Breeding against mycorrhizal symbiosis:Modern cotton (Gossypium hirsutum L.) varieties perform more poorly than older varieties except at very high phosphorus supply levels  

作　　者：WANG Xin-xin ZHANG Min SHENG Jian-dong FENG Gu Thomas W.KUYPER 

机构地区：[1]College of Resources and Environmental Sciences,China Agricultural University,Beijing 100193,P.R.China [2]State Key Laboratory of North China Crop Improvement and Regulation/Mountain Area Research Institute,Hebei Agricultural University,Baoding 071001,P.R.China [3]College of Resource and Environmental Sciences,Xinjiang Agricultural University,Urumqi 830052,P.R.China [4]Soil Biology Group,Wageningen University&Research,Wageningen 6700AA,The Netherlands

出　　处：《Journal of Integrative Agriculture》2023年第3期701-715,共15页农业科学学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(32272807 and U1703232);supported via project from State Key Laboratory of North China Crop Improvement and Regulation(NCCIR2021ZZ-1)。

摘　　要：Cotton (Gossypium hirsutum L.) is an importantfiber cash crop,but its root traits related to phosphorus (P) acquisition,including mycorrhizal root traits,are poorly understood.Eight cotton varieties bred in northwestern China that were released between 1950 and 2013 were grown in pots with or without one arbuscular mycorrhizal fungal (AMF) species(Funneliformis mosseae) at three P supply levels (0,50 and 300 mg P as KH_(2)PO_(4)kg^(-1)).Eleven root traits were measured and calculated after 7 wk of growth.The more recent accessions had smaller root diameters,acquired less P and produced less biomass,indicating an (inadvertent) varietal selection for thinner roots that provided less cortical space for AMF,which then increased the need for a high P fertilizer level.At the two lower P levels,the mycorrhizal plants acquired more P and produced more biomass than non-mycorrhizal plants (3.2 vs.0.9 mg P per plant;1.8 vs.0.9 g biomass per plant at P_(0);14.5 vs.1.7 mg P per plant;and 4.7 vs.1.6 g biomass per plant at P_(50)).At the highest P level,the mycorrhizal plants acquired more P than non-mycorrhizal plants (18.8 vs.13.4 mg per P plant),but there was no difference in biomass (6.2 vs.6.3 g per plant).At the intermediate P level,root diameter was significantly positively correlated with shoot biomass,P concentration and the P content of mycorrhizal plants.The results of our study support the importance of the outsourcing model of P acquisition in the root economics space framework.Inadvertent varietal selection in the last decades,resulting in thinner roots and a lower benefit from AMF,has led to a lower productivity of cotton varieties at moderate P supply (i.e.,when mycorrhizal,the average biomass of older varieties 5.0 g per plant vs.biomass of newer varieties 4.4 g per plant),indicating the need to rethink cotton breeding efforts in order to achieve high yields without very high P input.One feasible way to solve the problem of inadvertent varietal selection for cotton is to be aware of the trade-offs between the r

关 键 词：cotton varieties plant breeding arbuscular mycorrhizal fungi root economics space OUTSOURCING phosphorus acquisition 

分 类 号：S562[农业科学—作物学]