Determination of alfalfa resistance to atrazine

Abstract

With the rapid development of animal husbandry, finding efficient and sustainable feed resources has become an important issue for the industry's development. Alfalfa is rich in nutrients and has the characteristics of rapid growth and good palatability, which has attracted the attention of many dairy farmers. Atrazine is one of the commonly used herbicides in corn crop, and corn-alfalfa rotation is a common planting mode in the world. However, alfalfa is extremely sensitive to herbicides, so it is crucial to study the resistance of alfalfa to them. Indoor bioassay is a commonly used method for identifying herbicide resistance in crops, which has been widely applied in the study of tolerance to herbicides such as bensulfuron methyl in crops such as alfalfa and soybean. However, there are few reports on indoor bioassay methods for herbicide resistance in alfalfa and related studies on herbicide tolerance in alfalfa. The purpose of this study is to analyze the fresh weight of 60 alfalfa varieties under herbicide stress, to screen resistant and sensitive alfalfa varieties to herbicide influence, to determine the resistance level of alfalfa varieties to herbicide, and to provide theoretical reference for a deeper understanding of herbicide resistance mechanisms and variety improvement in alfalfa. This experiment used the potted soil toxicity method to determine the resistance of 60 alfalfa varieties. The pre experiment concentrations were set as follows: 5.00, 10.00, 20.00, 40.00, 80.00, and 160.00 mg/kg (for resistance determination) and 0.025, 0.05, 0.10, 0.20, 0.40, and 0.80 mg/kg (for sensitivity determination. The most resistant variety (SF8001) and the most sensitive variety (Juneng 2) to atrazine were screened. Among them, the IC50 of SF8001 was 14.875, and the IC50 of Juneng 2 was 0.2428. Compared with the variety Juneng 2, the resistance multiple (RI) of SF8001 was 61.26. The experimental results indicate that residual herbicides can have toxic effects on alfalfa, and different types of alfalfa have different resistance to herbicides. This provides a theoretical basis for the study of resistance mechanisms and a scientific basis for the selection of alfalfa varieties for rotation planting in corn crop.