Advance in Studies on Genetic Variation of Lignin Content in Tree Species

Genetic variation of the quantitative trait lignin content was remarked in detail.According tomany reports,it can be seen that lignin content possesses very complicate patterns of variation at levels of species,population and individual.Impacts of environmental factors on variation of lignin content can not be ignored.The lignin biosynthetic process has not been elucidated yet,and there are probably several alternative pathways.However,application of antisense transformation of genes of some enzymes such as PAL,C4H,4CL and CCR,can reduce level of lignin content to a certain extent; while transformation of other genes of enzymes like OMT,CAD and F5H has no effect on lignin content but lignin composition.These results remain to be confirmed in the field performance.Based on these progresses,study onmultiple transformation of genes of some enzymes is required so as to detect the roles of some enzymes in lignin content andmetabolic plasticity.In order to further study genetic variation of lignin content,it is necessary to conduct a study on geneticmapping,location determination and isolation of genes responsible for variation of lignin content,using pedigreematerials planted under different environemnts.Thismay also help us to elucidate the impacts of environmental factors on variation of lignin content atmolecular level.