Monteiro-Hara, A, Meletti, L. M. M., and Piedade, S. M. De S. 2011. Genetic transformation of passionflower and evaluation of R| and R, generations for resistance to Cowpea aphid bortie mosaic virus. Plant Dis. 95; 1021 -1025.We report on the production and evaluation of passionflower transgenic lines for resistance to Cowpea aphid home mosaic virus (CABMV). Genetic transformation was done using Agrobacterium tutnefaciens and transgene integration was confirmed by Southem blot analyses, resulting in nine transgenic lines for 'IAC 275' and three for iAC 277". Tran.sgenic lines were clonally propagated and evaluated for resistance to CABMV. After the third inoculation, under higher inoculum pressure, only propagated plants of the transgenic line T16 remained asymptomatic, indicating a high resistance to infection with CABMV, This transgenic line was self-pollinated and the R| generation was evaluated together with the R| generation of another resistant transgenic line (T2) identified previously. Plants were inoculated with CABMV by means of viruliferous Myzus nicotianae. All 524 T2R, plants became infected, whereas 13 of 279 T16R| remained asytnptomatic after four successive inoculations. A TlóR^ generation was obtained and plants were inoculated with CABMV mechanically or by aphids. After successive inoculations, 118 of 258 platits were symptomless, suggesting that the resistance to CABMV was maintained in the plant genome as the homozygous condition was achieved. Five selected resistant TI6Ri plants which contained the capsid protein gene are being crossed for further analyses.Brazil is the worid's largest producer of passion fruit, with an estimated planted area of 44,300 ha and fruit yield of 615,196 t (12), Corresponding author; J. A. M. Rezende,

In Brazil, passion flower is grown across almost the entire country. The predominant disease of the passion flower crop is passion fruit woodiness, caused by the potyvirus cowpea aphid‐borne mosaic virus (CABMV), and transmitted by aphids in a nonpersistent manner. The disease reduces the useful life of the orchard from 36 months to approximately 18 months. Up to now, there has not been an efficient method for disease management. The aim of this work was to evaluate the efficiency of systematic roguing of diseased plants through weekly inspections, for disease management in the field. The latent and incubation periods of CABMV in passion flower vines were determined in order to optimize roguing efficiency. Passion fruit plants inoculated with CABMV started to act as sources of inoculum from 3 days after inoculation (DAI), and the symptoms were expressed, on average, at 8 DAI. Five field experiments, conducted in the states of São Paulo and Bahia, Brazil, demonstrated that systematic roguing of diseased plants was significantly efficient for managing passion fruit woodiness disease. In order to facilitate identification and subsequent removal of the infected plants, they need to be grown separately. This cultural practice can be recommended for managing passion fruit woodiness disease, provided it is applied on a regional scale by all passion fruit growers. The development of some pilot plantings for the application of roguing in a passion flower‐producing region is recommended to validate the use of this technique for managing passion fruit woodiness disease.

Papaya ringspot virus type P (PRSV-P) systemically infects Carica papaya and species belonging to the family Cucurbitaceae. Attempts to recover PRSV-P from naturally infected cucurbit plants grown near or among diseased papaya trees have shown conflicting results worldwide. This study aimed to evaluate the natural infection of cucurbit species grown among and near papaya trees infected with PRSV-P in Brazil. Natural infection of cucurbits with PRSV-P occurred in zucchini squash but not in watermelon and cucumber. However, several attempts to recover PRSV-P from numerous Cucurbita pepo cv. Caserta (zucchini squash) plants grown 5-80 m from diseased papaya trees in the field failed. Mechanical inoculations of Cucurbita pepo cv. Caserta, Cucurbita maxima cv. Exposição (pumpkin), Cucumis sativus cv. Primepack Plus (cucumber) and Citrullus lanatus cv. Crimson Sweet (watermelon) with five Brazilian PRSV-P isolates showed that zucchini squash was the most susceptible species followed by watermelon and cucumber, while pumpkin was not infected. The results confirmed the variable susceptibility of cucurbit species to experimental and natural PRSV-P infection. Given these facts, the control of the disease through roguing should focus mainly on diseased papaya plants, as has been practised successfully in Brazil for many years, and on those cucurbits particularly known to be susceptible to natural infection with PRSV-P.

Sunn hemp {Crotalaria júncea) is widely grown in tropical and subtropical regions. In Brazil, this species is commonly used for green manure, since this legume is an efficient nitrogen fixer that produces organic residues for soil improvement. In July of 2012, C. júncea exhibiting intense shoot proliferation, leaf malformation, shortened internodes, and generalized yellowing were found in an experimental field located in Piracicaba, State of Sao Paulo, Brazil. The incidence was about 1 to 2% and the diseased plants were distributed at random. Since these symptoms are indicative of infection by phytoplasmas, the present study aimed to detect and identify the phytoplasma. Four symptomatic and two asymptomatic plants were sampled. Small segments of leaf veins were prepared for microscopy, as previously reported (1), and observations were made using a Jeol (Akishima/Japan) model Jem-1011 transmission electron microscope. Total DNA was extracted from leaves using a commercial kit (DNeasy Plant Mini, Qiagen Inc.), and nested PCR assays were performed with primers, Pi/Tint followed by R16F2n/R16R2 (2). The initial assumption that disease symptoms were associated with phytoplasma was confirmed by PCR amplification of 1.2 kb DNA fragments from the 16S rDNA gene. In contrast, no amplicon was generated with PCR using template DNA from asymptomatic plants. The phytoplasma detected from each symptomatic sample was considered to be an isolate. FCR products were purified and cloned in Escherichia coli DH5a, using the pGEM-T Easy Vector System I (Promega). Three isolates were selected and the cloned 16S rDNA sequences from three colonies of each isolate were sequenced. Since no sequence polymorphisms were found, a majority consensus sequence was selected for each isolate. These sequences were identical and one of them, designated CrSP-BrOl (crotalaria shoot proliferation) with 1,249 bp (GenBank Accession KC756947), was used as representative of the sunn hemp phytoplasma. The 16S rDNA nucleotide sequence of this phytoplasma shared 100% sequence identity with the reference phytoplasma for subgroup VII-C (Argentinian Alfalfa witches'broom phytoplasma, AY 147038). According to the in silico RFLP analysis for delineation of subgroups (3), which is based on virtual RFLP patterns and similarity coefficient calculation, the C. juneea phytoplasma was classified as a member of group lóSrVII, subgroup C. Phylogenetic analysis supported that this phytoplasma is closely related to the representative of subgroup 16SrVII-C, since both phytoplasmas emerged from the same branch. Transmission electron microscopic examination revealed the presence of phytoplasmas by visualization of pleomorphic and round bodies 100 to 400 nm in diameter, in the phloem vessels of symptomatic plants. The present study reports the first occurrence of a 16SrVIl-C phytoplasma in Brazil. In addition, C. juneea was identified as a new host for phytoplasmas belonging to this subgroup.

Sesame (Sesamum indicum L.) production in Paraguay has been severely affected by infection with Cowpea aphid-borne mosaic virus (CABMV), which causes a disease known locally as ka'are. Because very little is known about the epidemiology of this disease, a survey was performed in fields surrounding affected sesame plantations to identify CABMV-infected plants that may be acting as sources of inoculum. Samples from 48 plant species (symptomatic or asymptomatic, mostly spontaneous and a few cultivated) belonging to 17 families were evaluated by biological and serological assays. In a few select cases, confirmation of the infection was achieved by RT-PCR. The following species were found to be naturally infected by CABMV: Amaranthus hybridus, Arachis hypogaea, Crotalaria incana, Crotalaria juncea, Crotalaria spectabilis, and Vigna unguiculata. The absence of resistant/tolerant sesame cultivars along with the ineffectiveness of disease control through the chemical control of aphid vectors indicates that the only alternative available for disease management at present is the elimination and/or reduction of the sources of inoculum immediately before starting new plantations.