作 者 ：张万灵1,2,周 兵1*,肖宜安1,闫小红1,张争光1,李晓红1
期 刊 ：西北植物学报 2013年 3期 页码：483~493
Keywords:distyly, Fagopyrum dibotrys, floral syndrome, breeding system,
摘 要 ：通过野外实验观察和人工控制套袋等方法,从金荞麦的花部基本特征、开花动态、花粉胚珠比(P/O)、花粉活力、柱头可授性、杂交指数、套袋实验及访花昆虫等方面对其繁殖生态学进行了研究。结果显示:（1）金荞麦在同一居群中同时具有长柱型（L-型）和短柱型（S-型）两种花型,短花柱花直径（7.25±0.11 mm）显著大于长花柱花直径（6.79±0.11 mm）,长花柱花的柱头和花药高分别为3.39±0.04 mm和1.80±0.02 mm,短花柱花的柱头和花药高则分别为1.89±0.04 mm和3.19±0.06 mm,表现出互补式雌雄异位的花部特征。（2）金荞麦8~10月开花,单花序的花期为15~23 d,单花的花期为1~3 d,开花进程中,内轮雄蕊先散粉,外轮雄蕊后散粉;S-型花的花粉活力高于L-型花的花粉活力,但其单花花粉量低于L-型花,显示了两种花型的自我调控机制。（3）套袋实验表明,金荞麦自花自交不亲和,但具有型内和型间亲和性,L-型和S-型花的P/O值分别为810±40.48和526.5±42.24,表明其繁育系统为兼性异交,需要传粉者,但L-型花更倾向异交。（4）金荞麦的主要访花昆虫为膜翅目（Hymenoptera）、双翅目（Diptera）、鳞翅目（Lepidoptera）、半翅目（Hemiptera）和蜻蜓目（Odonata）19个科37种昆虫,其中,两种花型拥有12种共同的访花昆虫,L-型花访花昆虫14种,S-型花访花昆虫35种,表明S-型花对昆虫具有更强的吸引力。研究表明,金荞麦是典型的二型花柱植物,虽然具有严格的自交不亲和性,但显示一定的型内亲和性。
Abstract:Fagopyrum dibotrys is one of the widespread distylous plant in Fagopyrum Mill.of Phytolaccaceae,belonging to national protected 2nd plants.The reproductive traits of this species such as floral basic characteristics,phenology of flowering,pollen/ovule ratio,pollen viability,stigma receptivity,out-crossing index,emasculation,and flower-visiting insects were investigated by experimental observation and bagging treatment to study its reproductive ecology.The results showed that:(1)The individuals of F.dibotrys within a population exhibited two floral morphs as long-styled and short-styled morphs.Diameter in short-styled flower (7.25±0.11 mm) is higher than that in long one (6.79±0.11 mm).Stigma and anther heights in long-styled flowers are 3.39±0.04 mm and 1.80±0.02 mm,while in short-styled flowers are 1.89±0.04 mm and 3.19±0.06 mm,respectively and exhibiting reciprocal herkogamy.(2)F.dibotrys flowered during August to October in Dajing,Jinggangshan Mountain.The lifespan of a single capitulum is approximately 15 to 23 days,1 to 3 days for a single flower,the pollens of inner anthers scatter first,followed by the outer’s during flowering.The pollen viability of short-styled flower is higher than that of long one,but each short-styled flower has lower pollen number,which shows the phenomenon of the flower’s self-regulation.(3)Bagged experiments suggest that F.dibotrys is self-incompatible,but compatible for intramorph and intermorph,the P/O rations was 810±40.48 and 526.5±42.24,which suggests that the breeding system was facultative outcrossing.(4)The main floral visitors are insects of Hymenoptera,Diptera,Lepidoptera,Hemiptera and Odonata,12 common species for the two morphs,14 species for long-styled flower,35 species for short-styled flower,which showed that the short-styled flower has stronger attraction to visiting insects than long-styled flower.It could be concluded that F.dibotrys is a typically distylous species with strict self-incompatibility,but a little homomorphic compatibility.