The Physiological Integration Of Plant Glechoma Longituba Suffering From Heterogeneous Heavy Metal Pb Stress

In the natural environment, plant growth habitats in time and space are unevenly distributed by the same Genet connected clonal plant ramets, often in heterogeneous patches, and in the source sink relationship driven, by stoloniferous stems or rhizomes, into the water, nutrients and photosynthetic product resource sharing that clonal integration. And Pb is the main heavy metal pollutants in the environment, the content in the soil often show heterogeneous distribution. Therefore, this study use connection and disconnection stoloniferous stems of Glechoma longituba ramet fragment as materials, the determination of homogeneous and heterogeneous lead stress condition under, to clone plant matter Glechoma each rametbiological index and biomass index of determination and analysis. We divided this study into the following six treatments:Stolon connections between parent ramets and offspring ramets, ramets are all assigned to normal soil;Stolon connections are severed, ramets are all assigned to normal soil; Stolon connections between parent ramets and offspring ramets, offspring ramets are assigned to Pb stressed soil;Stolon connections are severed, offspring ramets are assigned to Pb stressed soil; Stolon connections between parent ramets and offspring ramets, parent ramets are assigned to Pb stressed soil;Stolon connections are severed, parent ramets are assigned to Pb stressed soil.The chlorophyll content, rate net photosynthesis, chlorophy flurescence parameters, maximum net photosynthetic and the activites of SOD were evaluated to study the patterns of physiological integration. The biomass and gowth of rametswere evaluatedto study thepatterns of the division of labor.The main results are as follows:(1) Applying Pb stress on clonal plants, clonal integration is not always favor of the stressed part. The photosynthetic indexes, SOD activity and biomass to plant resistance to environmental stress were improved at the cost of unstressed part by clonal integration when offspring ramets were assigned to Pb stressed soil. The photosynthetic indexes, SOD activity and biomass of parent ramets were significantly reduced when parent ramets were assigned to Pb stressed soil,which reduces the range greater than the first experiment;(2) The growth index of offspring ramets was improved by clonal integration when parent ramets were assigned to Pb stressed soil which mean the greater intensity of clonal integration;(3) By means of Pb contents in parents and offspring ramets indicates that the clonal integration in material transport is bidirectional. And carbon assimilation products transportation was mainlytransported from older ramets to the younger ramets by the biomass index analysis;(4) Clonal integration reduced root biomass/total biomass values of offspring ramets, increased the root biomass/total biomass value of parent ramets when offspring ramets were assigned to Pb stressed soil which occurred division of labor. But the root biomass/total biomass values did not change significantlywhen parent ramets were assigned to Pb stressed soil, sothe division of labor phenomenon is not obvious;(5) Clonal integration significantly increased the offspring ramets biomass and new ramets biomass, the whole clonal fragments significantly benefit by clonal integration. Clonal plant Glechoma longituba will weigh the ramet overall cost and consumptionwhen suffering from heterogeneous heavy metal Pb stress.