Yield sustainability of winter wheat under three limited-irrigation schemes based on a 28-year field experiment

Sustainable intensification is an agricultural development direction internationally.However,little is known about the yield sustainability of winter wheat(Triticum aestivum L.)under limited irrigation schemes on the North China Plain(NCP).A 28-year field experiment from 1991 to 2018 at Wuqiao Experimental Station was used to characterize long-term yield,evapotranspiration(ET),and water use efficiency(WUE)trends under three irrigation treatments(W1,irrigation just before sowing;W2,irrigation before sowing and at jointing stage;W3,irrigation before sowing,at jointing stage,and at anthesis).Yield gaps and the effects of genetic improvement,climate change,and climate variables on wheat yield and key phenological stages were estimated using the Agricultural Production Systems Simulator(APSIM)model.Grain yield and WUE of winter wheat increased during the 28 years under the three irrigation treatments,and the upward trend of WUE followed a saturation curve pattern.ET increased slightly.Simulation results showed that genetic improvement dramatically prolonged the phenological stages of vegetative growth period and contributed to yield increase by 0.03%-15.6%.The rapid increase in yield with lower water use was associated mainly with an increase in biomass with genetic improvement and partly with an increase in harvest index.A curvilinear relationship between WUE and yield emphasized the importance of obtaining high yields for high WUE.The yield gaps between potential yield and yield under W1 treatment increased from 1991 to 2018 but were relatively constant for the W2 and W3 treatments.Elevated atmospheric CO_(2) concentration offset the negative effects of temperature increase on yield,leading to minor(-2.3%to 0.3%)changes in yield under climate change.Thus,genetic improvement played a dominant role in yield increase,and limited-irrigation schemes(W2 and W3)can increase wheat yield and promote sustainability of crop production on the NCP.

Constructing cactus-like mixed dimensional MOF@MOF as sorbent for extraction of bisphenols from environmental water

Metal-organic frameworks(MOFs)received considerable attention to adsorption and removal of various environmental pollutants because of some inherent advantages.However,it is challenging but meaningful to design and fabricate hierarchical mixed-dimensional MOFs with synergistic effects to enhance the performance for removal and preconcentration of environmental pollutants.Herein,a new hierarchical two-dimensional(2D)-three-dimensional(3D)mixed-dimensional cactus-like MOF@MOF hybrid material(PCN-134@Zr-BTB)was prepared by in-situ growth of 2D MOF nanosheets(Zr-BTB)on the surface of 3D MOF(PCN-134).The PCN-134@Zr-BTB composites combine the advantages of 2D and 3D MOFs with extensive mesoporous structures and large surface area for effective removal and enrichment of bisphenols(BPs).In comparison with pristine PCN-134 and Zr-BTB materials,the PCN-134@Zr-BTB hybrid material presented excellent adsorption performance for BPs.The adsorption isotherms are consistent with the Langmuir model,and the maximum adsorption capacity of four bisphenols(BPs)ranged from 135.1 mg/g to 628.9 mg/g.The adsorption kinetics are in accordance with the pseudo-second-order model.The recoveries ranged from 72.8%to 108%.The limits of detection were calculated at 0.02-0.03 ng/mL.The enrichment factors were calculated in the range of 310-374.According to FT-IR and XPS analysis,the main adsorption mechanisms are hydrogen bonding and π-π stacking.Nevertheless,this work provides a new and convenient strategy for the preparation of new hierarchical mixed-dimensional MOF@MOF(PCN-134@Zr-BTB)hybrid material for extraction and enrichment of BPs from aqueous matrix.

Transcriptomic and metabolomic analysis of changes in grain weight potential induced by water stress in wheat

The sink strength of developing ovaries in wheat determines the grain weight potential.The period from booting to the grain setting stage is critical for ovary growth and development and potential sink capacity determination.However,the underlying regulatory mechanism during this period by which the wheat plant balances and coordinates the floret number and ovary/grain weight under water stress has not been clarified.Therefore,we designed two irrigation treatments of W0(no seasonal irrigation)and W1(additional 75 mm of irrigation at the jointing stage)and analyzed the responses of the ovary/grain weight to water stress at the phenotypic,metabolomic,and transcriptomic levels.The results showed that the W0 irrigation treatment reduced the soil water content,plant height,and green area of the flag leaf,thus reducing grain number,especially for the inferior grains.However,it improved the grain weight of the superior and inferior grains as well as average grain weight at maturity,while the average ovary/grain weight and volume during–3 to 10 days after anthesis(DAA)also increased.Transcriptomic analysis indicated that the genes involved in both sucrose metabolism and phytohormone signal transduction were prominently accelerated by the W0 treatment,accompanied by greater enzymatic activities of soluble acid invertase(SAI)and sucrose synthase(Sus)and elevated abscisic acid(ABA)and indole-3-acetic acid(IAA)levels.Thus,the sucrose content decreased,while the glucose and fructose contents increased.In addition,several TaTPP genes(especially TaTPP-6)were down-regulated and the IAA biosynthesis genes TaTAR1 and TaTAR2 were up-regulated under the W0 treatment before anthesis,which further increased the IAA level.Collectively,water stress reduced the growth of vegetative organs and eliminated most of the inferior grains,but increased the ABA and IAA levels of the surviving ovaries/grains,promoting the enzymatic activity of Sus and degrading sucrose into glucose and fructose.As a result,the strong sucrose utilization ability,the enhanced enzymatic activity of SAI and the ABA-and IAA-mediated signaling jointly increased the weight and volume of the surviving ovaries/grains,and ultimately achieved the tradeoff between ovary/grain weight and number in wheat under water stress.