对位于湖北京山、湖南城步、贵州兴义、重庆秀山、四川成都、广西桂林、山东费县和甘肃天水的8 个皂荚(Gleditsia sinensis Lam.)天然群体间果实和种子表型特性及种子萌发率的差异进行了研究,在此基础上,对种子特性与萌发率的相关性进行了分析。结果表明:不同皂荚群体间荚果的长度、宽度、厚度和质量以及种子长度、宽度、厚度和百粒质量均存在极显著差异(P<0. 01);在低纬度、高降雨量和干扰程度相对大的区域产生的荚果及种子均较大。在不同温度(昼/ 夜温度35 ℃/20 ℃、30 ℃/15 ℃、25 ℃/10 ℃和15 ℃/5 ℃)条件下,8 个皂荚群体间种子萌发率无显著差异,平均萌发率为7. 70%;种皮经人为损伤后种子萌发率总体上有所提高且在不同温度条件下差异显著,其中在昼/ 夜温度15 ℃/5 ℃的条件下种子萌发率低于其他处理温度。在不同温度条件下,种子的长度、宽度、厚度和百粒质量与萌发率均呈正相关,但总体上相关性不显著。研究结果说明:不同皂荚群体的荚果和种子特性变异较大,且在降雨量高的地区其果实和种子较大;低温对皂荚种子的萌发有一定抑制作用;种皮损伤处理可解除皂荚种子的物理性休眠,但皂荚种子还可能存在生理休眠现象;一定程度的种子复合休眠可能是皂荚群体适应不同生境的重要生存策略之一。

The variation of phenotypic characteristics of pods and seeds, and seed germination rate among eight natural populations of Gleditsia sinensis Lam. in Jingshan of Hubei, Chengbu of Hu’nan, Xingyi of Guizhou, Xiushan of Chongqing, Chengdu of Sichuan, Guilin of Guangxi, Feixian of Shandong and Tianshui of Gansu were researched, and on this basis, the correlation between seed characteristics and germination rate also was analyzed. The results show that there are extremely significant differences in length, width, thickness and weigth of pods, and in length, width, thickness and 100-seed weight of seeds among different populations of G. sinensis (P<0. 01), and pods and seeds are bigger in regions with low latitude, high rainfall and more disturbance. Under different temperatures ( day/ night temperatures of 35 ℃/20 ℃, 30 ℃/15 ℃, 25 ℃/10 ℃and 15 ℃/5 ℃), there is no significant difference in seed germination rate among eight populations of G. sinensis with an average germination rate of 7. 70%. After seed coat damaged artificially, the seed germination rate generally increases with the significant difference under different temperatures, in which, that is lower under day/ night temperature 15 ℃/5 ℃than that under other temperatures. Under different temperatures, there is the positive correlation in length, width, thickness and 100-seed weight of seeds with seed germination rate, but generally the correlation are not significant. It is suggested that there are obvious variation in pod and seed characteristics among different populations, and pods and seeds are bigger in high rainfall regions. The low temperature has an inhibition to G. sinensis seed germination. The physical dormancy of G. sinensis seed can be broken by seed coat damaged artificially, but its may possess the physiological dormancy, so the complex dormancy of seeds with a certain degree may be an important survival strategy of G. sinensis population at different habitats.