Biodiv Sci ›› 2012, Vol. 20 ›› Issue (3): 391-399.  DOI: 10.3724/SP.J.1003.2012.09064

Special Issue: 传粉生物学:理论探讨与初步实践 传粉生物学

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Effects of vegetative growth, plant size and flowering order on sexual reproduction allocation of Tulipa sinkiangensis

Aysajan Abdusalam, Dunyan Tan*(), Omarxat Tahan   

  1. Xinjiang Key Laboratory of Grassland Resources and Ecology & Ministry of Education Key Laboratory for Western Arid Region Grassland Resource and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Urümqi 830052
  • Received:2012-02-27 Accepted:2012-04-20 Online:2012-05-20 Published:2012-05-09
  • Contact: Dunyan Tan


The relationship between sexual reproduction and resource allocation plays an important role in plant life history and in the evolution of breeding systems. Tulipa sinkiangensis is an early spring perennial ephemeral species endemic to the desert zone of the northern piedmont of the Tianshan Mountains, Xinjiang, China. This species produces offspring only by sexual reproduction, and produces 1-8 flowers per individual in natural populations. The relationships between sexual reproduction allocation and vegetative growth and plant size, respectively, and resource allocation among flowers and fruits at different positions within the inflorescence were studied in T. sinkiangensis. Our aims were to explore the effect of vegetative growth, plant size and flowering order on sexual reproduction allocation in this species. There was a negative correlation between the resources that plants allocate to both vegetative organs (bulb and aboveground vegetative organs) and sexual reproductive organs at flowering stage and fruit maturation stage (P<0.01), suggesting that resource allocation between vegetative growth and sexual reproduction is a trade-off. Production of multiple flowers is a stable character in this species―the total number and biomass of flowers, total fruit biomass, and total number of seeds per individual were positively correlated with plant biomass (P<0.01), indicating that sexual reproduction allocation is size-dependent. In individuals with 2-5 flowers, the biomass of flowers, pollen and ovule production, fruit-set, fruit biomass, seed number, seed-set, and 100-seed weight declined successively with flowering order within the inflorescence, indicating that resource competition for floral allocation was significant and that resource limitation for each flower or fruit is related to flowering order. Plants ensure their reproductive success by reducing resource allocation to late flowers or fruits and increasing the resource allocation to early flowers or fruits in this species.

Key words: Tulipa sinkiangensis, sexual reproduction, resource allocation, plant size, resources competition