01663naa a2200253 a 450000100080000000500110000800800410001910000180006024501150007826000090019352009510020265000270115365000120118065000140119265000110120665000200121765300080123765300270124565300210127265300080129370000190130170000170132077300720133714589162000-08-29       1989    bl ---       0--  u    #d1 aMORROW, B. J.  aLoss of virulence in an isolate of an entomopathogenic fungus, Nomuraea rileyi, after serial in vitro passage.  c1989  aSerial in vitro passage of Nomuraea rileyi (Farlow) Samson (UFL 78-6 pathotype) altered both its growth and development on in vitro and in vivo substrates. After only six conidial transfers on Sabouraud maltose and yeast extract agar (SMAY) plates, a reduction in the ability of these cultures to produce the yeastlike, hyphal body stage was observed. Conidia derived from transfers 6-10, although virulent to neonatal Anticarsia gemmatalis Hubner larvae, failed to produce progeny conidia on larvae killed by N. rileyi. Continued serial conidial transfer (&gt10) of this pathotype on SMAY resulted in conidia with reduced virulence against neonatal larvae. By the 16th conidial transfer, progeny conidia were avirulent to larvae. The attenuation of N. rileyi was associated with the sporulation  process. After multiple vegetative transfers (&gt80) of the hyphal body stage on SMAY plates, no decrease in virulence to A. gemmatalis was observed.  aentomopathogenic fungi  aInsecta  apathogens  aInseto  aNomuraea Rileyi  aEUA  aFungo entomopatogenico  aFungo patogenico  aUSA1 aBOUCIAS, D. G.1 aHEATH, M. A.  tJournal of Economic Entomology, Lanhamgv.82, n.2, p.404-407, 1989.