ROLE OF BUD NAD ROOT ON BREAKING ENDO-DORMANCY IN JAPANESE PEAR TREE

对包括野生梨和日本梨在内的37种梨品种的破芽休眠需要量进行了测定。野生梨品种中，fauriei梨的低温需要量最低，而p.a aromatica和p.a communis的低温需要量最高。在主要的日本梨品种中，‘Hosui’的冷藏需求最低，其次是‘Kosui’、‘nijisisiki’和‘Niitaka’。‘新濑’和‘新穗’对低温的要求最高。在胚芽休眠期间，对‘ nijisisiki ’树进行根或梢冷却处理，然后在温室中强制种植。在不进行根冷处理的情况下，茎冷处理可以使幼芽完全萌发，但只有茎冷和根冷处理才能使幼芽生长达到最大值。由此可见，梨根具有与芽相同的内休眠类型。利用二维电泳技术（2-DE）研究了‘二生梨’花芽在休眠期间蛋白谱的变化。9种冷诱导蛋白（cip）在花蕾中的含量随冷单位（CU）值的增加而增加，但在芽休眠接近完成时变化不迅速。经高温和冷却处理后，19 kda CIP的等电点向碱性侧偏移。这些结果表明，19-KDa蛋白可能是衡量日本梨芽休眠程度的一个有用的标记。

Chilling requirement for breaking bud dormancy in 37 pear plants including wild pear species and Japanese pear cultivars were determined. Pyrus fauriei had the lowest chilling requirement in the wild pear species examined, while P.aromatica and P.communis had the highest chilling requirements. In the major Japanese pear cultivars, 'Hosui' had the lowest chilling requirement, followed by 'Kosui', 'Nijisseiki', and 'Niitaka'. 'Shinsetsu' and 'Shinsui' had the highest chilling requirements among the cultivars.'Nijisseiki' trees subjected to root or shoot chilling treatment during endodormancy, thereafter forced in a greenhouse. Complete budbreak could occur by shoot chilling without root chilling, but maximum shoot growth obtained only in the trees with both shoot and root chilling. Therefore, it was indicated that pear root has a type of endodormancy as bud has.Changes in the protein profiles of the floral buds in 'Nijisseiki' pear during dormancy were studied using two-dimensional electrophoretic analysis (2-DE). The quantities of nine cold-induced proteins (CIPs) increased in the floral buds with increases in chill unit (CU) value, but did not change rapidly when bud dormancy was near completion. The isoelectric point of the 19-KDa CIP shifted to the basic-side by high temperature treatment as well as by chilling. These results suggest that the 19-KDa protein may be a usable marker to measure the degree of bud dormancy in Japanese pear.