The Variation Of Zelkova Schneideriana Hand-Mazz. Provenances

As an endemic species, Zelkova schneideriana Hand.-Mazz. is valuable for economy andfor landscape designing. Because of the over exploitation, the resources become less and less,so that it was listed in Red Dated Book with second grade. In this paper, The seed and leafmorphologic characteristics, seedling growth rhythm, wood characteristics, photosynthesis anddrought-tolerance, and ITS sequence analysis of different provenances were conducted, and theresults were as following:（1） Highly significant differences were found among different provenances （individuals）in seed length, width, ratio of length to width, and1000-grain weight, and theirs heritabilitywere0.9018,0.9210,0.9221and0.9008at the provenance level, and0.9260,0.9792,0.9326and0.9925at the individual level, respectively. This indicated that these seed morphologiccharacters lied abundant genetic variation, and were in moderate to higher genetic controlled.There were highly significant correlation among seed length, width and1000-grain weight, andthese seed morphologic characters demonstrated no obvious longitude or latitude variationtendency, seed length was mainly affected by annual average temperature and frostless days,seed width was average temperature in January, While1000-grain weight was annual averagetemperature; Cluster analysis suggested that the geographic variation of seed morphologiccharacters of some distribution zones represented regional block variation pattern, while theothers showed random variation pattern.（2）The environmental variance （VE）, phenotypic variance （VP） of leaf traits amongdifferent provenances were equal to, or greater than the genetic variance（VG）, this indicatedthat these traits were mainly affected by the environment; And there were highly significantdifference between leaf length, width and area, and theirs coefficients of the regressionequation were greater than0.98; And the broad-sense heritability of length/width, form factorand thickness were0.7101,0.7064and0.7595, respectively, and theirs genetic variation coefficients were rather smaller, these revealed that these traits were in moderate to highergenetic controlled.（3） The growth rhythm of the seedling height and basal diameter belonged to full-timegrowth type, and matched perfectly with “S” curve, and was fitted by Logistic GrowthEquation at significant level; Compared among different provenances, there existed significantdifference among theirs phenophase and growth parameters of height and basal diameter, andthe ratio of total linear growth reached from54.60%to66.55%.（4）There were highly significant differences of the basic density among differentprovenances, While theirs CV were rather stable; There were no significant differences ofradial dry shrinkage among different provenances, While the individuals within oneprovenance revealed rather higher difference; Basic density was not closely related to radialdry shrinkage. Based on this, independent selection of basic density and radial shrinkage wereexpected to generate improved effects. And both of them had no significant correlation to thegeographic and meteorological factors too.（5）The diurnal change of net photosynthetic rate （Pn） showed double-peak curve with aslightly midday depression, with maximum values occurred at about8:00am and14:00pm.And the midday depression was mainly controlled by non-stomatal factors judging from thechanging tendency of net photosynthetic rate, intercellular CO₂concentration （Ci） and stomatallimitation （Ls）. Correlation and regression analyses showed that Tr、Vpdl、Ca and Ci wereimportant affecting factors on the photosynthesis.（6）Under the condition of400μmol·mol^-1CO₂, the regression equations between Pn andPAR is Pn=－9×10^-6PAR²+0.0212PAR+0.592; the light saturation point （LSP）， lightcompensation point（LCP） and apparent quantum yield （AQY）are1177.8μmol·m^-2·s^-1,20.0μmol·m^-2·s^-1,0.0345, respectively; the regressive equation between transpirationrate（Tr）and PAR is Tr=0.025PAR＋4.535, and the regressive equation between waterutilization efficiency（WUE） and PAR is WUE=^-2×10^-6PAR²+0.0033PAR+0.1939withR²=0.8222. Under the condition of1200μmol·m^-2·s^-1of PAR, the regressive equation betweenPn and CO₂contents is Pn=^-2×10^-5CCO₂2＋0.0621CCO₂2－5.5018with R²=0.936（n=45）, CO₂ saturation point （CSP）, CO₂compensation point （CCP） and Carboxylation efficiency （CE） are1552.5μmol·mol^-1、84.8μmol·mol^-1、0.0403, respectively; The regressive equation betweenWUE and CO₂contents is WUE=^-3×10^-6CCO₂2+0.0105CCO₂–0.9442。However, Tr keepssteadily with the increase of CO₂contents.（7） The diurnal variation of Pn of different provenances revealed different changetendency, and the Huaihua provenance showed single-peak curve, while the other threedemonstrated double-peak one, and the later all were limited by stomata factors, and thediurnal average of Pn of Huzhou provenance were higher significantly than the others; Thecorrelation analysis and stepwise regression analysis showed that the main affecting factorswere transpiration rate （Tr） and photosynthetic active radiation （PAR）, and so on; The testedprovenances showed similar responses of Pn to PAR and Ci with evident provenance differenceof light compensation point （LCP）, light saturation point （LSP）, CO₂compensation point （CCP）and CO₂saturation point.（8） There were highly significant difference of Pro, MDA, Soluble protein, Soluble sugarand Chl contents among different provenances, and the comprehensive evaluation of thedetermination of membership function revealed that the order of drought-tolerance of differentprovenances were Ganzhou>Huaihua>Chuzhou>Huzhou>Nanjing.（9） The length of ITS sequence, ITS1and ITS2ranged61～623bp,157～210bp and215～222bp, respectively. And the DNAMAN, genetic distance and UPGMA analysis showedthat the relationships between Nanjing provenance and Ganzhou provenance, and betweenHuzhou provenance and Huaihua provenance were closer than the others, and the Chuzhouprovenances was clustered one single groups.