Indices Related to the Resistance of Yuluxiang Pear to Stresses

玉露香梨抗逆性相关指标研究（英文）

To clarify the mechanism for slowing down vegetative growth to reduce withered floral buds occurring in Yuluxiang pear, the length and diameter of the new shoots, the activities of antioxidant enzymes and malondialdehyde （MDA） content in terminal buds of short shoots in a withered bud-occurring orchard in Wei County, Hebei Province and a normal bud-growing orchard of Wei County, and a normal bud-growing orchard in Taigu County, Shanxi Province were measured and com- pared. The results showed that the increases in the length and diameter of new shoots in the withered bud-occurring orchard were very significantly higher than those in the two normal bud-growing orchards, and the shoots in the withered bud- occurring orchard stopped growing later than in the two normal bud-growing or- chards. During the period of floral bud differentiation, the activities of superoxide dis- mutase （SOD）, catalase （CAT）, peroxidase （POD） and the content of MDA in the two normal bud-growing orchards all increased at first and decreased subsequently. But in the withered bud-occurring orchard, the activities of both SOD and POD gradually decreased during the period of floral bud differentiation, while the activity of CAT and the content of MDA increased at first and decreased subsequently. Withered floral buds had significantly lower activities of SOD, CAT and POD, but significantly higher content of MDA than normal buds. The results suggested that vigorous vegetative growth may lead to the occurrence of withered floral buds in Yuluxiang pear; in addition, the occurrence of withered floral buds in Yuluxiang pear may also be associated with the activities of SOD, CAT and POD.

为探讨减缓营养生长对降低玉露香梨僵芽发生的作用机制,该研究分析比较了河北魏县正常发育的玉露香梨短枝顶芽、山西太谷的正常发育的玉露香梨短枝顶芽和河北魏县玉露香梨僵芽在花芽形态分化期间活性氧代谢的变化规律。结果表明,魏县僵芽梨园新梢年生长长度和直径均极显著大于魏县正常梨园和太谷正常梨园,且枝条停长时间最晚;花芽形态分化期间,魏县正常梨园与太谷正常梨园玉露香梨芽内的SOD、CAT和POD活性以及MDA含量表现出先升高后降低的趋势,而魏县僵芽梨园芽内的SOD和POD活性呈下降趋势,CAT活性和MDA含量则呈先升后降趋势;魏县僵芽梨园芽内SOD、CAT和POD活性整体显著低于魏县正常梨园、太谷正常梨园,MDA含量显著高于正常梨园。可见,营养生长过旺可能导致玉露香梨僵芽的发生;同时,僵芽的发生与芽内SOD、CAT和POD活性密切相关。