Study On Breeding Of Eucalyptus Urophylla, E. Grandis And E. Urophylla Hybrids With N-ion-beam Implanting

E. urophylla,E. grandis and E. urophylla hybrids were researched by N-ion-beam implanting during seedling in nursery and standing trees in field, and the aim was to illuminate the method and effect of implanted-mutation breeding that it was introduced into tree-breeding. In the trials growing and form-quality traits of families were measured and scored to estimate single tree or family heritability, genetic gains, seedling quality and growing level, even to select excellent families, MET and ET trees that could be utilized to high-generation breeding programs and new clone exploitation. According to the selected effect of nursery and field by multi-traits and microsatellite (SSR) markers the METs and ETs could be get a fix on the site for future. The main conclusions were as follows:(1) The implanting effects of different N⁺ dosage indicated that germination capacity and germination rate had a remarkable difference among different dosage and had a up-down-up-down of trend along with the dosage rising. 1×10¹⁴ N⁺.cm^-2 and 1×10¹⁶ N⁺.cm^-2 in 7 kinds of dosage had a higher germination capacity and germination rate, and it indicated that implanting could promote the bourgeon of Eucalyptus seeds; There was a remarkable difference of traits by variance analysis among different dosage except 3 traits including GD. Synthesis analysis of growing effect indicated that medium dosage could restrain and injure GD and RL growing, but higher or lower dosage could improve growing and biomass level. The anlalysis effects of physiological traits indicated that 3 traits had more remarkable difference between implanting and no-implanting, and it revealed a difference of physiological and resistance level among Eucalyptus families. EC could be lower along with lower dosage and it indicated that resistance of tree could be improved after implanting; With a criterion by MCV of GD of seedlings, there were 28 selected-trees of MET or ET in 7 kinds of dosage, and mean MR or the range of positive MR was 7.910% or 0²1.67%, respectively. 1×10⁽15 N⁺.cm^-2 and 1×10⁽17 N⁺.cm^-2 in 7 kinds of dosage were the most suitable dosage to create MET. After implanting the growing and physiological effect of trees or seedlings had an obvious difference and it would help to MET selection. (2) Pn, E, gs, Ci,ε,WUE had a remarkable difference between implanting and no-implanting families by variance analysis and it indicated that implanting could improve the photosynthetic level to make for MET selection.εor WUE of the higher-dosage-implanted families was higher than no or lower-dosage families, and there were 5 most excellent families including No. 4, 14, 15, 16 and 17 that belong to 3 implanting and 2 no-implanted families could be selected in all familes according toεand WUE value.(3) The 3-site or single-site trial including 31 families or 15 families was afforested at 2005 or 2006. The effect indicated that growing or form-quality traits had a remarkable difference among family, site and interaction by variance analysis. There were a remarkable correlation of traits among different age, and the effects could make for early-age selection or growing prediction. 20 of 30 families in 3-site trial or 5 of 15 in single trial exceed mean SV and the proportion was 66.67% or 33.33%, respectively; 9 of 16 implanting families in 3-site or 4 of 7 implanting families exceed mean SV and the proportion was 56.25% or 57.14%, respectively. The growing taxis had an obvious difference between 2 treats of families in 4 field trails and it indicated that implanting could improve growth to make for MET or ET selection.(4)According to the effect of adaptability and stability analysis of families in 3-site trial, 30 families could be classified into 4 groups that had been named high-yeild and stable-growing group including of 12 families, high-yeild and unstable-growing group including of 6 families, low-yeild and stable-growing group including of 8 families, low-yeild and unstable-growing group including of 12 families. High-yeild and stable-growing group was fit for excellent-family selection and generalization. The effect of 8 traits-selection in 4 sites indicated that there was a remarkable correlation among traits except St, and the remarkable correlation effect of traits had supplied a method for multi-traits and less-quota selection to find target families; Growing-trait impact was stronger than that of form-quality traits by genetic factors, and the former was fitter for MET selection than the latter. Family heritability or genetic gain in 3-site trial was 0.0977⁰.7739 or 1.31%¹8.05%; family heritability or genetic gain in single site trial was 0.2732⁰.9028 or 23.16%⁵7.40%; family heritability was higher than single-tree heritability in the same site, and the effect indicated that family selection were better than single-tree selection, and had a more higher genetic gain and utility worthiness.(5)There were 10 families of 2 populations had been analyzed by microsatellite (SSR) markers. The effect indicated that there were 245 alleles (Na) to be detected in 17 loci and 10²0 Na in one locus by primer amplification reaction, and there were mean 14.41 Na and 7.68 Ne, too. 94 of 245 alleles (38.37%) appeared in 1³ families with lower frequencies. Some rare alleles in 2 populations were revealed by SSR. 54 Na were difference between implanting and no-implanting population including 18 in implantings'and 36 in no-implantings'by SSR markers. The different treat in same family which had different alleles could affect the increase, decrease or mutation of alleles, so we think that implanting is the cause of alteration or mutation; The correlation analysis between loci and traits indicated that there were a few QTLs in 17 loci including 1 to controlε, 3 to control WUE and 4 to control growing traits. Only one locus in all loci was peculiar to control Ba% which can be found by the correlation analysis after added the implanting data into the no-implanting data, so it indicated that the QTLs were the effect of mutation by implanting.(6) By trait value of taxis of coordinate assessment at 4 trial sites, there were 43 MET or ET to conform to MCV standard. The selected MET or ET of seedling-age trial in 2005 were 14 or 6 trees, and the selected rate were 4.375% or 2.0%, respectively; The MET or ET of seedling-age trial in 2006 were 21 or 2 trees, and the selected rate were 17.50% or 6.67%, respectively; MET or ET of field trial in 2005 and 2006 had 89 trees, and the selected rate was 2.285%; MET of all 4 site trial including Shiwan, Gonghe, Fengan, Luokeng were 11, 9, 7, 12 trees, and selected rate were 1.83%, 1.41%, 1.17% and 4.90%, respectively.(7)2 MET seedlings or 7 MET trees had been selected during seedlings or field trial by allied method of SSR markers and the taxis of coordinate assessment, and it indicated that MET owned excellent genes to control growing traits. The selected MET could be used to gene mapping, gene clone, the sequencing of the aim gene by SSR markers, and be used to multi-generation breeding and clone afforestation in production and popularization, too.