Studies on physiologically active substances in citrus fruit peel. Part XVIII. Structures of new limonoid glycosides in lemon (Citrus limon Burm. f.) peelings.

The detection of viruses, disease biomarkers, physiologically active substances, drugs, and chemicals is of great significance in many areas of our lives. Immunodetection technology is based on the specificity and affinity of antigen–antibody reactions. Compared with other analytical methods such as liquid chromatography coupled with mass spectrometry, which requires a large and expensive instrument, immunodetection has the advantages of simplicity and good selectivity and is thus widely used in disease diagnosis and food/environmental monitoring. Quenchbody (Q-body), a new type of fluorescent immunosensor, is an antibody fragment labeled with fluorescent dyes. When the Q-body binds to its antigen, the fluorescence intensity increases. The detection of antigens by changes in fluorescence intensity is simple, easy to operate, and highly sensitive. This review comprehensively discusses the principle, construction, application, and current progress related to Q-bodies.

Download Full-text

Screening Triploid Hybrids of ‘Lakeland’ Limequat for Resistance to Citrus Canker

Plant Disease ◽

10.1094/pdis.2004.88.10.1056 ◽

2004 ◽

Vol 88 (10) ◽

pp. 1056-1060 ◽

Cited By ~ 39

Author(s):

Z. Viloria ◽

D. L. Drouillard ◽

J. H. Graham ◽

J. W. Grosser

Keyword(s):

Bacterial Population ◽

Somatic Hybrids ◽

Rank Correlation ◽

Citrus Fruit ◽

Citrus Canker ◽

Citrus Limon ◽

Spearman’S Rank Correlation ◽

Inoculation Site ◽

Lesion Number ◽

Key Lime

Resistance of citrus genotypes to Xanthomonas axonopodis pv. citri, the cause of Asiatic citrus canker (ACC), was evaluated by injection infiltration of 103 and 104 CFU/ml through stomates on the abaxial surface of immature leaves. Citrus genotypes for screening comprised two autotetraploids and nine triploid hybrids of ‘Lakeland’ limequat (Citrus aurantifolia × Fortunella japonica) and their progenitors (‘Lakeland’ limequat, the autotetraploids ‘Femminello’ lemon (Citrus limon) and ‘Giant Key’ lime (C. aurantifolia), and the somatic hybrids ‘Key’ [also known as ‘Mexican’] lime + ‘Valencia’ orange and ‘Hamlin’ orange + ‘Femminello’ lemon). ‘Meiwa’ kumquat (Fortunella crassifolia) and ‘Pineapple’ sweet orange (C. sinensis) were used as known resistant and susceptible standards, respectively. Lesion number per inoculation site and bacterial population per lesion were recorded 15 to 19 days after inoculation. The assay was performed four times during a spring-summer-fall period under greenhouse conditions. Canker lesions were consistently produced by stomatal inoculation with 104 but not 103 CFU/ml. Susceptible and resistant genotypes were separated based on lesion number per inoculation site and bacterial population per lesion. Spearman's rank correlation analysis for lesion numbers on 15 genotypes common to all four assays showed significant correlations among the genotype rankings. Genotype rankings were also significantly correlated between the two bacterial population assays. Lesion number per inoculation site is sufficient for assessment of resistance of citrus genotypes to ACC without the necessity of conducting bacterial population assays. ‘Lakeland’ limequat is a promising seed parent for breeding acid citrus fruit that is resistant to ACC.

Download Full-text