Sumac Structure And Bark Of Urushiol And Urushiol Homologue Content Varied With The Change Of Seasons

Rhus verniciflua Stokes is a kind of important economic tree originated in China. Currently the research in it’s anatomy, development, the composition identfy of raw lacquer, analysis in the content of lacquer.But about it’s variety of chemistry composition and structure in different seasons,there is only one study about Rhus verniciflua Stokes in Jiwozi and Shangnan by Shuying Fu, moreover, she only mensurated the content of total urushiol by spcetrophotometry.On the content of urushiol Homologues produced in Pingli,which is a important origin of raw laqucer in China,no research had been carried out.This thesis we analyzed the change of the structure of bark, together with the change of urushiol Homologues’ and total urushiol in different seasons in the kinds of Dahongpao and Gaobachi,sum up their regularities and pertinence. The results would provide theory basis on validating whether the tradition period of laequer tapping is reasonable,making sure the most appropriate month,as well as establishing the structure standard for tapping laequer.1. Although exist some special trends, the change of the structure of bark as a whole show coherence except the number of stone cells.The laticiferous canals’number and area,the number of rays,the ratio of function phloem,s and non-function phloem,s thickness all show a trend that they first increase and then drop,the turning point is July. All these structure indexs have a highest numerical value in July and a lowest number in November.The area of stone cells overall continues increasing.The changes of stone cells’number are lack of commonality,except that they have the highest number in November in common.2.The content of total urushiol is all first increased and then dereased, compared with March, the content mainly increase.Semtember is a turning point of Dahongpao,while that is August in Gaobachi. The lowest content of Gaobachi is in March, Dahongpao is in May.Among urushiol homologues, the change of three-ene urushiol is same with total urushiol. Compared with March,the change of diene-ene urushiol’s content is lower in November in Dahongpao,The highest content is in July; In Gaobachi, the content of diene-ene urushiol in November is higher than March, and the highest content is in September, the lowest content is in March.About single-ene urushiol, its content all lower in November than in March, and the highest content is in Auguest. The overall trends of single-ene urushiol raise first and then reduce, the turning point is August. In Dahongpao, the lower month is November while that is March in Gaobachi.3.The correlation analysis results show that the number of laticiferous canals has a significant positive correlation with the content of diene-ene urushiol, three-ene urushiol and total urushiol; The content of diene-ene urushiol as a significant positive correlation with the area of laticiferous, a significant positive correlation with and the ratio of function phloem’s and non-function phloem’s thickness;The content of total urushiol and urushiol homologues show a significant positive correlation with the number of rays.4.Lacquer tapping is usually carried through in dog days traditionally,that is between mid-July to mid-August.According to our result, the content of total urushiol and urushiol homologues in August is high,and output is considerable,so this month is appropriate to tap lacquer largely.The output of lacquer is reduced in September,but the content of total urushiol and urushiol homologues is appropriate,it can also continue tapping lacquer.However,lacquer tapping stops around early September traditionally in Pingli.The time of stopping tapping lacquer can be delayed to the end of September according to this study.