Study On The Clonal Integration Of 5 Dwarf Bamboos Under Different Light Intensity

In the natural environment,the habitats of plant growth are often heterogeneous in time and space.Cloning plants can improve the adaptability of heterogeneous environ-ments by transporting and sharing material and resources between the clones by means of connective or spacer.In the urban environment,the illumination is the typical ecological factor which causes the environment heterogeneity due to the dense construction.In this study,five kinds of dwarf bamboos were used:Sasa argenteistriatus E.G.Camus,Sasa au-ricoma E.G.Camus,Shibataea chinensis,Pleioblastus kongosanensis‘Aureostriatus’,Sa-saella glabra‘Albostriata’Muroi.Through the shading treatment,simulate the natural dif-ferent light intensity conditions;By cutting off and retaining the bamboo whips of the connecting branches,the cloning and integration of five species of dwarf bamboo in the different light intensity environment were tested.The transmission direction and intensity of different bambodifferent light intensity conditionsspecies clones were determined by the shading of the female plant or subplant of the bamboo plant respectively,and the differ-ences of the clone integration were compared between different transmission directions（to the top transport and to the base transport）.Study measured the light response curve,co₂response curve,the chlorophyll content,specific leaf area,leaf nitrogen content and free proline,soluble protein and other indicators,and calculate the distribution coefficient of nitrogen in leaf photosynthetic mechanism,the photosynthetic characteristics,photosyn-thetic nitrogen allocation mechanism and physiological response of 5 species of dwarf bamboo has carried on the comparative study.The conclusions are as follows.（1）Shading treatment significantly affected the maximum net photosynthetic rate,chlorophyll content and ratio,specific leaf area,leaf unit mass nitrogen content,and solu-ble protein content of five species of dwarf bamboo.Sasa argenteistriatus E.G.Camus,Pleioblastus kongosanensis‘Aureostriatus’,and Shibataea chinensis grow better under shady conditions.The maximum net photosynthetic rate under shading conditions is sig-nificantly increased（53.8%,71.1%,and 27.6%,respectively）,showing strong resistance to negatives.It is more suitable for weak light environment;Sasa auricoma E.G.Camus,Sa-saella glabra‘Albostriata’Muroi preferably grown without shade environment,the maxi-mum net photosynthetic rate shade environment significantly reduced（64.5%and 58.2%）,expressed as shade intolerant,is more suitable for strong light environment.（2）Clone integration significantly improved the light environment adaptability of bamboo whip connecting bamboo plants,not only in the aspect of photosynthetic charac-teristics（maximum net photosynthetic rate,leaf shape,leaf nitrogen content and distribu-tion）,and also includes the ability to relieve the stress environment.For the Sasa argen-teistriatus E.G.Camus,Pleioblastus kongosanensis‘Aureostriatus’,and Shibataea chinen-sis,compared with the bamboo cutting bamboo whip,clonal integration of bamboo whip connecting bamboo strains has enhanced the ability of the non-shade bamboo strains to adapt to the full-light environment.For the Sasa auricoma E.G.Camus and Sasaella glabra‘Albostriata’Muroi,compared with bamboo whip cut bamboo,the clonal integration of the bamboo whip connecting bamboo strains has enhanced the ability of the shade bamboo strains to adapt to the shading environment.（3）The transfer direction of the clonal integration of five kinds of dwarf bamboos is bidirectional,but there are differences in the integration strength of different bamboo spe-cies to the top and to the base transportation.The clonal integration strength of Sasa ar-genteistriatus E.G.Camus and Sasaella glabra‘Albostriata’Muroi in the top transportation is greater than that in the base transportation.The clonal integration strength of Sasa auri-coma E.G.Camus and Pleioblastus kongosanensis‘Aureostriatus’in the top transportation is less than that in the base transportation.There was no significant difference between the combined strength of Shibataea chinensis in the transport and the base transport.（4）The five species of dwarf bamboo are adapted to different light environments through different nitrogen distribution mechanisms.For Sasa argenteistriatus E.G.Camus,by reducing fraction of leaf nitrogen allocated to bioenergetics and carboxylation,increase fraction of leaf nitrogen allocated to light-harvesting components,to adapt to the shade en-vironment.For the Sasa auricoma E.G.Camus,Sasaella glabra‘Albostriata’Muroi and Shibataea chinensis,by increasing fraction of leaf nitrogen allocated to carboxylation,re-duce fraction of leaf nitrogen allocated to bioenergetics and light-harvesting components,to adapt to the shade environment;For Pleioblastus kongosanensis‘Aureostriatus’,by re-ducing fraction of leaf nitrogen allocated to carboxylation and light-harvesting components,increase fraction of leaf nitrogen allocated to bioenergetics,to adapt to the shade environment.