02914nas a2200337   4500008004100000022001400041245014400055210006900199260009200268300001200360490000700372520169100379653002702070653002302097653001402120653002502134653002702159653001102186653002702197653001302224100002302237700002802260700002202288700002402310700002102334700002402355700002102379700002002400700002602420856013002446       2008                        eng d  a0958-315700aEffect of repeated in vitro sub-culturing on the virulence of metarhizium anisopliae against helicoverpa armigera (Lepidoptera : Noctuidae)0 aEffect of repeated in vitro subculturing on the virulence of met  a4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLANDbTAYLOR & FRANCIS LTDcMAY  a337-3550 v183 a<p>The effect of repeated conidial sub-culturing of Metarhizium anisopliae on its virulence against Helicoverpa armigera (Hbner) was studied. The LT(50) observed against third instar larvae of H. armigera for the first sub-culture was 3.4 days; it increased to 4.5 and 5.6 days for the 20th and the 40th sub-cultures, respectively. The LT50 values after passage of the 40th sub-culture on H. armigera decreased to 4.4 and 3.7 days for the 40th (first in vivo) and the 40th (fifth in vivo) passages, respectively. Similarly, the LC(50) of M. anisopliae towards third instar larvae of H. armigera increased from the first sub-culture (0.17x10(4)) to (3.0x10(4)) for the 40th conidial transfers on potato dextrose agar and again decreased to 0.74x10(4) and 0.23x10(4) in the 40th (first in vivo) and the 40th (fifth in vivo) passage, respectively. Similar trends for LC(50) and LT(50) values were seen when sugarcane woolly aphid, Ceratovacuna lanigera Zehntner was used as a host. Significant variation in appressorium formation and cuticle-degrading enzyme production such as chitinase, chitin deacetylase, chitosanase and protease during subsequent sub-culturing and passage through H. armigera was observed. Though there was no effect on internal transcribed spacer (ITS) sequence pattern, interestingly, in randomly amplified polymorphic DNA (RAPD), significant differences in the band intensities and in the banding pattern for different sub-cultures of M. anisopliae were observed. As stable virulence towards the insect pest is desirable for commercialisation of a mycoinsecticide, such changes in virulence due to repeated in vitro transfer need to be monitored and minimised.</p>10aappressorium formation10achitin deacetylase10achitinase10aHelicoverpa armigera10ain vitro sub-culturing10aLipase10aMetarhizium anisopliae10aProtease1 aNahar, Pallavi, B.1 aKulkarni, Shuklangi, A.1 aKulye, Mahesh, S.1 aChavan, Santosh, B.1 aKulkarni, Girish1 aRajendran, Armugham1 aYadav, Priya, D.1 aShouche, Yogesh1 aDeshpande, Mukund, V.  uhttps://library.ncl.res.in/content/effect-repeated-vitro-sub-culturing-virulence-metarhizium-anisopliae-against-helicoverpa-0