The Effect Of Nutrient Heterogeneity On Photosynthetic And Fluorescence Characteristics Of Zoysia Japonica Clonal Ramet

Nutrient heterogeneity is a common phenomenon of plants in various scale of habitats, connected ramets often survive in different nutrient levels, soil nutrient status affected by the soil characteristics, vegetation cover, and other community succession. As clonal plant, under heterogeneous conditions, its characteristics of nutrient transfer situation is different from non-clonal plants, water and nutrients could be transmited by spacer between their mother ramet and offspring ramet. In the long process of biological evolution, clonal plant Zoysia japonica evoluted a unique nutrient use mechanism. Adaptive response to nutrient heterogeneity of Zoysia japonica, which directly affect the storage and distribution of energy. Photosynthesis is a indispensable life process, photosynthesis and fluorescence characteristics can reflect the basic features of plant physiology. It can reflect sensitive response to external conditions of Zoysia japonica, and can reflect on soil nutrient absorption and utilization situation, which may adapt to the changes of nutrient. In different nutrient status, photosynthesis and fluorescence characteristics of Zoysia japonica is worthwhile discussioning, and had some ecological significance.The paper took clonal plant Zoysia japonica as research object, reached on photosynthetic and chlorophyll fluorescence parameters of clonal ramet of different nutrient pot experiment. Pot experiments simulated natural habitats nutrient heterogeneous condition, by applying different concentrations(high, medium and low) nitrogen, phosphorus and potassium gradient to mother ramet and offspring ramet. in order to gain knowledge of nutrient transport and utilization, experiment designed connection and disconnection treatment between mother ramet and offspring ramet, to understand photosynthesis and fluorescence characteristics of mother ramet and offspring ramet, the main conclusions are as follows:1. Effect on heterogeneous nutrient conditions of Zoysia japonica’s growth: regardless of Zoysia japonica connection or disconnection, high nutrient increased Zoysia japonica’s height, leaf length, leaf width significantly. Root length ratio was reduced when applying nutrients, which reduced mother ramet’s more than offspring ramet’s. Stolon length decreased compared to control when applying high nutrient. Dry weight, leaf biomass allocation ratio and root biomass distribution ratio of Zoysia japonica was not very different when applying medium or high nutrient. aboveground of Zoysia japonica is sensitive to high nutrient.2. Nutrient heterogeneity made chlorophyll content of Zoysia japonica increase significantly when applying medium nutrient, connection and disconnection of Zoysia japonica chlorophyll content had the same trend. In connection treatment, carotenoid content and photosynthetic pigment content of mother ramet and offspring ramet of Zoysia japonica increased significantly when applying medium nutrient. In disconnection treatment, carotenoid content and photosynthetic pigment of offspring ramet increased significantly when applying medium nutrient, mother ramet raise similar magnitude as applied in medium and high nutrient. Offspring ramet in mother ramet medium nutrient and mother ramet high nutrient group, carotenoid and photosynthetic pigment content in disconnect group was significantly lower than that of connected group, indicating that Zoysia japonica can not transmit nutrient to when disconnecting.3. When connection, Pn, Cond, Ci, WUE of Zoysia japonica applied medium nutrient in mother ramet or offspring ramet increased significantly than applied high nutrient. When disconnection, Pn, Cond, Ci, Tr, WUE of Zoysia japonica offspring plant applied medium nutrient increased significantly than applied high nutrient. Applied medium nutrient in mother ramet increased significantly than applied high nutrient. Pn and WUE of offspring ramet in mother ramet medium nitrogen treament and mother ramet high nitrogen treament disconnected group decreaced significantly than connection group. Connection helps improve plant’s Pn and WUE.4. Three fluorescence parameters Fo, Fm and Fv, whether connection or not, applied medium nutrient increased significantly compared to control and high nutrient ramet. There was no significant difference in medium nutrient and high nutrient ramet of several parameters Fv/Fm, Fv/Fo, ETR, ФPS II, q P, but ramet applied medium nutrient increaced higher than other ramets. Among offspring applied nutrient group, fluorescence parameters of mother ramet had no significant difference whether disconnected or not, fluorescence parameters of connected offspring ramet had increasing trend, indicating that when Zoysia japonica connected nutrient had advance in increseing fluorescence parameters, it may be that there is physiological integration between mother ramet and offspring ramet.