Establishment of mono-cultivar cultivation in the pear through inactivating stylar RNase by heavy metal-salt application

1 mM的CuSO4可使花柱核糖核酸酶活性降至对照的1/3以下，2 mM的CuSO4可使‘高穗’花蕾获得足够的座果量。使用含铜离子杀菌剂波尔多混合液也能诱导座果，大大缩短授粉和疏果所需的人工时间。花后1个月喷施赤霉素糊剂，不仅能促进果实生长，还能促进果实成熟，使果实产量充足。结果表明，铜离子不能克服梨的自交不亲和性，而是诱导单性结实。尽管乙烯生物合成抑制剂的处理促进了坐果，但CuSO4处理对乙烯释放、ACC合成酶和ACC氧化酶活性没有明显的抑制作用。

The stylar RNase activity was lowered to less than 1/3 of control by adding 1 mM CuSO_4, and enough fruit set was accomplished when 2 mM CuSO_4 was applied to the ‘Kosui’ flower buds. Bordeaux mixture application, a fungicide containing copper ions, also induced fruit set, and thus, the labor time necessary for pollination and fruit thinning was greatly reduced. The gibberellin paste treatment a month after anthesis promoted not only fruit growth but fruit maturation, resulted in enough fruit production. It was suggested that the copper ion does not overcome self-incompatibility of the pear but induce parthenocarpic fruit setting. Although the treatment of an inhibitor for ethylene biosynthesis accelerated fruit set, detectable inhibition of ethylene evolution, ACC synthase and ACC oxidase activities was not found in CuSO_4-treated flower cluster.