南方农区短期栽培紫花苜蓿分枝生长特性和根系碳氮养分的研究

发布时间：2018-05-19 08:06

本文选题：紫花苜蓿 + 秋眠性　；参考：《南京农业大学》2016年博士论文

【摘要】：南方农区紫花苜蓿(Mecdicago sativa L.)与粮经作物复种的短期栽培模式已取得了很大的发展。由于是短期栽培,选育能在短时间内获得高产的速生品种显得尤为重要。但是,选育优良品种和集成高产栽培技术需要有在这种生态条件下对紫花苜蓿产量形成及其生理机制的研究基础来支撑。本文主要研究了在南方农区秋播和春播的短期栽培模式下,秋眠型、半秋眠型和非秋眠型紫花苜蓿地上部分枝(根颈分枝和茎分枝)的生长特性对产量的影响,以及根系碳源和氮源的积累对刈割后地上部再生能力的影响,以期为选育适合南方短期速生栽培的紫花苜蓿品种及其高产栽培技术提供理论依据。主要研究结果如下:在秋播翌年刈割三茬的短期栽培条件下,对不同秋眠类型紫花苜蓿产量和地上部分枝生长关系的研究结果表明:秋眠级高的品种无论是在第一茬、第二茬还是第三茬均能获得较高的单株产量。综合三茬的结果,随着秋眠级的升高,总的单株产量显著增加。紫花苜蓿的根颈分枝数和茎分枝数在不同秋眠级品种间差异不大,但根颈分枝单枝重和茎分枝单枝重均随着秋眠级的升高而显著增加。根颈分枝是决定紫花苜蓿春季第一茬单株产量的主要分枝类型;茎分枝的比重在第二、第三茬中大幅上升,并成为决定第三茬单株产量的主要分枝类型;综合三茬结果,根颈分枝仍是决定紫花苜蓿产量的主要分枝类型。分枝单枝重对紫花苜蓿单株产量的影响大于分枝数;根颈分枝单枝重是决定春季第一茬单株产量的主要因子;随着刈割次数的增加,茎分枝单枝重逐渐成为决定单株产量的主要因子。在春播仅刈割两茬的短期栽培条件下,对不同秋眠类型紫花苜蓿产量和地上部分枝生长关系的研究结果表明:第一茬,非秋眠型紫花苜蓿品种的干草产量显著高于秋眠型品种;第二茬品种间的干草产量无显著差异;综合两茬来看,秋眠级高的品种的干草产量依然存在优势。第一茬中,根颈分枝对产量的贡献率占绝对的主导地位,达到94.41%～96.01%;第二茬中,茎分枝的比重大幅上升至38.47%～44.45%,但仍未能成为决定第二茬产量的主要分枝类型;综合两茬结果,根颈分枝是决定紫花苜蓿产量的主要分枝类型。分枝单枝重对紫花苜蓿产量的影响大于每株分枝数,且根颈分枝单枝重是决定每一茬草产量的主要因子。在秋播短期栽培条件下,对不同秋眠类型紫花苜蓿地上部再生和根系养分关系的研究结果表明:第一、第二和第三茬刈后12 d的地上部再生量和再生速度均随着品种秋眠级的升高而显著增加。刈割后0、6和12 d的根系C源(可溶性糖、淀粉和总的非结构性碳水化合物)含量在品种间的变化规律不明显,N源(总氮和可溶性蛋白)含量随品种秋眠级的升高呈增加的趋势。刈割时营养贮藏蛋白(VSPs)的含量在品种间的差异不显著。而C源和N源总量则随着品种秋眠级的升高呈显著增加的趋势。各品种刈割后的0-12d内,其C源和N源的含量和总量均下降明显,养分消耗量随品种秋眠级的升高显著增加。刈割后12 d的地上部再生量与刈割时根系C源和N源的含量并未持续呈显著正相关,但与其总量和刈后12 d的养分消耗量均持续呈显著正相关。在春播短期栽培条件下,对不同秋眠类型紫花苜蓿地上部再生和根系养分关系的研究结果表明:第一茬刈后14d的地上部再生量和再生速度在品种间差异不显著,第二茬刈后14 d半秋眠型和非秋眠型品种的地上部再生量和再生速度高于秋眠型品种。刈割后0、7、14和21 d的根系C源含量在品种间的变化规律不明显,N源含量随品种秋眠级的升高呈增加的趋势。刈割时VSPs的含量在品种间的差异不显著。而C源和N源总量则随着品种秋眠级的升高呈显著增加的趋势。各品种刈割后的0-14d内,其C源和N源的含量和总量均下降明显,养分消耗量随品种秋眠级的升高呈显著增加的趋势;刈割后的14-21 d,其C源和N源的含量和总量开始上升。刈割后14 d的地上部再生量与刈割时根系C源含量的相关性不显著,与N源含量并未持续呈显著正相关,但与C源和N源的总量和刈后14天的养分消耗量均持续呈显著正相关。综上所述,紫花苜蓿在冬季温和的南方地区进行短期栽培利用时,选用非秋眠型品种有利于提高产量。根颈分枝是决定紫花苜蓿产量的主要分枝类型,且分枝单枝重对产量的影响大于分枝数。因此,在选育适合南方地区短期栽培利用的品种时,应重视根颈分枝的发生发育,且应以分枝重量作为首要选择标准。决定紫花苜蓿刈割后早期再生能力的是根系养分的总量而非含量,因此为提高紫花苜蓿地上部的再生量需扩大根系的库容。
[Abstract]:The short-term cultivation model of Mecdicago sativa L. in Southern agricultural region and the replanting of grain crops has made great progress. Because it is short term cultivation, it is very important to select and breed the fast-growing varieties with high yield in a short time. However, the selection of fine varieties and integrated high-yield cultivation techniques need to be purple under this ecological condition. In this paper, the effects of the growth characteristics of the branches of autumn dormant, semi dormant and non dormant Alfalfa on yield, as well as the product of root carbon and nitrogen sources, were studied in the short term cultivation mode of autumn sowing and spring sowing in the Southern agricultural region. In order to provide a theoretical basis for breeding alfalfa varieties and high yield cultivation techniques suitable for short-term and fast-growing cultivation in the south, the main results are as follows: under the short-term cultivation conditions of three stubble cropping in the next year of autumn sowing, the yield of alfalfa and the growth of some branches on the ground of different fall dormancy types are made. The results of the study showed that high fall dormant varieties were able to obtain higher yield per plant in the first, second or third stubble. As the result of the three stubble, the total yield of the single plant increased significantly with the rise of the fall dormancy grade. The branch single branch weight and the single branch weight of the stem branch increased significantly with the rise of the fall dormancy grade. The root neck branch was the main branch type determining the first crop yield of Alfalfa in the spring, and the proportion of the stem branches increased significantly in the second and third stubble, and became the main branch type determining the yield of the third single plant; the comprehensive three stubble results, the root neck. Branch is still the main branch that determines the yield of alfalfa. Branch single branch weight has greater influence on the yield of Alfalfa than the branch number; the single branch weight of root neck branch is the main factor determining the yield of the first crop in spring. Under the short-term cultivation conditions of cutting two stubble, the study on the relationship between the yield of alfalfa and the growth of the branches on the ground with different fall dormancy types showed that the first, the hay yield of the non dormant alfalfa varieties was significantly higher than that of the autumn dormancy type, and the hay yield between the second stubble varieties had no significant difference, and the fall dormant level was high in the two stubble. In the first crop, the contribution rate of the root neck branch to the yield was dominant, reaching 94.41% to 96.01%, and the proportion of the stem branches increased to 38.47% ~ 44.45% in the second stubble, but it still failed to be the main branch to determine the second crop yield; the root and neck branches were determined by the comprehensive two results. The main branch type of alfalfa yield. The effect of branch single branch weight on the yield of alfalfa was greater than the number of branches per plant, and the single branch weight of root neck was the main factor determining the yield of every stubble. In the short term cultivation of autumn sowing, the study on the relationship of root regeneration and root nutrient of Alfalfa with different fall dormancy types showed that: first The regeneration rate and regeneration rate of 12 d after second and third clipping were significantly increased with the increase of autumn dormancy. The content of C source (soluble sugar, starch and total unstructured carbohydrates) in root system of 0,6 and 12 d after mowing was not obvious, and the content of N source (total nitrogen and soluble protein) with autumn dormancy The content of VSPs was not significant when mowing, while the total amount of C source and N source increased with the increase of fall dormancy level. The content and total of C source and N source decreased obviously in 0-12d after mowing, and the nutrient consumption was increased with the fall dormancy grade of varieties. There was no significant positive correlation between the shoot regeneration of 12 d after mowing and the content of root C source and N source during mowing, but it had a significant positive correlation with the total amount and the 12 d nutrient consumption after mowing. The results showed that there was no significant difference in the regeneration rate and regeneration rate of 14d after the first clipping. The growth and regeneration rate of the 14 d and half fall dormant and non fall dormant types after the second clipping were higher than those of the autumn dormancy type. The C source content of the root of 0,7,14 and 21 d after mowing was not obvious, and the content of N source was with the content of the root. The increase of autumn dormancy level was increasing. The difference of VSPs content was not significant when mowing, but the total amount of C source and N source increased with the increase of fall dormancy level. The content and total of C source and N source decreased obviously in 0-14d after mowing, and the nutrient consumption was increased with the increase of autumn dormancy grade. The tendency to increase significantly; the content and total amount of C source and N source began to rise at 14-21 d after mowing. The correlation of the root regeneration of 14 d after mowing was not significantly correlated with the C source content of the mowing, and did not have a significant positive correlation with the content of N source, but the total amount of the source of C and the source of N and the nutrient consumption of the 14 days after mowing were in a significant positive phase. In summary, the selection of non fall dormant varieties is beneficial to the increase of yield when the alfalfa is used for short-term cultivation in the mild southern region in winter. The root neck branch is the main branch that determines the yield of alfalfa, and the effect of branching single branch weight on yield is greater than the number of branches. The occurrence and development of the root and neck branch should be paid attention to, and the branch weight should be taken as the primary choice. The total root nutrient content is not the content of the early regenerative capacity of alfalfa. Therefore, the capacity of root system should be expanded to increase the regeneration of alfalfa.
【学位授予单位】：南京农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S541.9

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