小甘菊自然更新与种子萌发特点的研究

【目的】研究小甘菊自然更新途径以及促进小甘菊种子萌发的方法。【方法】通过样地法对小甘菊群落进行实地调查;根据春季气温条件,实验设置5个温度条件,以及温水、NaOH溶液、赤霉素溶液浸种处理和低温层积处理,对小甘菊种子进行萌发实验,测定其发芽率与发芽指数。【结果】自然群落中,植株平均密度为90.16株/m2;在实验设置的最高变温15/30(℃)条件下,种子发芽率与发芽指数分别达到最高46%与3.45,而2/5(℃)低温完全抑制了种子的萌发;室温温水浸种、种子发芽率与发芽指数无明显差异,随水温的逐渐升高,种子发芽率与发芽指数逐渐降低;随着NaOH溶液和低温层积处理时间的延长,种子的发芽率与发芽指数明显降低;750 mg/L浓度的赤霉素浸种处理种子发芽率与发芽指数分别提高至78%与8。【结论】种子繁殖为小甘菊天然更新的唯一方式,自然界中,小甘菊巨大的种子量有效保障了种群的良好延续;室内萌发试验表明小甘菊种子存在明显的休眠现象,温度是影响小甘菊种子萌发的重要因素之一,种子萌发率与温度之间呈正相关关系;小甘菊种子种皮透性良好,不是导致休眠的原因,而种内含有某种萌发抑制物质可能是引起休眠的关键因素;应用适当浓度的激素处理可有效提高种子萌发率,可作为今后生产中提高小甘菊种子萌发的有效手段。

Study on the Natural Regeneration and Seed Germination in Cancrinia discoidea(Ledeb.) Poljak

【Objective】This study was carried out to investigate the natural regeneration and the way of promoting seed germination in Cancrinia discoidea.【Method】Community of Cancrinia discoidea field survey was done by plot method.The experiment set 5 different temperatures 2/5℃,5/15℃,10/20℃,15/5℃,15/30℃(12 h light/12 h dark),seed soaking with NaOH and GA3,and low temperature stratification treatment to measure the seed germination rate and germination index.【Result】The average density reached 90.16 plants/m2.The highest germination rate was 46% and germination index 3.45 of seed was recorded at 15/30℃.Low temperature could inhibit seed germination.Seed did not germinate at 2/5℃.By NaOH soaking and low temperature stratification treatment,the seed germination rate and germination index dropped.By soaking with 750 mg/L concentration of GA3 acid,germination rate and germination index reached 78% and 8.【Conclusion】Seed propagation was the only way to natural regeneration of C.discoidea.In nature,rich seed resources could protect the population of good continuation.Low seed germination in the laboratory test indicated there was apparent dormancy in the seed of C.discoidea.Temperature was an important factor for the seed germination.There was a positive correlation between seed germination rate and temperature.Seed germinated better in higher temperature than that in lower one.The results revealed that the seed coat permeability of C.discoidea was well,and it could not inhibit seed germination.The main causes might be some inhibitory substances in the seed.Hormone treatment could be an effective means to improve the seed germination of C.discoidea in the future production.