CLASSIFICATION OF DORMANCY STAGE IN ASIAN PEAR BUDS UNDER THE INFLUENCE OF NATURAL ENVIRONMENT

Understanding the environmental adaptation of fruit trees and accurately dividing the stages of dormancy in fruit trees have important theoretical significance for guiding the regulation of fruit yield and time to maturity. In this study, paraffin sections of Iluanghua' and 'Mixue' lateral flower buds in different natural environments were collected, their microscopic morphology was observed, and the pattern of dormancy in Asian pear buds was established. In the flower buds, the fusion of pistils into the carpel was used as a marker of entering endodormancy, and the healing of the pistil to form the ovary was used as a marker of the pear flower buds breaking dormancy. The respiratory rate was used to validate the accuracy of the growth stage. The results showed that the Asian pear cultivars entered dormancy in early December, were in the endodormancy phase between early December and late January, broke dormancy in mid- to late January, were in the ecodormancy phase from mid-January to late February, and were in the sprouting stage from late February to mid-April. The results also indicated that there was a high correlation between respiratory intensity and dormancy, and the respiratory intensity was significantly affected by the external temperature.