The Happening State Of Monochoria Korsakowii And Sagittaria Sagittifolia In Main Paddy Rice Fields In Jilin Province And Study On Resistance Mutation Site With Als Of Sagittaria Sagittifolia

Monochoria Korsakowii and Sagittaria sagittifolia are one of the most harmful weeds in paddy rice fields in Jilin province, and their occurrence area is expanding rapidly in recent years. The effect of the weed controlled with Bensulfuron-methyl is less useful. So the experiments studied the distribution survey and resistance identification of Monochoria Korsakowii and Sagittaria sagittifolia in paddy rice fields in Jilin province. The experiments were conducted to determine the resistant levels of Sagittaria sagittifolia to Bensulfuron-methyl, and further to ascertain the resistant mechanism. The results of the study as follows are useful for the risk assessment and effective control of the resistant Sagittaria sagittifolia.1. The survey result showed that Sagittaria sagittifolia and Monochoria Korsakowii are one of the most harmful weeds in paddy rice fields in Jilin province; the occurrence of suspected resistance weeds from different paddy rice fields is different, the harmful of weeds is serious in paddy rice fields in Yanbian and Tonghua, relatively light in paddy rice fields in Songyuan、Changchun and Jilin.2. The resistance of Sagittaria sagittifolia and Monochoria Korsakowii to bensulfuron-methyl is different in paddy rice fields in Jilin province. The ED50of Sagittaria tri folia in Jinlin baiqi and si jiazi to Bensulfuron-methyl is18.46and36.87. TheED50of Monochoria Korsakowii in Yanbian helong to Bensulfuron-methyl is9.71; But the ED50of Sagittaria tri folia in Jinlin baiqi to Penoxsulam is45.6. It indicated that Sagittaria trifolia is resistant to Bensulfuron and Penoxsulam, and it may have cross resistance.3. This is the first report that the full length gene sequence of bensulfuron-methyl target enzyme acetohydroxyacid synthase (ALS) of Sagittaria sagittifolia in paddy rice field has obtained. The results showed that the full DNA sequence length were2055bp, encoding684amino acids (GenBank:KC287227.1). Comparison with BLAST software, the full length amino acid sequence of susceptible Sagittaria sagittifolia is similar to Sagittaria tri folia (GenBank:AB301496) of Japan with the highest100%similarity. These results indicated that the Sagittaria sagittifolia ALS genes and those coded ALS amino acid sequence were correct. This is the first report in China.4. ALS genes of Arabidopsis thaliana as reference frame were compared with Sagittaria sagittifolia, the mutational site of resistant Sagittaria sagittifolia is the ninth of ALS amino acid sequence (Thr9to Prp9) and the324th of ALS amino acid sequence (Thr324to Ala324) which may be the main resistance mechanism.