模拟增温条件下接种AMF对夏蜡梅幼苗生长与光合生理特性的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 模拟增温条件下接种AMF对夏蜡梅幼苗生长与光合生理特性的影响 DOI: 10.5846/stxb201501220177 作者: 作者单位: 台州学院生态研究所,台州学院生态研究所,台州学院生态研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31400423）；浙江省自然科学基金（LQ14C030001）；台州学院生态学浙江省重点学科开放课题（EKD2013-07） Effects of AMF inoculation on growth and photosynthetic physiological characteristics of Sinocalycanthus chinensis under conditions of simulated warming Author: Affiliation: Taizhou University,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:全球变暖已对植物尤其是珍稀濒危植物产生重要影响。AMF对植物应对气候变化具有重要意义，但是在濒危植物应对气候变暖过程中发挥的作用并不清楚。以濒危植物夏蜡梅（Sinocalycanthus chinensis）一年生幼苗为对象，研究人工模拟增温条件下接种AMF对其生长、形态建成、光合生理、抗氧化酶活性和膜脂过氧化程度、营养物质积累和叶绿素相对含量的影响。实验共4个处理：模拟增温条件下添加AMF（AMF+SW）、添加AMF（AMF）、模拟增温（SW）和对照（CK）。结果表明：（1）接种AMF对幼苗株高、叶宽长比、总根长、根平均直径、根尖总数、比根长和比根表面积有显著影响。（2）AMF+SW条件下幼苗光合日进程呈现出明显"双峰"曲线，AMF显著提高叶片日均净光合速率（Pn）；光合有效辐射大于50 μmol m-2 s-1时，AMF+SW和AMF处理的Pn、最大净光合速率Pnmax和呼吸速率Rd显著高于CK；胞间CO2浓度大于100 μmol CO2/mol时，AMF+SW与AMF处理的Pn、AMF+SW处理的初始羧化效率（α）及AMF处理的光合能力（Amax）显著高于CK，而AMF+SW和AMF处理的CO2补偿点均低于CK。（3）AMF处理的叶可溶性糖显著高于其它处理，AMF+SW和AMF处理的叶可溶性蛋白显著高于CK。因此，AMF能显著促进夏蜡梅幼苗的形态建成和光合作用；在模拟增温条件下，接种AMF对夏蜡梅光合生理具有显著影响。 Abstract:The global climate warming is affecting ecosystems, especially endangered plant species whose distribution is mostly restricted to few areas. Arbuscular mycorrhizal fungi (AMF) form symbiotic associations with many plant species, supplying mineral nutrients to their host plants. Sinocalycanthus chinensis is a national second-class protected plant species, distributed in only a few areas in Zhejiang and Anhui provinces in China. Preliminary investigation has revealed higher infection rate of natural populations of S. chinensis by AMF. The role of AMF in S. chinensis under global warming has remained unknown. To reveal the effects of AMF on S. chinensis under the conditions of global climate warming, the pot experiment was conducted with one-year-old S. chinensis seedlings inoculated with AMF (inoculation of rhizosphere soil at a rate of 5%, v/v; soil without AMF was used as control) and temperature increase was simulated by an electric radiant infrared heater (+ 2℃ measured around the leaves; normal temperature was used as control). Growth rate, morphogenesis, photosynthetic physiological characteristics, antioxidant activities, membrane lipid peroxide level, nutrient content of S. chinensis seedlings were compared under four treatments: AMF, simulated warming (SW), both AMF inoculation and simulated warming (AMF + SW), and control (CK). The results showed that: (1) AMF inoculation had a significant positive effect on plant height and average root diameter, and a negative effect on the width-to-length ratio of mature leaves, total root length, total number of root tips, special root length (root length/root biomass), and special root surface area (root surface area/root biomass). Double-factor variance analysis showed that the average root diameter and total number of root tips was significantly correlated with AMF and SW. This showed that symbiotic association between AMF and S. chinensis may modify the nutrient absorption strategy of S. chinensis through modification in root morphology. (2) The diurnal change in net photosynthetic rate (Pn) of leaves in S. chinensis seedlings under AMF + SW treatment had a typical bimodal curve that was determinately regulated by stomatal conductance. AMF affected significantly the daily mean Pn. After fitting the photosynthesis light response using modified models of rectangular hyperbola, we found that Pn in plants with AMF + SW and AMF treatments were distinctly higher than that of CK when light intensity was more than 50 μmol m-2 s-1. The double-factor variance analysis showed that AMF significantly affected the daily mean Pn, maximum net photosynthetic rate, light saturation point (LSP), and dark respiration rate, whereas SW had a significant effect on LSP. Fitting of the CO2 response by using modified models of rectangular hyperbola revealed that Pn in plants under AMF + SW and AMF treatments was significantly higher than that in the CK with increasing the concentration of CO2. Initial carboxylation efficiency under AMF + SW treatment and photosynthetic capacity under AMF treatment were significantly higher than that of the CK. The CO2 compensation point after the treatment by AMF + SW or AMF was significantly lower than that of the CK. (3) The content of soluble sugars in leaves after the treatment with AMF was significantly higher than that in other treatments. The content of soluble proteins in leaves of plants treated with AMF + SW or AMF was distinctly higher than that of the CK. The double-factor variance analysis showed that SW and AMF + SW interaction had significant effect on the content of soluble sugars in leaves, and both AMF and SW had significant effect on the content of soluble proteins in leaves. The results provided the theoretical foundation for conservation and artificial cultivation of S. chinensis under conditions of global climate change. 参考文献 相似文献 引证文献