黑河中游和烟台海滨中国柽柳的传粉生态学研究

中国柽柳(Tamarix chinensis)是干旱及半干旱地区的重要建群物种.为便于其有效利用和引种栽培,对黑河中游和烟台海滨的中国柽柳的开花动态、花粉活力、柱头可授性、访花者种类、花粉-胚珠比(P/O)、杂交指数(OCI)及座果率进行观测,结果表明:黑河中游和烟台海滨柽柳的花期和柱头可授性相似,花序花期为2-5天,开花当天柱头可授活性最大,之后逐渐下降,第4天柱头无可授性；花粉活力和访花者种类差别较大,黑河柽柳开花第1天花粉活力为(62±4.31)％,最高为(82.12±7.23)％,4天后花粉完全失活.烟台柽柳的花粉活力在开花后第1天最高为(89.13±7.23)％,第4天花粉活力下降为(11±1.12)％.黑河中游和烟台海滨柽柳的访花者均以膜翅目昆虫为主,黑河柽柳以黑带斑沙蜂(Bembix melanura)、卡切叶蜂Megechile (Amegachile) kagiana]和黑带食蚜蝇(Episyrphus balteatus)等为主要访花者；烟台柽柳以姬蜂(Ichneumon sp.)、大灰食蚜蝇(Metasyrphus corollae)和灰地种蝇(Delia platura)等为主要访花者.二者P/O值、OCI及座果率差异不显著,黑河和烟台柽柳的P/O值分别为373.6±71.9和382.1±86.2;最高座果率分别为(89.72±7.76)％和(93.17±8.21)％；OCI均为3.上述研究结果显示,黑河中游和烟台海滨柽柳均为兼性异交的繁育系统.

Pollination Ecological Studies of Tamarix chinensis in the Middle Reaches of Heihe River and Yantai Seashore

Tamarix chinensis is an important species in arid and semi-arid areas. For its effective use and cultivation, we conducted a field investigation of the flowering dynamics, pollen viability, stigma receptivity, floral visitors, pollen ovule rate （P/O）, outcrossing index （OCI）, and rate of fruitset of T. chinensis in the middle reaches of Heihe river and Yantai seashore areas. Stigma receptivity and flowering period were similar in the two areas. The inflorescence flowered at 2 to 5 days. At flowering day, the stigma receptivity in both areas was the highest; after 4 days, the stigma receptivity was re- duced to 0. The pollen viability and floral visitors greatly differed in the two areas. On the first flowering day at Heihe river, the pollen viability was as high as （62＋4.3）%, with peak viability at （82.1＋_7.2）%; after 4 days, the viability was reduced to 0. On the first flowering day at the Yantai seashore, the peak pollen viability was （89.1＋7.2）%, and after 4 days, the vi- ability decreased to （11＋_1.12）%. The most common floral visitors in the two areas were from the order hymenoptera, with Bembix melanura, Megachile （Amegachile） kagiana, and Episyrphus balteatus effective pollinators at the Heihe river. Ichneumon sp., Metasyrphus corollae, Delia platura were the main pollinators at the Yantai seashore. The two areas did not differ in P/O, OCI, or fruitset rate. The P/O rates for the two areas were 373.6＋_71.9 and 382.1＋86.2 for the river and seashore, respectively; the fruitset rates were （89.7＋7.8）% and （93.2＋8.2）%; and the OCI was 3. Outcrossing is the main form of breeding system for T. chinensis in the two areas.