Assessment of genetic and epigenetic changes in virus-free garlic (Allium sativum L.) plants obtained by meristem culture followed by in vitro propagation.

This is the first report assessing epigenetic variation in garlic. High genetic and epigenetic polymorphism during in vitro culture was detected.Sequencing of MSAP fragments revealed homology with ESTs.

Detection and identification of a novel 16SrXIII subgroup phytoplasma associated with strawberry red leaf disease in Argentina.

Strawberry red leaf phytoplasma was found in strawberry plants from production fields in Lules (Tucumán province) and Bella Vista (Corrientes province), Argentina. Characteristic strawberry red leaf symptoms were stunting, young leaves with yellowing at the edges, mature leaves which curled and were reddish at the abaxial face, flower and fruit deformation and death. The pathogen was detected with phytoplasma-universal primer pairs P1/P7 followed by R16F2n/R16R2 as nested primers in 13 diseased plants.

Detection and identification of the first viruses in chia (Salvia hispanica).

Chia (Salvia hispanica), an herbaceous plant native to Latin America, has become important in the last 20 years due to its beneficial effects on health. Here, we present the first record and identification of two viruses in chia plants. The comparison of the complete nucleotide sequences showed the presence of two viral species with the typical genome organization of bipartite New World begomovirus, identified as Sida mosaic Bolivia virus 2 and Tomato yellow spot virus, according to the ICTV taxonomic criteria for begomovirus classification.

Changes in the Concentration of an Allexivirus During the Crop Cycle of Two Garlic Cultivars.

Garlic can be infected by a number of viruses, including allexiviruses. The coat protein sequence of an Allexivirus was detected in Argentina and deposited in the EMBL database as Garlic mite-borne filamentous virus (accession number X98991); it has high homology with Garlic virus A (GarV-A). For reliable virus detection, plants should be sampled when virus titer is high to reduce the risk of identifying infected plants as healthy.

Ultra-sensitive detection of two garlic potyviruses using a real-time fluorescent (Taqman) RT-PCR assay.

A method for the detection of Onion yellow dwarf virus (OYDV) and Leek yellow stripe virus (LYSV), the two most prevalent garlic potyviruses, has been developed that combines IC-RT-PCR/RT-PCR with the use of TaqMan probes. Comparisons with ELISA results obtained with identical OYDV and LYSV infected samples showed sensitivity in detecting these viruses increased up to 10(6)-fold. OYDV and LYSV were detected using different fluorochromes in the probe, thus allowing unequivocal diagnosis for each of them.

Yield Losses Associated with Virus-Infected Garlic Plants During Five Successive Years.

Virus-free garlic plants, when planted in the field, are quickly infected by viruses, but it is not known to what extent this affects the yield over successive crop cycles. The yield loss curve was studied for these plants during 5 years of tests in the field. Highly significant differences were detected in the weight and perimeter of bulbs in relation to the years of exposure to virus infection.

Variations of Leek yellow stripe virus Concentration in Garlic and Its Incidence in Argentina.

The purpose of this work was to determine variations in titer of Leek yellow stripe virus (LYSV) throughout the crop cycle and bulb storage, and to evaluate the incidence of infected plants in the main garlic-production regions of Argentina. One hundred plants with LYSV from each of five cultivars were analyzed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) in six different vegetative stages in White- and Red-type garlic cultivars and seven stages in cv. Rosado Paraguayo, throughout the year.