舞花姜属3种植物繁殖策略比较

Comparative Studies on Reproductive Mechanisms of Three Species in Globba (Zingiberaceae)

选择自然分布于西双版纳地区的毛舞花姜(GlobbabartheiGagnepain)、双翅舞花姜(G.schomburgkiiJ.D.Hooker)和澜沧舞花姜(G.lancangensisY.Y.Qian)为实验材料,比较了3种植物的有性和无性繁殖特性。毛舞花姜和双翅舞花姜在自然状况下开花不结实,人工自交与异交、人工去除珠芽均不能使其恢复有性繁殖能力;花粉败育(毛舞花姜)或花粉活力低(双翅舞花姜,花粉萌发率<12%)可能是这2种植物不能结实的主要原因。毛舞花姜和双翅舞花姜均以珠芽为主要繁殖体,一年生植株每花序产珠芽分别为16.46±3.56(平均值±标准差,N=60)和14.25±3.63(平均值±标准差,N=153)。澜沧舞花姜具有雄花两性花同株的性表达特征,自然状态下以种子繁殖为主,结实率(种子/胚珠比)可达64.5%±12.1%(N=36),人工自交结实率显著低于异交结实率,有明显的自交不亲和现象;花序上产生少量珠芽[每花序产珠芽2.24±1.41(平均值±标准差,N=184)]。此外,3种舞花姜属植物还具有通过地下茎进行克隆繁殖的能力。3种舞花姜属植物的拜访昆虫均为蜂类,毛舞花姜的拜访昆虫只有排蜂(Megapisdorstata)。双翅舞花姜拜访昆虫主要为排蜂、黄绿彩带蜂(Nomiastrigata)及木蜂(Xylocopasp.);澜沧舞花姜的拜访昆虫主要为排蜂和黄绿彩带蜂。

The characteristics of sexual and asexual reproduction of three species of Globba (G. barthei, G. schomburgkii, and G. lancangensis) those are native perennial herbs in Xishuangbanna, Yunnan Province of Southeast China were studied. Both G. barthei and G. schomburgkii mostly depended on bulbils for their reproduction, and the one year aged plants produced 16.46±3.56(mean±SD,N=60) and 14.25±3.63 (mean±SD,N=153) bulbils per ramet. No seed set were observed for the two species while by artificial selfing and crossing. The abnormal pollens (>98% of total pollens observed) in G. barthei and low pollen viability in G. schomburgkii ((<12%)) may be ascribable to no seed-set. For G. lancangensis, however, it mainly engaged in sexual reproduction with a seed-set ratios (seed/ovule ratios) of 64.5%±12.1% in the field (N=36) and produced relatively few bulbils (2.2±1.4 per ramet, N=184). G. lancangensis bears both male and hermaphrodite on same ramet, which is termed as andromonocy. There were no (signifi)-(cant) differences for the fruit-set ratios between hand-selfing and hand-crossing,but significant differences of seed-set ratios (seed/ovule ratios), which suggested that this plant might maintain the mechanism of self-incompatibility. Additionally, three species of Globba have the (ability) of clonal reproduction with underground stems. The corolla tuber length of three species differed significantly by the order: G. barthei>G. schomburgkii>G. lancangensis. All pollinators of three Globba we observed were definitely honeybees other than butterflies, and the latter was previously suggested by other authors. Megapis dorstata was the only pollinator for G. barthei, while M. dorstata, Nomia strigata and Xylocopa collaris visited G. schomburgki, M. dorstata and N. strigata were the main visitors for G. lancangensis. Three species have much longer corolla tuber comparing with the tongue length of three visitors. Nectar in G. barthei (during) a day can only reach the height of 3/4 corolla tuber length, which may prevent bee with short tongue (e.g., Nomia strigata) visiting the flowers. The flowers of G. schomburgkii produce large amount of nectar and nectar overflows the corolla tuber after 9∶00 A.M., which make bees with different tongue length, can easily suck the nectar. Thus, the visitation of different bees appeared to be influenced by both corolla tuber length and the amount of nectar produced.