作 者 ：白志强1,毛培利2,刘 华3*,刘 端1,韩燕梁1,郭仲军1
期 刊 ：西北植物学报 2012年 11期 页码：2321~2327
Keywords:Armeniaca vulgaris Lam., photosynthesis, eco-physiological adaptability,
摘 要 ：在新疆天山西部伊犁野果林资源发展研究中心的野杏林选定野生成年杏树为样株，用Li-6400光合仪测定晴天和阴天两种天气状况下野杏的光合生理生态特性，并通过相关分析、通径分析、回归分析探讨其净光合速率与生理生态因子的关系。结果显示：(1)野杏的最大净光合速率(Pnmax)和光饱和点(LSP)分别为12.63和1 389.44 μmol·m-2·s-1，属喜光的阳生树种。(2)晴天和多云天气下野杏的净光合速率(Pn)日变化最大值和日均值之间差异不显著，晴天Pn日变化为单峰型，而多云为双峰型，具典型的“午休”现象，而且是由非气孔限制因素造成，与叶温(Tl)的降低有关。(3)野杏气孔导度(Gs)与Pn和蒸腾速率(Tr)呈显著正相关；随着其Tl的增加，晴天Pn、Gs和Tr为单峰形；多云Pn和Tr呈线性增加，而Gs呈线性降低；Tl增加超过最适值后Gs的降低是晴天野杏产生严重光抑制的重要原因；气孔的快速关闭降低了Tr，造成Tl增加和Pn降低，在最大程度上控制了水分丢失。(4)晴天和多云天气下影响野杏叶片Pn日变化主导生理因子均为Gs，主要限制因子为胞间CO2浓度(Cl)；主导生态因子为空气相对湿度(RH)，限制因子为气温(Ta)。研究表明，野杏能够适应高光强环境条件，这是野杏主要分布在较为干旱阳坡上的重要原因之一；多云天气条件对野杏进行光合作用的抑制程度较弱，这为野杏种群天然更新环境条件的人工调节提供一定的理论依据。
Abstract:Armeniaca vulgaris Lam.is the most important constructive species of wild fruit forests in the Tianshan Mountains,Northwest China.Our objective was to clarify the existence status and photosynthetic characteristics of A.vulgaris and the relationships between wild fruit forest and some eco-physiological factors.Saplings of A.vulgaris were selected at the Center for Research and Development of Wild-Fruit Forest Resources,Yili Kazak Autonomous Prefecture,Xinjiang Province,China.And the response of photosynthetic rate to photosynthetic effective radiation,diurnal change of photosynthetic rate and eco-physiology factors,were analyzed in situ by Li-6400 Portable Photosynthesis Analysis System under natural conditions,Relative analysis,path coefficient analysis and stepwise regression equation were used to discuss how related factors influenced diurnal changes of photosynthetic rate.The results showed that:(1)The maximum net photosynthetic rate (Pnmax) and light compensation point (LSP) were 12.63 and 1 389.44 μmol·m-2·s-1,respectively.It is a heliophilous plant.(2)Diurnal change of Pn showed a unimodal curve in sunny days.But the diurnal change of Pn showed a bimodal curve in cloudy days,and there was obvious midday depression of photosynthesis,because of the non-stomata limitation,which indicated the degree of photoinhibition reduced in cloudy days.(3)The reduction of photoinhibition was caused by the decrease of leaf temperature (Tl).Stomatal conductance was positive correlation with both Pn and transpiration rate (Tr).With the increase of Tl,Pn,Gs and Tr exhibited a unimodal curve in sunny days.However,in cloudy days,Pn and Tr was positive correlation with Tl,whereas Gs was negative with Tl.The decrease of Gs due to Tl exceeding the optimal value was an important reason for the appearance of severe photoinhibition in sunny days.The decrease of Tr by closing stomata quickly controlled the lose of water to the utmost extent,in spite of leading to the increase of Tl and decrease of Pn,which was one of the important physiological characteristics for A.vulgaris to distribute the arid adret.(4)The main physiological factor affecting the characteristic of Pn of A.vulgaris was Gs,Ci was the main limiting factor;and the main ecological factor was RH,Ta was the limiting factor both in sunny days and cloudy days.The results indicated that A.vulgaris adapt to high-light’s capability,it is a heliophilous plant,and the photosynthesis were no visible inhibition in cloudy days,while the environmental conditions under forest crown artificial accommodated to suit the self-restoration of A.vulgaris population.