Study on Morphological Differentiation and Characteristics of Flower Bud in ‘Danhua’ Pear

The ‘Danhua’ pear (abbreviation DH) was a novel bud sport variety with single flower, which was found on branch of over 20 years old tree from ‘Daxiangshui’ pear (abbreviation DXS) (Pyrus ussriensis) in 1999. It was released in 2015. In this research, flower bud characteristics and flower bud differentiation process on ‘DH’ pear and ‘DXS’ pear were studied by field investigation and microscopic observation. The result shows the ‘DH’ pear has two types of flower bud, 56% “incomplete-mixed flower bud” and 44% “pure flower bud”, which is entirely different with ‘DXS’ pear and other pear varieties. The single flower of inflorescence of ‘DH’ pear occurs at the process of flower bud morphological differentiation. That means the ‘DH’ pear forms only one flower primordium in each inflorescence, which is completely different with the maternal ‘DXS’ pear.