| Bamboo (Phyllostachys heterocycla cv.Pubescens) and Chinese fir (Cunninghamia Lanceolata) are important tree species in south China, They are widely distributed in large area of China, both bamboo and Chinese fir are more important in ecological systems and the national economy. Toughness of bamboo material is well, and bamboo uses widely. Chinese fir material is good too, and it is fast growing.However,it is extremely detrimental to the forest productivity under the business model of pure forest of bamboo or the pure forest of Chinese fir, particularly, there is a phenomenon of cytotoxicity with Chinese fir. It made a great challenge to sustainable management of forest. The mixed woodland is an effective way to solve decline in productivity, and to achieve sustainable business.However, it is especially important to choose the associated species to make mixed forests,In addition to considering the biological characteristics of other species, the relationship between the chemical ecology have been taking into account,the later named allelopathy.Allelopathy refers to the plants make effects on the surrounding plants in a direct or indirect way. through the release of chemicals into the environment.By studying the effects of bamboo on germination of seeds and growth of seedlings of Chinese fir,the paper provide theoretical guidance for bamboo and Chinese fir mixed forests.This study includes:Effects of bamboo organs and rhizosphere soil water extracts on Chinese fir seed germination process, seedling length, protective enzyme system,contents of endogenous hormones,and the initial mass spectrometry analysis of the composition of water extracts. conclusions of the study are as follows:1. The effects is differ on Chinese fir seed germination of various organs and rhizosphere soil water extracts of bamboo.Generally speaking,Fresh leaves,branches,stems and rhizosphere soils water extracts of bamboo showed benign anxo-actions in Chinese fir seed germination process,meanwhile, dried leaves, deciduous, rhizome and root water extracts showed obvious inhibiting effect.For each treatment, apart from bamboo rhizome water extracts,the higher concentrations inhibit the growth of the Chinese fir seedlings,the lower concentrations are expressed as catalytic role. Rhizosphere soil extracts promote seed germination of various concentration, and the results are obvious.Except for fresh leaves, most water extracts of every concentratians can promote seed germination potential,but most of the water extracts showed inhibitory in the early germination,and some proved promote seed germination in the later germination,while the others showed inhibitory.2. Different effects of various organs and rhizosphere soils water extracts of bamboo on the growth of Chinese fir seedlings. Deciduous and rhizosphere soils water extracts generally expressed as catalytic role to radicle elongation , rhizosphere soils play the most significant role in promoting. Other treatment liquid is manifested in inhibition, and root and fresh leaves of bamboo showed significantly inhibited.Compare to radicle, the effects on hypocotyl is not obvious.Deciduous and rhizosphere soils water extracts showed a significant role in promoting,and bamboo rhizome water extracts inhibited significantly.Root and deciduous of bamboo water extracts showed significant effect on inhibiting the growth of cotyledons, stems and rhizome of bamboo water extracts role in promoting greater play the most significant role in promoting the growth of cotyledons. Fresh leaves and branches of bamboo water extracts promote an increase in fresh weight of Chinese fir seedlings, but the rhizome and root of bamboo water extracts promoted significant reduction of Chinese fir seedlings.3. The impact differ on protective enzymes systems of Chinese fir seedlings by each water extracts of bamboo.Fresh leaves, stems water extracts can reduce the contents of malondialdehyde(MDA) in cell, Fresh leaves showed significantly reduction, indicating that it can protect the integrity of cell membrane.Other water extracts of bamboo promoted the accumulation of malondialdehyde, especially with the effect of dried leaves and rhizome of bamboo water extracts,the contents of malondialdehyde increased by 50% or more,indicates serious injury to cell membrane. Most of the water extracts of bamboo enhanced superoxide dismutase (SOD) activity and catalase (CAT) activity.Fresh leaves and root of bamboo water extracts increased SOD activity significantly, Under the effects of fresh leaves, stems, and rhizome soils water extracts,the CAT activity was enhanced significantly in Chinese fir seedlings. Fresh leaves,dried leaves and deciduous of bamboo water extracts reduce the Peroxidase(POD) activity of Chinese fir seedlings, meanwhile,the branches,stems,rhizome,root,rhizosphere soils water extracts enhanced POD activity in the cells of Chinese fir seedlings,and the branches and stems of bamboo water extracts shows significantly enhancement, as much as 50% or more. Within each treatment,the malondialdehyde contents increase with the concontration of the water extracts, the POD activity and CAT activity showed a similar law,and the SOD activity changed within a relatively small range.4. Besides the rhizosphere soils water extracts,all of other water extracts lower the contents of endogenous hormones,such as auxin(IAA) and gibberellins(GA3), to the contents of abscisic acid(ABA) ,and vice the versa.The content of endogenous hormone of Chinese fir seedlings was detected with High Performance Liquid Chromatography (HPLC), the results show that :Besides the rhizosphere soils water extracts,all of other water extracts lower the contents of endogenous hormones,such as auxin(IAA) and gibberellins(GA3), the higher the concentration, the greater the decline.With the effects of fresh leaves,branches and rhizome of bamboo water extracts,the GA3 contents in the cells of Chinese fir seedlings is less than half the control values. Fresh leaves and dried leaves of bamboo water extracts on the IAA contents is significantly affected.With the effects of rhizosphere soils water extracts,the IAA contents and GA3 contents in the cells of Chinese fir seedlings increased significantly,which will promote seed germination and the growth of the Chinese fir seedlings,rhizome and rhizosphere soils water extracts reduced the contents of ABA,especially with effects of the rhizosphere soils water extracts, the ABA contents in the cells of of Chinese fir seedlings reached the lowest value.and the ABA contents is higher with the effects of dried leaves and branches of bamboo water extracts.5. Variety of ingredients are detected in each kind of water extracts of bamboo,some of these ingredients appeared in a variety of water extracts of bamboo.Variety of ingredients were detected in each kind of water extracts of bamboo by CE-MS,some of these ingredients were detected in each water extracts of bamboo,for example, the substance with molecular weight be equal to235.0,279.2,332.8 and 219.0 were detected in each water extracts of bamboo.Except for branches,a unique element was detected in others. Some of the ingredients were detected in several treatments with unequal times. |
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