MORPHOLOGICAL AND GENOMIC VARIABLITY OF SCLEROTIUM ROLFSII SACC. CAUSING STEM ROT OF TUBEROSE

Tuberose is one of the most important ornamental bulbous flower crop cultivated for cut and loose flower trade. The flower has been used for ornaments, bouquets and buttonholes or crown and frequently used during marriages and religious ceremonies. The tuberose was often infected by various numbers of diseases; among that S. rolfsii is the one of the major disease which causes stem rot disease. The S. rolfsii were collected from various locations of Tamil Nadu were examined for morphological and genomic variability. Fifteen isolates of S. rolfsii was assessed and various morphological growth parameters (Mycelia growth, No. of sclerotia/ plate, colour of sclerotia, time taken for sclerotial production (days) and variations among S. rolfsii isolates was recorded. ITS region of rDNA amplification with specific ITS1 and ITS4 universal primers produced approximately 600 to 700 bp in all the isolates confirmed that all the isolates obtained are S. rolfsii. The sequences of isolates viz., Sr1 and Sr2 were identified as S. rolfsii through BLAST search in NCBI website (www.blast.ncbi.nlm.nih.gov/Blast). The sequences were deposited in the Gene Bank with the accession numbers MK880692, MK880693.