Improvement of Sugar Content and Composition in Fruits, and Classifications of East Asian Pears by the Principal Component Analysis of Sugar Compositions in Fruits

Abstract

It is sugcrested that cultivated pears in Japan are improved from the wild pears, Pyrus serotina Rehder, or that original pears had been introduced from China and or Korea to ancient Japan. Besides P. serotina, two wild pear species, P. hondoensis Nakai et Kikuchi, and P. aromatica Kikuchi et Nakai, grow in Japan. Therefore, there may have been hybridizations among the three above-mentioned species and also Chinese pears. So, there is still a problem in the taxonomical position of cultivated pears in Japan.