In vitro selection to increase Huanglongbing tolerance of citrusderived from in vitro breeding

Until now, Huanglongbing-HLB disease caused by a simple bacterium (Ca. Liberibacter spp) and distributed by Asian citrus psyllid vector (Diaphorina citri) and clonal propagation (grafting), was a major challenge in the national citrus production even almost all citrus nation production center in Asia, Africa also at the USA. This disease attack at phloem vessels by callouses forming that covering plasmodesmata and could be crop failure. There have been no citrus varieties reported resistant to HLB attack. Plant ploidy increase derived from in vitro breeding through somatic hybridization and endosperm culture expected to increase the plant's defense system. The aim of this study was to evaluate the tolerance of polyploidy plant to HLB attack. Tolerance of in vitro shoot of citrus regenerated from protoplast fusion (Citrus nobilis + C. unshiu) and culture of tangerine (C. nobilis) endosperm were screened by HLB pathogen suspense as selecting an agent and local lime as a negative control (HLB susceptible citrus). In vitro selection result that in vitro shoots derived from somatic hybridization shows resistance increase to HLB and characterize by recoverability after were selected.