| A provenance-by-planting density-interaction trial of masson pine at age nine on mid-fertility field in Wuping of Fujian was used to investigate growth response pattern of five superior provenances to initial planting density. Results showed that the growth response to planting density varied largely with provenances tested. Chongyi of Jiangxi and Wuping of Fujian were both provenances with higher sensitivity to planting density, while Cenxi of Guangxi and Gaozhou of Guangdong were both provenances with less sensitivity to planting density, and the growth sensitivity of Xinyi of Guangdong to planting density was found to be moderate. Analysis indicated that three south provenances including Cenxi of Guangxi, Gaozhou and Xinyi of Guangdong were suitable for short rotation management under high planting density of 1.5m×2.0m with high growth increment of height, DBH and timber volume per area, and were also fit for low planting density of 2.0m×2.5m to cultivate big-diameter timber. Both provenances of Chongyi of Jiangxi and Wuping of Fujian exhibited well at moderate planting density of 2.0m×2.0m. Growth differentiation among provenances was found to be related to initial planting density and to be great under high or low planting density. Early selection of provenances seemed to have great efficiency under higher planting density. It was also showed that provenance×density interaction and block×provenance×density interaction were remarkable, thus different planting density were needed according to different soil and different provenances for optimizing the layout of superior provenances and planting density.A provenance-by-phosphorus-interaction trial of masson pine at infertile site with phosphorus deficiency located the west of Fujian at age 10 was used to investigate the growth response characteristic of superior provenances to fertilizer supply and persistence of phosphorus effect. Significant differences in growth response to phosphorous fertilizer among five provenances were detected, providing sufficient evidence that both Xinyi GD and Wuping FJ were excellent provenances with tolerance of low phosphorus, while Cenxi GX was sensitive to phosphorus in the early growth stage and less sensitive in later stage. For Gaozhou GD and Chongyi JX, phosphorus effect for height growth was marked in early stage, while phosphorus effect for DBH and volume was significant at age ten. Thus, appropriate scheme of fertilizer application ought to be arranged according to the growth responses differences to phosphorus between provenances. Phosphorous effect was found to be varied with provenances tested, but to be obvious and last for a long period for all the provenances. Compared to height growth, the influence of phosphorus to DBH was greater and more permanent. Result showed the effect of high phosphorus supply was greater than low supply, indicating that phosphorus supply was an effective method just as breeding in high-yield plantation establishment of masson pine. The experiment showed that provenance by phosphorus interaction was significant in early age and absent at later growth stage, implying that relative growth performance of provenances tested was not influenced by phosphorous supply. Though tree height differentiation among provenances was increased by phosphorous supply, the influence to differentiation of DBH was small. Further, individual growth heterogeneity within provenances were markedly reduced by phosphorous supply.The 15 P. massoniana tester strains were used to investigate illustrate inheritance and variation of phosphorus efficiency and its related traits between tester descendants. The results indicate that there exists great difference between tester descendants for phosphorus efficiency and the highest ones are five times as high as those of the lowest. It is P use efficiency, not P absorption efficiency in the great differences of P efficiency and dry matter accumulation. P efficiency is found to be closely related to seedling height, ground diameter and dry matter accumulation, which could be well used to appraise the P efficiency of families of P. massoniana. The results also show that some traits related to P efficiency are under moderately and strongly genetic control.The 15 Pinus massoniana tester strains were used to investigate the relative importance of GCA and SCA of seedling growth and root parameters, the mode of gene action and the effect of phosphorus level. Result showed that the seedling growth and root parameters of Pinus massoniana exhibited statistically significant difference between various phosphorus level and were strongly genetically controlled , with the full-sib family heritability being 0.745-0.920. Analysis showed that the seedling growth traits were controlled more by GCA and SCA of female parent than that of male. Under high phosphorus level, the Pinus massoniana seedlings were genetically controlled mainly by dominant gene effect and secondly by the additive gene effect especially root traits. Hybridization between superior parents selected from the South and the North could generate new hybrid varieties more developed roots and better growth performance. The total root length, root surface area and root volume were still genetically controlled by the dominant gene effect under low phosphorus level, but the mode of gene action on seedling height, diameter and lateral root number in low phosphorus level were changed to additive gene effect, which being the dominant gene effect under high phosphorus levels. Therefore, the selecting of new varieties with high phosphorus efficiency could be performed through the SCA breeding of specific indexes such as total root length, root surface area and root volume and so on .
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