairs amplified 21 alleles with 2.33 alleles per primer. Considerable length variations (561 to 668 bp) in rDNA regions were found and restriction digestion of amplified rDNA region produced forty eight different DNA bands. Three molecular markers revealed varying degree of genetic diversity in the selected isolates ranging from 54% in case of RAPD to up to 35% with ITS markers. Based on the coefficient of similarity, the isolates grouped into two major clusters in the dendrogram. Isolates from North Indian regions grouped in same cluster, whereas isolates from north east regions and eastern region fell in another cluster. This information will be helpful for pathologists and plant breeders to design effective resistance breeding programs in lentil taking into account the diversity in wilt pathogen.

Key words: Indian isolates, Fusarium oxysporum f.sp. lentis, vascular wilt,  molecular diversity.

Abbreviation

Fol, Fusarium oxysporum f.sp. lentis; PIC, polymorphic information content; rDNA, ribosomal DNA; SSR, simple sequence repeat; ITS, internal transcribed spacer.