| In order to monitor the resistant situation and the developmental speed of the resistant level on Rape Field Alopecurus aequalis Sobol towards quizalofop-P-ethyl and clethodim. A. Aequalis collected from 4 province 13 cities 17 regions in Yangtze River region were determined using petri-dishes bioassay and whole-plant bioassay respectively. And in order to initially clear the resistance Mechanism of A. Aequalis Metabolic, the glutathione-s-transferase (GSTs) enzyme activity was sdudied in resistant biotype (R-TY) and susceptible biotype (S-NJ) with quizalofop-P-ethyl and clethodim, using plant physiology and biochemistry of resistance measurement techniques. The results are as follows:(1) Quizalofop-P-ethyl monitoring results using petri-dishes assay were as followed: There are seven biotypes which has higher level of resistance, the highest is TY biotypes, the relative resistance ratio was 15.85, GR50 was 2.457. HZ biotypes was most sensitive to quizalofop, the relative resistance ratio was 0.177, GR50 was 1.14, while the relative ratio of other biotypes are ranged from 2.02-9.83. Comparing with the monitoring results of 9 rape fields in Hunan area in 2013, the results showe that the growth rate of YY is the fastest, which is 3.38 times of the relative resistance of the same period. TY, YZ, AX, LD biotypes resistant have slower growth, which in the same period of resistances between 1.18 to 1.72 times. Whole-plant assay results are as follows:There are 3 biological types of higher resistance levels, which were TY, YZ, BLD, TY and were the highest, GR50 was 90.183, and the relative resistance factor was 28.92. Moderate level of resistance biotypes have six, GR50 between 20.556-28.754, the level of relative resistance factor between 6.59-9.16. And 9 low-resistant biotypes and a sensitive biotypes. Compared with the results of the 2013 Hunan area, the results of the YY biological were the largest increase in the type, which was 1.89 times as high as that in 2013, consistent with the petri-dishes bioassay results.(2) Using whole-plant bioassay to deterct the sensitive tolethodim, the results show that: there was a cross-resistance between quizalofop and clethodim in TY and BLD biotype, GR50 was 43.084 and 35.607, the relative resistance ratio is 14.27 and 11.79 respectively. While DYX, the quizalofop sensitive biotype, is resistant to clethodim, GR50 is 51.745, the relative resistance ratio is 17.14, indicating that A. aequalis biotypes may existed another resistance patterns.(3) Different chemical irritation after A.aequalis GSTs activity results showed that:after the treatment of quizalofop-P-ethyl, sensitive biological type GSTs activity before the 3day rose faster, reaching the maximum value of third days, is 1.23 times the control of the same period, fifth days began to decline. The resistant biotype GSTs activity by chemical treatment after rising more slowly, reached a peak on the fifth day, is 1.36 times compared with the control,6th and 7th days, no change in GSTs activity. After treatment of Clethodim, sensitive biological type GSTs activity began to rise sharply in 2 to 3 days,3rd and 4th day maintained at the maximum value, is 1.65 times the control over the same period. The GSTs activity of resistant biological type increased rapidly in the first 5 days, reach the maximum after 6 days, GSTs activity is 1.94 times higher than that of the control group. And after the treatment of two drugs, the GSTs activity in R-TY biotypes was always higher than the sensitive biotypes S-NJ, indicating that the TY biotypes became resistant to drug may due to GSTs which enhanced the metabolism. |
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