丛枝菌根真菌对甘薯源库关系、养分吸收和产量的影响

Effects of arbuscular mycorrhizal fungi on source-sink relationship,nutrient uptake,and yield of sweet potato

丛枝菌根真菌(AMF)能与作物根系形成共生关系,甘薯(Ipomoea batatas L.)是一种适应性强、高产、多用途的粮食作物,对AMF的依赖性较强。为探究接种AMF对甘薯全生育期源库关系、养分吸收和收获期产量的影响,以徐薯28和与之能建立良好共生关系的幼套近明球囊霉为试验材料,设接菌和不接菌两个处理,将大田与盆栽试验相结合,利用盆栽试验分析接种AMF对甘薯全生育期的茎叶生长状况、块根膨大、植株生物量和根际效应的影响,利用大田试验验证AMF对甘薯收获期块根产量和商品性的影响。结果表明:接种AMF降低了分枝结薯期、旺长期和薯块膨大期的茎叶鲜重;显著提高了分枝结薯期、旺长期和薯块膨大期的根冠比;显著提高了分枝结薯期和薯块膨大期缓效钾的根际效应,显著提高了分枝结薯期和旺长期块根氮、磷、钾的积累量;显著增加了全生育期块根鲜重。相比不接菌根,收获期的单株产量在盆栽试验中增加了32.58%,大田试验中增加了23.05%。因此,接种AMF能促进根际土壤中的钾活化,促进养分吸收的同时,抑制养分和干物质向地上部分配,协调了源库发展,促进了块根形成与膨大,并提高产量。

Arbuscular mycorrhizal fungi(AMF)could form symbiotic relationships with crop roots.Sweet potato(Ipomoea batatas L.)was a highly adaptable,high-yielding,and versatile food crop,which was highly dependent on AMF.In order to explore the effects of AMF inoculation on the source-sink relationship,nutrient absorption,and yield of sweet potato during the whole growth period,this experiment took Xu 28 and Claroideoglomus etunicatum,which could establish a good symbiotic relationship,as experimental materials.Two treatments of mycorrhizal and non-mycorrhizal were designed in field experiments combine with pot experiments.Pot experiments were used to analyze the effects of AMF inoculation on the growth of stems and leaves,root tuber expansion,plant biomass,and rhizosphere effects of sweet potato during the entire growth period.Field experiments were used to verify the effects of AMF on root tuber yield and commercialization during the harvest period of sweet potato.The results showed that inoculation with AMF reduced the fresh weight of stems and leaves at seedling stage,flourishing stage,and tuber expansion stage;Significantly increased the root cap ratio at seedling stage,flourishing period,and tuber expansion stage;Significantly increased the rhizosphere effect of slow-release potassium at seedling and tuber expansion stages,and significantly increased the accumulation of nitrogen,phosphorus,and potassium in root tubers at seedling and flourishing stages;Significantly increased the fresh weight of root tubers during the entire growth period.Compared to non-mycorrhizal inoculation treatment,the yield per plant during harvest of mycorrhizal inoculation treatment increased by 32.58% in pot experiments and 23.05% in field experiments.In conclusion,inoculation with AMF could promote the activation of potassium in the rhizosphere soil,promote nutrient absorption,inhibit the distribution of nutrients and dry matter to the shoot,coordinate the development of source and sink,promote the formation and expansion of root tubers,and improve yield.