Efficient development of new Japanese pear cultivars with high functions by genetic engineering methods

鸟取大学的研究人员成功地培育出了两个自交不亲和的品种，“秋葵”和“醉树”，它们抗黑斑病，品质高。并育成了早熟、抗黑斑病、品质优良的新菊品种。这些品种已经注册，并向公众开放。特别是秋水仙品种，在国内享有较高的声誉，2003年栽培面积增加到40公顷。他们将这些品种与抗梨黑星病的“Kinchaku”杂交，以产生抗梨黑星病的新品种。日本梨果实的货架期与最大乙烯产生量相关。他们通过分析乙烯生物合成途径的基因，成功地开发了日本梨品种和品系耐贮藏性的基因诊断。这一诊断使得有可能释放新品种具有高货架期。在黑斑病发病机制方面，从链格孢菌（Alternaria alternata）中鉴定了两个AK毒素的候选受体蛋白。AK受体蛋白基因克隆的试验正在进行中。鸟取园艺研究中心的研究人员开发了自交亲和性的基因诊断。这也使得在没有人工授粉的情况下很容易找到新的品种。

Tottori University researchers succeeded to release two self-compatible cultivars, 'Akibae' and 'Zuishu', which were resistant to black spot disease and had high quality. Moreover they released an early maturing cultivar 'Shinju', which were also resistant to black spot disease and had high quality. These cultivars already have been registered, and are open to public. Especially the cultivar, 'Akibae' deserved high reputation and its cultivated area increases to 40ha in 2003. They crossed these cultivars with 'Kinchaku', which is resistant to pear scab to produce new cultivars with resistance to pear scab. Shelf life of Japanese pear fruit is correlated with maximum ethylene production. They succeeded to develop the gene diagnosis for storage ability in Japanese pear cultivars and strains by analysis of genes for ethylene biosynthetic pathway. This diagnosis makes it possible to release new cultivars with high shelf life. With regard to mechanisms of black spot disease, two candidate receptor proteins for AK toxin from Alternaria alternata were identified. A trial for the gene cloning of the AK receptor protein is in progress. Researchers of Tottori Horticultural Research Center developed the gene diagnosis for self-compatibility. This also makes it easy to find new cultivars without artificial pollination.