ABSTRACT
Rice (Oryza sativa L.) is the one most important food crop of world’s population. Among the major insect pests of rice, yellow stem borer (YSB) (Scirpophaga incertulas), a monophagous pest is considered as one of the most important pest of rain-fed low land and flood-prone rice ecosystems. YSB larvae feeds inside the rice stem, causes “dead heart” in the vegetative stage ultimately leading to “white head” in the reproductive stage. Breeding of YSB resistance in rice is difficult due to the complex genetic traits, inherent difficulties in screening and poor understanding of the genetics of resistance in the cultivated rice. The uses of chemical pesticides were effective for the control of this pest in rice field. Though, for an extended time, chemical control has shown to be ineffective because the insect larvae feed inside the stem pith and remain out of the reach to the sprayed pesticide. Resistance rice varieties will be useful for the managing against YSB. However, good level of resistance against the YSB has been rare in the cultivated rice germplasms. Transgenic rice developed by cry gene from Bacillus thuringiensis showed very good level of resistance in laboratory as well as in field conditions.
