Studies On The Morphology, Biological Characteristic And Main Chemical Components Of Tengcha

Tengcha(Ampelopsis grossedentata W.T.Wang),belonging to Ampelopsis Michx of Vitaceae,is distributed widely in the south of the Yangtze River.Rich in flavones,such as dihydromyricetin(DMY),Tengcha is used for drinking and medicine among the folk.The tender stems and leaves of Tengcha have been made into a healthy drink which is called "mystic tea" for treating rheum,fever,gall of fauces,hepatitis and so on.This tradition has a long history of several hundred years among Zhuang and Yao Minority_in China.In recent years,much attention has been focused on identification of active constituents and biological activities of flavones.However,there are few reports on its botany and biological characteristics.Three Tengcha materials,from Dingnan County,Jiangxi Province;Hengdong County,Hu'nan Province and Enshi County,Hubei Province respectively,planted in the same ecological condition.This paper deals with the morphological characteristics and anatomical structures,growth-development law of new shoots,secondary shoots and leaves,dynamic changes of net photosynthetic rate, dynamic changes of main chemical components for the first time.The results provide scientific foundations for its classification,new variety breeding,best harvest time deciding and quality control.1.Morphological and biological characteristics of Tengcha1.1 Morphological characteristicsBuds,new shoots,tender shoots,leaves and flowers of the three Tengcha materials were observed and recorded.The results show that external morphologic characteristics of the three materials are similar,but not the same.The similarities are as follows: no villus on shoot tip,and the colour is mauve;tendrils distribution type is discontinuous and two bifurcate;leaf type is pinnately compound leaf,young leaves have no villus;the flower,as a cyme,is bisexual.The differences lie in the colour of buds,leaves,new shoots and tendrils;the shape and size of buds and leaves;the number of inflorescence on each new shoot and so on.The results indicate that genetic diversity may exist in the three Tengcha materials.1.2 Biological characteristics of TengchaPhenological period of Tengcha:The results of observation show that germination stage is in the second and last thirds of February,florescence is from the last third of May to the last third of August,fruit maturity stage is at the end of September and beginning of October. The growth of new shoots:Observation results indicate that the growth of new shoots showed a typical single sigmoid curve.The growth was slow from the last third of March to the first third of April,then went up and presented slow vertical line ascending from the middle third of April to the middle and last thirds of June,up to the first third of July,rapidly grown and presented vertical line ascending,afterward,the growth became flat.During the same period,Enshi Tengcha new shoots showed the slowest growth before June,but after that they grew fastest among the three materials.The growth characteristic of Hu'nan Tengcha new shoots was opposite.The growth of the three's secondary shoot went up and presented slow vertical line ascending from the first third of May to the last third of June.In the middle of July,the growth quickened,afterward,the growth became flat.The growth of Hu'nan Tengcha new shoot is the slowest,while its secondary shoot grew the fastest.The results show the apical dominance of Hu'nan Tengcha shoots is not strong,and it is easy to branch.Dynamic changes of net photosynthetic rate(Pn) of Tengcha leaves:Diurnal changes of net photosynthetic rate(Pn) of three Tengcha leaves present typical "noon-drop" bimodal curves,which express a obvious lunch break phenomenon.The lowest Pn point of Hu'nan Tengcha and Enshi Tengcha appear at around 14 o'clock, however,the Jiangxi Tengcha's lowest point is at around 12 o'clock.Season dynamic changes of Pn of three Tengcha leaves all present a single-peak curve,its high photosynthetic duration occurs in the second third of July and the first third of August.To use light energy and increasing yield better,we suggest north-south row direction cultivation postures.2.Research on anatomical structure of TengchaStructure anatomy of root,stem,leaf and flower of the three Tengcha materials were observed by microscope and Scanning Electron Microscope(SEM).Rich calcium oxalate crystals are observed in transverse section of root,stem and leaves of the three by microscope.Observed by SEM,epidermal cells and non-glandular hairs of stems from the three are obviously different;also there are obvious differences in spongy tissue voidage, the shape and density of upper epidermis non-glandular hairs of leaves,stomatal density and shape of guard cell of lower epidermis,cuticle texture of upper and lower epidermis;The observing results of the three Tengcha pollen show that the type of aperture is tricolporate,exine ornamentation is foveola,while the differences in the sizes and shapes of the three Tengcha pollen grains are obvious. 3.Chemical components of TengchaChemical component contents of the three Tengcha,such as,total flavone, dihydromyricetin,polyphenols,amino acids,protein and soluble sugar were analyzed. The results show that trends of major chemical component contents are similar and the peak appear in the middle third of June,and this suggests the optimum period of harvesting.Main chemical component contents of Jiangxi Tengcha and Hu'nan Tengcha are higher,and the two are optional materials of improved variety.Chlorophyll and anthocyanidin contents of the three Tengcha leaves were analyzed. The findings are as follows:dynamic change trends are similar;the contents of chlorophyll,chlorophylla and Carotenoids increased with the growth of leaves;picked at the same time,the pigment content of Hubei Tengcha is the highest,and the anthocyanidin content of Jiangxi Tengcha is the highest,that's why the colour of Jiangxi Tengcha buds and leaves is mauve.