the present disclosure relates to nucleic acid molecules comprising the genome of the citrus sudden death virus , the causative agent of citrus sudden death 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 .