Low temperatures of the tropical and temperate regions of the world make it difficult for rice breeders to develop varieties with high yield and desired quality. Cold temperature stress impairs growth of rice both at vegetative as well as anthesis stages. More in-depth study is required to study the genetics of cold tolerance in rice. This would enable breeders to tailor varieties for cold environments in a better way. In this study, crosses were made between cold tolerant and susceptible rice varieties. Subsequent generations were grown in phytotron at International Rice Research Institute (IRRI), Manila, Philippines. The data were analyzed and genetics of spikelet fertility associated with cold tolerance was studied.

Mr. Dil Rosh Khan (Late): Ex-Rice Breeder at Agriculture Research Institute (North), Mingora, Swat, KPK, Pakistan. Had vast experience of rice breeding and developed many varieties of rice for Swat, KPK, Pakistan. Mohammad Tahir: Research Officer/Breeder, Sugar Crops Research Institute, Mardan, KPK, Pakistan.