野生木黄耆种子休眠解除与萌发研究

Seed Dormancy Break and Germination of Wild Astragalus arbuscula

木黄耆(Astragalus arbuscula)为荒漠草地的重要组成植物,在植被恢复中具有潜在的价值。通过室内萌发试验,研究了野生木黄耆种子萌发对模拟生长季昼夜变温15/5℃、20/10℃、25/15℃及30/20℃(昼12 h/夜12 h)的响应、擦破种皮、低温层积、原生境埋放对种子休眠解除的作用、种子休眠和萌发对短期和长期干贮藏的响应。结果表明:鲜种子在30/20℃(昼12 h/夜12 h)的萌发率最高,达56%。擦破种皮后种子在适宜条件下萌发率达100%,低温层积和原生境埋放只解除个别种子的休眠,短期干贮藏的萌发率比鲜种子分别降低了9、3、6个百分点,长期干贮藏的萌发率比鲜种子分别降低了21、17、27个百分点,干贮藏促进了种子休眠。

Astragalus arbuscula is a shrub of legume and has a potential candidate in vegetation restoration.Effects of alternated temperature on seed germination of A.arbuscula.And seed dormancy-breaking by scarification or cold stratification and buried on original habitat.Effects of short and long term dry storage on seed germination and dormancy breakage were studied here.Result shows that the fresh seeds germination percentage was 56%(P<0.05)at 30/20℃(day 12 h/night 12 h).The germination percentage of seeds reaches 100%under suitable conditions afterscarification.Cold stratification and buried on original habitat could breaking dormancy of individual seeds.At 15/65°C,20/10°C and 25/15°C,the germination rate of short-term dry storage is 9,3&6 percentage points lower than that of fresh seeds,and the germination rate of dry long-term dry storage is 21,17&27 percentage points lower than that of fresh seeds.Dry storage promoted seed dormancy.