Abstract:

Korla fragrant pear was used as the test material, natural (CK) treatment and warming treatments at the early flowering （T1）and full flowering（T2）stages were set up control experiments on pear trees in orchards. The mineral element content in the fruit and calyx at the beginning of fruit setting stage, abscission zone formation stage and calyx abscission stage was measured to explore the effect of temperature changes during the pear flowering period on the calyx abscission rate and fruit setting rate of Korla fragrant pear fruit, as well as its relationship with mineral element accumulation and to provide a basis for clarifying the regulation of fruit shape formation in the environment of temperature changes during the flowering period. The results showed that compared with control treatment, the calyx abscission rate was decreased with warming treatment at different flowering stages, and reached the significant level at full flowering stage treatment which decreased from 48.06% to 20.95% that was 27.11 percentage points lower than the control group, while the fruit setting rate of each treatment group had no significant difference. At the beginning of fruit setting, N，P，Zn content in fruit and calyx was increased, but K and Ca content was decreased, while Fe content was increased and Mg content decreased in fruit. During the abscission zone formation stage, the P content in the calyx of abscission zone non-formated fruit was higher than that in the calyx of abscission zone formated fruit, and the K and Mg content were lower than that, while the Fe and Mg content in the abscission zone formated fruit is higher than the abscission zone non-formated fruit. During the calyx abscission period, the N, Fe, and Zn content in the calyx persistent fruit was higher than that in the calyx abscission fruit, but the Ca and Mg content was lower than that in the calyx abscission fruit. Warming treatment at different stages of flowering would increase the accumulation levels of N, Fe, and Zn in different parts of young fruits at the beginning of fruit setting stage, which may lead to calyx persistence, but the effect on fruit setting rate was not significant. In the context of global climate change, corresponding control measures should be taken according to weather variations during the flowering period to manage the microenvironment of orchards, and reasonable fertilization should be applied to improve fruit setting and calyx abscission rate, achieving the goal of high efficiency and yield.

Key words: Korla fragrant pear, Calyx abscission, Global warming, Warming treatment at flowering stages, Fruit setting rate