祁连山不同海拔珠芽蓼光合特性和繁殖策略  

Photosynthetic characteristics and reproductive strategies of Polygonum viviparum at different altitudes in the Qilian Mountains

作　　者：宋昕旖 聂瑾璐 杨梦涵 喻懋椿 陶梁明 冯虎元[1] 潘建斌[1] SONG Xinyi;NIE Jinlu;YANG Menghan;YU Maochun;TAO Liangming;FENG Huyuan;PAN Jianbin(School of Life Sciences,Lanzhou University,Lanzhou730000,China)

机构地区：[1]兰州大学生命科学学院,兰州730000

出　　处：《应用与环境生物学报》2022年第6期1527-1533,共7页Chinese Journal of Applied and Environmental Biology

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0301);国家标本平台教学标本子平台(2005DKA21403-JK);国家自然科学基金项目(31971445,31870494);兰州大学学生创新创业行动计划项目(20200180013)资助。

摘　　要：珠芽蓼是青藏高原的广布种,存在有性和无性两种繁殖方式,其繁殖策略对环境变化非常敏感.为揭示海拔对珠芽蓼光合特性与繁殖策略的影响,以祁连山东段6个海拔梯度的珠芽蓼居群为研究对象,分析光合特性、生长特性、繁殖特性对海拔梯度的响应.结果显示:(1)随着海拔升高,珠芽蓼净光合速率呈现升高趋势,在海拔3 700 m时达到最高值(14.39μmol m^(-2)s^(-1)),珠芽蓼叶片气孔导度总体上呈现升高趋势,蒸腾速率呈现先升高后下降趋势,胞间CO_(2)浓度在不同海拔间没有明显差异.(2)随着海拔升高,珠芽蓼的株高和叶面积总体呈现下降趋势,地上与地下生物量均减少,比叶面积呈现先下降后升高趋势,叶绿度指数总体呈上升趋势,叶片上、下表皮气孔数均呈现先上升后下降趋势.(3)随着海拔升高,花序轴长占比、珠芽轴长占比、珠芽数量占比均呈现升高趋势.(4)空气温度和光照强度是海拔梯度上珠芽蓼光合特性和植物性状的主要影响因素.可见,随着海拔升高,珠芽蓼受环境限制,总体上获得的能量减少,但珠芽蓼通过提高单位面积的光合能力以适应恶劣的高山环境;随着海拔升高,珠芽蓼通过降低营养生长、增加繁殖生长的能量权衡,来维持种群数量,并且更多地倾向无性繁殖.(图6表2参32)Polygonum viviparum, which reproduces sexually and asexually, is widely distributed in the QinghaiTibet Plateau, and its reproduction strategies are very sensitive to changes in the environment. This study aimed to elucidate the effect of altitude on the photosynthetic characteristics and reproductive strategies of P. viviparum. This study was conducted to investigate the responses of photosynthetic, vegetative, and reproductive traits of P. viviparum populations along six altitudinal gradients in the eastern part of the Qilian Mountains in China. Our results indicated that, with increasing altitude, the net photosynthetic rate of P.viviparum showed an increasing trend, reaching its maximum value(14.39 μmol m–2s–1) at 3 700 m above sea level. The transpiration rate showed an increasing trend, followed by a decreasing trend, and the intercellular CO2concentration did not differ significantly between altitudes. With increasing altitude, the plant height and leaf area of P. viviparum showed a downward trend, the aboveground and underground biomass decreased,and the specific leaf area initially decreased and then increased. However, the leaf greenness index showed an upward trend, and the number of stomata in the upper and lower epidermis of leaves initially increased and then decreased. With increasing altitude, the proportion of inflorescence length per plant(the ratio of inflorescence length to plant height), the proportion of bulbil length per inflorescence(the ratio of bulbil length to inflorescence height), and the proportion of the number of bulbils per inflorescence(the ratio of the number of bulbils to the total number of flowers and bulbils) showed an increasing trend. Air temperature and light intensity are the major environmental factors affecting the photosynthetic characteristics and functional traits of P. viviparum.Thus, P. viviparum is exposed to more environmental stresses and obtains less energy when altitude increases,but it adapts to the harsh alpine environment by increasing the photosynthe

关 键 词：珠芽蓼 高山植物 光合特性 繁殖策略 海拔 

分 类 号：Q945[生物学—植物学]