Citrus huanglongbing (HLB) is a highly destructive disease of citrus presumably caused by 'Candidatus Liberibacterasiaticus' (Las), a gram-negative, insect-transmitted, phloem-limited α-proteobacterium. Although almost all citrus plants are susceptible to HLB, reports have shown reduced susceptibility to Las infection in lemon (Citrus limon) plants. The aim of this study is to identify intra-sp...

This is an in vitro study to evaluate five different commercially available citrus fruits: viz., Sweet orange (Citrus sinences Osbeck), Grape [Citrus maxima (J. Buruan) Merrile], Lemon [Citrus limon (Burn F.) and Lime (Citrus aurantifolia Swingle. Evaluation of their pHs and neutralizable acidity were made. A 50 mL of each fruit was prepared by juice press. Initial pH was measured in triplicate...

ABSTRACT Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC), a destructive disease of sweet orange cultivars in Brazil. Polymerase chain reaction (PCR)-based assays constitute the principal diagnostic method for detection of these bacteria. In this work, we established a real-time quantitative PCR (QPCR) assay to quantify X. fastidiosa in naturally and artificially infe...

Digital image processing is employed in numerous areas of biology to identify and analyse problems. This approach aims to use image processing techniques for citrus canker disease detection through leaf inspection. Citrus canker is a severe bacterium-based citrus plant disease. The symptoms of citrus canker disease typically occur in the leaves, branches, fruits and thorns. The leaf images show...

Scirtothrips aurantii Faure (Thysanoptera: Thripidae) is a major pest of citrus fruit in subtropical southern Africa. Population monitoring is an important aspect of S. aurantii control, but additional information is required on its phenology. Dispersal of mature larvae onto the soil surface from the tree canopy, and emergence of adults, were assessed using dispersal/emergence (D/E) traps in an...

Carrizo citrange (Citrus sinensisxPoncirus trifoliata) is a citrus hybrid widely used as a rootstock, whose genetic manipulation to improve different growth characteristics is of high agronomic interest. In this work, transgenic Carrizo citrange plants have been produced overexpressing sense and antisense CcGA20ox1 (a key enzyme of GA biosynthesis) under control of the 35S promoter to modify pl...

The constitutive characters of plants can be structural or biochemical and play an important role in their defence against pathogens. Citrus postbloom fruit drop (PFD) caused by Colletotrichum spp. is one of the most important fungal diseases of citrus. The pathogen infects the flowers, leading to premature fruit drop and reducing citrus production. However, flower buds smaller than 8 mm long a...

Nearly 65,000 citrus EST (Expressed Sequence Tags) have been investigated using the CitEST project database. Microsatellites were investigated in the unigene sequences from Citrus spp. and Poncirus trifoliata. From these sequences, approximately 35% of the non-redundant ESTs contained SSRs. The frequencies of different SSR motifs were similar between Citrus spp and trifoliate orange. In general...

Argyrotaenia sphaleropa (Meyrick) is associated with various fruit species in South America. This tortricid was first detected in citrus, Citrus sinensis (L.) Osbeck, in Brazil, in commercial groves in northern Paraná, during the 1994/95-crop season. The aim of this work was to study the biology of this lepidopteran under laboratory conditions (28 +/- 2 degrees C, 70 +/-10% UR, 14h photofase) u...

Plant tryptophan decarboxylase (TDC) converts tryptophan into tryptamine, precursor of indolealkylamine alkaloids. The recent finding of tryptamine metabolites in Citrus plants leads to hypothesize the existence of TDC activity in this genus. Here, we report for the first time that, in Citrus x limon seedlings, deuterium labeled tryptophan is decarboxylated into tryptamine, from which successiv...