多效唑提高广西种源马尾松苗抗寒性的效应

原产地广西的马尾松种子，４月下旬在南京播种育苗，１０月中旬以２５和５０ｍｇ·Ｌ￣（－１）多效唑溶液淋灌处理，对松苗越冬有良好的效应，尤以５０ｍｇ·Ｌ￣（－１）处理的效果较为明显。在越冬期间多效唑处理苗的电解质渗漏率低于对照，超氧物歧化酶与吲哚乙酸氧化酶活性比对照显著增强，接近于抗寒性强的江苏种源马尾松苗。此外，多效唑处理苗的可溶性糖含量及生物量（包括根和茎叶的鲜重、干重）均明显高于对照，而五个月的高生长增加量仅为对照的７９％和５５％。

EFFECTS OF PP_(333) ENHANCING THE COLD RESISTANCE OF GUANGXI MASSON PINE

Seeds of pinns massoniana Lamb.(masson pine) from Guangxi were sown in Nanjing on April 25, 1992. The seedlings were treated with 25 and 50 mg. L-1 Paclobutrazol(PP_(333)) on October 19, during the winter time. It was shown that the electrolytic leakage of PP_(333) treated seedling leaves was decreased, the activity of superoxide dismutase(SOD) and the content of water-soluble sugar were increased. Moreover, in early spring, the activity of lAAoxidase in PP_(333) treated leaves was promoted obviously. PP_(333)(25. 50 mg. L-1) could retard the height of seedlings in the field esperiment. The fresh and dry weight of treated seedlings were superior to the control and the effects of 50 mg. L-1 were much stronger than that of 25 mg. L-1. These results suggest that 50 mg. L-1 PP_(333) can enhance the resistance of masson pine seedlings under low temperatures.