Abstract: The present disclosure relates to nucleic acid molecules comprising the genome of the Citrus Sudden Death Virus (CSDV), the causative agent of Citrus Sudden Death (CSD) disease. The cloned CSDV nucleic acid molecules can be used as probes or can be used to design oligonucleotide primers useful in assays, such as a polymerase chain reaction, for detecting the presence of CSDV in biological samples, particularly leaves, roots and other tissues or organs of plants, such as plants from the genera Citrus and Poncirus. The disclosure also comprises the nucleic CSDV nucleic acid molecules, in whole or part, as well as transgenic plants, such as monocots and dicots, containing the CSDV nucleic acid molecules, in any kind of combination, so that expression increases resistance to CSD disease.