The Research Of The Development Process And Structure Charateristics Of Cell Wall In Cinnamomum Camphora(L.) Presl

The thickness and characteristics of the secondary wall decided the wood properties,studies on the main cells development process and the structure at each stage had great influence on understanding wood formation and wood properties.In this paper,the change of cell wall structure and other relevant parties during the process of wood formation in micro and ultrastructure level were studies.From the following aspects to explore:In this study,the Secondary xylem cells development of Cinnamomum camphora(L.)Presl.was studied in the tissue and cellular level,trying to explore the change of cell walls during the wood formation,main from several areas to explore as follow:Using scanning electron microscopy(SEM)technique to observe the change of secondary xylem in a growth cycle,similarities and differences of camphor Tension wood,observed the arrangement of microfibrils(Microfibril,CMfs)on the cell wall;Making ultrathin sections,combined with transmission electron microscopy to observe the ultrastructure changes of camphor cells during the active phase and dormant;Utilization of phenolic compounds on the cell wall autofluorescence and Wiesner reactions reveal cell wall ligniflcation process.The main research results were as follows:1.Observed the development of secondary xylem cells by scanning electron microscopy,with the formation of secondary xylem cell layer activities were closely related,in March began to sprout,ducts,fiber cells begin to differentiate,the cell wall was thin,with the cambium activity,cell wall gradually thickening,in December complete the process of cell wall lignification,cell contents change from the rich to reduce,to the accumulation of wealth has changed little,and finally was rich,this process has a close relationship with cambium activity.Camphor tension wood in their T-area had large number of glial fibrillary and the number and size of the vessel were small than other areas,the S-area followed by T-area,and the O-area had largest number and size of vessel.2.Secondary wall of wood fiber cell wall had three layers:S1 layer was established by a gentle spiral CMfs,S2 layer from Z spiral CMfs composition,S3 layer consists of gentle Z-helical of CMfs components.Vessel molecules at a location away from the pits for the three-tier structure,S2 layer was formed by relatively steep spiral CMfs S-type composition,S3 layer was made of Z-type spiral CMfs gentle composition.The CMfs were arranged in disorder in the pits of vessel.The cell walls in ray parenchyma cells were complex structures,which were composed of are different arrangement of CMfs and amorphous layer.3.Using transmission electron microscopy to observer the ultrastructures of secondary xylem in Cinnamomunm camphora(L.)Presl.active and dormant.The differentiation of fiber cells and vessel were the process of programmed cell death.The fiber had two differentiation ways:condensation type and autolysis type;The vessel had only one differentiation way:autolysis type.Secondary wall deposition and protoplast recession composed of the PCD process.Golgi apparatus,mitochondria,the endoplasmic reticulum involved the PCD process.Secondary wall deposition on the cell wall was uneven.4.Camphor T-area cellulose content was higher than S-area and O-area.Lignin content in reaction wood T-area is higher than S-area,O-area has lowest lignin content.The arrangement of cell wall was neat and compact in normal wood,the O-area was the secondary,the arrangement of cell wall in S-area and T-area were loose.The secondary wall thickness of the same layer was not the same,the distribution of lignin in the same layer was uneven in T-area;The cell wall was not a typical three layer structure in S-area,there were a lot of transitional layer,the corner of the cell had rich lignin,but there were a lot of transition layer;They all had pits structures and the pits of O-area had rich substance.5.Using fluorescence microscopy observe secondary xylem vessel and secondary thickening and wood fiber cell wall lignification process in camphor,lignin in the cell comers and compound middle lamella deposition began,followed in secondary wall deposition.Wood fiber cells fluorescent was higher than vessel at start time,after lignifications complete the two convergence.Fluorescence intensity in camphor reaction wood T-area was lower than S-area and O-area.Wiesner staining had the same result with fluorescence.