Occurrence of African cassava mosaic virus (ACMV) and East African cassava mosaic virus – Uganda (EACMV-UG) in Jatropha curcas

Poster presentation from IUFRO Tree Biotechnology Conference 2011: From Genomes to Integration and Delivery Arraial dAjuda, Bahia, Brazil. 26 June - 2 July 2011(VLID)90654

Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas

<p>Abstract</p> <p>Background</p> <p>Geminiviruses infect a wide range of plant species including <it>Jatropha </it>and cassava both belonging to family <it>Euphorbiaceae</it>. Cassava is traditionally an important food crop in Sub - Saharan countries, while <it>Jatropha </it>is considered as valuable biofuel plant with great perspectives in the future.</p> <p>Results</p> <p>A total of 127 <it>Jatropha </it>samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA) for RNA viruses and polymerase chain reaction for geminiviruses. <it>Jatropha </it>samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA) were negative for all three RNA viruses tested: <it>Cassava brown streak virus </it>(CBSV), <it>Cassava common mosaic virus</it>, <it>Cucumber mosaic virus</it>, Three cassava samples from Busia district (Kenya) contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to <it>African cassava mosaic virus </it>(ACMV) and <it>East African cassava mosaic virus </it>- <it>Uganda</it>. This information enabled the design of novel primers to address different questions: a) primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in <it>Jatrophia</it>; b) primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in <it>J. curcas</it>. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in <it>Jatropha</it>.</p> <p>Conclusion</p> <p>Cassava geminiviruses occurring in <it>Jatropha </it>might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully.</p

Identification and GroEL gene characterization of green petal phytoplasma infecting strawberry in Italy

none5The presence of phytoplasmas in strawberry showing malformation of the fruits together with the typical green petals symptoms was detected in some North Western Italy cultivations. Nucleic acids extracted from these plants were used in nested-PCR assays with primers amplifying 16S rDNA and GroEL sequences specific for phytoplasmas. Bands of 1.2 kb were obtained in both cases after nested-PCR assays and RFLP analyses allowed to classify the detected phytoplasmas in the aster yellows subgroup 16SrI-C, the GroELI grouping confirm all the strains from strawberry to be identical to each other and to GroELI-VI group. This is the first multigene molecular identification of strawberry green petals phytoplasmas in Italy.openContaldo N.; J.F. Mejia; S. Paltrinieri; A. Calari; A. BertacciniContaldo N.; J.F. Mejia; S. Paltrinieri; A. Calari; A. Bertaccin

Investigation of genetic variation in Jatropha curcas by Ecotilling and ISSR

The ability of species to adapt to different environments resides in their genetic diversity. This diversity, most commonly manifested as Single Nucleotide Polymorphisms (SNPs), can provide clues to the adaptive processes and population histories that have played a role in the species ’ evolution. A number of different techniques for identifying SNPs have been developed, all having their limitations. Reverse genetics approaches rely on the detection of sequence alterations in target genes to identify allelic variations in natural or mutant populations. Ecotilling, a variant of TILLING (Targeting Induced Local Lesions IN Genomes) technique, allows high-throughput analyses of natural genetic diversity in plants [1], particularly in species with limited genetic diversity. Jatropha curcas L. is a perennial, monoecious shrub of the Euphorbiaceae family, native to America but distributed widely in the tropical and subtropical areas [2]. Wild or semi-cultivated types of J. curcas can grow well under unfavourable climatic and soil conditions [3]. J. curcas has attracted a great deal of attention worldwide, regarding its potential as a new energy plant. The seeds of J. curcas contain 30-45 % oil [4] with a high percentage of monounsaturated oleic and polyunsaturated linoleic acid [5]. For genomic analyses, J. curcas is an interesting model species, since it has a relatively small genome (2C DNA content of 0.850 ± 0.006 pg or C DNA content of 0.416 × 109 bp) [6]. However, to achieve specific breeding goals in Jatropha for wider ecological adaptation, disease resistance and novel seed quality, the use of germplasm from different group and regions is necessary. Understandin

La virescenza della Digitale lanata

Considerando l’importanza nel settore erboristico delle specie appartenenti al genere Digitalis e specificatamente di quella lanata (vedi riquadro), nonché il ruolo sempre maggiore che nell’ultimo decennio stanno assumendo i fitoplasmi nell’ambito della patologia delle piante officinali,si ritiene utile riportare i risultati delle ricerche eseguite sulla Virescenza della digitale lanata La malattia della virescenza è stata osservata all’inizio di maggio in un piccolo impianto di digitale lanata, al secondo anno di coltivazione, del Giardino delle Erbe di Casola Valsenio. La sintomatologia è apparsa subito alquanto complessa e consistente, per quanto riguarda le foglie, in giallumi e, a volte, anche arrossamenti del lembo. Caratteristici apparivano i sintomi a livello dei fiori, soprattutto al momento della fioritura (fine maggio), con racemi in parte costituiti da fiori normali, in parte da fiori completamente verdi. La localizzazione dei singoli fiori virescenti lungo la spiga appariva del tutto casuale: nella zona distale od in quelle laterali. A volte, le spighe erano multiple, ossia arricchite da altre di piccole dimensioni, con virescenza e fillodia (scopazzi); nei casi più gravi, al posto dei racemi si formavano ammassi di minuscole foglioline verdi e/o giallastre (fillodia e rosettamento), con conseguente nanismo della pianta. Le analisi molecolari eseguite sui campioni di digitale lanata hanno portato all’identificazione di fitoplasmi appartenenti al sottogruppo 16SrI-B. Il gruppo 16SrI (giallume dell’astro: AY) è associato ad un numero molto elevato di malattie importanti dal punto di vista economico. E’ un gruppo diffuso in tutto il mondo, ma come accennato nella introduzione, nessun fitoplasma, né di questo, né di altri gruppi tassonomici, era mai stato individuato in D. lanata. All’incirca 10 anni fa, nello stesso Giardino delle Erbe, un’altra specie di digitale, D. lutea L. (affetta da giallume) era stata riscontrata infetta da fitoplasmi appartenenti sempre al sottogruppo 16Sr-IB. Dal punto di vista epidemiologico è quindi lecito supporre che il patogeno si conservi da un anno all’altro in questo Giardino in specie spontanee e/o coltivate, oppure negli stessi insetti vettori (cicadellidi), responsabili della sua trasmissione alle piante sane

Identification of phytoplasmas belonging to aster yellows ribosomal group in vegetables in Serbia

Leaf and root samples of carrot, and flower samples of broccoli with symptoms referable to phytoplasma presence were collected and tested for phytoplasma presence. Detection, identification and molecular characterization were performed on 16S rDNA, Tuf, rpS3, putative aminoacid kinase and putative DNA helicase phytoplasma genes. Analyses of all five DNA fragments showed that carrot was infected with aster yellows phytoplasmas belonging to ribosomal subgroups 16SrI-A and 16SrI-B and broccoli only with phytoplasmas belonging to ribosomal subgroup 16SrI-B

Detection and molecular characterization of a phytoplasma associated with frogskin disease in Cassava.

none7Cassava frogskin disease (CFSD) is an economically important root disease of cassava (Manihot esculenta) in Colombia and other South American countries, including Brazil, Venezuela, Peru, Costa Rica, and Panama. The roots of severely affected plants are thin, making them unsuitable for consumption. In Colombia, phytoplasma infections were confirmed in 35 of 39 genotypes exhibiting mild or severe CFSD symptoms either by direct or nested polymerase chain reaction (PCR) assays employing ribosomal (r)RNA operon primer pairs. The CFSD-associated phytoplasmas were identified as group 16SrIII strains by restriction fragment length polymorphism (RFLP) and sequence analyses of amplified rDNA products, and results were corroborated by PCRs employing group 16SrIII-specific rRNA gene or ribosomal protein (rp) gene primers. Collectively, RFLP analyses indicated that CFSD strains differed from all phytoplasmas described previously in group 16SrIII and, on this basis, the strains were tentatively assigned to new ribosomal and ribosomal protein subgroups 16SrIII-L and rpIII-H, respectively. This is the first molecular identification of a phytoplasma associated with CFSD in cassava in Colombia.mixedAlvarez E.; J.F. Mejia; G.A. Llano; J.B. Loke; A. Calari; B. Duduk; A. BertacciniAlvarez E.; J.F. Mejia; G.A. Llano; J.B. Loke; A. Calari; B. Duduk; A. Bertaccin

Characterization of a phytoplasma associated with frogskin disease in cassava

Cassava frogskin disease (CFSD) is an economically important root disease of cassava (Manihot esculenta) in Colombia and other South American countries, including Brazil, Venezuela, Peru, Costa Rica, and Panama. The roots of severely affected plants are thin, making them unsuitable for consumption. In Colombia, phytoplasma infections were confirmed in 35 of 39 genotypes exhibiting mild or severe CFSD symptoms either by direct or nested polymerase chain reaction (PCR) assays employing ribosomal (r)RNA operon primer pairs. The CFSD-associated phytoplasmas were identified as group 16SrIII strains by restriction fragment length polymorphism (RFLP) and sequence analyses of amplified rDNA products, and results were corroborated by PCRs employing group 16SrIII-specific rRNA gene or ribosomal protein (rp) gene primers. Collectively, RFLP analyses indicated that CFSD strains differed from all phytoplasmas described previously in group 16SrIII and, on this basis, the strains were tentatively assigned to new ribosomal and ribosomal protein subgroups 16SrIII-L and rpIII-H, respectively. This is the first molecular identification of a phytoplasma associated with CFSD in cassava in Colombia