| Anhui province is on the northern margin of Camellia oleifera Abel. Thus there aremany factors which affecting the development of C. oleifera, especially low temperatureand drought. To promote the healthy development of Anhui C. oleifera industry and toprovide more theoretical basis for jiang huai region, C. oleifera of7ages were selected asexperimental materials, and leaves physiological and biochemical characteristics such asleaf water content, the relative conductivity value, enzyme activities, benzene-ethanolextracts and cellulose content, and the differences of active substances in different ageswere studied, the results showed that as follows:1. Determination on the bound water/free water ratio and the relative conductivityvalue in camellia of different ages found that, with the growth of tree age, leaf boundwater/free water ratio determination results showed that with the increase of tree age, thecamellia leaf bound water/free water ratio increased and later stay stable, in which50yearsold ones got the maximum values, which is0.0912,and it is34.3%higher than that of2years old ones, which is only0.0679.2. C. oleifera leaf relative conductivity of2to5year old ones were on the high side,while that of10-100year old ones were relatively lower, as a whole, the relativeconductivity value declined when the tree age increased, and reached a significantdifference between different age.3. The comparison of MDA and Pro content in different tree age of C. oleifera leavesfound that camellia leaf MDA content maintain a decrease trend with the increase of treeage in all7different ages, old basic, with2years old ones the most, reached5.10mmol/gFW, while100year old ones got the least, which is only2.59mmol/g FW; Pro content isbasically on the rise with the increase of tree age, whose value range from1166.13μg/g in3year old ones to1281.37μg/g in50year old ones. The results showed that within therange2–100years old, the older the tree is, the stronger stress resistant plant maintains.4. The results of measurement upon activities of two enzyme: CAT and POD of sevenages of C. oleifera showed that CAT activity in the body of C. oleifera plants increases atfirst but get stable later with the age grows, within which the10year old ones reach thehighest, which was67.20U/g.min; By contrast, the POD activity in C. oleifera plantsdecreased with the increment of the age, change in the range of0.75U/g.min to1.53U/g.min. 5. Analysis of variance showed that POD activity of seven different age of C. oleiferareached significant difference on the range of ages(p<0.05), CAT activity of seven differentage of C. oleifera reached significant difference level too on the range of ages (p<0.05);6. The result shows that along with the increase of tree age, C. oleifera leaves boundwater/free water ratio keep rising at first and stop growing later; holo-cellulose and lignincontent in leaves and shoots grows at first and stop growing after10a,the minimum(58.2%)and maximum(64.2%) of shoots holo-cellulose were in2a and10a,that of lignin in shootswere in2a (19.8%) and10a (30.3%), while the cellulose content keep rose, that ofcellulose were in2a(25.4%) and100a(23.9%). Variance analysis showed that: among7different tree age, the difference of holo-cellulose and lignin in shoots reached highlysignificant level (p<0.01), and lignin in shoots also reached highly significant level(p<0.01). Difference of cellulose content in shoots and leaves reached significant level（p<0.05）and lignin content in leaves also reached significant leve（lp<0.05）while that ofholo-cellulose in leaves did not reach significant level. It implies that the stress resistanceof C. oleifera of young C. oleifera(2a-5a) were weak while that of older C.oleifera(10a-100a) were strong.7. With the declining of temperature, the change of MDA content and activity of POD,CAT as well as soluble sugar content increased. MDA and soluble sugar content increasedunder10℃and0℃, and the value were86%and181%,32%and92%respectively.Activity of CAT and POD declined first and then remained stable, the decreasingamplitude of CAT was33%and40%respectively and that of POD were14%and47%respectively. Under-10℃stress, the MDA content rose sharply, the increasing rate reached319%. The content of soluble sugar increased first and then stopped rising, the increasingrate reached47%. Activity of CAT and POD continued to decline and dropped into90%and71%respectively. This result showed that the physiological adaptive mechanism couldstill be formed to resist the injury in C. oleifera container seedlings under cold stress withinthe range of10℃-0℃. However,-10℃or even lower temperature stress lead to plantmetabolism function unbalancing. |
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