Developing wheat that acquires and uses phosphorus(P)more efficiently is a promising and low-cost solution for increasing grain yield and reducing P-related environmental impacts.The present study identified agronomic...Developing wheat that acquires and uses phosphorus(P)more efficiently is a promising and low-cost solution for increasing grain yield and reducing P-related environmental impacts.The present study identified agronomic and physiological traits that contribute to genetic variation in the P acquisition,remobilization,and utilization efficiency of 11 wheat cultivars from southwest China grown in P-deficient purple lithomorphic soil(Olsen P=4.7)with balanced(75 kg P ha^(−1))and excess P(120 kg P ha^(−1))supplies.On average,soil P deficiency(–P)reduced root P uptake(17.0%–60.8%),P remobilization(33.9%–52.8%),dry mass yield(11.5%–39.2%),and grain yield(17.7%–54.4%).Balanced P(+P)increased grain yield via increased plant biomass rather than increased HI.–P increased phosphorus uptake efficiency(PUpE,4.5-fold),phosphorus utilization efficiency(PUtE,1.25-fold),and phosphorus use efficiency(PUE,5.4-fold)compared with those under+P,and PUtE explained most(58.1%–60.8%)of the genetic variation in PUE under both–P and+P.The high root P uptake of P-efficient cultivars under–P was regulated by root surface area and root length density in the 0–10 cm soil layer but not in the 10–20 and 20–40 cm soil layers,suggesting that a topsoil foraging strategy is a more economical approach than deeper root exploration for increasing P uptake.Root P uptake before anthesis and P remobilization after anthesis were critical for increasing the PUtE of wheat,given that P-efficient cultivars showed higher Pn(net photosynthetic rate)and sucrose levels than P-inefficient cultivars.Pn reduction by–P resulted from decreased Gs and Ci,and high evapotranspiration under+P increased shoot P%by increasing root P uptake.Genetic variation in the source-to-sink ratio was observed in consequence of a+P-induced allometric increase in sucrose in leaves and kernels.Owing to these beneficial effects,+P increased the kernel N and P yields of the 11 cultivars by 9.9%–52.4%and 12.3%–48.8%,respectively.The findings of this study could help improve wheat in future breeding efforts and P management by identifying desirable Pefficient phenotypes in P-deficient farming systems.展开更多
基金support from the Sichuan Province Science and Technology Support Program(2021YJ0504,2021YFYZ0002)National Key Research and Development Program of China(2016YFD0300406)+1 种基金Special Fund for Agro-scientific Research in the Public Interest(20150312705)Crops Breeding Project in Sichuan Province(2016NYZ0051,22ZDZX0018).
文摘Developing wheat that acquires and uses phosphorus(P)more efficiently is a promising and low-cost solution for increasing grain yield and reducing P-related environmental impacts.The present study identified agronomic and physiological traits that contribute to genetic variation in the P acquisition,remobilization,and utilization efficiency of 11 wheat cultivars from southwest China grown in P-deficient purple lithomorphic soil(Olsen P=4.7)with balanced(75 kg P ha^(−1))and excess P(120 kg P ha^(−1))supplies.On average,soil P deficiency(–P)reduced root P uptake(17.0%–60.8%),P remobilization(33.9%–52.8%),dry mass yield(11.5%–39.2%),and grain yield(17.7%–54.4%).Balanced P(+P)increased grain yield via increased plant biomass rather than increased HI.–P increased phosphorus uptake efficiency(PUpE,4.5-fold),phosphorus utilization efficiency(PUtE,1.25-fold),and phosphorus use efficiency(PUE,5.4-fold)compared with those under+P,and PUtE explained most(58.1%–60.8%)of the genetic variation in PUE under both–P and+P.The high root P uptake of P-efficient cultivars under–P was regulated by root surface area and root length density in the 0–10 cm soil layer but not in the 10–20 and 20–40 cm soil layers,suggesting that a topsoil foraging strategy is a more economical approach than deeper root exploration for increasing P uptake.Root P uptake before anthesis and P remobilization after anthesis were critical for increasing the PUtE of wheat,given that P-efficient cultivars showed higher Pn(net photosynthetic rate)and sucrose levels than P-inefficient cultivars.Pn reduction by–P resulted from decreased Gs and Ci,and high evapotranspiration under+P increased shoot P%by increasing root P uptake.Genetic variation in the source-to-sink ratio was observed in consequence of a+P-induced allometric increase in sucrose in leaves and kernels.Owing to these beneficial effects,+P increased the kernel N and P yields of the 11 cultivars by 9.9%–52.4%and 12.3%–48.8%,respectively.The findings of this study could help improve wheat in future breeding efforts and P management by identifying desirable Pefficient phenotypes in P-deficient farming systems.
