The Sudanese citrus industry is mainly based on oldline cultivars of grapefruit, sweet orange and willow leaf mandarin, grafted almost exclusively on sour orange. Infection with graft-transmissible agents, viroids in particular, may have deleterious effects on the productivity of these citrus species and, more importantly, limits the choice of rootstocks should sour orange be replaced by altern...

Viroids are small (246-401 nucleotides), single-stranded, circular RNA molecules that infect several crop plants and can cause diseases of economic importance. Citrus are the hosts in which the largest number of viroids have been identified. Citrus exocortis viroid (CEVd), the causal agent of citrus exocortis disease, induces considerable losses in citrus crops. Changes in the gene expression p...

background and aims: citrus exocortis disease is naturally limited to citrus plants and causes a serious disease on sensitive rootstocks such as trifoliate orange. the aim of this study was to sample new variants of citrus exocortis viroid from fars trees with yellowing and suberization symptoms and comparison with other isolates of this viroid. materials and methods: a number of symptomatic or...

Abstract Citrus exocortis viroid (CEVd), the causal agent of exocortis, is a pathogen that thought to infect all citrus varieties, although it asymptomatic in most. Symptoms develop on susceptible rootstocks, resulting stunting and yield reduction. To aid detection management CEVd, rapid near-field assay was developed using reverse transcription loop-mediated isothermal amplification (RT-LAMP) ...

Abstract Citrus exocortis is a grafting disease caused by Exocortis Viroid (CEVd). The knowledge of the viroid’s incidence and distribution are necessary to further apply control measures. objective this work was real time PCR assay for detection CEVd in samples collected from symptomatic CEVd-infected plants Mitidja (North Algeria). showed an excellent diagnostic specificity where 38 out 50 po...

Highly purified isolates of potato spindle tuber viroid (PSTV) from Lycopersicon esculentum cv. Rutgers and citrus exocortis viroid (CEV) from Gynura aurantiaca have been compared. Two-dimensional fingerprinting analysis of PSTVand CEV-RNA labeled in vitro with lzrI has demonstrated that (i) each of these RNA species has a complexity compatible with the size estimate of 250X350 nucleotides and ...

Figure 1 Figure 2 Citrus fruits are traditional agricultural products in Egypt. Citrus volkameriana is the best rootstock for growing citrus in Egypt’s desert areas (newly reclaimed land). It is far superior to other rootstocks used in Egypt in its resistance to Citrus tristeza virus as well as its tolerance to drought. Constraints to fruit production are mainly related to tree decline caused b...

Citrus species grown in Japan are affected by several viruses and viroids, including satsuma dwarf virus, citrus vein enation exocortis viroid, other viroids. Recently, a comprehensive review was made on the occurrence, history, research of following three major Japan: tatter leaf virus (apple stem grooving virus), tristeza (Iwanami 2022). As sequel, this study reviews development viroids as we...

Background and Aims: Citrus exocortis disease is naturally limited to citrus plants and causes a serious disease on sensitive rootstocks such as trifoliate orange. The aim of this study was to sample new variants of citrus exocortis viroid from Fars trees with yellowing and suberization symptoms and comparison with other isolates of this viroid. Materials and Methods: A number of symptomat...

Prolonged infection of tomato hybrid (Lycopersicon esculentum x Lycopersicon peruvianum) by Citrus exocortis viroid (CEVd) resulted in viroid-like enlarged structures, detected by gel electrophoresis. This population included two new enlarged variants or D-variants, D-87 and D-76, and three transient species or D-forms, D-38, D-40 and D-43. Sequence analyses exposed a locus near the terminal re...