青藏高原东缘不同海拔波缘风毛菊资源分配及花部特征对种子数目和质量的影响

通过采样调查法和烘干称量法检测了青藏高原东缘不同海拔种群波缘风毛菊(Saussurea undulata)花期与果期的形态特征, 研究了其花期与果期的资源分配, 并对花期花部特征对果期种子特征的影响作出分析。结果表明: 1)波缘风毛菊在花期将更多的资源投入繁殖器官, 而在果期增加了对种子的资源投资; 2)波缘风毛菊花期部分花部特征的变异导致其果期产生的种子随海拔升高数量减少、百粒重增加, 因为波缘风毛菊需要在高寒草甸的极端环境下保证每粒种子的存活能力, 因此采取了产生更少但更大种子的生存策略。

Effects of resource allocation and floral traits on the number and mass of Saussurea undulata seeds from different elevations in eastern Qinghai-Xizang Plateau

Aims This paper studies the resource allocation during flowering and fruiting, as well as the relationship between variations in floral traits and seed characters in Saussurea undulata.
Methods Field sampling and measurements of dry mass were used to evaluate morphological characteristics of S. undulata distributed at different elevations in eastern Qinghai-Xizang Plateau.
Important findings Saussurea undulata invested more resources in the reproductive organs during flowering, whereas it invested more resources in seed during fruiting. The variations in floral traits during flowering led to a decline in seed number and an increase in 100-seed mass in S. undulate during fruiting with increasing elevation, because the species adopted survival strategies that produce less but larger seed to ensure survival of each seed under the extreme environment of alpine meadow in eastern Qinghai-Xizang Plateau.