Studies on the Acaricide Resistance of the Citrus Red Mite, Panonychus citri (McG.) V. Relation between the resistance to Phenkapton and one of the esterase bands detected by the thin layer electrophoresis

• Published in: Kyushu Plant Protection Research Vol. 15; pp. 155 - 158
• Main Authors: TANAKA, Manabu, INOUE, Kouich, KITA, Keiri
• Format: Journal Article
• Language: Japanese
• Published: The Association for Plant Protection of Kyushu 1969
• ISSN: 0385-6410; 1884-0035
• DOI: 10.4241/kyubyochu.15.155

The purpose of this investigation is to make clear the relation between resistance level to Phenkapton and character of E1 esterase detected by thin layer electrophoresis. Activity of E1 esterase was calculated as follows. The size and colour density of each band, which was thought to signify the activity of each separated esterase, were transformed to the area enclosed with density curve by densitometer, and then the rate of the area of E1 esterase band to the whole was calculated. Resistance level to Phenkapton was estimated from the corrected mortality (Abbott) of eggs. By using β-Naphthyl acetate as a substrate, the esterase was separated into four bands, which were designated as E1, E3, E4 and E5 band. The colour density and area of E1 band as the activity of E1 esterase, showed individual difference. All the individuals of following four hybrid progenies showed presence of E1 band; RR×R, F1 (RR×S)×R, RR×S and SS×R. In F1(SS×R)×S progeny about 65% of individuals showed presence of E1 and the susceptible strain SS×S showed no E1. Therefore, it may be said that the mite having the resistant factor even as a heterozygote, showed E1 band, and the individuals without resistant factor did not show. Difference of the activity of E1 esterase was observed between male and female of resistant strain. The male showed higher activity than the female. The activity of E1 esterase of the hybrid progeny of resistant and susceptible strains was lower than pure line of resistant strain. The activity of E1 esterase correlated closely with resistance level to Phenkapton. A correlation coefficient of r=-0.854 was obtained. In conclusion, the E1 esterase is responsible for genetic factor of Phenkapton resistance, and the resistance level depended on the rate of E1 esterase activity.