Cold Resistance Characteristics Of Tea Clonal Seedlings | Posted on:2003-08-25 | Degree:Master | Type:Thesis | Country:China | Candidate:X Z Song | Full Text:PDF | GTID:2133360062995498 | Subject:Silviculture | Abstract/Summary: | PDF Full Text Request | Evaluation of cold resistance of tea seedlings is a critical technique in tea introduction to Shandong tea area. Materials in this test are 1-2-year old tea seedlings of 8 clones. Correlation of growth, morphological, physical and biochemical characters with cold resistance is systematically studied by main component analysis, regression analysis, cluster analysis and path analysis. Primary conclusions are as follows:Field survival investigation of 8 tea clones reveals difference of cold resistance among clones, which appears more significant under conditions of no cold protecting measures.Analysis of electrolytic leakage indicates electrolytic leakage of tea blades possesses a low-fast-low change in response to stable decrease of low temperature. This process is simulated by LOGISTIC equation, whose M is little while R and LN(K/Y-1) is large in high resistant clones. Lt50 is approved to have special physical importance and can be used in cold evaluation. Change of electrolytic leakage in response to cold treating period is analyzed by time interval analysis. Results indicate that electrolytic leakage becomes comparatively stable after a continue increase. Electrolytic leakage of tea leaves treated in -10'C for 4 hours can be used in resistance evaluation.Analysis of MDA indicates MDA content of tea blades after 4 hour treatment in -10 癈 condition can be used in resistance evaluation. Clones, with MDA content less than 0.2, are approved to have high resistance while clones with MDA content lager than 0.28 are less resistant.Analysis of protective enzyme indicates SOD activity and decrease of CAT activity are closely related with cold resistance. High resistant clones have comparatively high SOD activity (around 278 units) and less decrease in CAT activity (around 18.4 units) after 2 days treatment in -10癈 condition.Analysis of soluble sugar indicates: enrichment of soluble sugar in tea leaves is a physi-biochemical index closely related with cold resistance of tea tree. Clones whose soluble sugar enriched by 0.846 after 5~day treatment in -10C condition are high resistant ones. Low resistant clones enrich merely about 0. 357.Analysis of tea leaf color and chlorophyll a/b indicates light-colored tea blades and little ratio of chlorophyll a/b is characteristics of high resistance. Clones with SPADR 42.0 and chlorophyll a/b 2.51 are high resistant ones. Clones with SPADR 52.9 and chlorophyll a/b 2.55 are low resistant ones.Analysis of growth indicates growth indexes of tea sprouts are insignificantly related with cold resistance. Thus grow indexes are not suitable as evaluation indexes.Analysis shapes of tea leaves indicates shape of tea leaf is closely related with cold resistance. Width at back quarter of blade can be used in cold resistance evaluation, clones with a width of 2. 49cm are high resistant ones while clones whose width is around 1.49 cm are low resistant. The result from integrated evaluation with versatile indexes is better.Analysis of anatomical structure of tea blade indicates: cold resistance of tea tree is not only affected by the layers and length of palisade tissue but also affected by epidermic cells. Hence result of integrated evaluation with versatile indexes may be more credible.Analysis of stomata indicates character of stcmata in tea leaves is closely related with cold resistance. Density and width of stomata are the most efficient indexes in resistance evaluation. Width of stomata is positively related with cold resistance, the wider the stomata is, the higher resistant the clone is. High resistant clones possess wider stomata (2.77 urn) and more rarely distributed stomata (28.59 per eyesight). Low resistant clones have thinner stomata (2.39 jim) and densely distributed storaata (34.81 per eyesight).Analysis of water indicates ratio of binding water to free water in tea leaves affects cold resistance. But, fresh weight, tissue water content and binding water content are indexes that affect resistance most.Analysis of inner substance of tea lea... | Keywords/Search Tags: | tea seedling, cold resistance, seedling stage, integrated evaluation, main component analysis, regression analysis, cluster analysis, path analysis | PDF Full Text Request | Related items |
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