Phenotypic Plasticity And Regulatory Mechanism Of Clonal Plant Under Heterogeneous Salinity In Duchesnea Indica

Soil salinization is a global resources and ecological problems,and salinity become to one of the most adverse abiotic stress factor in plant growth.In nature,the salinity of soil is not only uneven distribution in time and space,but also in plant rhizosphere soil.Clonal plant procude connected ramets by clonal growth,which enable water and mineral nutrition could be distributed by physiological integration.Then it alleviates the negative influence of environmental heterogeneity of plant effectively and improve the adaptability of clonal plants to heterogeneous environment.Duchesnea indica?Andr.?Focke is a stoloniferous clonal plant with strong ability of space development and survival competition.Studying regulation mechanism of physiological integration in Duchesnea indica under heterogeneous salinity provide reasonable and effective scientific basis of efficient saline-alkali land cover by clonal plant and improving the ecological environment and offer an new idea to cultivating new salt-tolerant varieties.Taking ramet pairs of Duchesnea indica clone which were in same feature as experimental materials disposed with different salt concentrations to the pot experiment,studied the mechanism of physiological integration under stress.The main results are as follows:?1?NaCl stress influenced growth and physiological metabolism of clonal plant Duchesnea indica and with the increase of NaCl concentrition,the inhibited effect of ramets were more serious.Under NaCl stress,the leaf damage rate increased and even dry to death.The nember of new ramets deccreased or had no new ramets uner high NaCl concentrition.The dry matter acccumulation ability decreased,the leaves accelerated the loss of water,chlorophyll synthesis was inhibited and the cell membrane system was damaged badly,which resulted the change of cell membrane permeability.Membrane lipid peroxidation reaction and strengthen the accumulation of a large number of H₂O₂ and prolina content.?2?physiological integration of connected ramets significantly improve the adaptive capacity of Duchesnea indica under heterogeneous NaCl stress.The growth and physiological metabolism of proximal ramet with connecting distal ramet had a better behabiour than which were severed.It was indicated that clonal ramets could communicate and recieve the signal and share the materia by stolon to ease the hurt of disposed ramets.The lifetime could be lengthened and adaptive capacity could be enhanced.?3?It was ignificant that effect on the distal ramets connecting with proximal ramet treated by different NaCl concentration.Especially under high salinity.H₂O₂ and prolina content of the distal ramets was increased and chlorophyll content was decreased evidently.However during14 days,the effect was increased first and then decreased under 300mmol·L^-11 NaCl concentrition,which ensured the well-balanced physiological metabolism and survival rate.?4?There was Molecular response mechanism between the connected clonal ramets under heterogeneous salinity.The stolons of connected ramets which were disposed with heterogeneous salinity produced expressed differently protein.Salinity induced aquaporin,calmodulin-binding protein,ribosomal protein to express differently,which relieved the harm of salinity and enhanced the salt tolerance.