摘要
植物有性繁殖与资源分配的关系研究对于揭示植物生活史特征及繁育系统进化具有重要意义。新疆郁金香(Tulipa sinkiangensis)是新疆天山北坡荒漠带特有的一种多年生早春短命植物。在自然生境中,该物种仅以有性繁殖产生后代,每株能产生1-8朵花,且不同植株上的花数及果实数以及花序不同位置上的花与果实大小明显不同。本文通过对新疆郁金香有性繁殖与营养生长及植株大小的关系以及花序中不同位置花及果实间的资源分配研究,旨在揭示营养生长、个体大小及开花次序对其繁殖分配的影响。结果表明:在开花和果实成熟阶段,新疆郁金香植株分配给营养器官(鳞茎和地上营养器官)与繁殖器官的资源间均存在极显著的负相关关系(P<0.01),说明其植株的营养生长与生殖生长间存在权衡关系。多花是新疆郁金香的一个稳定性状,其植株上花数目、花生物量、果实生物量和种子数量与植株生物量间均呈极显著的正相关关系(P<0.01),说明新疆郁金香植株的繁殖分配存在大小依赖性。在具2-5朵花的新疆郁金香植株中,花序内各花的生物量、花粉数和胚珠数、结实率、果实生物量、结籽数、结籽率及种子百粒重按其开花顺序依次递减,说明花序内各花和果实的资源分配符合资源竞争假说。植株通过减少晚发育的花或果实获得的资源来保障早发育的花或果实获得较多的资源,从而达到繁殖成功。
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.
出处
《生物多样性》
CAS
CSCD
北大核心
2012年第3期391-399,共9页
Biodiversity Science
基金
新疆维吾尔自治区高技术研究发展计划(200810102)
国家自然科学基金(31060047)
国家国际合作项目(ISTCP
2011DFA31070)
