羽脉山黄麻2个居群种子萌发特性研究

Study on the Germination Characteristics of Two Populations of Trema levigata Seeds

摘要:

为了解羽脉山黄麻(Trema levigata)种子的休眠特性，以采自石屏居群(SP)和元谋居群(YM)的种子为材料，探讨不同恒温、变温、赤霉素、光照强度对种子萌发的影响，并对种子的形态、千粒重、含水量进行测量。结果表明，SP和YM的千粒重分别为(1.203±0.005)和(0.945±0.006) g。在恒温条件下，SP仅在30 ℃下萌发；YM仅在25 ℃和30 ℃下萌发；变温对2个居群种子的萌发影响显著且一致，随变温温度增加，发芽率增高，发芽时滞和平均萌发时间减短；赤霉素对2个居群种子的萌发有一定的促进作用，YM尤其显著，说明羽脉山黄麻存在浅型生理休眠；不同光照强度对2个居群种子的萌发影响都不显著，说明羽脉山黄麻属于光中性种子。在30 ℃/20 ℃、光照70~140 μmol/(m²·s)下SP和YM的发芽率分别为86.67%~ 95.00%和81.67%~95.00%，这是羽脉山黄麻最合适的萌发条件。这为羽脉山黄麻和同属植物造林育苗提供理论依据和技术指导。

Abstract:

To understand the dormancy characteristics of Trema levigata seeds, seeds from the Shiping population (SP) and the Yuanmou population (YM) were used as materials to explore the effects of constant temperature, alternating temperature, gibberellin, and light intensity on seed germination. The morphology, 1000-seed weight, and moisture content of the seeds were also measured. The results showed that the 1000-seed weight of SP and YM was (1.203±0.005) and (0.945±0.006) g, respectively. Under constant temperature conditions, SP only germinated at 30 ℃; YM only germinated at 25 ℃ and 30 ℃. Alternating temperature significantly and consistently affected the germination of seeds from both populations. As the alternating temperature increased, the germination rate increased, and the germination lag and average germination time decreased. Gibberellin had a certain promoting effect on the germination of seeds from both populations, especially for YM, indicating that T. levigata has shallow physiological dormancy. Different light intensities had no significant effect on the germination of seeds from both populations, suggesting that T. levigata is a light-neutral seed. Under 30 ℃/20 ℃ and 70–140 μmol/(m²·s) light intensity, the germination rates of SP and YM were 86.67%–95.00% and 81.67%- 95.00%, respectively. These were the most suitable germination conditions for T. levigata. This provides a theoretical basis and technical guidance for afforestation and seedling cultivation of T. levigata and other species in the genus.