■了解杂草的生殖生物学对于有效管理杂草至关重要。Diplachnefusca(禾本科)是一种广泛分布的杂草物种,对农业生产力构成了重大挑战。然而,尚不清楚D.Fusca的土壤种子库如何应对环境变化,以及该物种是否存在休眠周期。
■我们调查了D.fusca的种子休眠是如何被打破的,以及它对自然环境变化的反应。孵化温度的影响,曝光,4°C的冷分层,研究了赤霉素(GA3)对种子萌发/休眠的影响,以及通过每月挖掘和实验室孵化2年以上的埋藏种子来评估发芽能力的季节性变化。
■结果表明,新成熟的D.fusca种子处于休眠状态,随着GA3促进发芽,冷分层,和在环境房间条件后成熟。暴露在黑暗中抑制了发芽。观察到发芽的季节性模式,发芽高峰发生在较凉爽的月份,在炎热的夏季明显下降。被埋葬两年后,大约40%的种子仍然存活。
■总之,D.fusca的种子表现出非深层生理休眠,并保持持久的土壤种子库。埋在土壤中的种子经历每年的休眠/非休眠周期。这种休眠周期阻止了种子发芽和秋季出苗,这促进了幼苗在不利季节的存活,然而,这也使得根除这种杂草更具挑战性。
UNASSIGNED: Understanding the reproductive biology of weeds is crucial for managing them effectively. Diplachne fusca (Poaceae) is a widely distributed weed species that poses significant challenges to agricultural productivity. Nevertheless, it remains unclear how the soil seed bank of D. fusca responds to environmental shifts, and whether a dormancy cycle is present in this species.
UNASSIGNED: We investigated how seed dormancy in D. fusca is broken and how it responds to natural environmental changes. The impact of incubation temperature, light exposure, cold stratification at 4 °C, and gibberellic acid (GA3) on seed germination/dormancy-break was investigated, along with assessing seasonal changes in germinability through monthly excavation and laboratory incubation of buried seeds over 2 years.
UNASSIGNED: Results indicated that newly ripened seeds of D. fusca were dormant, with germination facilitated by GA3, cold stratification, and after-ripening at ambient room conditions. Exposure to darkness inhibited germination. Seasonal patterns of germination were observed, with peak germination occurring in cooler months and a marked decline during the hot summer months. After 2 years of being buried, approximately 40% of the seeds remained viable.
UNASSIGNED: In summary, seeds of D. fusca exhibit non-deep physiological dormancy and maintain a persistent soil seed bank. Seeds buried in the soil undergo a yearly dormancy/non-dormancy cycle. This dormancy cycle prevents seed germination and seedling emergence in autumn, which boosts the survival of seedlings in less favorable seasons, yet it also makes it more challenging to eradicate this weed.