极度濒危植物大果木莲种子的休眠与萌发

大果木莲种子具吸水性，胚未完全发育。新鲜种子25℃下的萌发率仅2％，在30／20℃和20／10℃的条件下30d内分别有27％和36％种子萌发。在20／10℃下，1000mg·L^-1浓度的GA3可以有效打破种子休眠。冷层积120d的种胚生长不显著，大果木莲种子具有条件休眠特性，属于浅度简单型形态生理休眠。种子经冷层积60d的萌发率最高，而后下降，提示其可能有休眠循环现象。

Seed Dormancy and Germination of the Critically Endangered Manglietia grandis Hu et Cheng

The seeds of Manglietia grandis Hu et Cheng had good water-absorption and the embryos were underdeveloped. Only 2% fresh seeds germinated at 25℃, while the germination rate could reach 27% and 36% under the condition at 30/20℃ and 20/10℃ during 30 days, respectively. Seeds dormancy could be broken by 1 000 mg.L^-1GA3 effectively at 20/10℃. Embryos did not grow markedly during 120 days cold stratification, indicating the seeds were conditionally dormant, which belonged to morphophysiological simple dormancy. When the seeds had been in cold stratification for 60 days the germination rate was maximum and then decreased, indicating that the seeds could have dormancy cycles.