入侵植物黄花草木樨的生殖构件性状及种子萌发特性研究

Study on Characteristics of Reproductive Structures and Seed Germination of Invasive Plant Melilotus offcinalis

黄花草木樨是广泛分布于我国的一种外来入侵植物,对被入侵地的生物多样性造成严重威胁。通过样方调查和种子萌发实验,对黄花草木樨的生殖构件特性和种子休眠萌发特性进行研究,并探讨其繁殖能力。结果表明,密度对黄花草木樨各生殖构件性状影响各不相同,单枝种子量、总种子量和百粒重与密度成反比,而分枝数在中密度下达到最大,高密度和低密度的株高和分枝数均比中密度下的小;在生殖构件性状相关性方面,总种子量与单枝种子量(r=0.946)呈极显著正相关,百粒重与单枝种子量(r=0.178)呈显著正相关;在萌发特性方面,冷藏对黄花草木樨种子的萌发有促进作用,萌发率提高了约10%,而冷冻对黄花草木樨种子的萌发有抑制作用,萌发率降低约30%;在常温条件下,黄花草木樨种子休眠特性表现为前7个月波动变化很大,7~20个月之间变化基本平稳,萌发率保持80%左右,之后开始逐渐下降,5年后下降至10%以下。研究表明,黄花草木樨具有较高的种子产量和持久的高萌发率,有利于其种群的扩散和定殖。

Melilotus offcinalis is an alien invasive plant widely distributed in China,which poses a serious threat to the biodiversity of the invasive areas.The characteristics of reproductive structures and seed germination of M.offcinalis were studied based on quadrat investigation and seed germination experiment.The results showed that density had different effects on the characteristics of reproductive structures of M.offcinalis.The number of seeds per branch,total number of seeds and 100-seed weight were inversely proportional to density,while the branch number reached the maximum at medium density,and the plant height and branch number at high density and low density were lower than those at medium density.And,there was a significant positive correlation between total seed quantity and single branch seed quantity(r=0.946),and a significant positive correlation between 100-seed weight and single branch seed quantity(r=0.178).In terms of germination characteristics,cold storage promoted the germination of M.offcinalis seeds,increasing the germination rate by about 10%,while cold storage inhibited the germination of M.offcinalis seeds,decreasing the germination rate by about 30%.At room temperature,the dormancy characteristics of M.offcinalis seeds fluctuated greatly in the first 7 months,and remained stable from 7 to 20 months.The germination rate kept about 80%,then gradually decreased,and decreased to less than 10%after 5 years.The results showed that melilotus melilotus had higher seed yield and higher germination rate,which was beneficial to its population diffusion and colonization.Melilotus offcinalis is an alien invasive plant widely distributed in China,which poses a serious threat to the biodiversity of the invasive areas.The characteristics of reproductive structures and seed germination of M.offcinalis were studied based on quadrat investigation and seed germination experiment.The results showed that density had different effects on the characteristics of reproductive structures of M.offcinalis.The number of seeds per branch,total number of seeds and 100-seed weight were inversely proportional to density,while the branch number reached the maximum at medium density,and the plant height and branch number at high density and low density were lower than those at medium density.And,there was a significant positive correlation between total seed quantity and single branch seed quantity(r=0.946),and a significant positive correlation between 100-seed weight and single branch seed quantity(r=0.178).In terms of germination characteristics,cold storage promoted the germination of M.offcinalis seeds,increasing the germination rate by about 10%,while cold storage inhibited the germination of M.offcinalis seeds,decreasing the germination rate by about 30%.At room temperature,the dormancy characteristics of M.offcinalis seeds fluctuated greatly in the first 7 months,and remained stable from 7 to 20 months.The germination rate kept about 80%,then gradually decreased,and decreased to less than 10%after 5 years.The results showed that melilotus melilotus had higher seed yield and higher germination rate,which was beneficial to its population diffusion and colonization.