Study on the phenotype of flower buds in ‘Danhua’ pear

Breeding pear cultivars with strong stress resistance, good quality and easy management is of great importance in the world. According to the data, almost all of pear cultivars usually contain more than 5 flowers per inflorescence. The new pear cultivar ‘Danhua’, selected from a variant branch with single-flower feature of ‘Daxiangshui’ pear in 1999, was released in 2016. The female parent is traditional cultvar of Pyrus ussuriensis and was grown in Northeast China before 1990s. The fruit ripens during Mid-September at Jilin Province of China. Through asexual reproduction, single-flower trait can remain stable in subsequent generations of plants. The flower buds of ‘Danhua’ pear were slender and fusiform, and the volume of the flower buds increased with the number of flower buds. It had two types of flower buds, incomplete mixed bud and para-pure flower bud. Its fruit spur had no secondary shoots, 10.9% of the fruit spur had normal leaves, 45.1% had abnormal leaves, 44% had no leaves. Then, 97.8% of the inflorescences only had one flower, and 2.2% of the inflorescences was composed of 2-4 flowers. Microscope observation showed that the formation of a single flower in ‘Danhua’ pear occurred at the early stage of flower primordia differentiation. The flowering phenology of ‘Danhua’ pear was from mid-April to mid-May. The flower and fruit characteristics were basically the same as those of ‘Daxiangshui’ pear.