BIOCHEMICAL BASIS OF RESISTANCE IN RICE VARIETIES AGAINST YELLOW STEM BORER SCIRPOPHAGA INCERTULAS

摘要

Screening of 25 rice varieties was done to study their biochemical basis of resistance against yellow stem borer, Scirpophaga incertulas (Walker). A field screening experiment was conducted at the NARP Farm, Navsari Agricultural University, Navsari, Gujarat, during kharif 2011 and 2012. The varieties GAR 13 and IR 22 were observed with resistant reaction. Thirteen varieties viz., Narmada, NAUR 1, GR-6, GR-7, GR 12, GR-102, GR-103, Pawna, IR 28, IR-50, IR-66, PRH 10 and PR 116 were moderately resistant. The varieties GR 4, GR 10, GR-101, GR-104, Dandi, GR-5 and Gurjari were moderately susceptible, while GR 11 and GR 9 were susceptible. Significantly higher infestation was observed in the highly susceptible variety, Jaya. Moreover, deadheart and whiteearhead damage were found exhibiting significant positive correlation with nitrogen, phosphorous, protein and chlorophyll content. Negative correlation was observed with potassium, phenol and silica content. Thus, rice varieties with lower nitrogen, chlorophyll and protein content with high phenolic compounds and silica content could be utilized for developing yellow stem borer resistant varieties.