Abstract: Study on the polymorphism of wheat canopy temperature and its relationship with kernel quality differentiation has been carried out on the basis of a long-term observation of wheat canopy temperature. Some wheat materials with different canopy temperature have been planted in the different environments, meteorological conditions in particular for causing the variations of wheat kernel quality. Results show that all wheats are divided into 3 types according to the canopy temperature, that is, cooler typal wheat having constant lower canopy temperature than that of check variety during kernel filling, warm typal wheat having constant higher canopy temperature than that of check variety during kernel filling, and intermediate typal wheat having 6 canopy temperature states including the temperature states of cooler typal wheat and warm typal wheat in different growth conditions. Differentiation level of wheat kernel quality relates closely to the stability of wheat canopy temperature under different environment conditions, and the differentiations of cooler typal wheat, warm typal wheat and intermediate typal wheat are smallest, middle and largest in all wheats, respectively. The stability of wheat kernel quality is connected closely with the stability of the metabolic functions of different temperature type wheats in essence. Owing to the good stability of cooler typal wheat in kernel quality, so it is possibly an effective way for solving the questions with excellent adaptability to a wide range of ecological conditions that lowering plant temperature and breeding cooler typal wheat.

Key words: Wheat, Polymorphism of canopy temperature, Temperature type, Quality differentiation, Relationship