| Pins massoniana Lanb. is an important local species in region of subtropical zone of China as well as industrial material wood. Its area of woods and storage capacity occupied a remarkale proportion in those of southern commercial forest. Since 1980, the gentic improvement of Pinus massoniana has been listed in the national key scientific research projects. Through cooperating for many years, great progress was made in provenance selection, plus tree election, seed orchard establishment, progeny test and the research of quantitative and population genetics. While protection, studies and utilization of fine type of regional trees were not attached much importance. With natural mature forests and overmature forests cut in a large amount, high yield, high quality masson pine will disappear. More attention should be paid to research on fine red heartwood of Masson Pine, to provide valuable information for follow-up breeding.This study on distuibution and variation of the red heartwood in Pinus massoniana was made in the fine nature stands of fine provenance in Fujian Province. Based on comparison tree, 80 candidate trees were obtained. The relationship among different characters and main factors affecting red heartwood were discussed by means of mutli-character correlation analysis, regression analysis, path analysis, and principal component analysis. The quantitative approach and criteria of plus tree selection are laid down. These candidate trees belong to the phenotype, but it does not mean their genotype is fine. So in order to get genetics parameter and provide necessary information, we must go on genetic test. The main results and conclusions is presented as follows:1. Study on distribution of red heart wood in natural Masson Pine forest show that red heart wood is in normal distribution, the average red heart-wood ratio reaches 43%, coefficient of variation is 0.391, Masson pine with red heart ratio over 70% accounts for 7.82% of the wood.2. The survey of variation in red heart wood ratio between individual and within a single tree showed that red heart ratio rose with the increasing of DBH and growing ring. The maximum was 6 times more than the minimum. Even in the same growing ring and DBH group, the coefficient of variation is over 0.2. The result of paired-sample T test showed: the insignificant variance existing in direction and height within a single tree.3.In the fine natural stands of fine provenance, 80 candidate trees were obtained through 1-4 comparison, with the average tree height 23.9m, the average DBH 72.66cm, the average volume 3.93m3, the average red-heart ratio 71.01%. Protection, studies and utilization should be done in time to these resources.4. Selection method of masson pine plus tree is discussed. The results of analysis showed that comparison method with 3 as a suitable method, because the precision is thelargest. In this thesis, the criterion of 3-comparison trees selection method is made. 16 of 55 candidate trees are considered as plus tree according to the criterion. The criteria were as follows: the red-heart ratio over 75%, the heart-wood radius of the candidate trees should be 1.5 times the reference trees, DBH and volume is not smaller than dominant trees, each quality index should not smaller than 4, the total should be above the average of dominant trees.5.By means of analysis of stepwise regression, heartwood radius, sapwood radius, twig thick were considered as the main characters of selection. Quantitative approach and criteria of complex selection were discussed in this paper. Comprehensive grading criteria and minimal mark for selected trees were founded by character weight.6.The results of correlation analysis by the 333 trees investigated in plus tree election indicate that there were middle to strong correlativity among red heart-wood ratio and radial factor, middle correlativity among red heart-wood ratio and volume factor, weak correlativity among red heart-wood ratio and trunk or crown factor. Relatively heavy factors in the direct path an...
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