| For selecting and breeding improved varieties that are suitable for cultivate in southwestmountain, genetic diversity of populations, heredity and variation of germplasm provenances,and families and clones breeding are studied in Catalpa fargesii Bur. f. duclouxii (Dode)Gilmour. In according to the procedure to estimate the superior families by genetic parameters,in Guizhou and Yunnan where Catalpa fargesii distribute concentrately, genetic diversity ofpopulation were investigated, excellent germplasm were selected, collected and evaluated, aswell as progeny test of the collecting excellent tree were conducted. The above researchobtains main results as following:Firstly, variation of phenotypic traits was vary rich, and its genetic diversity was high levelin population of Catalpa fargesii. Floral phenotypic differences were significantly big within17populations and among17populations. Variation coefficient among population is19.88%～35.75%, the mean phenotypic differentiation coefficient of characters (VST) was28.26%, therange of change was18.91%～42.15%. Differentiating coefficient of phenotype frequency(Pst) is0.5147. Shannon-Weaver diversity index (H’) varies was1.3490～2.5225. Repeatabilityof floral phenotypic traits in catalpa fargesii was high, its highest value was the flower calyx,namely0.685on average. Morethan, length of flower calyx lip, length of calyx lip anddiameter of flower traits has strong stability. There was a significant correlation between floraltraits and geographic factors, and length of flower calyx lip, length of calyx lip, flowerdiameter was significantly correlated with the latitude and longitude, squid length wassignificant negatively correlated with altitude.8fruit phenotypic traits differentiatesignificantly among populations and within populations in Catalpa fargesii. The variationcoefficient among populations was31.03%(24.53%～39.28%), Phenotypic differentiationcoefficient VSTwas22.81%(10.53%～39.28%), Lst, Ls and Pst of the average fruit diversitycoefficient were0.0359,0.755and0.0453respectively, Shannon-Weaver diversity index (H’) was in1.6184～2.3617. Mean value of repeatability in the fruit characters was0.543, variationrange was in0.399～0.694, it was lower than flower characters. By UPGMA cluster of fruitcharacters in9populations from different provinces, the result showed that the fruit phenotypicvariation in Catalpa fargesii was not in accordance with the geographical distance, but was inaccordance with the results of floral traits cluster.Secondly, seed germinating variation of different climate, provenance, family in Catalpafargesii. Variation coefficient of seed quality and sowing quality in Catalpa fargesii has veryobvious difference in climate, provenances, families. Range of variation coefficient in the seedweight, germination rate, germination potential, and germination index were2.41%～20.57%,3.67%～28.89%,8.92%～30.82%and8.75%～34.13%respectively. Seed weight weresignificantly negative correlation with mean tempreture in July and effective accumulatedtemperature, R value of the correlation coefficient was-0.593and-0.662.Thirdly, growth traits variating of family progeny was very rich in Catalpa fargesii. Byvariance analysis for one or biennial s, traits of the height and ground diameter showsignificant differences in climate types, provenance and family. Difference of height andground diameter for one year old reached significant level, and2year old height andground diameter of different families had no significant difference in climate types, but otherdifference reached significant level. Correlation analysis of showed that one or biennialdiameter growth were significant (R=0.672and0.595) with July temperature in origin. thebiennial diameter showed a significant negative correlation with longitude (R=-0.589).Family heritability of height, ground diameter for one year old were0.805and0.664respectively. Family heritability of height, ground diameter for two year old were0.837and0.603respectively. One or biennial family genetic variation coefficients of height and grounddiameter were18.798%,11.053%and10.141%,6.589%respectively; the phenotypic variationcoefficients of height and ground diameter of family for one or biennial year were39.477%,28.461%and28.818%,35.408%. Genetic gain of one or two years was up to24.96%and35.32%respectively. Acording to I value,31superior families were selected from seedings for two year old, that distributed in10provenances, eg: XingRen county, Pan county and Wengancounty so on.Fourthly, superior clones selecting in Catalpa fargesii. There were significant differencesin growth traits, leaf characters and wood properties of clone among clones. Repeatability ofheight, footstalk length, leave area, basic density, cell wall percentage, fiber length and doublewall thickness were respectively0.921,0.960,0.946,0.842,0.872,0.792and0.725in clones.Wood basic density of clones were significantly related to anatomical characters of plant cellwall, double wall thickness, ratio of diameter to chord, cellular tangential diameter. It was notsignificant correlation between actual fiber length and other traits. According to the geneticparameters, correlation analysis results, physical mechanics indexes, superior clones ingrowing rapidly, good anatomical structure and stable physical properties of wood werecollected during early selection of clones. By genetic parameter, correlating analysis, study ofprincipal component, cluster analysis, and method of synthetical score so on,7superior cloneswere selected using growth traits and leaf characters. Combining growing traits withanatomical structure and mechanics traits of wood,5superior clones were selected that weregrowing rapidly, anatomical structure well, steady physical behavior of wood. |
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