濒危树种极东锦鸡儿(Caragana fruticosa)种子的萌发特性

Seed Germination Characteristics of an Endangered Species-Caragana Fruticosa

以濒危树种极东锦鸡儿成熟种子为材料,研究极东锦鸡儿种子物理性状和温度对其种子萌发及幼苗生长的影响。结果表明:极东锦鸡儿种荚结实率较低,且约有1/4种子受虫害;成熟种子含水量为6.6%,千粒重18.6 g。种子长、宽和厚存在一定变异。种子长度平均为0.42 cm,宽度平均为0.27 cm,厚度平均为0.24 cm,长宽比为0.64。种皮透水性良好。不同温度条件对种子发芽率具有极显著影响。25℃条件下种子发芽率最高,为38.33%。随着温度的升高或降低,种子发芽率降低。发芽试验的第八天是计算种子发芽势的适宜时期。不同温度条件对极东锦鸡儿幼苗高度的影响极显著,对胚根长度影响显著。25℃有利于幼苗高度和胚根长度的增加,较高温度(30℃)有利于幼苗生物量增加。

Caragana fruticosa is an endangered tree species of Caragana.Physical traits of mature seeds and the effects of temperature on the seeds germination and seedlings growth of C.fruticosa were investigated.The results indicated that seed setting rate was low,and there were about 1/4 seeds damaged by insects.The moisture content of mature seeds was 6.6%,and the 1000-seed weight of mature seeds was 18.6 g.The seed length,seed width,and seed thickness existed some variation.The seeds were 0.42 cm long,0.27 cm width,and 0.24 cm thickness in average,the ratio of length and width was 0.64.The water permeability of seed coat was fine.Effects of different temperatures on germination percentage of C.fruticosa seeds were highly significant.The seed germination percentage was the highest（38.33%）in 25℃.With the temperature rise or reduce,the germination percentage of C.fruticosa seeds was reduced.The 8th day of germination test was the suitable period for calculating the seeds germination potential.Differences in the seedling height of C.fruticosa under different temperatures were highly significant,and the differences in the radicle length were significant.25℃ was the optimum temperature for seedling height and radicle length increment,however,higher temperature（30℃）was conducived to be better for the seedling biomass accumulation of C.fruticosa.