梨组织显微特性与抗寒力的关系研究

研究表明：越冬期间，梨枝条中的多糖、还原糖和脂类物质的分布、数量以及变化动态与抗寒性密切相关。主要表现在休眠期淀粉大量水解。而还原糖含量保持较高的水平，脂类物质向形成层密集。抗寒品种还原糖迅速减少，淀粉含量高，脂类物质密集于形成层处。解除休眠后，各种类、品种还原糖迅速减少，淀粉重新积累。且抗寒品种还原糖、脂肪下降幅度均低于不抗寒品种，淀粉积累也晚于不抗寒品种。扫描电镜观察发现：不同种类、品种的淀粉粒在分布、形态、大小以及变化动态与抗寒性密切相关。抗寒性强的品种淀粉粒小而且排列紧密，在越冬期间水解彻底。而不抗寒的品种淀粉粒大，松散不规则，而且在越冬期间水解不彻底。在解除休眠后淀粉重新积累，但抗寒性品种淀粉积累量低于不抗寒品种。

THE RELATIONSHIP BETWEEN MICRO CHARACTER OF TISSUES AND COLD RESISTANCE OF PEAR

The results indicated that the distribution, quantity and dynamic state of reductive sugar, multi-sugar and fat were dosely relevant to the cold resistance during the dormancy period. The main phenomenon were that the most of the starch disappeared during the dormany period, the content of the reductive sugar maintain higher level,the fat concentrated to the combiam layer. After the dormancy the reductive sugar decreased quickly, starch accumalated again. The decreasing degree of reductive sugar and fat of the hardy varieties were lower and the accumulation of starch were later than the non-hardy varieties. Through the scaning electronic microscope the distribution,shape, size and changes of starch grain were closely relavanted to the cold resi stance.The starch grain were small and tight on hardy variety, alsothey hydrolyzed completely; but the starch grain were graet and loose on non-hardy variety, also they didn't hydrolyzed completely. After the dormancy, the starch accumulated again, but the quantity of the starch accumulation of hardy varieties was lower than that of the non-hardly varieties.