Chin J Plant Ecol ›› 2009, Vol. 33 ›› Issue (3): 449-459.DOI: 10.3773/j.issn.1005-264x.2009.03.004

• Research Articles • Previous Articles     Next Articles

FLOWERING PATTERN AND PROTANDRY IN BOESENBERGIA LONGIFLORA

YANG Shu-Xia1,2, GAO Jiang-Yun1,*()   

  1. 1Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
    2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2008-12-08 Accepted:2009-01-18 Online:2009-12-08 Published:2009-05-31
  • Contact: GAO Jiang-Yun

Abstract:

Aims Boesenbergia longiflora (Wallich) Kuntze is a perennial protandrous ginger widely distributed in Asian tropics. It usually grows in crevices of calcareous rocks of limestone monsoon rainforests or in sedimentation soil on the roadside, forming patches in the understory. Its floral longev-ity is 2 days. Flowers are in male stage during the first day and in female stage during the second day of flowering. Autogamy is avoided because two sexual functions are not overlapping in a single flower. Our objectives were to investigate if any other floral mechanism reinforced protandry to avoid geitonogamy and to determine the pollinators and their visiting patterns on the flowers in different sexual stages of different populations.

Methods Flowering phenology was monitored once a week for two years. Floral morphology was studied and compared for three populations of different habitats. Flowering pattern was studied by investigating number of flowering inflorescences and flowers in male or in female stage in four populations and under cultivation. We also investigated natural seed-sets and plant density for different populations. Pollinators were observed in three populations.

Important findings Most of individuals of B. longiflora had only one flowering inflorescence at a time and produced one flower every other day. About 10% of all individuals investigated had male and female stage flowers at the same time, both in four natural populations and under cultivation. The pollination system was generalized with different insects as pollinators, including Apis florae, Bombus sp., Amegilla fimrata, Anthophora plagiata, Amegilla yunnansis, Nmia ellioti and Apis cerana in different populations. Plant and floral sizes did not differ significantly among populations. The flowering pattern of most individuals was one flower every other day, which reinforced protandry and avoided selfing.

Key words: protandry, flowering pattern, floral biology, Boesenbergia longiflora, Zingiberaceae