An Improved Reference Gene for Detection of " Liberibacter asiaticus" Associated with Citrus Huanglongbing by qPCR and Digital Droplet PCR Assays.

Citrus huanglongbing (HLB) disease associated with the ' Liberibacter asiaticus' (CLas) bacterium has caused significant financial damage to many citrus industries. Large-scale pathogen surveys are routinely conducted in California to detect CLas early in the disease cycle by lab-based qPCR assays. We have developed an improved reference gene for the sensitive detection of CLas from plants in diagnostic duplex qPCR and analytical digital droplet PCR (ddPCR) assays.

Codon Usage Bias Analysis of : Higher Codon Adaptation to Host.

(CTV), a member of the aphid-transmitted closterovirus group, is the causal agent of the notorious tristeza disease in several citrus species worldwide. The codon usage patterns of viruses reflect the evolutionary changes for optimization of their survival and adaptation in their fitness to the external environment and the hosts. The codon usage adaptation of CTV to specific citrus hosts remains to be studied; thus, its role in CTV evolution is not clearly comprehended.

Analyses of 3' half genome of citrus tristeza virus reveal existence of distinct virus genotypes in citrus growing regions of India.

Citrus tristeza virus (CTV, genus ) is one of the most serious pathogens responsible for huge loss of citrus trees worldwide. Four Indian CTV isolates, Kat1 (/Central India), D1 (/North India), B5 (/South India) and G28 (/Northeast India) collected from different regions of India were characterized based on sequencing of 3' half genome (~ 8.4 kb) comprising 10 open reading frames (ORFs2-11) and 3' UTR and the sequences were submitted to NCBI database as Acc.

Changes in Anthocyanin Production during Domestication of .

Mandarin (), citron (), and pummelo () are important species of the genus and parents of the interspecific hybrids that constitute the most familiar commercial varieties of : sweet orange, sour orange, clementine, lemon, lime, and grapefruit. Citron produces anthocyanins in its young leaves and flowers, as do species in genera closely related to , but mandarins do not, and pummelo varieties that produce anthocyanins have not been reported. We investigated the activity of the gene, which encodes a MYB transcription factor controlling anthocyanin biosynthesis, in different accessions of a range of species and in domesticated cultivars.

Long-Term Field Evaluation Reveals Huanglongbing Resistance in Citrus Relatives.

Citrus huanglongbing (HLB) is a destructive disease with no known cure. To identify sources of HLB resistance in the subfamily Aurantioideae to which citrus belongs, we conducted a six-year field trial under natural disease challenge conditions in an HLB endemic region. The study included 65 Citrus accessions and 33 accessions belonging to 20 other closely related genera.

Huanglongbing: An overview of a complex pathosystem ravaging the world's citrus.

Citrus huanglongbing (HLB) has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increase to support research that in return has resulted in significant information on both applied and basic knowledge concerning this important disease to the global citrus industry. Recent research indicates the relationship between citrus and the causal agent of HLB is shaped by multiple elements, in which host defense responses may also play an important role.

Detection of citrus huanglongbing-associated 'Candidatus Liberibacter asiaticus' in citrus and Diaphorina citri in Pakistan, seasonal variability, and implications for disease management.

We report the detection of the huanglongbing (HLB)-associated bacterium 'Candidatus Liberibacter asiaticus' from both plants and insects in Pakistan and the seasonal variability in the numbers of 'Ca. L. asiaticus'-positive psyllid vector, Diaphorina citri.

Mild strain cross protection of tristeza: a review of research to protect against decline on sour orange in Florida.

Tristeza, caused by Citrus tristeza virus (CTV), has long been present in Florida but outbreaks of decline on sour orange rootstock were occasional events until the late 1970s. Sour orange rootstock was valued for the high quality of fruit produced and was widely used because of its tolerance of citrus blight, a disease of unknown etiology. Research was directed towards the selection and screening of mild strains of CTV which could protect against sour orange decline strains.

A six nuclear gene phylogeny of Citrus (Rutaceae) taking into account hybridization and lineage sorting.

Background: Genus Citrus (Rutaceae) comprises many important cultivated species that generally hybridize easily. Phylogenetic study of a group showing extensive hybridization is challenging. Since the genus Citrus has diverged recently (4-12 Ma), incomplete lineage sorting of ancestral polymorphisms is also likely to cause discrepancies among genes in phylogenetic inferences.

Effects of insecticides on behavior of adult Bactericera cockerelli (Hemiptera: Triozidae) and transmission of Candidatus Liberibacter psyllaurous.

The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a serious pest of potatoes (Solanum tuberosum L.) that can cause yield loss by direct feeding on crop plants and by vectoring a bacterial pathogen, Candidatus Liberibacer psyllaurous. Current pest management practices rely on the use of insecticides to control the potato psyllid to lower disease incidences and increase yields.