The search for new antimicrobial compounds is ongoing. Its importance cannot be overemphasized in an era of emerging resistant pathogenic organisms. This study therefore investigated the phytochemical composition and antioxidant and antimicrobial activities of different citrus juice concentrates. Fruit juices of Citrus tangerine (tangerine), Citrus paradisi (grape), Citrus limon (lemon), and Ci...

In situ hybridization of 18S-5.8S-25S rDNA probes labeled with biotin or rhodamine and 5S rDNA probes labeled with digoxigenin was used to locate rDNA sites on root-tip metaphase chromosomes of Citrus sinensis L. (2n = 2x = 18), Poncirus trifoliata L. Raf. (2n = 2x = 18), and Citrus x Poncirus hybrids (2n = 2x = 18). Counterstaining with the fluorochromes chromomycin A3 and DAPI uniquely identi...

Host plant resistance to the Diaprepes root weevil, Diaprepes abbreviatus (L.) was assessed for seedlings of 54 Poncirus trifoliata (L.) Raf. selections and two families of progeny from crosses between Citrus and P. trifoliata. Weight gain was consistently lower when larvae were reared in pots containing the progeny of Citrus reticulata Blanco 'Sunki' x P. trifoliata 'Flying Dragon' compared wi...

1 Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom, 2 Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, London, United Kingdom, 3 Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland, 4 International Agency for Research on Cancer (IARC) Lyon, France, 5 Depa...

The postharvest control of arthropod pests is a challenge that the California citrus industry must overcome when exporting fruit overseas. Currently, methyl bromide fumigation is used to control postharvest pests on exported citrus, but it may soon be unavailable because of use restrictions and cost of this health-hazard ozone-depleting chemical. Ethyl formate is a natural plant volatile and po...

A new medium designated Liber A has been designed and used to successfully cultivate all three 'Candidatus Liberibacter spp.,' the suspect causative agents of huanglongbing (HLB) in citrus. The medium containing citrus vein extract and a growth factor sustained growth of 'Ca. Liberibacter spp.' for four or five single-colony transfers before viability declined. Colonies, positive for 'Ca. L. as...

Huanglongbing or citrus greening disease is causing devastation to the citrus industry. Liberibacter asiaticus, an obligate intracellular pathogen of citrus, is one the causative agents of the disease. Most of the knowledge about this bacterium has been deduced from the in silico exploration of its genomic sequence. L. asiaticus differentially expresses genes during its transmission from the ps...

Seven citrus orchards on reduced to no pesticide spray programs were sampled for Thysanoptera in central and south central Florida. Inner and outer canopy leaves, fruits, twigs, trunk scrapings, vines and ground cover plants were sampled monthly between January 1995 and January 1996. Thirty-six species of thrips were identified from 2,979 specimens collected from within citrus tree canopies and...

To determine the effects of salinity on relative growth rate (RGR), net assimilation rate on a leaf weight basis (NAR(w)), leaf weight ratio (LWR), and nutrient uptake and utilization of citrus, we grew four citrus rootstocks (sour orange, Cleopatra mandarin, Carrizo citrange and Citrus macrophylla) in nutrient solutions containing 0, 10, 20, 40 or 80 mM NaCl for 20, 40 or 60 days. For each ele...