【作者】 乔海涛；

【导师】 杨洪强；

【作者基本信息】 山东农业大学 ， 果树学， 2009， 硕士

【摘要】 本文以苹果砧木幼苗为试材,采用水培、砂培以及盆栽试验与果园调查相结合的方式,研究了苹果根系构型以及非生物胁迫、土壤类型、施肥、生物等因素对砧木根构型及根区土壤生物学特性的影响,结果如下:1、PEG胁迫下,新疆野苹果幼苗的根系总长度、侧根长度、平均直径、表面积、体积和脯氨酸的积累量高于平邑甜茶,MDA含量反之。随着PEG浓度的升高,根系的分形维数和幼苗细根比例减少。2、氯化钠胁迫下,随着浓度的增加,根系分形维数、细根比例、根系总长度、主侧根长度、平均直径、表面积、体积减小。3、缺氮或缺铁处理后,幼苗细根比例增大,根系直径变小,一级侧根与主根的夹角整体上增大,大夹角植株数量普遍增多,根系趋向于水平分布;根系分形维数降低,缺铁比缺氮时根系分形维数下降更多。4、10-20 mg?L-1的氯化镉使根系分形维数、侧根长度、根系表面积、根系体积、根系直径以及细根所占比例均显著降低,降低程度随着氯化镉浓度的升高而增大;根系脯氨酸、丙二醛含量和粗根所占比例也随着氯化镉处理浓度的增加而显著增加。5、蚯蚓处理使果园土壤微生物种类和数量明显增多,酶活性增加。微生物群落组成因土壤质地类型而不同,壤土中微生物的群落组成最丰富,其次是沙土,最后是粘土。6、“壤土+羊粪+蚯蚓”处理明显提高土壤酶活性,促进根系发育,根区细菌群落约有10种优势菌群,对DGGE图谱5条优势主带进行测序,其中2个序列与Genebank中已登录的细菌种群的同源性为100%,属于一个种,其他三个序列的同源性分别为95%、92%和89%。7、根区土壤微生物DGGE图谱中有7个优势条带,其中4个序列与Genebank中已登录细菌种群的同源性为100%,1个序列的同源性为98%,另外两个序列的同源性分别为93%和91%。土壤酶活性变化具有季节性并与施肥有一定联系,大量施用有机肥,能够明显提高酶活性,增加根区土壤微生物多样性。更多还原

【Abstract】 The root architecture of apple stock, and the effect of abiotic stress, soil types, fertilization and organism on root architecture and biological characteristics of rhizosphere with seedling and perennial apple stock taken as materials have been studied in this article, by using the combined methods of water-culture, sand-culture, soil-culture in pot and orchard experiments. The results are as the follows:1. The total length, lateral root length, avgdiamten, surface area and volume, Proline content of the drought-resistant young seedlings of Malus sieversii (Ledeb.)Roem. were higher than the drought-sensitive young seedlings of Malus hupehensis Rehd., but lower MDA content. The proportion of fine root and the value of fractal dimension decreased with the enhancement of PEG concentration.2. The value of FD, proportion of fine root, total length, taproot and lateral root length, avgdiamten, surface area and volume of roots were decreased in all treatments with the enhancement of salt stress intensity.3. The proportion of fine root increased significantly, the root diameter and the fractal dimension decreased significantly, the angle between main root and first lateral root enlarged, and root tends to horizontal distribution under nitrogen-deficient or iron-deficient condition. The root fractal dimension in iron-deficient condition is less than that in nitrogen-deficient.4. 10-20 mg?L-1 cadmium chloride decreased significantly the Fractal dimension (FD) of roots, taproot length, surface area, volume and diameter of roots and the proportion of fine roots. The degree of decrease rose with the increasing of CdCl2 concentration and presented dosage relation. The content of proline and MDA in root and the proportion of thick root all increased significantly with the increasing of CdCl2 concentration.5. The modified orchards, raised the activity of enzyme, with the types and quantities of microorganisms raised. But the types of soil texture affected the composition of microbial communities, Loam were highest to the composition of microbial communities, secand was sand, third was clay.6. Loam+Sheep excrement+earthworms were beneficial to enzyme activities and root development, there were about 10 kinds of dominant microorganisms in rhizosphere, five dominant 16S rDNA DGGE bands a, b, c, d and e were sequenced. Bands a and b had DNA sequence with similarity rate of 100% to that of GenBank accession nos., which belong to one species. Bands c, d and e had DNA sequence with similarity rate of 95%, 92% and 89% to that of GenBank accession nos.. oot activity in soil.7. By analysis of the community dynamic directly obtained from the DGGE profiles, seven dominant 16S rDNA DGGE bands a, b, c, d, e, f and g were isolated and sequenced. a, b, e and f had DNA sequence with similarity rate of 100% to that of GenBank accession nos., band d had DNA sequence with 98% similarity rate to that of GenBank accession no. Band c and g had DNA sequence with similarity rate of 93% and 91% to that of GenBank accession nos.. The change of enzyme had seasonal and contacted with application system, a large number of organic manure, could significantly increase the enzyme activities and the diversity of rhizosphere microorganisms.更多还原