两种草质藤本杂草营养生长与生殖生长研究

圆叶牵牛（Pharbitis purpurea)和五爪金龙（Ipomoea cairica)是华南地区草质藤本，圆叶牵牛主要通过种子进行有性繁殖，其新鲜种子由于种皮的机械阻碍导致胁迫休眠，经硫酸浸泡处理25－35min才能打破休眠，种子萌发对温度适应性较广，15－40℃之间都能正常萌发，幼苗每天须光照6h以上、温度在25℃以上才能正常生长，开花结实与光照强度和时间有一定关系，每天光照6h以上可提高其结实率，五爪金龙则主要通过茎干扦插进行无性繁，其成熟植株生长速度达8．1－11．9cm/d，无论在光照或荫蔽条件下，无性繁裂世代营养休平均每天生长2．4cm，叶面积每天增加1．4cm^2。

A Study on the Vegetation and Reproduction of Two Weedy Herbaceous Vines

Pharbitis purpurea and lpomoea cairica are worst weeds of herbaceous vines in south China. Sexual reproduction of seed is main reproductive way of P. purpurea and asexual multiphcation of stem segnents is main reproductive way of I. cairica in south China. Fresh-ripe seed germination percentage of P. purpurea was only 0.7 %, but treated the fresh-ripe seeds with ψ = 98% H2SO4 in 25～30 minutes the gernination percentage reached 95.0% ～ 100% . The seed germination was only affected by low or high temperature. At 15 ～40 °C, the germination percentage reached 95.7%～ 99.0%, however at 10℃, only 13.7%, and at 45℃, the seeds died. Light was found to have effects on fruiting, phytoperiod of 12 hours per day had a fruiting percentage of 84.6%, and had a seed number of 12 010～15 508 square meter sample area. l. cairica grow rapidly, the growth rate reached 8.1～11.9 cm/d and it's leaf area index was 3.86. The asexual growth of stem segments reached 29.1 cmwith leaf-surface of 16.3 cm2 in 12 days. Aboveground phytomass of the plant was 3 245.3 g/m2 fresh weight in one year.