Author: G. Mehreen and F. Shahina

Publishing Date: 2013

E-ISSN: 0255-7576

Volume: 31 Issue: 2


The genetic diversity and phylogenetic intraspecific relationship among thirty heat tolerant strains of Stainernanto siamkayai from Pakistan were investigated during summer season. DNA fragment lengths of amplified ITS region obtained from eighteen Steineniema strains ranged from 742 to 1009 by (182 by nucleotide difference). There were high intraspecific variations among the Pakistani strains detected from different regions of Pakistan 0.01 to 0.09 %.
However, the fragment length of twelve strains of amplified 12S rDNA gene ranged from 500 to 594 bp. The intraspecific variation of the sequences ranged from 0.02 to 0.07 % (94 by nucleotide difference). Phylogenetic relationships based on both molecular makers ITS rDNA and 12S rDNA gene was constructed by using Bayesian Interference (31) and Maximum Parsimony (MP) tree. Both the rDNA ITS! and I2S rDNA genes sequences are useful for resolving relationships among S. siamkayai strains. The highest survival rate for heat tolerance was observed in PAK.S.S.38 (56005.5 Us/m1) at 39.5 °C. In Galleria mellonella. the mortality % was 10011=2.8 in PAK.S.S.58 and the reproduction rate was 1018.87-65.5 (Us/mg larvae) in PAK.S.S.38 strain. The mortality % and reproduction rate was found maximum in PAK.P.S.80 of Planococcus fru/ (95.7412.8; 223.312.8 Us/mg larvae).