茜草科二型花柱植物滇丁香传粉精确性研究

异型花柱是一种受遗传因素控制的花型多态性现象，其适应意义在于提高不同花型间传粉精确性，从而促进异交。为检验二型花柱植物滇丁香（Luculia pinceana）是如何促进异交并确定有效传粉者的类型，实验统计自然种群中长、短柱型的植株数量，测量花部特征，统计自然种群植株柱头上的型间花粉落置的数量和比例，比较型内、型间花粉的萌发率以及花粉管长度，比较不同人工授粉处理结实情况，观察传粉昆虫类型并测量虫体特征。结果表明（1）滇丁香自然居群中长、短柱型植株的数量没有显著性差异。长柱型的筒深、筒直径、开口直径、雄蕊长和柱头长均显著小于短柱型，而长柱型的叶片长和宽、雌蕊长、花药体积、花粉粒体积、柱头厚均显著大于短柱型。（2）自然种群植株柱头上型间花粉所占比例显著低于型内花粉的比例。（3）型间授粉的花粉萌发率以及花粉管长度均大于型内授粉和混合授粉。（4）型间授粉的结实率显著高于型内授粉的结实率，型内授粉具有一定的结实。（5）夜行性长喙条背天蛾（Cechenena lineosa）是滇丁香的有效传粉者，其吻长和滇丁香的花筒深相适应。本研究表明二型花柱植物滇丁香主要是通过与其花部特征相匹配的长喙天蛾实现有效的传粉，通过促进型间花粉的萌发和花粉管的伸长而有利于型间授粉结实，提高传粉精确性。

A study of pollination accuracy in distylous Rubiaceae species (Luculia pinceana)

The heterostylous plants have been hypothesized to promote compatible pollination between floral morphs within species. To test how the distylous Luculia pinceana promotes compatible pollination and identify the pollinator species, the number of long-styled morph (L-morph) and short-styled morph (S-morph) in the natural populations was counted. Floral traits of the two morphs were measured. The number of intermorph and intramorph pollen grains on the stigmas of the natural populations was counted. The germination rate and pollen tube length between intramorph and intermorph pollination treatments were compared. Several artificial pollination treatments were conducted to test whether L. pinceana was self-incompatible. The visiting insects were observed and the body traits of effective pollinator were measured. The results showed that:(1) there was no significant difference in the plant number of L-morph and S-morph in natural populations. The tube depth, tube diameter, opening diameter, stamen length, and stigma length of L-morph were significantly lower than those of S-morph, while the leaf length, leaf width, pistil length, anther volume, pollen grain volume and stigma thickness of L-morph were significantly higher than those of S-morph. (2) The proportion of intermorph pollen grains on the stigmas of the natural population was significantly lower than that of intramorph pollen grains. (3) The pollen germination rate and pollen tube length of intermorph pollination were significantly larger than those of intramorph and the mix pollination. (4) The seed set of the intermorph pollination treatment was significantly higher than that of intramorph pollination treatment, and intramorph pollination treatment could produce some seeds. (5) The nocturnal and long-tongued hawkmoth (Cechenena Lineosa) was an effective pollinator and its tongue was fit to floral tube of L. pinceana. Our research indicated that distylous L. pinceana promoted compatible pollination by facilitating intermorph pollen germination and pollen tube extending, and was pollinated by the long-tongued hawkmoth which was mechanical fit with its floral traits.