西瓜连作障碍中自毒作用的研究

发布时间：2018-05-09 19:38

本文选题：西瓜 + 化感作用　；参考：《浙江大学》2004年硕士论文

【摘要】： 目前，随着西瓜生产的产业化、规模化发展，西瓜连作障碍问题日趋严重。许多研究证实自毒作用是导致作物产生连作障碍的主要原因之一。因此，开展西瓜自毒作用机理的研究为西瓜连作障碍问题解决提供十分重要的理论依据。本试验利用活性炭添加与否，研究了西瓜根系分泌物对自身的毒害效果，结果表明西瓜根系分泌物使同茬植株相对电导率增加、膜渗漏增加，根系中总酚含量升高；并降低了体内叶绿素含量，植株光合产物积累减少，最终导致植株根系生长发育不良，影响了西瓜果实的正常膨大。在研究西瓜重茬液对下茬西瓜幼苗生长及其生理生化特性的试验中，结果表明西瓜根系分泌物能改变西瓜幼苗根系中抗氧化酶系统的活性，导致幼苗根系中GPOD活性降低，积累过多的活性氧和MDA，根系发生膜脂过氧化，导致幼苗生物产量下降。重茬液中添加活性炭后，根系分泌物中一些有毒物质被吸附，缓解了西瓜重茬液的自毒作用，保证了西瓜幼苗的正常生长发育。试验研究表明西瓜重茬液含有对下茬西瓜生长具有自毒作用的根系分泌物。重茬液处理的西瓜幼苗根系中PAL活性较高，促进了酚类物质合成，毒害严重，导致西瓜幼苗生长发育受阻；而添加活性炭后，由于活性碳吸附了重茬液中的自毒物质，从而减弱了重茬液的自毒作用，西瓜幼苗根系中PAL活性保持在一个较低的水平，合成的酚类物质及其衍生物减少，降低了西瓜水培液中酚类物质的浓度，使得酚类物质毒害作用降低，幼苗生长受阻现象减轻。利用西瓜叶、茎、根进行浸提，研究了西瓜不同组织残茬浸提液的生物活性，结果表明西瓜残茬浸提液均具有生长抑制作用。浸提液的作用效果一般表现为低浓度不具有抑制作用，甚至具有促进作用，但随浓度的升高，抑制作用也随之增强。其中西瓜叶、茎浸提液较根浸提液的抑制作用更强，，西瓜残茬的自毒作用可能与不同组织有关。不同溶剂浸提残茬所得浸提液对种子萌发的影响不同，其中以水浸提的效果更为显著。利用同一组织浸提液进行西瓜种子生物活性检测表明水浸提液的自毒作用较95％乙醇浸提液的自毒作用强。通过生物活性检测试验验证了西瓜残茬的自毒作用存在。根茬水浸提液和乙醇浸提液的水溶性组分在高浓度时，显著地抑制种子萌发，而低浓度对种子萌发影响不大；而其酸性组分和碱性组分在此浓度范围内几乎不影响莴苣种子萌发数。各组分对莴苣胚根和胚轴生长的抑制作用也随浓度的增加而加强，而以水溶性组分抑制率增加最为显著。因此，根茬浸提液不同组分的抑制活性大小一般表现为水溶性组分酸性组分) 碱性组分。试验研究水培西瓜营养液残液及活性炭吸附的根系分泌物的生物活性，结果表明西瓜根系分泌物影响了葛芭种子萌发及其胚根或胚轴伸长，并且这种作用效果与浓度有关。西瓜根系分泌物在种植过程中积累，达到一定浓度后才会对西瓜产生自毒作用;随着不断的积累，抑制作用随之增强。不同方法收集的根系分泌物中酸性组分的抑制效果不同。从活性炭浸提出根系分泌物的酸性组分在高浓度具有显著抑制作用，而随浓度下降抑制作用也随之下降;而营养残液中根系分泌物的酸性组分在试验浓缩倍数范围内，其抑制作用效果几乎没有变化。不同方法收集的西瓜根系分泌物的碱性组分都不具有抑制作用或抑制作用较小。水溶性组分对葛芭种子萌发及其胚轴长和胚根长影响最为显著。西瓜根系分泌物的各组分抑制作用大小顺序:水溶性组分酸性组分碱性组分或表现为水溶性组分酸 J胜组分或碱性组分。
[Abstract]:At present, with the industrialization and large-scale development of watermelon production, the problem of watermelon continuous cropping obstacle is becoming more and more serious. Many studies have confirmed that the effect of self toxicity is one of the main causes of crop continuous cropping obstacles. Therefore, the research on the mechanism of self toxicity of watermelon provides a very important theoretical basis for solving the problem of watermelon continuous cropping obstacle. The effect of the root exudates on the root exudates of watermelon was studied. The results showed that the relative conductivity of the root exudates of watermelon increased, the membrane leakage increased, the total phenol content in the root increased, and the content of chlorophyll in the body was reduced, the accumulation of Photosynthate in the plant decreased, and the root growth of the plant eventually led to the growth and development of the plant root. The results showed that the root exudates of watermelon can change the activity of antioxidant enzyme system in the roots of watermelon seedlings, and lead to the decrease of GPOD activity in the root system of the seedlings and the excessive accumulation of active oxygen and MDA, roots. When the membrane lipid peroxidation occurred, the biological yield of the seedlings decreased. After adding activated carbon in the heavy stubble liquid, some toxic substances in the root exudates were adsorbed, which alleviated the self toxic effect of the watermelon recrop solution and ensured the normal growth and development of the watermelon seedlings. The experimental study showed that the watermelon recrop solution contained the self toxic effect on the growth of the next stubble watermelon. In root exudates, the activity of PAL was higher in the roots of watermelon seedlings treated with heavy stubble liquid, which promoted the synthesis of phenols and serious toxicity, resulting in the growth and development of watermelon seedlings. After adding activated carbon, the self toxic substances in the stubble liquid were adsorbed by active carbon, thus reducing the self toxicity of the heavy stubble liquid, and the activity of PAL in the root of watermelon seedlings was guaranteed. At a lower level, the synthesis of phenolic substances and their derivatives reduced the concentration of phenols in watermelon hydroponics, reducing the toxic effects of phenolic substances and reducing the resistance of the seedlings.
The biological activity of the extract of the different stubble of watermelon was studied with the extraction of the leaves, stems and roots of watermelon. The results showed that the leaching solution of the watermelon stubble had the inhibitory effect on growth. The effect of the leaching solution generally showed that the effect of the extract was not inhibited and even promoted, but the inhibition effect increased with the increase of concentration. The effect of Watermelon Leaf Extract is stronger than that of root leaching solution. The self toxic effect of watermelon residue may be related to different tissues. The effect of extraction solution on seed germination is different, and the effect of water extraction is more significant. The bioactivity of watermelon seed is detected by the same tissue extraction solution. The self toxic effect of the aqueous extract of clear water is stronger than that of the 95% ethanol extract. Through the biological activity test, the self toxic effect of the watermelon residue is verified. The water soluble components of the root stubble water extract and the ethanol extract significantly inhibit the seed germination, but the low concentration has little effect on the seed germination. The seed germination number of lettuce was hardly affected by the components and basic components in the concentration range. The inhibitory effects of each component on the growth of raduca raduca and the hypocotyl of lettuce were also increased with the increase of concentration, and the most significant increase in the water soluble fraction inhibition rate.
Therefore, the inhibition activity of different components of root extract is generally expressed as acidic components of water-soluble components.
Basic components.
The biological activity of root exudates adsorbed by water culture watermelon nutrient solution and activated carbon was studied.
The results showed that the root exudates affected the seed germination and radicle or hypocotyl elongation of the seeds.
The effect is related to concentration. The root exudates of watermelon will accumulate in the process of planting and reach a certain concentration.
Melon has its own toxic effect, and its inhibition is enhanced with increasing accumulation.
The inhibitory effect of acidic components in the secretions is different. The acidic components of root exudates are highly concentrated from activated carbon leaching.
The degree of inhibition decreased with the decrease of concentration, while the root system in nutrient residue decreased.
The acidic components of the secreted substances showed almost no change in the concentration range of the test.
The alkaline components of watermelon root exudates collected by the method had no inhibition or inhibition effect.
The effects of composition on seed germination, hypocotyl length and radicle length were the most significant.
The order of inhibition is: water-soluble components, acidic components, basic components or water soluble components.
J victory component or alkaline component.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2004
【分类号】：S651

【引证文献】