Abstract: Transgenerational plasticity is an important strategy with which plants adapt to adverse conditions,it is not clear if perennial shrub Caragana korshinskii Kom. enhances its drought adaptability by that strategy. Hence,germination test under three temperatures (20℃,25℃,30℃) and five water potential (0,-0.25,-0.4,-0.6,-0.8 MPa) gradients was used to study the difference of hydrotime model parameters (hydrotime constant θ_H,water potential threshold ψ_b(50),and standard diviation σ_ψb) during germination of different C. korshinskii source seeds along precipitation gradient. The results showed that seed source had a significant or marginally significant effect on the θ_H and ψ_b(50). The θ_H of Ansai source of C. korshinskii was significantly lower than those of other three sources,and the ψ_b(50) of Ansai and Shenmu sources was significantly lower than that of Gonghe. No significant difference of σ_ψb was found between the sources. Germination temperature had significant effects on all hydrotime model parameters,and its effect was larger than that of seed source. The ψ_b(50) of different seed sources was mainly affected by the mean annual temperature. Seeds from a high mean annual temperature source have a lower ψ_b(50). Hence,drought-induced adaptive transgenerational plasticity does not exist during seed germination of C. korshinskii.

Key words: Transgenerational plasticity, Drought, Hydrotime model, Germination, Caragana korshinskii Kom.

摘要： 跨代可塑性是植物适应逆境条件的一种重要策略，多年生植物柠条锦鸡儿(Caragana korshinskii Kom.)是否具有跨代可塑性以增强其对干旱环境的适应性尚不明晰。为此，本文以不同种源的柠条锦鸡儿种子为试验材料，采用3个温度(20℃，25℃和30℃)和5个水势(0，-0.25，-0.4，-0.6，-0.8 MPa)梯度下的萌发试验，探究了种子萌发的水势模型参数[阈值水势(ψ_b(50))、水势常数(θ_H)和标准差(σ_ψb)]的差异。结果表明：种源对水势常数和水势阈值有显著或接近显著的影响，陕西安塞种源的水势常数显著低于其他3个种源，陕西安塞和神木的水势阈值显著低于青海共和，不同种源的标准差无显著差异。萌发温度对水势模型参数均有显著影响，且其影响大于种源。不同种源萌发的水势阈值主要决定于年均温，年均温高的种源其萌发的水势阈值较低。因此，柠条种子萌发过程中不存在干旱信号诱导的适应性跨代可塑性。

关键词: 跨代可塑性, 干旱, 水势模型, 种子萌发, 柠条