<正>为选择银杏耐热品种（系），对银杏2年生盆栽苗分别进行4h的40、44、48℃高温（CK为28℃）处理，观察了银杏的形态变化，研究了银杏相对电导率、丙二醛（MDA）含量及超氧化物歧化酶（SOD）活性和抗坏血酸（ASA）、可溶性蛋白、可溶性糖含量的变化规律。结果表明：银杏在高温胁迫下其体内发生了一系列的生理生化变化，尤其当胁迫由44℃加重到48℃时，各项生理生化指标急剧上升；28℃和40%的处理下银杏形态未受影响，在44℃处理下出现轻度萎蔫现象；银杏在抵御高温胁迫过程中，SOD、ASA、可溶性糖和可溶性蛋白起到了积极的作用；不同温度处理下，银杏MDA含量之间均有极显著差异，温度与MDA含量之间具有良好的线性关系，由此认为MDA对银杏而言是较好的耐热筛选指标，其他指标在处理时段设为4h时，48℃条件下均与对照有显著的差异，说明48qC较其他温度适于筛选银杏抗热品种。

The investigation was carried out to evaluate the effects of five plant growth regulators (PGRs) on a normal-seeded cultivar of longan (Dimorcarpus longana Lour. cv. ’Wulongling’) for inducing abortive seeds. Results showed that all the five plant growth regulators induced some abortive seeds in certain extent. MH and 6-BA were preferable inducers. The best two treatments were 6-BA(100mg/L)+CPPU(30mg/L) and MH (800mg/L)+CPPU(30mg/L) were the best of all. It was seen that the weights of seeds were reduced by 38.5% and 38.0% respectively, compared with the control weights 9.77g and 8.42g. Total soluble solid contents are 18.57% and 18.23%. The degenerated seed percentages were 62.2% and 83.5%.