黄花草木樨种子形成的传粉生物学  

Melilotus officinalis seed formation in relation to pollination biology

作　　者：梁珍才 韩佳玲 古丽斯旦·艾尼瓦尔 张爱勤 LIANG Zhencai;HAN Jialing;Gulisidan·Ainiwaer;ZHANG Aiqin(Xinjiang Key Laboratory of Biological Resources and Genetic Engineering/College of Life Science&Technology,Xinjiang University,Urumqi 830017,Xinjiang,China)

机构地区：[1]新疆大学生命科学与技术学院/新疆生物资源基因工程重点实验室,新疆乌鲁木齐830017

出　　处：《草业科学》2023年第5期1326-1334,共9页Pratacultural Science

基　　金：国家级大学生创新训练计划项目(201910755079);新疆维吾尔自治区自然科学基金(2021D01C064)。

摘　　要：在有花植物中,因传粉、资源限制或者母本选择,植物常存在“花(胚珠)多果(种子)少”的现象。黄花草木樨(Melilotus officinalis)是一种被广泛种植的优质豆科牧草,具多枚胚珠,但仅形成1~2粒种子,在传粉方面是否存在影响种子形成的因素仍不清楚。为此,对其传粉系统及种子形成过程进行研究。结果表明:黄花草木樨为混合式交配系统类型,无孤雌生殖现象。自交亲和,但不能自动自花授粉,需要借助传粉昆虫。居群5月下旬进入初花期,花期40 d左右,单花期为1~1.5 d。该植物为泛化的传粉系统,蜂类、蝇类和食蚜蝇为其主要传粉者。自然状态柱头花粉数为18.19粒,去雄后柱头花粉数为6.04粒,不存在花粉限制。在人工异花授粉条件下,从基部开始,1号位有80%、2号位有21.8%的胚珠可以发育并形成种子;3~7号位的胚珠基本不发育,在授粉后第4天开始大量败育。说明黄花草木樨在传粉方面(花粉来源和数目)不存在制约种子产量形成的因素。黄花草木樨这种通过败育绝大多数胚珠而保留个别种子的现象,可能是为了增加种子适合度或种子扩散强度的一种生殖对策,通常是一种由母本调控的种子选择性败育类型。The phenomenon of“more flowers(ovules)and fewer fruits(seeds)”often exists in angiosperms due to limited pollination,resource or maternal selection.Melilotus officinalis is a widely cultivated and high-quality legume forage.It contains multiple ovules but only 1~2 develop into mature seeds.It remains unclear whether pollination plays a role in seed formation.Therefore,this study was done to investigate the pollination system and seed formation process of M.officinalis.The results showed that there was a mixed mating system type in M.officinalis without apomictic reproduction,which was self-compatible,but not automatically self-pollinated as it requires the aid of pollination insects.It was observed that the population began to bloom in late May,with florescence lasting for approximately 40 d,and the opening of a single flower lasting 1~1.5 d.M.officinalis had a general pollinating system,with the main pollinators being bees,flies and hoverflies.The number of pollens on stigmas were 18.19 in the natural state,and 6.04 in the emasculated state,without pollen restriction.Under artificial cross-pollination conditions,80%of the ovules at position 1(observed from the base of pod),and 21.8%at position 2 develop and form seeds.The ovules at positions 3~7 did not develop,and had undergone massive abortions starting on the 4th day after pollination.Therefore,it was inferred that there were no factors restricting seed formation in terms of pollination(pollen source and the intensity of pollination)in M.officinalis,This phenomenon is known as a type of seed selective abortion by maternal regulation,which may be a reproductive strategy to increase seed fitness or seed dispersal ability.

关 键 词：黄花草木樨 传粉生态 花粉传递 交配系统 胚珠发育 种子形成 母本选择 

分 类 号：S541.9[农业科学—作物学]