Growth and physiological characteristics of Fritillaria cirrhosa in response to high irradiance and shade in age-related growth phases
Growth and physiological characteristics of Fritillaria cirrhosa in response to high irradiance and shade in age-related growth phases
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DOI：
10.1016/j.envexpbot.2009.07.005
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发表时间：
2009-11-01
影响因子：
5.7
通讯作者：
Chen, Shilin
中科院分区：
文献类型：
--
作者：
Li, Xiwen;Dai, Yong;Chen, Shilin
川贝母（Fritillaria damensa）为国家三级保护植物，为多年生草本植物，原产于川西高原.遗憾的是，大规模引进并不成功。我们假设过量的辐照度是限制其引入的关键因素。尤其是年轻的阶段。本研究比较了光照和遮荫在三个年龄相关的生长阶段，以确定是否遮荫是栽培的主要限制因素。采用聚丙烯遮阳网模拟理塘杜鹃（Rhododendron litangense boscages）的自然遮荫率，研究了不同遮荫率下的理塘杜鹃群落结构。研究了其生长和生理特性。结果表明，遮荫能极显著地提高各时相的净同化量（p < 0.01）。YP（一批野，2年生）同化净增加主要是由于VPD（水汽压亏缺）降低和气孔导度（g_1）增加。SE（苏尔子，3岁）和DL（邓龙华，4岁）净同化量的增加主要是由于VPD降低和WUE（水分利用效率）提高所致。然而，阴影不是唯一的限制因素。我们还研究了林冠的重要性，以F sa增长。最大光化学效率（Fv/Fm）和非光化学猝灭（qN）在全光照和遮荫条件下差异均不显著（p > 0.05），表明DL在无遮荫条件下也能正常生长。YP和SE的Fv/Fm有显著性差异（p < 0.01），开放部位的Fv/Fm均小于0.80。YP和SE在没有冠层的情况下仅弱生存。该实验提供了对辐照度和阴影的定量反应的原始观察，向更广泛的观众介绍了F.遮荫提高了幼蚁的存活率和净同化量（前三个阶段）。(C)2009爱思唯尔有限公司版权所有。
Fritillaria cirrhosa is a perennial and protected species (grade 3) inhabiting the Chuanxi altiplano, of China. Unfortunately, large-scale introduction has not been successful. We hypothesized that excess irradiance is a key factor limiting its introduction. especially young phases. The current study compared responses to irradiance and shade in three age-related growth phases to determine whether shading was the primary limiting factor in cultivation. Polypropylene shading nets were used to mimic a natural shading rate under Rhododendron litangense boscages, the primary community type of F cirrhosa. Growth and physiological characteristics were investigated. Results showed that shade Could increase net assimilation of all phases significantly (p < 0.01). The net increased assimilation in YP (YiPiye, two years old) was mainly due to decreasing VPD (vapor pressure deficit) and increasing g, (stomatal conductance). Net increased assimilation in SE (SuErzi, three years old) and DL (DengLonghua, four years old) resulted primarily from decreasing VPD and increasing WUE (water use efficiency). However, shade was not the only limiting factor for introduction. We also examined the importance of canopies to F cirrhosa growth. Maximum photochemical efficiency (Fv/Fm) and non-photochemical quenching (qN) did not differ markedly in DL (p > 0.05), either in full light or under a shading net, which indicated that DL could grow well without canopies. Significant differences were observed (p < 0.01) in Fv/Fm of YP and SE; both values were lower than 0.80 in open sites. YP and SE only weakly subsisted without a canopy. This experiment provides original observations on the quantitative responses to irradiance and shade, introducing F cirrhosa life history to a wider audience. Shading increased the rate of survival and the net assimilations of young E cirrhosa (in the first three phases). (C) 2009 Elsevier B.V. All rights reserved.