【作者】 刘春娜；

【导师】 郭亚芬；

【作者基本信息】 东北林业大学 ， 土壤学， 2010， 硕士

【摘要】 落叶松(Larix gmelinii)是中国东北林区最重要的工业用材树种,而且在北温带森林中具有重要的生态学意义。落叶松的种植区域内气温低、冬季长,氮素矿化速度低,供氮不足常常成为落叶松生长的限制因素。本研究采用水培试验培养方法,设置有机态氮(甘氨酸、谷氨酸、赖氨酸)以及NH4+-N、NO3--N不同配比的氮素营养供给,对不同处理能够为落叶松幼苗提供的有机、矿质氮营养,落叶松幼苗的生长对氮素吸收、利用以及对落叶松幼苗根系和叶片中NR和GS氮同化酶活性等方面讲行了研究,结果表明：(1)生物量方面无机态氮不同配比处理,以NH4+/NO3-比值为4：0,3：1和1：1时落叶松幼苗总生物量较高；氨基酸态氮处理落叶松幼苗总生物量高于NH4+-N、缺氮处理；落叶松幼苗体内全氮含量大小顺序为：甘氨酸>谷氨酸>硫酸铵>赖氨酸>硝酸钙>缺氮处理；加入生物抑制剂氨基酸处理总生物量、全氮量与未加入生物抑制剂氨基酸处理之间不显著。(2)在植株生长方面氨基酸态氮对落叶松幼苗株高和根长的影响都显著高于硫酸铵、硝酸钙处理；加入生物抑制剂氨基酸处理的根长和植株总长度与未加入生物抑制剂的氨基酸处理之间差异不显著。(3)对N、P、K养分吸收方面无机态氮不同配比,在完全供应N03--N时,植株体内N浓度最低,其它四个处理植株体内N浓度均较高,随着NH4+-N比例的增加落叶松幼苗体内P的浓度增高,K的浓度下降；甘氨酸、谷氨酸能够显著促进植株吸收N、P、K养分,赖氨酸对促进植株吸收NP的影响与硫酸铵等效,对促进植株吸收K的影响与硝酸钙等效,均高于硫酸铵处理；无论是否加入生物抑制剂的氨基酸态氮处理落叶松幼苗体内的N、P、K浓度大小均为：甘氨酸>谷氨酸>赖氨酸,且加入生物抑制剂的氨基酸处理落叶松幼苗体内N、P、K浓度与未加入生物抑制剂的氨基酸处理之间不显著。(4)对矿质氮吸收浓度方面无机态氮不同配比,幼苗吸收NH4+-N的强度以NH4+/NO3-为4：0,3：1时较高,吸收N03--N的强度以NH4+/NO3-为1：3和0：4时较高；氨基酸态氮处理,在同一取样周期内,甘氨酸、谷氨酸态氮供应NH4+-N的能力最高,赖氨酸与硫酸铵供应NH4+-N的能力等效,缺氮处理对落叶松幼苗供应NH4+-N能力最低；对NO3--N的供应能力大小为：甘氨酸>谷氨酸>赖氨酸>硫酸铵>缺氮；在同一取样周期内加入生物抑制剂的氨基酸处理落叶松幼苗吸收NH4+-N、NO3--N浓度与未加入生物抑制剂氨基酸处理之间不显著。(5)对酶活性影响方面所有处理的落叶松幼苗根系NR活性高于叶片处理,氨基酸态氮处理的落叶松幼苗根系NR活性明显低于NH4+/NO3-为1：1,1：3和0：4处理,氨基酸态氮处理的幼苗叶片中NR活性低于对照外的其它所有处理；高浓度的NH4+-N(4：0,3：1和1：1)处理条件下GS活性高,三种形态的氨基酸态氮均能促进幼苗根系和叶片GS的活性提高,但甘氨酸使根系和叶片中GS活性分别提高22.5%和24.1%,赖氨酸使二者GS的活性提高18.6%和22.9%，而谷氨酸使根系和叶片中GS活性分别提高43.1%和48.3%,叶片中GS活性在各处理中均高于根系。本实验条件下可以得出：落叶松能够吸收有机氮源；在甘氨酸、谷氨酸的条件下生长状况好于在赖氨酸及硫酸铵状况下的生长,明显好于在硝态氮条件下的生长。更多还原

【Abstract】 Larix gmelinii is the most important industrial tree species in northeast China forest, which has very important ecological meanings in ecosystem. In Larch planted areas, owing to low temperature and long winter, low N mineralization rate, nitrogen deficiencies often becomes the limited factor. The effects of different nitrogen、NH4+/NO3- and their different supply ratios on the growth of Larix gmelinii seedlings were studied by water culture system. Research the supply organic、mineral nutrient for Larix gmelinii, the growth of Larix gmelinii, the absorption and utilization of nitrogen, and Larix gmelinii seedling roots and leaves of the nitrogen with the enzyme activity assay. The results show that:(1) In the accumulation of biomass, different supply ratios of mineral N, NH4+/NO3- 4:0, 3:1 and 1:1 with a higher total biomass of larch; amino acids treat total biomass was higher than NH4+-N and ck.; The total nitrogen content in Larix gmelinii show that:Gly>Glu> NH4+-N >Lys>NO3--N>ck, and amino acid treatment significant difference with NO3--N、ck. The total biomass of imputing inhibitor amino acid was higher than amino acid which not imputed inhibitor, and significant difference between the two. Total nitrogen content of imputing inhibitor amino acid significantly higher than amino acid which not imputed inhibitor.(2) In terms of plants’growth, effects on plant height and root length of amino acid were higher than NH4+-N and NO3--N; the root length and total length of imputing inhibitor amino acid were lower than amino acid which not imputed inhibitor, between each treatment had no significant difference except gly. But imputing inhibitor amino acid better than amino acid which not imputed inhibitor for height growth.(3) The absorption of N、P、K nutrient, different supply ratios of mineral N, when the supply of nitrate completely, Larix gmelinii seedling hold the lowest concentration of potassium,and other treatment plants at high nitrogen concentration, with the increase in the proportion of NH4+-N Larix gmelinii seedlings increased the concentration of P, K concentrations decreased; Glu can significantly promote the absorption of N、P、K nutrients, Lys uptake capacity for NP nutrient was equal to NH4+-N, Lys uptake capacity for K nutrient was equal to NO3--N, imputing inhibitor amino acid or not imputed in Larix gmelinii, N、P、K nutrient concentrations showed:Gly treatment was the highest, the lowest lys. The N、P、K nutrient concentrations in Larix gmelinii of imputing inhibitor amino acid were higher than amino acid which not imputed inhibitor,but had no significant difference.(4) The absorption of mineral N, different supply ratios of mineral N, NH4+/NO3- 4:0 and 3:1 with high intensity to absorb NH4+-N, and NH4+/NO3- 1:3 and 0:4 with high intensity to absorb NO3--N; amino nitrogen treatment, in the same sampling period, Glycine and Glu supply capacity of the highest NH4+-N, the supply capacity of Lysine was equal to ammonium, he supply capacity of ck was the lowest. Supply of NO3--N was showed:Gly>Glu>Lys> NH4+-N>ck; the absorption concentration of NH4+-N in imputing inhibitor amino acid was significantly higher than mino acid which not imputed inhibitor(except Lys), but they had no significant difference; imputing inhibitor amino acid or not imputed, supply of NO3--N was showed:Gly>Glu>Lys, and the NO3--N concentration in imputing inhibitor amino acid were higher than mino acid which not imputed inhibitor instead of Lys.(5) In terms of enzyme activity, NR activity in the leaves treated by all treatment was lower than which in the roots. NR activity in the leaves treated by Amino nitrogen was lower than NH4+/NO3- 1:1,1:3 and 0:4. NR activity in the leaves treated by Amino nitrogen was lower than all other treatment except control. Under high concentration of NH4+-N cultivation conditions showed a higher GS activity. Three forms of the amino nitrogen can also promote GS activity of root and leaf increased,however, GS activity in roots and leaves of Gly increased by 22.5% and 24.1% separately, of Lys increased by 18.6% and 22.9%, of Glu increased by 43.1% and 48.3%, GS activity in leaves of all treatment were higher than GS activity in roots.As can be seen from the above conclusions:Larix gmelinii can absorb organic nitrogen, and under the conditions of supply of amino nitrogen Larix gmelinii seedling growth is better than inorganic nitrogen supply.更多还原