不同施氮水平下丛枝菌根真菌对藜麦生长和根系生理特征的影响

Growth and Physiological Characteristics of Quinoa Inoculated with Arbuscular Mycorrhizal Fungi under Different Nitrogen Levels

采用盆栽实验,以藜麦品种‘亿隆1号’为实验材料,探究在不同施氮量(纯氮用分别为0、0.2、0.4和0.6g/kg)接种2种丛枝菌根真菌(AM)即摩西球囊霉(Gm)和扭形球囊霉(Gt)对藜麦及其根系生长指标以及生理指标的影响,为提高氮肥利用率提供理论依据。结果表明:(1)在0.4g/kg施氮量下,接种Gm藜麦根系侵染率和菌根依赖性最大。(2)同一接种处理下,藜麦株高、基径、叶面积、地上部生物量、总根长等根系生长指标,以及根系抗氧化酶活性均随施氮量的增加呈先增加后减小的趋势;与未接种处理相比,接种AM真菌后上述各指标均显著增加,均在0.4g/kg施氮量下达到最大值,且接种Gm的增幅大于接种Gt。(3)同一接种处理下,藜麦根系MDA含量、可溶性糖含量和脯氨酸含量随施氮量的增加均呈先减小后增加的趋势;与未接种处理相比,接种AM真菌后藜麦根系MDA含量显著减小,而其根系可溶性糖含量和脯氨酸含量增加,且接种Gm根系MDA含量降幅以及可溶性糖含量和脯氨酸含量的增幅显著大于接种Gt。研究表明,适量施氮可显著增加藜麦根系摩西球囊霉和扭形球囊霉的侵染率及其菌根依赖性指数,促进藜麦地上部及根系的生长,同时增加其根系抗氧化酶活性和渗透调节物质的积累,减少了体内有害物质的积累,并以摩西球囊霉配合施氮0.4g/kg效果最佳。

The seeds of quinoa variety ＂Yilong No.1＂ were used as experimental material in pot in 2016.We studied the effects of inoculating two kinds of arbuscular mycorrhizal fungi （AM） including Glomus mosseae （Gm） and Glomus tortuosum （Gt） on the quinoa growth,root growth indicators and root physiological indicators under the different nitrogen application rates of 0,0.2,0.4 and 0.6 g/kg,to provide the theoretical basis for increasing the utilization rate of nitrogen fertilizer and improve the growth of quinoa.The main results showed that： （1） inoculation of Glomus mosseae had the highest infection rate and mycorrhizal dependency of quinoa under 0.4 g/kg nitrogen application rate.（2） Under the same inoculated treatment,plant height,stem diameter,leaf area,aboveground weight,total root length and other root growth indicators,antioxidant enzyme activities of root system of quinoa seeds were initially increased and then decreased with the increasing nitrogen application rate;compared with the uninoculated treatment,the above indicators were significantly improved after AM fungi was inoculated.The values reached the maximum in the 0.4 g/kg nitrogen application rate,and the increase of Gm was greater than that of Gt.（3） Under the same inoculated treatment,MDA content,soluble sugar content and proline content were initially decreased and then increased with the increasing nitrogen application rate;compared with the uninoculated treatment,the MDA content was significantly reduced after AM fungi was inoculated,soluble sugar content and proline content were significantly increased after AM fungi was inoculated.Meanwhile,after inoculating Gm the decrease of MDA content,the increase of soluble sugar content and proline content were greater than that of incoculating Gt.These results showed that the infection rate and mycorrhizal dependency in root of quinoa with the proper nitrogen application rate increasing,the growth of aboveground and root of quinoa were promoted,meanwhile,increased the accumulation of antioxidant enzymes and osmotic adjustment substances,decreased the accumulation of harmful substances,especially 0.4 g/kg nitrogen application rate and Glomus mosseae were favorable for quinoa seeds to increase growth.