Time-resolved multiomics analysis of the genetic regulation of maize kernel moisture

Maize kernel moisture content(KMC)at harvest greatly affects mechanical harvesting,transport and storage.KMC is correlated with kernel dehydration rate(KDR)before and after physiological maturity.KMC and KDR are complex traits governed by multiple quantitative trait loci(QTL).Their genetic architecture is incompletely understood.We used a multiomics integration approach with an association panel to identify genes influencing KMC and KDR.A genome-wide association study using time-series KMC data from 7 to 70 days after pollination and their transformed KDR data revealed respectively 98and 279 loci significantly associated with KMC and KDR.Time-series transcriptome and proteome datasets were generated to construct KMC correlation networks,from which respectively 3111 and 759 module genes and proteins were identified as highly associated with KMC.Integrating multiomics analysis,several promising candidate genes for KMC and KDR,including Zm00001d047799 and Zm00001d035920,were identified.Further mutant experiments showed that Zm00001d047799,a gene encoding heat shock 70 kDa protein 5,reduced KMC in the late stage of kernel development.Our study provides resources for the identification of candidate genes influencing maize KMC and KDR,shedding light on the genetic architecture of dynamic changes in maize KMC.

Phase states of moisture content in different maize kernel types

Accurate determination of the moisture content in maize kernels conduces to screen maize germplasm materials with efficient dehydration.Low-field nuclear magnetic resonance(LF-NMR)single-kernel non-destructive testing technology was used to determine the moisture content at different phase states in the kernels for selected types of maize.The NMR T 2 relaxation inversion spectrum was monitored in maize kernels to determine the variation in the moisture content in different phase states with time.The total water and free water peaked at the filling stage of the maize kernels and then declined to a minimum at physiological maturity.The semi-bound water generally increased to a long-lasting peak in the dough stage and then declined.The bound water increased from kernel formation to maturity and then remained stable.The contents of total water,free water,semi-bound water,and bound water had significant differences among kernel types but not among varieties of the same type.The contents of semi-bound water and free water were linearly correlated with the dehydration rates of the kernels.The results of this study can provide a means for creating new germplasm materials.

Development and application of polymetric surfactant emulsification and viscosity reduction system

Compounding polymer AP-P4 with high viscosity-reducing Gemini Surfactant HD,which is used as an emulsifier viscosity reduce,to improve the stability of the O/W emulsion while the viscosity reduction rate is kept.A polymeric surfactant emulsification and viscosity reduction system capable of forming a relatively stable O/W emulsion of heavy oil(0.5%HD+0.1%AP-P4)is then compounded.The system has been characterized as a high viscosity reduction rate and high stability.Meanwhile,the production liquid does not need to be added with a demulsifier and only needs to be heated to 70°C to achieve effective demulsification.The influencing factors of the performance of the polymetric surfactant emulsification and viscosity reduction system were studied.When the oil-water ratio was 70:30 and 60:40,the viscosity reduction rate was 97.47%and 99.09%,respectively;after 15 h at 30°C,the dehydration rates were 95.8%and 99.2%,respectively.The dehydration rate after 15 h at 70°C was 98.1%and 99.4%,respectively;at 30∼50°C,the water phase temperature has a greater impact on the viscosity;at 60°C,70°C,the water phase temperature has little effect on the viscosity;as the temperature of the aqueous phase increased,the stability of the emulsion deteriorated.When the aqueous phase temperature was 30°C,50°C and 70°C,the dehydration rates of the emulsion after 15 h were 95.8%,96.7%and 98.1%,respectively;As the degree of mineralization increases,the viscosity reduction rate decreases,and the stability of the emulsion deteriorates.The system has been used in field test for 2 injection wells,and the production rate of the two wells increased with a peak value of 25 m3/d and 20 t/d,respectively.