Differential preference for oviposition — a potential indicator of antixenosis in maize genotypes against Sesamia inferens (Walker)

ABSTRACT

Host choice for oviposition by insects is an indicator of the antixenotic factors present in a plant. The expression of antixenosis in 20 maize genotypes against Sesamia inferens (Walker) was measured by studying its relative ovipositional preference under multi-choice test and confirmed by no-choice test. The genotype WNZPBTL 6, E9-B and HKI 1040-11-7 expressed significantly high level of antixenosis in terms of less number of eggs (4.33, 4.67 and 5.33) under multi choice test. The genotype E37-A (O) displayed least antixenosis as indicated by the highest number of eggs (112.33) laid on it by the gravid females. The least number of plants (8.33 percent) utilized for egg laying in E9-B and E30 showed the ovipositional aversion of females on these genotypes. In no-choice test, the genotypes E9-B, AEB(Y)C5 55-1 and AEB(Y)C5 34-1 were found least preferable as only single egg mass per plant was deposited on these genotypes. The egg load per plant varied from 13.33 eggs in E9-B to 88.5 eggs in Hyd 05R/2-1. Significantly less number of plants of the genotypes E5-O, E9-B, E30, AEB(Y)C5 55-1 and AEB(Y)C5 34-1 chosen for egg laying indicated their high degree of antixenosis. Relatively less egg load per plant in genotypes E9-B, AEB(Y)C5 55-1, AEB(Y)C5 34-1, HKI 1040-11-7 and PFSR S3 in both the test situations suggest high antixenosis in these genotypes. The results revealed that the genotypes E30, E 60(FC)O and HKI 164-7-4 ER-3 were not preferred for oviposition under multi-choice test while the female offloads some of its eggs on these genotypes in duress under no-choice test. The correlation coefficient of 0.59 between number of eggs per plant in multi-choice and no-choice test confirm the variable ovipositional preference among these germplasm