簇枝补血草花的二态性及繁育系统研究

白花丹科被列为异型花柱较多的科,该文以补血草属簇枝补血草为材料,通过对野外居群的花部特征、花期物候和繁育系统等研究,探讨花部形态多态性及其对生殖的影响。簇枝补血草具有两种类型植株,具玉米状柱头和A型花粉的植株称为C型植株;具乳头状柱头和B型花粉的植株称为P型植株,且A/B型花粉的大小、外壁纹饰不同。单花发育过程中两型植株的花萼、雌蕊大小差异明显,随着花的成熟差异逐渐消失。两型植株都为雌蕊高于雄蕊,柱头探出式雌雄异位;C型植株的花期较P型植株长约2 d。一天当中,A型花粉活力高峰期为13:00,B型花粉在11:00和15:00都表现为高峰期;玉米状柱头可授性最强时期在13:00～15:00,乳头状柱头则在15:00。两型花粉可育性在盛花期最高,终花期时B型花粉可育性明显高于A型。荧光染色观察发现花粉萌发和花粉管的生长速度都为:异型授粉＞同型授粉,B型花粉在乳头状柱头上不能完成受精。此外,人工授粉实验也表明异型授粉结实率显著高于同型,P型植株经同型授粉结实现象并不明显,存在少量无融合生殖。研究表明簇枝补血草花部具二态性,繁育系统为兼性异交,其中乳头状柱头对A型花粉亲和,对B型花粉不亲和,但玉米状柱头却对A/B型花粉都亲和,这打破了该科的异型自交不亲和的例证。     

珍稀濒危植物瑶山苣苔开花生物学及繁育系统研究

对仅分布于广西金秀老山自然保护区的国家Ⅰ级保护植物瑶山苣苔进行了开花生物学和繁育系统研究.结果显示:(1)瑶山苣苔花期从8月底至11月初,开花无固定时间.单花开放过程可分为萌动、露白、盛开、凋落4个阶段,且花朵具明显的增大再生长现象.(2)单花、花序、单株水平上的开花物候都表现出开花不同步性,单花花期约5~14 d,单花序花期约11~20 d,单株花期约8~20 d.花粉活力在散粉后6 d内相对较高,但花粉在野外通常于散粉3 d内被昆虫啃食完.(3)柱头在花药散粉时明显高于花药,便于接受异花花粉,柱头在散粉后第4天具可授性,可持续5~6 d.(4)瑶山苣苔杂交指数(OCI)为5,花粉-胚珠比(P/O)为379.64±145.61,繁育系统为兼性异交,自交亲和,传粉过程需要传粉媒介.研究表明,不稳定的传粉环境可能是该物种至濒的主要生殖生物学原因,自发自交"是其在开花期间对不稳定传粉环境的一种适应.     

大血藤生殖生物学研究

通过野外观测、实验室分析以及人工套袋授粉等方法,研究了大血藤的繁育系统、开花习性、传粉方式以及花粉-胚珠比等生殖生物学特征.结果表明,大血藤的花为单性花,雌雄同株.雄花单花花期为7~10 d,雌花单花花期为2~3 d,种群开花历时14~17 d,散粉高峰期为4月11~17日,属风媒传粉植物.大血藤花粉-胚珠比为600±20,属兼性异交类型,人工套袋实验进一步证明,大血藤的交配系统为兼性异交类型,但以异交为主.     

珍稀濒危植物距瓣尾囊草(Urophysa rochkii)的开花物候和繁育系统特性

通过野外观察,运用套袋授粉和联苯胺-过氧化氢法等实验方法对距瓣尾囊草开花物候以及种群的繁育系统特性进行研究。研究结果:1)距瓣尾囊草为两性花,聚伞状花序,花期较长,从头年12月持续到次年4月,单花花期持续8—15 d,种群花期可持续4个月左右。2)距瓣尾囊草在花朵未开放前花粉没有活力,花药开裂当天花粉活力达到94.8%,第2天为90.3%,第3天为81.6%,第4天为62.9%,此后其花粉活力明显减弱;柱头可授性于散粉后第3天开始出现,散粉后4—5天最强,散粉后第8天柱头失去可授性;柱头可授性和花粉活力有5 d左右的重叠期。3)其花粉胚珠比P/O为938.5±250,按照Cruden标准划分,其有性繁育系统为兼性异交。4)按照Dafni的标准,距瓣尾囊草的OCI=4,即繁育系统为异交、部分自交亲和、需要传粉者。5)人工异花授粉结实率达80%以上,略高于自然结实率78.94%;直接套袋结实率为5.71%;去雄套袋和去雌套袋均不结实。以上结果表明,距瓣尾囊草繁育系统表现为异交为主、部分自交亲和并且不存在无融合生殖现象,其开花物候、花部特征和繁育系统为适应特殊的环境提供了一定的生殖保障,本次研究结果为距瓣尾囊草的迁地保护和种群的繁衍复壮提供理论依据。     

贯叶连翘的开花动态与繁育系统研究

野外观察贯叶连翘的开花进程和花部形态特征,运用花粉萌发、杂交指数、花粉-胚珠比等方法测定其繁育系统。结果显示:贯叶连翘雌雄异熟,柱头先花药成熟,雌雄蕊无明显异位。单花花期4～5d。仅在开花当日有昆虫传粉,蜜蜂为主要传粉者。花粉在花药开裂1h后活力最大,萌发率达40.10%,花粉在柱头萌发3h后接近子房。根据杂交指数(OCI)推测其繁育系统属于异交,部分自交亲和,有时需要传粉者。花粉-胚珠比(P/O)则表明贯叶连翘的繁育系统为兼性异交。贯叶连翘结实率低,可能与花粉活力,花粉管的生长速度及花粉在柱头的竞争有关。     

类短命植物异翅独尾草的传粉特性

该文对生长于新疆古尔班通古特沙漠的类短命植物异翅独尾草(Eremurus anisopterus)的传粉习性做了观察研究,结果如下:异翅独尾草的花期从4月下旬至5月中旬,单花花期一般为1 d,而当遭遇最高温度不足20 ℃的阴雨天气时,单花花期可延长至2 d。单花的开花时间一般为每天10∶30~15∶00,大约4~5 h,单个花药的散粉时间约为40 min,但其6枚花药的开裂与散粉具有明显的不同步性,显著地延长了单花的散粉时间,这是对干热多风的沙漠生境中传粉者不确定性高度适应的结果。异翅独尾草花粉借风传播的距离可达70 m,但其中约60%花粉的散布距离集中在20 m以内;昆虫是异翅独尾草的重要传粉媒介,蜜蜂、食蚜蝇、麻蝇、切叶蜂、隧蜂等是主要的传粉者。蜜蜂和食蚜蝇访花时,都是先飞落到花基部黄绿色斑点处,然后沿着花被片的紫色脉纹进入到花内,黄绿色斑点是对花蜜的拟态,是异翅独尾草对高温多风沙环境高度适应的结果。昆虫的访花行为最活跃的时间在10∶30~13∶30之间。一天当中单花的开放时间与沙漠中风速的日变化及访花昆虫的活动习性之间呈现出显著的相关性。异翅独尾草的花粉与胚珠比(P/O)等于6 164,为适合于异花传粉的类型。人工套袋试验结果表明自交是可育的,这可能是对占据了不稳定的、先锋生境的异翅独尾草缺乏远交机会的有效补偿。不存在无融合生殖现象。     

濒危植物凹叶厚朴的花部综合特征和繁育系统

为了解凹叶厚朴(Magnolia officinalis subsp.biloba)濒危的生殖生物学原因,通过野外观测,运用杂交指数、花粉-胚珠比、花粉活力和柱头可授性观测、人工授粉和套袋实验等方法,对凹叶厚朴种群的开花生物学、繁育系统进行了研究。结果表明:凹叶厚朴单花花期一般为4～5d,单花花期根据形态和散粉时间可分为4个时期:蕾期、初开期、盛开期和凋零期;种群于4—5月开花,一般开花历时30d左右,但不同地点、年份间有所差异;种群无开花高峰,单株平均开花数量为171.4～188.8朵,平均开花振幅为5～6朵·株-1·d-1;凹叶厚朴杂交指数为4,花粉胚珠比为5728.86,结合人工套袋和授粉实验结果可确定,繁育系统为异交,传粉过程需要传粉者;花粉活力较高(94%),且花粉活力可维持至散粉后的第6天。散粉后,柱头可授性显著下降,花粉高活力期与柱头可授期有5～6h的重叠;自然状况下结果率和单果出种百分率低,异株异花授粉可明显提高结果率和单果出种百分率,二者相对自然状况分别提高14.25%和43.66%。表明自然状态下传粉效率低、柱头最佳可授期短、同株自花授粉败育严重是其濒危的主要生殖生物学原因。     

濒危植物翅果油树种群传粉生物学研究

对山西省南部平陆、乡宁和翼城3个翅果油树(Elaeagnus mollisDiels)种群分别进行了传粉生物学观察.结果表明:(1)翅果油树花期一般为8~12 d,单花花期3~4 d,结实率仅为0.42%;(2)访花者多属于膜翅目、鞘翅目、双翅目、鳞翅目昆虫,蜂类是有效的传粉者;(3)翅果油树依靠芳香气味、花蜜、花粉和适度紧缩的生殖枝吸引访花昆虫;(4)昆虫的访花活动主要集中在11:00~16:00,访花活动易受气象因素影响;(5)自然条件下,翅果油树平均每日每花被访问的频次为(1.93±1.64)次,人工放蜂可显著增加传粉强度;(6)交配系统属居群内的异花传粉,仍属于广义的自花传粉范畴.传粉昆虫少,传粉效率低是翅果油树致濒的重要因素之一.     

黄花牛耳朵(苦苣苔科)的传粉生物学

通过野外观察和繁育系统的实验,对黄花牛耳朵(Chirita lutea Yan Liu et Y.G.wei)的传粉生物学进行了研究.结果表明,黄花牛耳朵的花期从7月初至8月底,单株花期约35～47 d,单花化期约6～10 d,花的开放无固定的时间.在花期内花粉活性约80%,柱头可授性约75%～90%.花粉/胚珠比率(P/O)为1 215.73±266.13.柱头在花药散粉时已生长至花筒口部,明显高于花药,便于接受异花花粉.黄花牛耳朵不存在无融合生殖,高度白交亲和,但较难发生自动的白花授粉,产生种子主要依靠传粉媒介.自然授粉的结实率明显低于人工授粉的结实率,存在传粉限制,蜜蜂(Apidae sp.)、方头泥蜂(Crabro sp.)、无垫蜂(Ameglla sp.)是主要的传粉者.     

巫山淫羊藿开花物候与生殖特征

研究巫山淫羊藿(Epimedium wushanense)3个种群的开花物候进程和生殖特征,分析了不同种群中的花部特征、开花物候指数和结实率差异,以及开花物候指数对巫山淫羊藿生殖成功的影响。结果表明:巫山淫羊藿花期为3月初到4月中下旬,种群开花一般历时22～27d;单株花期(花序)约12～17d;单花花期一般为3～4d。3个种群的个体水平的开花振幅曲线呈单峰型曲线,均具有较高的开花同步指数,表现出一种集中开花式样。相关分析表明:坐果数与开花高峰期、终花期、花期持续时间和花蕾数均呈极显著正相关,但坐果数与始花期无相关关系。开花物候变异系数分析表明:3个种群中花期持续时间、单花持续时间、终花期、开花高峰期和坐果数差异极显著;总花数、开花振幅和结实率差异显著;开花同步指数和始花期无显著差异性。3个种群中除同步性指数外,其余指数的变异系数均有差异,此外,巫山淫羊藿中结实率受到距的长短的影响。表明巫山淫羊藿的开花物候和生殖特征受到微环境的影响,同时生殖特征还受到花部特征距的影响。     

Many to flower, few to fruit: the reproductive biology of Hamamelis virginiana (Hamamelidaceae)

Hamamelis virginiana flowers from late September to late November. In 1977, we began studying the reproductive biology of this eastern North American arborescent shrub by examining floral phenology and rewards, pollen-ovule ratios, breeding system, pollination, pollinator and resource limitation, and seed dispersal. The homogamous, self-incompatible flowers emit a faint odor, bear nectar with sucrose ratios typical of bee- and fly-pollinated flowers, and produce abundant sticky pollen. Flowers were visited infrequently by insects representing six orders. Flies were the most common floral visitors, specifically members of the genus Bradysia, but small bees also carried high percentages of Hamamelis pollen. Despite high pollen/ovule ratios (11?445 grains/ovule), bees and flies are likely pollinators, as experiments indicate wind pollination is less likely. Pollen quantity and resource availability did not appear to limit reproductive output, but pollen quality did. Tests of >40?000 flowers showed natural fruit set to be <1%. The flowering time, breeding system, and clumped distribution of plants, likely due in part to limited seed dispersal, combine to yield this remarkably low fruit set. Because all other species of Hamamelis flower from late winter to early summer, it may be that H. virginiana evolved a fall flowering phenology to avoid competition for pollinators with the closely related H. vernalis.     

FLORAL BIOLOGY,HUMMINGBIRD POLLINATION AND FRUIT PRODUCTION OF TRUMPET CREEPER (CAMPSIS RADICANS,BIGNONIACEAE)

Trumpet creeper is self-incompatible and bears long, tubular, orange flowers from June to September. Flowering peaks rapidly, then declines and continues at low levels for several weeks. The initial burst of flowering may attract pollinators that return even during subsequent reduced flowering. Most flowers open before noon and nectar production totals 110 μl of 26% sucrose equivalents per flower, an exceptionally high production for a temperate zone plant. Production ceases within 20–30 hr of flower opening, but corollas persist for several days and may serve to attract pollinators. Effective pollination reduces the period of stigma receptivity and speeds closing of stigma lobes. Only 1–9% of flowers produced mature fruits at four sites in Illinois and Missouri. Roughly 400 pollen grains had to be deposited on a receptive stigma to cause fruit development beyond an initial period of high abortion. At two sites, 17% and 89% of stigmas received over 400 pollen grains. Assuming 50% of deposited grains were from the same plant, fruit production at one site was clearly pollinator limited, that at the second site may have been. Ruby-throated Hummingbirds (Archilochus colubris) deposited ten times as much pollen per stigma per visit as honeybees (Apis mellifera) and bumblebees (Bombus spp.). Fruit set was highest where rubythroat visitation was most frequent. Trumpet creeper appears primarily adapted for hummingbird pollination, but can also be adequately pollinated by honeybees and bumblebees. This is one of the first attempts to relate pollen-depositing capabilities of pollinators of any plant to pollen requirements for fruit production. Several characteristics suggest that trumpet creeper may be adapted to pollination at low densities (often called traplining) in its presumed original, woodland, habitat.     

A ballistic pollen dispersal system influences pollination success and fruit‐set pattern in pollinator‐excluded environments for the endangered species Synaphea stenoloba (Proteaceae)

The critically endangered Synaphea stenoloba (Proteaceae) has numerous scentless flowers clustered in dense inflorescences and deploys a ballistic pollen ejection mechanism to release pollen. We examined the hypothesis that active pollen ejection and flowering patterns within an inflorescence influence the reproductive success (i.e. fruit formation) of individual flowers within or among inflorescences of S. stenoloba in a pollinator‐excluded environment. Our results showed that: (1) no pollen grains were observed deposited on the stigma of their own flower after the pollen ejection system was manually activated, indicating self‐pollination within an individual flower is improbable in S. stenoloba; (2) fruit set in the indoor open pollination treatment and the inflorescence‐closed pollination treatment indicated that S. stenoloba is self‐compatible and pollen ejection can potentially result in inter‐floral pollination success; (3) fruit set in the inflorescence‐closed pollination treatment was significantly lower than that of indoor open pollination, indicating within‐ and between‐flower pollination events in an inflorescence are most likely limited, with pollination between inflorescences providing the highest reproductive opportunity; and (4) analysis of the spatial distribution of cumulative fruit set on inflorescences showed that pollen could reach any flower within an inflorescence and there was no functional limitation on seed set among flowers located at various positions within the inflorescence. These data suggest that the pollen ejection mechanism in S. stenoloba can enhance inter‐plant pollination in pollinator‐excluded environments and may suggest adaptation to pollinator scarcity attributable to habitat disturbance or competition for pollinators in a diverse flora. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170 , 59–68.     

An Examination of the Function of Male Flowers in an Andromonoecious Shrub Capparis spinosa

The pollen donor and pollinator attractor hypotheses are explanations for the functions of the male flowers of andromonoecious plants. We tested these two hypotheses in the andromonoecious shrub Capparis spinosa L. (Capparaceae) and confirmed that pollen production and cumulative volume and sugar concentration of nectar do not differ between male and perfect flowers. However, male flowers produced larger anthers, larger pollen grains and smaller ovaries than perfect flowers. Observations on pollinators indicated that two major pollinators (Xylocopa valga Gerst and Proxylocopa sinensis Wu) did not discriminate between flower morphs and that they transferred pollen grains a similar distance. However, there were more seeds per fruit following hand pollination with pollen from male flowers than from perfect flowers. Individuals of C. spinosa with a larger floral display (i.e. bearing more flowers) received more pollen grains on the stigma of perfect flowers. Female reproductive success probably is not limited by pollen. These results indicate that male flowers of C. spinosa save resources for female function and that they primarily serve to attract pollinators as pollen donors.     

Early blooming's challenges: extended flowering season, diverse pollinator assemblage and the reproductive success of Gynodioecious Daphne laureola

BACKGROUND AND AIMS: The scarcity and unpredictability of active pollinators during late winter in temperate areas tends to favour extended flowering seasons and increased floral longevity in early blooming species, which are usually pollinated by diverse sets of insects. Daphne laureola is a gynodioecious woody perennial that flowers from January to April in southern Spain, a period characterized by cold temperatures, frequent rains and irregular snowfalls. METHODS: Pollinators were excluded at four different times during the flowering season in order to determine the effect of decreased exposure to pollinators on fruit set in female and hermaphrodite individuals. The role of nocturnal and diurnal pollination on reproductive success in each gender was simultaneously evaluated by selective exclusion. KEY RESULTS: A 50 % reduction in the flowering period decreased fruit set of females by 50 %, whereas the corresponding decrease in self-compatible hermaphrodites was only approx. 25 %. Day-active hymenopterans and lepidopterans were infrequent visitors, and nocturnal pollinators were inefficient, suggesting that pollen beetles, Meligethes elongatus, were the main pollinators of D. laureola in the study region. CONCLUSIONS: Beetles were less abundant in pollenless females, although discrimination did not apparently result in pollination limitation of female reproduction. A preference of beetles for sunny locations emphasized the relevance of abiotic conditions for pollination of this early blooming shrub.     

Multifunctional bracts enhance plant fitness during flowering and seed development in Rheum nobile (Polygonaceae), a giant herb endemic to the high Himalayas

Specialized bracts are thought to be important for the successful reproduction of some plants and are regarded as adaptations to diverse driving forces. However, few empirical studies have quantified the adaptive significance of bracts within a cost–benefit framework. We explored the adaptive significance of large and showy bracts for reproduction in Rheum nobile, a giant herb endemic to the high Himalayas. We examined whether the bracts enhance reproductive success during flowering and seed development. Bracts increased flower and fruit temperature on sunny days, greatly decreased the intensity of ultraviolet-B (UV-B) radiation reaching flowers and fruits, and prevented pollen grains being washed away by rain. Experiments indicated that high temperature could promote pollen germination, while pollen grains exposed to rain and UV-B radiation at ambient levels were seriously damaged. Furthermore, bract removal decreased the number of pollinators visiting flowers. When bracts were removed before or after flowering, fecundity and progeny quality were adversely affected, but seed predation by larvae of pollinators decreased. A cost–benefit analysis demonstrated that the cost of bracts, i.e., increased seed predation, is modest. Our results suggest that the bracts of R. nobile promote pollen germination, protect pollen grains from rain and intense UV-B radiation, enhance pollinator visitation during flowering, and facilitate the development of fertilized ovules during seed development. We conclude that multifunctional bracts of R. nobile are an effective adaptive strategy in alpine environments and might have been selected for because of abiotic environmental conditions as well as for enhancing pollination success.     

沙丘稀有种准噶尔无叶豆花部综合特征与传粉适应性

植物花部特征进化与传粉适应性一直是进化生态学领域关注的核心问题之一。以古尔班通古特沙漠自然生长的准噶尔无叶豆为对象,对其花部特征和传粉特性进行了野外观察和室内的分析研究。结果表明:种群花期历时21 d,花序花期历时7-12 d,单花花期一般3 d,若遇阴雨天气,花期可延长1-2 d,整个花期龙骨瓣一直保持闭合状态。单花10枚花药在旗瓣微张时已全部完成散粉。准噶尔无叶豆主要靠分泌花蜜、鲜艳的花色以及旗瓣基部的黄色辐射状纹理结构吸引传粉者。准噶尔无叶豆花期的有效传粉者为4种蜂类昆虫,它们的平均访花频率为(7.75±0.57)次·花^-1·d^-1,访花高峰期表现为三峰型: 13:00-14:00,16:00-17:00和19:00-20:00。准噶尔无叶豆人工套袋实验表明该种为自交亲和型,主动自交少见,生殖成功依赖传粉者。胚珠成功受精至果实完全成熟阶段存在自交衰退,柱头角质层结构和花粉刷结构是准噶尔无叶豆在进化过程中形成的减少自交,倾向异交的机制。     

Changes in Florets’ Vertical Direction within Inflorescence Affects Pollinator Behavior,and Fitness in <i>Trifolium repens</i>

Ecological interactions between flowers and pollinators greatly affect the reproductive success. To facilitate these interactions, many flowers are known to display their attractive qualities, such as scent emission, flower rewards and floral vertical direction, in a rhythmic fashion. However, less is known about how plants regulate the relationship between these flower traits to adapt to pollinator visiting behavior and increase reproduction success. Here we investigated the adaptive significance of the flower bending from erect to downward in Trifolium repens. We observed the flowering dynamic characteristics (changes of vertical direction of florets, flowering number, pollen grain numbers, pollen viability and stigma receptivity over time after blossom) and the factors affecting the rate of flower bending in T. repens. Then we altered the vertical direction of florets in inflorescence of different types (upright and downward), and compared the pollinator behaviors and female reproductive success. Our results showed that florets opened sequentially in inflorescence, and then bend downwards slowly after flowering. The bending speed of florets was mainly influenced by pollination, and bending angle increased with the prolongation of flowering time, while the pollen germination rate, stigma receptivity and nectar secretion has a rhythm of “low-high-low” during the whole period with the time going. The visiting frequency of all the four species of pollinators on upward flowers was significantly higher than that of downward flowers, and they especially prefer to visit flowers with a bending angle of 30°–60°, when the flowers was exactly of the highest flower rewards (nectar secretion and number of pollen grains), stigma receptivity and pollen germination rate. The seed set ratio and fruit set ratio of upward flowers were significantly higher than downward flowers, but significantly lower than unmanipulated flowers. Our results indicated that the T. repens could increase female and male fitness by accurate pollination. The most suitable flower angle saves pollinators’ visiting energy and enables them to obtain the highest nectar rewards. This coordination between plants and pollinators maximizes the interests of them, which is a crucial factor in initiating specialized plant-pollinator relationships.     

海南三七（姜科）的食源性欺骗传粉

有花植物为繁殖成功,进化出各种各样的花部特征来吸引传粉者,如为传粉者提供花蜜、花粉、栖息地等,然而在33科146属的被子植物中也存在着不提供任何报酬而欺骗昆虫为其传粉的现象。这种欺骗性传粉模式主要出现在高度进化的具有多样化传粉模式的兰科植物中。报道了在姜科植物中首次发现的食源性欺骗传粉模式。对姜科山柰属海南三七进行连续2年的传粉生物学观察和研究发现,海南三七的花在早上5:30～6:00之间开放,下午17:00～18:00左右闭合萎蔫,持续大约11～12h。开花过程中花粉活性与柱头可受性均保持较高水平(>90%)。花粉/胚珠比率(P/O)为82.20±47.89(n=20)。木蜂是其主要的访花和传粉昆虫,访花目的是吸取花蜜。海南三七虽有细长线形的蜜腺,但并不分泌花蜜作为传粉昆虫访花的报酬,采用食源性欺骗的方式欺骗木蜂为其传粉。繁育系统的研究表明广西弄化的海南三七居群主要是通过根茎进行无性繁殖。     

异型花柱植物喀什补血草的传粉者功能群与花粉转移效率

异型花柱是受遗传控制的花柱多态现象, 被达尔文认为是植物通过在传粉者体表不同部位滞落花粉以促进型间花粉准确传递的一种适应。该现象虽已受到广泛关注, 但在一些花型变异较大且不稳定的传粉系统中, 不同传粉者对各花型繁殖所产生的影响仍知之甚少。该研究以分布于新疆天山南坡的一个有同长花柱共存的异型花柱植物喀什补血草(Limonium kaschgaricum)种群为研究对象, 对其花型构成及频率、传粉者及花粉转移效率等进行了调查分析。结果表明: 1)种群中除了存在雌/雄蕊长度交互对应的长(L)/短(S)花柱型花外, 还有雌/雄蕊同长的花(H型), 且各花型花的花冠口直径、花冠筒长及花粉量等参数间无差异, 但花粉纹饰和柱头乳突细胞形态具二型性。其中, H型花的花粉和柱头形态与L型花(或S型花)的一致。2)花型内和自花授粉均不亲和; 型间授粉时, 花粉和柱头形态不同的花型间亲和, 反之不亲和。3)种群内存在长/短吻两类传粉昆虫。在以短吻传粉者为主的盛花初、中期, L和H型花柱头上的异型花粉数均显著高于S型花的, 且L和S型花高位性器官间的异型花粉传递效率高于低位性器官间的; 而在以长吻传粉者为主的盛花后期, L和S型花的柱头间异型花粉数无显著差异, 且高/低位性器官间具有相同的异型花粉转移效率; 与传粉者出现时期相对应的、在花期不同阶段开放花的结实率也明显不同。4)长/短吻昆虫具明显不同的传粉功能, 短吻昆虫只能对L和H型花进行有效传粉, 且访花频率和型间花粉转移效率较低, 为低效传粉者; 而长吻昆虫对各花型均能有效传粉, 具高的访花频率和型间花粉转移效率, 为高效传粉者。因为长吻昆虫的阶段性出现所形成的不稳定传粉系统, 使低效的短吻昆虫可能会成为种群中花型变异的驱动力, 并使S型花受到更大的选择压力。H型花克服了柱头缩入的弊端, 可能会成为不稳定传粉系统下的一个替代花型而持续存在。