Graft compatibility of Citrus with plants in the Aurantioideae and their susceptibility to citrus tristeza virus

Wild relatives of citrus, including 22 species in 19 genera, were evaluated for susceptibility to citrus tristeza virus (CTV). They were grafted onto rootstocks of Citrus spp., graft-inoculated with a severe strain of CTV, with the exception of a seedling of Sydney hybrid (a hybrid between species of Microcitrus), which was graft-inoculated to its stem directly. All the species used were graftable to Citrus; however, the rate of graft success varied from 27 to 100%, and growth varied markedly. Severinia buxifolia, Atalantia monophylla, A. citroides, Fortunella polyandra, Clymenia polyandra, Swinglea glutinosa, Feronia limonia, and Feroniella lucida grew as well as Citrus grafted onto Citrus. Other species grew poorly or very poorly. Fortunella polyandra, Clymenia polyandra, Microcitrus australis, Sydney hybrid, Eremocitrus glauca, Atalantia monophylla, A, citroides, Citropsis articulate, Pleiospermium sp., Hesperethusa crenulata, Swinglea glutinosa, Aeglopsis chevalieri, Clausena excavata, C, lansium, and Merrillia caloxylon were infected with CTV based on double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) using polyclonal antibodies against CTV. On the other hand, no evidence of CTV infection was found in Severinia buxifolia brachytic form, Triphasia trifolia, Aegle marmelos, Feronia limonia, Feroniella lucida, Glycosmis pentaphylla, Murraya koenigii, and M. paniculata. Two sources of Severinia buxifolia from different stocks showed different responses to CTV.