小麦残茬对连作西瓜生长及根际土壤微生物的影响

发布时间：2018-01-23 21:10

本文关键词： 小麦西瓜生长超显微结构西瓜枯萎病根际微生物芽孢杆菌　出处：《东北农业大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着农业产业结构的调整,设施蔬菜已逐渐形成规模化和专业化生产,由于耕地面积的限制和经济利益的驱使,设施内蔬菜种植出现连续复种,指数在不断提高,种植品种比较单一,随之而来的设施蔬菜连作障碍的产生,连作常导致蔬菜作物产生病虫害,植株提早老化,产量也降低,品质也显现降低趋势。西瓜是设施园艺的主栽种类之一,连作障碍问题严重制约着西瓜产业的可持续发展。目前,为了解决西瓜连作障碍,尤其是西瓜连作导致的西瓜枯萎病害,人们不断对其产生机理进行探索研究,这一问题已被列为当代农业生产中急需解决的课题。有研究表明麦类作物与瓜类作物伴生,或利用小麦残茬能够有效的缓解瓜类连作障碍。本试验研究了两种小麦残茬对连作西瓜形态学指标、生理指标以及根尖内部超显微结构的影响,应用稀释平板法来测定本试验中处理植株根际土壤微生物数量的变化,并通过Real-time PCR对西瓜根际土壤中功能微生物芽孢杆菌和西瓜专化型尖孢镰刀菌的数量进行分析。结果表明： 1、D123和D125处理对西瓜植株的株高、茎粗和鲜重均有一定的促进作用,但D125处理在定植第40d时西瓜植株株高显著高于对照；在定植第30d、40d时D125处理的鲜重显著高于对照。在西瓜定植第20d时,处理植株的根系活力低于对照,其中D125处理与对照差异显著；在定植30d时,两个处理组植株的根系活力高于对照,但差异基本不显著。从试验植株根尖的超显微结构可以看出,D125处理细胞生命特征强于对照和D123处理,且D125处理的西瓜植株根系总长度和总体积显著高于对照。 2、不同品种小麦残茬处理后的西瓜植株发病情况不同,D123处理的发病率和病情指数高于D125处理和对照,而D125处理的西瓜枯萎病发病率和病情指数表现出均低于对照。 3、施入小麦残茬后,随着西瓜植株的生长,土壤pH呈增加趋势；D125处理土壤的EC值随着植株生长呈现上升趋势,D123处理土壤的EC值变化趋势与D125相反。 4、随着西瓜植株的生长,两个处理和对照根际土壤中真菌、细菌和尖孢镰刀菌的数量呈现上升趋势,且各时期处理的测定值均也高于对照,定植30d时处理和对照间差异已经达到显著水平。 5、随着西瓜植株不断的生长,处理组根际土壤中芽孢杆菌的数量均高于对照,在定植30d时达到显著差异;随着植株的生长,处理和对照根际土壤中西瓜专化型尖孢镰刀菌的数量均呈现增长趋势,但各时期处理的病原菌的数量均低于对照,且在定值后第40d时达到显著差异。
[Abstract]:Along with the adjustment of agricultural industrial structure, the facility vegetable has gradually formed the large-scale and specialized production, because of the cultivated land area limit and the economic benefit drive, the facility vegetable planting appears the continuous multiple cropping. The index is increasing, the planting variety is relatively single, followed by the establishment of continuous vegetable cropping obstacles, continuous cropping often lead to vegetable crops to produce pests and diseases, early aging plants, yield is also reduced. Watermelon is one of the main planting species in protected horticulture, and the problem of continuous cropping seriously restricts the sustainable development of watermelon industry. At present, in order to solve the problem of watermelon continuous cropping obstacles. In particular, watermelon wilt caused by continuous cropping, people continue to explore the mechanism of its production. This problem has been listed as an urgent problem in contemporary agricultural production. Some studies have shown that wheat crops can be associated with melon crops or wheat residues can effectively alleviate the obstacles of continuous cropping of melons. The effects of two wheat residues on the morphological and physiological indexes of continuous cropping watermelon and the ultramicrostructure of root tip were studied in this experiment. Dilution plate method was used to determine the changes of microbes in rhizosphere soil treated in this experiment. The number of functional microorganism Bacillus and watermelon specific Fusarium oxysporum in rhizosphere soil of watermelon were analyzed by Real-time PCR. The results showed that: 1the plant height, stem diameter and fresh weight of watermelon were promoted by D123 and D125 treatments, but the plant height of D125 treatment was significantly higher than that of the control at the 40th day of planting. The fresh weight of D125 treatment was significantly higher than that of the control on the 30th day of planting, and the root activity of the treatment was lower than that of the control at the 20th day of planting, and the difference between the D125 treatment and the control was significant. The root activity of the two treatment groups was higher than that of the control at 30 days, but the difference was not significant. The ultrastructure of the root tip of the experimental plant could be seen. The cell life characteristics of D125 treatment were stronger than those of control and D123 treatments, and the total root length and volume of D125 treatment were significantly higher than that of control. 2. The incidence and disease index of watermelon treated with different wheat residues were higher than that of D125 and control. The incidence and disease index of watermelon wilt treated with D 125 were lower than that of control. (3) with the growth of watermelon plants, soil pH increased with the application of wheat stubble. The EC value of soil treated with D125 increased with the growth of plant. The change trend of EC value of soil treated with D123 was opposite to that of D125. 4. With the growth of watermelon plants, the number of fungi, bacteria and Fusarium oxysporum in rhizosphere soil of two treatments and control showed an increasing trend, and the measured values of each treatment were also higher than that of the control. The difference between treatment and control reached significant level at 30 days after colonization. 5. With the continuous growth of watermelon plants, the number of Bacillus in rhizosphere soil of the treatment group was higher than that of the control group, and reached a significant difference at 30 days after planting. With the plant growth, the number of watermelon specific Fusarium oxysporum in the rhizosphere soil of treatment and control showed an increasing trend, but the number of pathogens treated in each stage was lower than that of the control. The difference was significant at 40 days after the value was fixed.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：S512.1;S651

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