The context of the trait expression studies with special reference to the boro rice, an effort was taken in this endeavor to assemble and compiled information about the pattern of cold tolerance and genetic variability of different boro rice cultivar of diverse origin for important morpho-physiological traits under the low-temperature environment. The whole content is further portioned into different chapters. The first two chapters mainly dealt with importance and exploration of the study followed by the chapter which explained the methodology of the investigation including biometrical analyses. The remaining chapters are compiled with the outcomes of the study which is briefly discussed and it is concluded that present study was evidence for the existence of an exploitable level of genetic variability for important adaptive traits in the boro season. Validation of the results is, however, suggested to gather information on the genetics of important adaptive traits in a cold environment and also to understand the GE interaction under temporal variation within the boro season.