Pear (Pyrus L.) Genetic Resources from Northern Japan: Organoleptic Evaluation of Ornamental Pear Trees

Although ornamental pear trees (Pyrus calleryana) are popular in North America and Australia, we have no ornamental pear cultivar in Japan. Two pear accessions available for ornamental trees were selected from 'Iwateyamanashi' (Pyrus ussuriensis var. aromatica) endemic in northern Japan. 95 accessions deposited as germplasm collection at Kobe University were selected first with the PCA based on the 9 floral morphological traits such as numbers of petal, stamen, stigma, flowers per bud, pedicel length, flower diameter, colour of petal edge, petal length and petal width, and flowering date, tree form, fruits quality and autumnal leaf colouration. And then 30 accessions were chosen from evenly considering PCA score plot. Finally two accessions of 'i1717' and 'i1525' were organoleptically evaluated by 123 panelists for full size pictures of flower, corymb and flowering branch. They had longer petal length, flower diameter, and petal width compared to those of other accessions and the petal shapes were circle. By PCA and the organoleptic evaluation, 'i1525' and 'i1759' were selected. The former showed rose pink petal edge, better fruit quality, and compact tree form. The latter possessed better fruit quality and compact tree shape, and the leaf turned a deep red colour in the fall. Two accessions had unique ornamental traits not found in Japanese pear cultivars (Pyrus pyrifolia). Pear genetic resources collected from the northern part of Japan will provide new resources for breeding and industry.