Cellulase in Anoplophora glabripennis adults emerging from different host tree species

In order to investigate different kinds of cellulase in insect pests, we selected male and female adults of Anoplophora glabripennis （Motschulsky） emerging from four different host species （Populus alba var. pyramidalis, P. nigra var. thevestina （Dode） Bean., P. simonii × P. pyramidliscr cv. Opera 8277 Hsu. and Salix matsudana f. lobato-glandulosa） as our research material. The enzyme activitives of three kinds of cellulase in the intestines of the adult insects were measured. The Cx-cellulase isozymes were detected with a CMC-incorporated polyacrylamide gel. The results show that： there are no statistically significant differences between the enzyme activities of males and females emerging from the different host species. The order of magnitude in activity is： Cx-cellulase 〉 β-glycosidase 〉 C1-cellulase. When the adults emerge from the same host species, there are no statistically significant differences between male and female enzyme activities of β-glycosidase and C1-cellulase, but the enzyme activity of Cx-cellulase of males is clearly higher than that of females. The patterns and migration of Cx-cellulase isozymes of males and females emerging from differ-ent hosts trees are clearly not different, and neither are they different when emerging from the same hosts.

Cellulase in Anoplophora glabripennis adults fed on original host tree species and non-original host trees

Cellulase activities of Anoplophora glabripennis （Motsch.） adults from two host plants （Populus simonii x p pyramidliscr cv. Opera Hsu. and Salix matsudana Koidz） fed on three different host tree species （Acer negundo Linn., S. matsudana Koidz and P simonii x P pyramidliscr cv. Opera Hsu.） were investigated. Enzyme activities of endoglucanase and β-glucosidase in the intestines of the insects were measured. The results show that there are no statistically significant differences in the enzyme activities of endoglucanase between male and female insects from the two host plants fed on three host trees, neither inβ-glucosidase. No statistically significant differences in the enzyme activities of endoglucanase and β-glucosidase were found between males and females from the two plants fed on three host tree species, except that the endoglucanase activity in males from the opera poplar fed on Hankow willow is lower than that fed on ash-leaf maple and opera poplar.

Analysis of the Abnormal Segregation of Pathogenicity in Magnaporthe grisea by Using a Genetic Cross of Oryza and Eleusine Isolates

A genetic cross between Oryza isolate Y93-164a-1 and Eleusine isolate SA98-4 was established, and the pathogenicity of 151 F1 progeny isolates was investigated on both host plants rice and finger millet. Results showed that the segregation of pathogenicity in this genetic cross was abnormal, i.e., most of the progeny isolates were nonpathogenic on both host plants. However, no abnormal segregation was observed when middle repetitive sequence MGR586 and 31 single-copy RFLP markers from all of the chromosomes were genetically analyzed. At the same time, comparison of the chromosomal organization among two pairs of parental isolates did not find any genomic abnormity. These results suggested that the ＂abnormal＂ inheritance of pathogenicity in this cross was most likely due to the reassortment of numerous host species specificity genes but not the biased segregation of the host species specificity genes. The host species specificities in M. grisea were likely to be multigenically controlled, at least in the genetic cross involving rice pathogen and the grasses pathogen other than rice.