唐古特大黄种子灌浆充实动态及发芽特性研究

选用甘肃省甘南州卓尼县种植4年的唐古特大黄种株,从花后第10天开始每隔3 d测定种子发育动态直至种子全部成熟,风干后测定种子发芽特性,旨在揭示唐古特大黄种子灌浆动态及其与发芽质量的内在联系,为确定种子最佳采收期提供理论和技术依据。结果表明,唐古特大黄种子百粒干重的变化趋势呈“S”型曲线,符合Logistic方程,快增期在花后12~39 d,开花60 d后灌浆基本结束。种子脱水速率随灌浆进程的递进持续加快,含水量稳定下降。开花22 d开始采收的种子具较低萌发能力,此后随灌浆进程的递进,发芽质量指标均显著提高,花后49 d开始,种子发芽质量指标趋于稳定,开花55 d后种子含水量下降至10%以下。种子的发芽质量指标与百粒干重和灌浆持续期均呈极显著正相关,而与含水量呈极显著负相关,灌浆速率受天气影响较大,说明唐古特大黄种子成熟度对种子的发芽质量具有显著的影响,种子最佳采收期应在开花后55~60 d(7月下旬至8月上旬),种子含水率在10%左右时分批采收为宜。

The filling dynamics and germination traits of Rheum tanguticum seeds

Flowers of four-year-old Rheum tanguticum plants were labeled with cards on Flourish-blossom Day in Zhuoni county in the Gannan Tibetan autonomous prefecture, Gansu province. The cards were hung on inflorescences with consistent development signs. Seed filling dynamics were measured once every three days during filling duration, starting 10 days after the experiment’s launch. Germination traits were measured after air drying in order to explore the relationship between seed filling dynamics and germination, providing a theoretical and technical basis for standardizing seed harvesting. The 100-seed dry weight fitted to a logistic equation, with rapid increases during 12-39 days after blossoming and finishing on the 60^th day. The seeds’ water content decreased during the seed filling process. Seeds harvested on the 22^nd day following blossom showed low germination ability. Following this point in time, germination quality significantly improved and remained stable until 49 days after blossom. Water content in the seeds decreased to below 10% from 55 days after blossom. Germination quality indicators were significantly and positively related to the 100-seed dry weight and seed filling duration, but were negatively related to the water content in seeds. The seed filling rate was significantly affected by the weather. The study thus showed that seed maturity affects germination quality. The best harvest time is 55-60 days after blossom (in late July and early August), when seed water content is approximately 10%.