Conidia of Fusarium proliferatum infected epidermal cells of stigma, hairs and filaments on maize when sprayed on maize filament. Hyphae of F. proliferatum extended along with the parenehyma and vascular cells in the ...Conidia of Fusarium proliferatum infected epidermal cells of stigma, hairs and filaments on maize when sprayed on maize filament. Hyphae of F. proliferatum extended along with the parenehyma and vascular cells in the filaments, and infected toward ovary. Both the parenchyma cells and the epidermal cells were wrinkled, and the filament was deformed. The result showed that F. proliferatum could infect filaments directly and cause maize ear rot through filament channel.展开更多
Traditional maize ear harvesters mainly rely on manual identification of fallen maize ears,which cannot realize real-time detection of ear falling.The improved You Only Look Once-V4(YOLO-V4)algorithm is combined with ...Traditional maize ear harvesters mainly rely on manual identification of fallen maize ears,which cannot realize real-time detection of ear falling.The improved You Only Look Once-V4(YOLO-V4)algorithm is combined with the channel pruning algorithm to detect the dropped ears of maize harvesters.K-means clustering algorithm is used to obtain a prior box matching the size of the dropped ears,which improves the Intersection Over Union(IOU).Compare the effect of different activation functions on the accuracy of the YOLO-V4 model,and use the Mish activation function as the activation function of this model.Improve the calculation of the regression positioning loss function,and use the CEIOU loss function to balance the accuracy of each category.Use improved Adam optimization function and multi-stage learning optimization technology to improve the accuracy of the YOLO-V4 model.The channel pruning algorithm is used to compress the model and distillation technology is used in the fine-tuning of the model.The final model size was only 10.77%before compression,and the test set mean Average Precision(mAP)was 93.14%.The detection speed was 112 fps,which can meet the need for real-time detection of maize harvester ears in the field.This study can provide technical reference for the detection of the ear loss rate of intelligent maize harvesters.展开更多
To make up for the gap in the research on high water content maize threshing by airflow,this study took high-speed,low flow,low-speed high flow airflow,and high water content maize ear as the research basis.The variat...To make up for the gap in the research on high water content maize threshing by airflow,this study took high-speed,low flow,low-speed high flow airflow,and high water content maize ear as the research basis.The variation of air flow impacted threshing in numerical simulation,and the variation process of smoke visualization in the threshing area was compared.Taking the maize ear direction,the angle between the maize ear and the air pipe,the diameter of the air pipe,and the flow rate of the air compressor as factors,single-factor and quadratic regression orthogonal rotation combination tests were carried out,and the parameters were optimized.Finally,high-speed photography was used to shoot the maize kernels’shelling process,and movement rules were analyzed from both the front and side views.The results showed that the velocity changes of each section under the numerical simulation are consistent with the flow state changes of smoke.The velocity reached its maximum on the circumference of the maize ear surface and presented a symmetrical distribution.Due to the velocity gradient and pressure gradient difference,the high-speed airflow would entrain the phenomena of the low-speed airflow.When the transverse maize ear,the angle between the maize and the airflow tube)was 45°,the diameter of the airflow tube was 7 mm,the flow rate of the airflow tube was 33 m/s,the loose amount was 10 pieces,the threshed amount was 15 pieces,and the damage rate was below 3%.Through high-speed photography,it was found that the cyclic force circle was destroyed after the maize kernel fell off,the motion of the removed maize kernel was similar to the oblique throwing motion,and the threshing process was carried out in the unit of“arrangement unit”.The threshing process followed the“arrangement law”,and the threshing track was“spiral”.The results of this research can provide ideas for the mechanical design and development of high-moisture-content maize threshing by air.展开更多
For some Cas nucleases,trans-cleavage activity triggered by CRISPR/Cas-mediated cis-cleavage upon target nucleic acid recognition has been explored for diagnostic detection.Portable single and multiplex nucleic acid-b...For some Cas nucleases,trans-cleavage activity triggered by CRISPR/Cas-mediated cis-cleavage upon target nucleic acid recognition has been explored for diagnostic detection.Portable single and multiplex nucleic acid-based detection is needed for crop pathogen management in agriculture.Here,we harnessed and characterized RfxCas13d as an additional CRISPR/Cas nucleic acid detection tool.We systematically characterized AsCas12a,LbCas12a,LwaCas13a,and RfxCas13d combined with isothermal amplification to develop a CRISPR/Cas nucleic acid-based tool for single or multiplex pathogen detection.Our data indicated that sufficient detection sensitivity was achieved with just a few copies of DNA/RNA targets as input.Using this tool,we successfully detected DNA from Fusarium graminearum and Fusarium verticillioides and RNA from rice black-streaked dwarf virus in crude extracts prepared in the field.Our method,from sample preparation to result readout,could be rapidly and easily deployed in the field.This system could be extended to other crop pathogens,including those that currently lack a detection method and have metabolite profiles that make detection challenging.This nucleic acid detection system could also be used for single-nucleotide polymorphism genotyping,transgene detection,and qualitative detection of gene expression in the field.展开更多
基金Supported by Science and Technology Innovation Team Support Program for Colleges and Universities in Henan Province(2010JRTSTHN012)Henan Foundation and Frontier Technology Research Program of Henan Science and Technology Department(162300410137)+1 种基金Henan Educational Committee Key Research Projects of Henan Higher Education(16A210034)Nanyang Normal University Special Project(ZX2016002)
文摘Conidia of Fusarium proliferatum infected epidermal cells of stigma, hairs and filaments on maize when sprayed on maize filament. Hyphae of F. proliferatum extended along with the parenehyma and vascular cells in the filaments, and infected toward ovary. Both the parenchyma cells and the epidermal cells were wrinkled, and the filament was deformed. The result showed that F. proliferatum could infect filaments directly and cause maize ear rot through filament channel.
基金This work was funded and supported by the Shandong Provincial Key Science and Technology Innovation Engineering Project(Grant No.2018CXGC0217)the 13th Five-Year National Key Research and Development Program(Grant No.2018YFD0300606).
文摘Traditional maize ear harvesters mainly rely on manual identification of fallen maize ears,which cannot realize real-time detection of ear falling.The improved You Only Look Once-V4(YOLO-V4)algorithm is combined with the channel pruning algorithm to detect the dropped ears of maize harvesters.K-means clustering algorithm is used to obtain a prior box matching the size of the dropped ears,which improves the Intersection Over Union(IOU).Compare the effect of different activation functions on the accuracy of the YOLO-V4 model,and use the Mish activation function as the activation function of this model.Improve the calculation of the regression positioning loss function,and use the CEIOU loss function to balance the accuracy of each category.Use improved Adam optimization function and multi-stage learning optimization technology to improve the accuracy of the YOLO-V4 model.The channel pruning algorithm is used to compress the model and distillation technology is used in the fine-tuning of the model.The final model size was only 10.77%before compression,and the test set mean Average Precision(mAP)was 93.14%.The detection speed was 112 fps,which can meet the need for real-time detection of maize harvester ears in the field.This study can provide technical reference for the detection of the ear loss rate of intelligent maize harvesters.
基金funded by the National Natural Science Foundation of China(Grant No.52275245)the Henan Science and Technology Research Project(Grant No.222103810041)。
文摘To make up for the gap in the research on high water content maize threshing by airflow,this study took high-speed,low flow,low-speed high flow airflow,and high water content maize ear as the research basis.The variation of air flow impacted threshing in numerical simulation,and the variation process of smoke visualization in the threshing area was compared.Taking the maize ear direction,the angle between the maize ear and the air pipe,the diameter of the air pipe,and the flow rate of the air compressor as factors,single-factor and quadratic regression orthogonal rotation combination tests were carried out,and the parameters were optimized.Finally,high-speed photography was used to shoot the maize kernels’shelling process,and movement rules were analyzed from both the front and side views.The results showed that the velocity changes of each section under the numerical simulation are consistent with the flow state changes of smoke.The velocity reached its maximum on the circumference of the maize ear surface and presented a symmetrical distribution.Due to the velocity gradient and pressure gradient difference,the high-speed airflow would entrain the phenomena of the low-speed airflow.When the transverse maize ear,the angle between the maize and the airflow tube)was 45°,the diameter of the airflow tube was 7 mm,the flow rate of the airflow tube was 33 m/s,the loose amount was 10 pieces,the threshed amount was 15 pieces,and the damage rate was below 3%.Through high-speed photography,it was found that the cyclic force circle was destroyed after the maize kernel fell off,the motion of the removed maize kernel was similar to the oblique throwing motion,and the threshing process was carried out in the unit of“arrangement unit”.The threshing process followed the“arrangement law”,and the threshing track was“spiral”.The results of this research can provide ideas for the mechanical design and development of high-moisture-content maize threshing by air.
基金supported by the National Natural Science Foundation of China(31771808 and 32001551)the China Postdoctoral Science Foundation(2020M680779)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(S2021ZD03)。
文摘For some Cas nucleases,trans-cleavage activity triggered by CRISPR/Cas-mediated cis-cleavage upon target nucleic acid recognition has been explored for diagnostic detection.Portable single and multiplex nucleic acid-based detection is needed for crop pathogen management in agriculture.Here,we harnessed and characterized RfxCas13d as an additional CRISPR/Cas nucleic acid detection tool.We systematically characterized AsCas12a,LbCas12a,LwaCas13a,and RfxCas13d combined with isothermal amplification to develop a CRISPR/Cas nucleic acid-based tool for single or multiplex pathogen detection.Our data indicated that sufficient detection sensitivity was achieved with just a few copies of DNA/RNA targets as input.Using this tool,we successfully detected DNA from Fusarium graminearum and Fusarium verticillioides and RNA from rice black-streaked dwarf virus in crude extracts prepared in the field.Our method,from sample preparation to result readout,could be rapidly and easily deployed in the field.This system could be extended to other crop pathogens,including those that currently lack a detection method and have metabolite profiles that make detection challenging.This nucleic acid detection system could also be used for single-nucleotide polymorphism genotyping,transgene detection,and qualitative detection of gene expression in the field.
