Resistance Induction in Two Alfalfa Varieties to Bean Leafroll Virus and Citrus Excortis Viroid Using Some Botanicals and Amino Acids Preparations

Abstract

Many researches have been conducted so far in the topic of controlling the Bean leafroll virus and Citrus exocortis viroid. This study was conducted in a private farm at Balad district from September 1, 2023, to January 6, 2024, and aimed to evaluate the efficacy of azolla and clover plant extract, fosetyl aluminum pesticide, and Debal against Bean leafroll virus in the presence of Citrus exocortis viroid in diseased alfalfa. The diagnosis was confirmed for the whole genome of the virus and viroid under study using next generation sequencing technology. The resulting sequences were compared in the International Gene Bank database NCBI. The virus was the 1st record registered in Iraq, which was registered with a accession number PP889325, and the viroid genome was registered for the first time in the NCBI database with an accession number PP869624. Findings of the field experiment showed that the treatments were effective in reducing infection rates and disease severity beside increasing plant defense enzymes (catalase, polyphenol oxidase, and peroxidase) in virus infected alfalfa. Debal treatment, individual or in combination, recorded the highest rate leaf content of catalase (8.00), polyphenol oxidase (3.70), and peroxidase (4.13), with values significantly differed from infected untreated control treatment that recorded 3.33, 0.91, and 0.81, respectively.