Dissertation > Excellent graduate degree dissertation topics show

The Effects of Allelochemicals of Chinese-fir Leaf Litter Treated by Different Nitrogen Sources on Chinese-fir Seed in Different Decomposition Stages

Author: YouFenLei
Tutor: CaoGuangQiu
School: Fujian Agriculture and Forestry University
Course: Forestry
Keywords: Chinese fir Litter Allelochemicals Allelopathic effect Ammonia nitrogen Nitrate
CLC: S791.27
Type: Master's thesis
Year: 2010
Downloads: 61
Quote: 0
Read: Download Dissertation

Abstract

Fir southern China, the most important one of the fast - growing timber species, the fir plantation area and volume are the first place in the national timber species in the proportion and order of precedence. The long-standing practice of forestry production fir plantation planted even lead to soil fertility decline, serious impact on the sustainable management of Chinese fir plantation and fir fast growing forest base construction. Many research results show that The fir autotoxicity is fir forest soil fertility decline, an important cause of the decline in productivity. By analyzing the different nitrogen sources and different nitrogen levels under conditions lanceolata litter decomposing phase polarity and weakly polar allelochemicals of Chinese fir seed germination effect. Experimental results show that: ammonia nitrogen treatment conditions fir litter decomposing stage the weakly polar allelochemicals fir seed germination different allelopathic effect. Stronger inhibitory effect on the from nitrogen levels deal with the differences of view, three months after decomposing of NH4Cl 50g deal with dead branches of fir deciduous weakly polar allelochemicals of Chinese fir seed germination of each index NH4Cl 100g processing; decomposed six months and nine months later, NH4Cl 50g deal with dead branches of fir deciduous weakly polar allelochemicals on fir seed radicle length, hypocotyl length, fresh weight and dry weight substances stronger inhibitory effect on NH4Cl 100g processing, and showed absolute germination percentage and absolute germination potential role in promoting stronger than NR4Cl 100g processing. Allelopathic the difference between the concentration of the substance in terms of overall performance, fir seed germination inhibition gradually increased with elevated concentrations of allelochemicals. Ammonia nitrogen treatment conditions fir litter the decomposing stage Polarity Allelochemicals fir seed germination have different effects. After 3 months from decomposing nitrogen level processing differences of NH4Cl 100g processed fir litter polarity allelochemicals of Chinese fir seed germination inhibition of each indicator strong in NH4Cl 50g processing; decomposing 6 stronger inhibitory effect after months of NH4Cl 50 g of processed fir litter polarity allelochemicals of Chinese fir seed absolute germination potential, radicle length, fresh weight and dry matter weight substances handled in NH4Cl 100g, absolute germination rate and embryo the shaft length handle in NH4Cl 100g, the strong role; decomposing nine months, NH4Cl 50g processing fir litter polar allelochemicals fir seed to bud indicators stronger inhibitory effect on NH4Cl 100g processing. Allelopathic the difference between the concentration of the substance in terms of overall performance, fir seed germination inhibition gradually increased with elevated concentrations of allelochemicals. Nitrate treatment conditions fir litter decomposing stage weakly polar allelopathic substances on fir seed germination different allelopathic effect. Differences from the nitrate level processing decomposing after 3 months, NaNO3 50g processing of fir litter weakly polar allelochemicals of Chinese fir seed absolute germination potential and strong inhibition of hypocotyl length handle in NaNO3 100g, fir the absolute seed germination rate, radicle length, the quality of the fresh material and dry biomass role in promoting strong in NaNO3 100g, processing; the decomposing of 6 months and 9 months, NaNO350g processing of fir litter weakly polar allelochemicals on fir germination indicators promote stronger NaNO3 100g processing. Allelopathic in terms of the difference between the concentration of the substance, the nitrate treatment conditions fir litter decomposing stages weakly polar allelochemicals of Chinese fir seed germination overall performance with elevated concentrations of allelochemicals its fir seed germination inhibition gradually increased. Nitrate processing conditions under fir litter the decomposing stage Polarity Allelochemicals fir seed germination have different effects. Stronger than decomposing 3 months from the nitrate level processing differences, NaNO3 50g processing fir litter polar allelochemicals of Chinese fir seed hypocotyl length, fresh matter weight and dry weight of inhibition NaNO3 100g treatment on fir the absolute seed germination rate, absolute germination potential and the radicle length role in promoting stronger than NaNO3 100g processing; 6 months and 9 months after decomposing 50g processing of NaNO3 fir litter polarity the allelochemicals on fir seed fresh weight and dry weight substances stronger inhibitory effect in NaNO3 100g, processing, absolute germination potential of the fir the absolute seed germination rate, radicle length and hypocotyl length promote stronger NaNO3 100g. processing. Allelopathic differences between the concentration of the substance, nitrate processing conditions under fir litter the decomposing phase polarity of allelochemicals on fir seed germination overall performance for as allelochemicals concentration increased its fir seed germination inhibition gradually increased.

Related Dissertations

CLC: > Agricultural Sciences > Forestry > Forest tree species > Coniferous > Chinese fir
© 2012 www.DissertationTopic.Net Mobile