摘要:
以树势健壮、结果正常的库尔勒香梨单株为试验材料，在展叶期(2013年5月6日)第一次喷施不同浓度的外源GA3 (50, 75, 100 mg/L)，每隔20天喷施一次，共喷施三次。在休眠期枝条取样，在人工低温胁迫条件下测定膜透性、丙二醛、脯氨酸、可溶性蛋白质、可溶性糖和淀粉含量等抗寒性指标，并计算各综合指标的隶属度。试验结果表明：100 mg/L GA3一次处理的平均隶属度大于0.7，为高抗；50 mg/L GA3一次处理、75 mg/L GA3一次处理、50 mg/L GA3二次处理、75 mg/L GA3二次处理、100 mg/L GA3二次处理、100 mg/L GA3三次处理的平均隶属度均大于0.4，因此以上处理均为中抗；50 mg/L GA3三次处理、75 mg/L GA3三次处理的平均隶属度大于0.3，因此这两种处理为低抗。可初步认为，最佳GA3喷施浓度为100 mg/L，处理一次，能够抵抗−24℃的低温，但确定最佳喷施时间和外源激素浓度需进一步深入研究。
Abstract: In this experiment, the Korla Pear plant with strong tree vigor, and normal fruit was used as test materials to survey the freezing resistance. In leaf stage (May 6, 2013 ), different concentrations of exogenous GA3 (50, 75, 100 mg/L ) were sprayed once every 20 days, for three times. In the period of dormancy, the Korla Pear plant branches were collected. And the hardiness index, such as conductivity, MDA, proline, soluble protein, soluble sugar and starch content were surveyed and the degree of membership of each composite indicator was evaluated under artificial low tempe- rature conditions. The results show that: with 100 mg/L GA3 once processed, the average member- ship is more than 0.7, which is high resistance; the average membership of the treatments of 50 mg/L GA3 once, 75 mg/L GA3 once, 50 mg/L GA3 twice, 75 mg/L GA3 twice, 100 mg/L GA3 twice and 100 mg/L GA3 for three times are all more than 0.4, which are middle resistance; the average membership of the treatments of both 50 and 75 mg/L GA3 for three times are more than 0.3, which are lower resistance. This result shows that the best spraying GA3 concentration is 100 mg/L, treatment time is once, and it can resist low temperature at −24˚C. But to determine the optimal spraying time and concentrations of exogenous hormone needs further study.