| Fine root is the major organ to absorb the water and nutrients and an important part of element cycle in Forest ecosystem. Furthermore, fine root has a complex branch system, and the morphological characteristic has an important influence to the function of fine root absorption and turnover. This research was selected 10 different tree species of magnoliaceae and lauraceae family, in Fengxin forest region, Jiangxi province. And the main research parts have morphological characteristics, nutrient characteristics analysis and the trnL kinship analysis of these tree species, the fine root characteristic database, exploring the relationship among the tree morphological structure, chemical composition, physiological and ecological function, exploring the relationship between the characteristics parameters and the genetic characteristics of the fine root.This research mainly from the following two aspects:(1) Molecular technique has become an important method in the research of plant roots which was high stability, less affected by environmental conditions and high information content. This study was selected 10 different tree species of magnoliaceae and lauraceae family, in Fengxin forest region, Jiangxi province. The 10 different tree species includes Liriodendron genus (L.chinense), Magnolia genus (M.denudate), Manglietia genus (M.insignis and M.chingii), Michelia genus (M.maudiae, M.chapensis and M.figo), Parakmeria genus (P.lotungensis), Cinnamomum genus (C. camphora), Sassafras genus (S.tzumu). After the fine root DNA extraction, we amplified and purified the plastid trnL(UAA) intron. Then, we sequenced the plastid trnL(UAA) intron spacer and analyzed these species sequences.The results show that the trnL gene sequence analysis is consistent with previous studies of other sequence analysis. It successfully distinguished magnoliaceae and lauraceae family. In magnoliaceae family, L.chinense and M.denudate effectively distinguished as single structure. But due to the short sequence fragment, less variation loci, less intergeneric resolution, Manglietia, Michelia and Parakmeria genus were not separated, and interspecific were less information.(2) Different levels of fine root have obvious differences in physiological function. The morphological structure and nutrient composition of fine root has important influence on the underground niche research to explore tree species characteristics and biogeochemical cycle. This study tracked mining method is used to collect the fine root of 10 tree species of subtropical magnoliaceae and lauraceae family. According to Pregitzer classification methods, using Win-RHIZO system analyzed fine root architecture parameters determination, the determination of all levels of fine root biomass and the content of C, N, and discussed the functional characteristics of the different tree species at all levels of fine root, revealed the relationship between the different tree species and the nutrient strategy.The results show that with the increase of root order,10 species of fine roots specific root length, specific surface area showed a trend of decrease, but the diameter and root tissue density showed a trend of increase. In addition to the individual tree species, the morphological parameters in the same species of different root order level and different tree species in the same order level have significant differences.By comparison, with the exception of lauraceae family plants density is greater than the magnoliaceae family plants. No difference was seen morphological parameters have other regularity in this two family plants.The C content of 10 species of fine roots increased as the root order increased, C /N ratio is increased with the root order increased, and fine root N content declined with the root order increased. |
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