Variations in Fruit Shapes of Japanese Pear Culti-vars (Pyrus serotina Rehder var. culta Rehder); Geographic Differentiations and Changes by Breeding

Abstract

It is said that a fruit shape of most Japanese pear cultivars is round or oblate. But a wide variation in fruit shape existed before the native cultivars were cleared otLt by the two outstanding round or oblate shaped cultivars, Nijisseiki and Chojuro. Although most 'of those native cultivars have been already cut down, sketches or photos of Lruits are left :in literatures as the only track of the native cultivars at present. Using these sketches from 52 Iiteratures, the wide range of fruit shape variations of :349 Japanese pear cultivars (Pyrus serotina Rehder) were evaluated and were compared with those of two chinese pear species, 55 Chinese pear cultivars (P. Bretschneideri Rehder), and 23 Ussurian pear cultivars (P. ussuriensis Max.). The geographic differentiation and the historical changes of cultivars by breeding were clarified from the view-point of fruit =shape.