角果藜的地上地下结果性与种子萌发行为

Amphicarpy and seed germination behavior of Ceratocarpus arenarius L.(Chenopodiaceae)

对角果藜(Ceratocarpus arenarius L.)的种子形态进行了观测,并进行了种子萌发实验,探讨了角果藜的地上地下结果特性。结果表明:角果藜的地上果实和地下果实的颜色、大小、质量均存在差异;种子的异质性导致了地上种子、地下种子(果实)的不同萌发行为;角果藜地上种子、地下种子的萌发率均较低,分别为32%、27%(30d)(5℃/25℃);划破种皮可显著提高地上种子和地下种子的萌发率(P<0.05);延长储藏时间能显著提高地上种子的萌发率(P<0.05),也能部分提高地下种子的萌发率,表明地上种子和地下种子均属于生理休眠,但地上种子的休眠程度浅;角果藜的地上地下结果性是对荒漠极端环境适应的一种特殊繁殖策略。

Ceratocarpus arenarius L. is an annual herb in the Chenopodiaceae family distributed in Central Asia and Caucasia. It has amphicarpy, i. e. , produces aerial fruits above ground and subterranean fruits in soil. In this paper, the modality of C. arenarius seed was observed, and a 30-day germination experiment was conducted at different alternating temperatures of 5 ℃（2/15℃, 5 ℃/25 ℃, and 15 ℃/25℃ in a photoperiod of 12 h dark/12 h light. The results showed that the aerial and subterranean fruits of C. arenarius were differed in color, size and mass, and the seeds had different germination behaviors. The germination rates of aerial and subterranean seeds were rather low, being 32% and 27% at 5 ℃/25 ℃, respectively. Scarifying the coat of aerial and subterranean seeds could markedly hasten their germination and increase their germination rate. Prolonging storage period could also increase the germination rate of aerial seeds and partly increase the germination of subterranean seeds, suggesting that both aerial and subterranean seeds had the characteristics of physiological dormancy, but aerial seeds had a slight one. The amphicarpy of C. arenarius should be a reproductive strategy to adapt to the extremely bad environments in desert.