醉马草种子水媒扩散特性的研究  

Study on the Water Dispersal Characteristics of Achnatherum inebrians Seeds

作　　者：吴雪儿 刘文昊 靳瑰丽[1] 韩万强 马建 吾鲁帕·阿得尔卡里 伊丽米努尔·亚森 WU Xueer;LIU Wenhao;JIN Guili;HAN Wanqiang;MA Jian;Urupa·Adelkali;Iriminour·Yassen(College of Grassland Science,Xinjiang Agricultural University/Xinjiang Key Laboratory of Grassland Resources and Ecology/Key Laboratory of Grassland Resources and Ecology of Western Arid Region,Ministry of Education,Urumqi 830052,China)

机构地区：[1]新疆农业大学草业学院/新疆草地资源与生态重点实验室/西部干旱荒漠区草地资源与生态教育部重点实验室,新疆乌鲁木齐830052

出　　处：《中国草地学报》2023年第4期51-58,共8页Chinese Journal of Grassland

基　　金：新疆维吾尔自治区高峰学科项目(CXGFXK-2017-02)。

摘　　要：以草原毒害草醉马草(Achnatherum inebrians)为研究材料,采用了室内模拟和野外控制性试验,测定种子吸水、脱水能力和漂浮能力,以及在自然降雨条件下可扩散的距离,分析其种子在不同水媒条件下的扩散规律。结果表明,醉马草种子的吸水率呈现快速、缓慢吸水2个阶段,前2 h快速吸水,32 h达到饱和。种子在0和25 r/min低转速下漂浮168 h后,漂浮率保持在70%以上;而在50 r/min和100 r/min高转速下漂浮2 h后,漂浮率下降至10%;种子持续漂浮在河流中时,漂浮率持续降低,至168 h后,漂浮率为13%;有芒种子在低转速和河流中漂浮率显著低于去芒种子(P<0.05)。在自然降雨作用下,种子一次扩散距离和种子掉落数随株高的增加都有所提高,高、中植株扩散距离为0~220 cm,种子二次扩散距离范围为0~12 cm。在3种不同植株高度中,高植株种子掉落率与距离的拟合效果最好,其模型为:y_(高)=0.0116+0.0056x-0.000023535x^(2)。因此,种子通过快速吸水能增加种子重量与土壤的附着度,从而降低其二次扩散距离,种子缓慢失水特性可使种子保持活力,但长时间浸泡降低种子活力;附属物芒抑制了种子水媒扩散距离。种子在河流作用下实现其远距离扩散,在自然降雨下为短距离扩散。Indoor simulations and field experiments were carried out to determine the water absorption and dehydration capacity,floating capacity seeds,and diffusible distance under natural rainfall conditions.The study also analyzed the diffusion patterns of Achnatherum inebrians seeds under different hydrophily conditions.The results showed that the seeds of Achnatherum inebrians exhibited a biphasic water absorption pattern characterized by rapid and slow absorption stages.Specifically,the seeds rapidly absorbed water within the first 2 h,followed by a slower absorption phrase until reaching saturation after 32 h.After floating for 168 h at low speed of 0 and 25r/min,the floatation rate of seeds remained above 70%.However,the floating rate decreased to 10% after only 2 h of floating at higher speeds of 50 r/min and 100 r/min.As the seeds continued to float in a river,the floating rate further decreased,reaching 13% after 168 h.Notably,the seeds with awn exhibited significantly lower floating rate than those without awn,both at low speed and in the river(P<0.05).Under natural rainfall conditions,both the primary seed dispersal distance and the number of seed drops increased with increasing plant height,with the dispersal distance ranging from 0 to 220 cm for tall and medium height plants and the secondary seed dispersal distance ranging from 0 to 12 cm.Among the three different plant heights,tall plants exhibited the strongest correlation between seed drop rate and distance.The best-fit model for this relationship was found to be y=0.0116+0.0056x-0.000023535x^(2),where y represents the plant height.Therefore,rapid water absorption of seeds can increase seed weight and attachment to soil,thus reducing secondary seed dispersal,while slow water loss characteristics of seeds can maintain seed viability.However,prolonged soaking can negatively affect seed vigor.In addition,the presence of appendage awn on the seed can inhibit seed dispersal distance in the water.Seeds can undergo long-distance dispersal via watercourses such a

关 键 词：水媒 降雨 扩散距离 漂浮能力 

分 类 号：S812.6[农业科学—草业科学]