异质性生境中匍匐茎草本野草莓(Fragaria vesca)的克隆内资源共享

Intraclonal resources sharing of stolon herb Fragaria vesca in response to heterogeneous habitat

研究了不同海拔高度(1800和3900m)的匍匐茎克隆植物野草莓(Fragaria vesca)种群对光照和养分资源斑块性分布生境的响应。结果表明:与资源的空间同质性处理(Ⅰ)和(Ⅱ)相比,资源的空间异质性处理(Ⅲ)和(Ⅳ)中2个种群的野草莓的近端、远端分株部分和整个克隆片段的生物量和分株数均明显增加。当近端分株部分经历低光高养,而与其相连的远端分株部分经历高光低养时,相比于整个克隆片段都处于低光高养的同质性生境,来自2个海拔的种群的近端分株部分都会增加对根的生物量分配;当近端分株部分经历高光低养,而与其相连的远端分株部分经历低光高养时,相比于整个克隆片段都处于低光高养的同质性生境,来自2个海拔的种群的近端分株部分都会减少对根的生物量分配,远端分株部分也被观察到类似的生物量分配格局。相比于高光低养的同质性生境,当与低光高养的远端分株部分相连时,经历高光低养的近端分株部分有更大的叶面积;相比于低光高养的同质性生境,当与低光高养近端分株部分相连时,经历高光低养的远端分株部分有更大的叶面积。结果表明,野草莓在资源交互斑块性生境中发生了克隆内分工,克隆内分工有利于克隆植物对异质性资源的利用,对克隆植物在资源斑块性分布生境中的生存和生长具有重要的意义。

The essential resources for plant growth could be negatively correlated with each other within the patches. In this paper, the clonal fragments of stolon herb Fragaria vesca from two altitudes （1800 m and 3900 m above sea level） were subjected to reciprocal patchiness of light and soil nutrient resources. The fitness-related traits （biomass and number of ramets） and the plasticity of the species in root/shoot ratio and leaf area were investigated. Our results demonstrated that the biomass and number of ramets in proximal clonal part, distal clonal part, and whole clonal fragment from the two altitudes had a significant increase in the resources heterogeneity treatments （Ⅲ and Ⅳ）, compared with in the resources homogeneity treatments （Ⅰ and Ⅱ）. The proximal ramets in the treatment with low light and high nutrient allocated more biomass to the below-ground as connected to the distal ramets grown in high light and low nutrient than as connected to the distal ramets grown in low light and high nutrient. The proximal ramets in the treatment with high light and low nutrient allocated more biomass to the above-ground as connected to the distal ramets grown in low light and high nutrient than as connected to the distal ramets grown in high light and low nutrient. The similar allocation patterns were observed in the distal ramets. The proximall ramets grown in high light and low nutrient presented larger leaf area as connected to the distal ramets grown in low light and high nutrient than as connected to the distal ramets grown in high light and low nutrient. The similar allocation patterns were observed in the distal ramets. These results suggested that there existed a reciprocal translocation of assimilates and nutrients between the interconnected ramets, while root/shoot ratio and leaf area were plastic, which led to an environmentally induced specialization for uptake of locally abundant resources. Therefore, sharing intraclonal resources was very significant for the survival and growth of clonal plants in heterogeneous habitat.