Athelial stage induction in Sclerotium rolfsii by leaves and rhizomes of Cyperus rotundus

Abstract

Twelve isolates of Sclerotium rolfsii from seven hosts, viz., two isolates each from Cicer arietinum, Cyperus rotundus and Vigna mungo, one isolate each from Phaseolus vulgaris, Amorphophallus campanulatus, Lotus berthelotii and Colocasia variegata and two isolates from soil of different geographic localities were tested for their ability to produce athelial stage on Cyperus rotundus rhizome meal agar (CRMA) medium. Four isolates, i. e., two from C. arietinum, one each from P. vulgaris and A. campanulatus produced abundant athelial stage on CRMA medium whereas the other six isolates did not. Fresh rhizome meal and leaves of C. rotundus induced athelial stage in C. arietinum isolate of S. rolfsii (Varanasi isolate), whereas dried rhizome and leaf powder were not effective even at higher concentrations. Six and 8% concentrations (w/v) of fresh rhizome powder incorporated in the CRMA medium were highly effective in inducing athelial stage whereas fresh leaf paste showed maximum effect at 12 and 15% (w/v). However, the induction of athelial stage was more at 6 and 8% fresh rhizome powder compared to fresh leaf paste.