Diverse Regulations of Viral and Host Genes in Tomato Germplasms Responding to Tomato Yellow Leaf Curl Virus Inoculation

Tomato yellow leaf curl virus(TYLCV)is the dominating pathogen of tomato yellow leaf curl disease that caused severe loss to tomato production in China.In this study,we found that a TYLCV-resistant tomato line drastically reduced the accumulation of viral complementary-sense strand mRNAs but just moderately inhibited that of viral DNA and virion-sense strand mRNAs.However,two other resistant lines did not have such virus inhibition pattern.Analysis of differential expressed genes showed that the potential host defense-relevant processes varied in different resistant tomatoes,as compared to the susceptible line,suggesting a diversity of tomato TYLCV-resistance mechanisms.

Performance Evaluation of Two-Vector-Based Model Predictive Current Control of PMSM Drives

Conventional model predictive current control(MPCC)applies only one vector during one control period,which produces large torque and flux ripples and high current harmonics in permanent magnet synchronous motor(PMSM)drives.Recently MPCC with duty cycle control has been proposed to improve the steady state performance by applying one non-zero vector and one null vector during one control period.However,the prior method requires lots of calculations and predictions to find the optimal voltage vectors and calculate their respective duration.Different from prior enumeration-based MPCC,this paper proposes an efficient two-vector MPCC by applying two arbitrary voltage vectors during one control period.The reference voltage vector is firstly calculated based on the principle of deadbeat current control.Two optimal vectors and their duration are then obtained in a very efficient way,which does not require the calculation of current slopes in prior MPCC methods.The proposed method is compared to the state-of-the-art predictive control methods,including conventional MPCC,MPCC with duty cycle control,deadbeat control with space vector modulation(SVM)and modulated model predictive control(M2PC).Both simulation and experimental results prove that the proposed method achieves better steady state performance than conventional MPCC with or without duty cycle and the dynamic response is not degraded.Under the condition of insufficient dc bus voltage,the proposed method outperforms deadbeat control and M2PC by presenting even higher speed range and less torque ripples.