Biochemical Basis for Antibiosis Mechanism of Resistance in Sugarcane to Early Shoot Borer, Chilo infuscatellus Snellen

Abstract

Studies on biochemical basis of resistance of sugarcane to early shoot borer, Chilo infuscatellus Snellen in different sugarcane genotypes, viz., four least susceptible (LS), four moderately susceptible (MS) and four highly susceptible (HS) genotypes in comparison with one susceptible check were carried out under in vitro conditions at Regional Agricultural Research Station, Anakapalle, Andhra Pradesh, India during 2009-10. The results revealed reduced larval survival (26-30%), weight (79.9-84.6 mg/larva), and prolonged larval period (21.32-22.26 days) on LS genotypes compared to HS genotypes (64- 84.2%; 149.3-179.9 mg/larva; 16.56-18.78 days, respectively). The lowest mean growth index was found on LS genotypes (1.53-1.73) compared to HS genotypes (3.51-4.71). Results indicated the presence of antibiosis mechanism in the shoot tissues of LS genotypes either by accumulation of toxins or by the absence of very essential nutrients or feeding stimulant or by the presence of some feeding deterrent. Biochemical analysis indicated that low total sugar (5.34-6.38%), reducing sugar (0.078-0.089%) and higher phenol (11.20- 12.30 mg/g), neutral detergent fiber (24.09-27.20%), acid detergent fiber (54.79-57.26 %), lignin (6.61-7.09%), silica (1.33-1.53%) and cellulose (25.95-28.58%) contents in the shoot tissues of LS genotypes (Co 0110, 98 A 165, Co 6806, 98 A 125) increased its resistance to early shoot borer by influencing the biology, establishment of early shoot borer and played an important role in the antibiosis mechanism.