草业学报2024，Vol.33Issue(3)：85-96,12.DOI:10.11686/cyxb2023143
连续间作下的紫花苜蓿/燕麦根系与碳氮代谢特性研究
Root and carbon-nitrogen metabolism characteristics of alfalfa-oat mixed stands under continuous intercropping
摘要
Abstract
This research investigated the root growth characteristics,carbon and nitrogen metabolism characteristics,and the long-term effects of their coupling mechanisms under continuous leguminous-gramineous forage intercropping.A field frame planting,soil culture experiment was conducted to study the root characteristics,carbon and nitrogen metabolism characteristics,and their mutual co-ordination of alfalfa(Medicago sativa)-oat(Avena sativa)intercropping for two consecutive years after planting.Alfalfa monoculture and oat monoculture crops were used as a reference.It was found that the biomass of intercropped oats was significantly higher than monoculture oats(P<0.05).The root surface area and root average diameter of intercropped oats were significantly higher than monoculture oats(P<0.05).The transpiration rate(Tr),net photosynthetic rate(Pn),stomatal conductance(Gs),ribulose-1,5-bisphosphate carboxylase(RuBPCase)activity,the activities of four nitrogen metabolism enzymes,and carbohydrate accumulation of intercropped oats were significantly higher than monoculture oats(P<0.05),while alfalfa showed an opposite trend.Correlation analysis found that the biomass was positively correlated with photosynthetic gas exchange parameters,nitrogen metabolism enzyme activities and root characteristics.Root surface area and root average diameter were significantly positively correlated with Tr,Pn,Gs,nitrate reductase(NR)activity,nitrogen accumulation,and total protein content(P<0.05).Root volume,root surface area,and root average diameter were highly significantly positively correlated with nitrate reductase activity and glutamate synthase activity(P<0.01).Thus,the intercropping of alfalfa and oat is more conducive to optimizing the root morphology of oat,while also significantly increasing the net photosynthetic rate and transpiration rate of oat,enhancing the activities of carbon and nitrogen metabolism enzymes such as RuBPCase,NR,and glutamine synthetase in oat,thereby promoting the accumulation of carbohydrate and protein to improve oat biomass and quality.Continuous intercropping weakened the inhibition of root surface area and root volume of alfalfa within the system,and expanded the total root length of alfalfa,but overall,intercropping inhibited root growth and carbon-nitrogen metabolism,which was not conducive to the accumulation of its metabolites and biomass.Moreover,total root length,root surface area,and root volume significantly promote carbon-nitrogen metabolism,the improvement of root system and carbon-nitrogen metabolism in the alfalfa/oat intercropping system effectively increased the biomass and total protein content in the system.关键词
紫花苜蓿/燕麦/连续间作/根系特性/碳氮代谢特性Key words
alfalfa/oat/continuous intercropping/root characteristics/carbon and nitrogen metabolism characteristics引用本文复制引用
汪雪,刘晓静,王静,吴勇,童长春..连续间作下的紫花苜蓿/燕麦根系与碳氮代谢特性研究[J].草业学报,2024,33(3):85-96,12.基金项目
国家自然科学基金项目(32171674)和甘肃省重点研发计划项目(20YF8NA130)资助. （32171674）
