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

鸟取县大学的研究人员成功地推出了两种自交品种“秋叶”和“醉树”，这两种品种对黑斑病具有抗性，品质优良。此外，他们还推出了抗黑斑病、品质优良的早熟品种“信菊”。这些品种已经注册，并向公众开放。特别是“秋叶”品种享有很高的声誉，2003年栽培面积增加到40公顷。他们将这些品种与抗梨赤霉病的‘Kinchaku’杂交，培育出抗梨赤霉病的新品种。日本梨果的保质期与最大乙烯产量有关。他们通过对乙烯生物合成途径基因的分析，成功地建立了日本梨品种和品系贮藏能力的基因诊断。这为培育高保存期的新品种提供了可能。在黑斑病发病机制方面，鉴定了两种候选的交替稻瘟毒素受体蛋白。AK受体蛋白的基因克隆试验正在进行中。鸟取园艺研究中心的研究人员开发了自相容性的基因诊断。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.