Reaction of durum wheat cultivars to mixed SBWMV and WSSMV infection in central Italy

Forty-three cultivars of durum wheat (Triticum durum Desf.) were grown during the 1998–99 growing season in a field near Rome with natural inoculum sources of Soilborne wheat mosaic virus (SBWMV) and Wheat spindle streak mosaic virus (WSSMV), to evaluate their resistance to the mixed infection. Leaf extracts from twelve cultivars had relatively low ELISA values for WSSMV, and thirteen had low ELISA values for SBWMV. Results confirmed the high level of resistance to SBWMV of the cultivars Colorado, Ionio and Neodur. The reactions of the cultivars to SBWMV were consistent with those recorded in previous trials near Bologna, northern Italy, indicating that the SBWMV strains at the two test sites were pathogenically similar. Disease severity was significantly correlated with grain yield, thousand-kernel weight, heading date and the SBWMV-ELISA value, but not with the WSSMVELISA value. Regression analysis showed that, as a result of the mixed infection, the four cultivars with the most severe disease symptoms headed about 5 days later than normal, and suffered grain yield and kernel weight reductions of about 56 and 10% respectively. Cultivars with milder symptoms were also severely affected

Mapping genetic factors for resistance to Soil-borne cereal mosaic virus (SBCMV) in durum wheat

Article first published online: 8 FEB 2014OBJECTIVE: In an unselected group of women with signs of preterm labour, maintenance tocolysis is not effective in the prevention of preterm birth and does not improve neonatal outcome. Among women with signs of preterm labour, those who are fetal fibronectin positive have an increased risk of preterm birth. We investigated whether maintenance tocolysis with nifedipine would delay delivery and improve neonatal outcome in women with threatened preterm labour and a positive fetal fibronectin status. STUDY DESIGN: Women with a singleton pregnancy in threatened preterm labour (24(+0) to 33(+6)  weeks) with a positive fetal fibronectin test were randomised to nifedipine or placebo. Study medication was continued until 36 completed weeks' gestation. The primary endpoint was prolongation of pregnancy of seven days. Secondary endpoints were gestational age at delivery and length of NICU admission. RESULTS: Of the 60 participants, 29 received nifedipine and 31 placebo. Prolongation of pregnancy by >7 days occurred in 22/29 (76%) in the nifedipine group and 25/31 (81%) in the placebo group (relative risks, RR 0.94 [0.72-1.2]). Gestational age at delivery was 36.1 ± 5.1 weeks for nifedipine and 36.8 ± 3.6 weeks for placebo (P = 0.027). Length of NICU admission [median (interquartile ranges, IQR)] was 27 (24-41) days and 16 (8-37) days in nifedipine and placebo groups, respectively (P = 0.17). CONCLUSION: In women with threatened preterm labour who are fetal fibronectin positive, maintenance tocolysis with nifedipine does not seem to prolong pregnancy, nor reduce length of NICU admission.Emma Parry, Carolien Roos, Peter Stone, Lynsey Hayward, Ben Willem Mol and Lesley McCowa

A major QTL for resistance to soil-borne cerealmosaic virus derived from an old Italian durum wheat cultivar

The genetic basis of resistance to soil-borne cereal mosaic virus (SBCMV) in the Triticum turgidum L. var. durum cv. Neodur was analyzed in this study, using a linkage mapping approach. We performed phenotypic and molecular analyses of 146 recombinant inbred lines derived from the cross Cirillo (highly susceptible)×Neodur (highly resistant). A major quantitative trait locus (QTL) that explained up to 87% of the observed variability for symptom severity was identified on the short arm of chromosome 2B, within the 40-cM interval between the markers Xwmc764 and Xgwm1128, with wPt-2106 as the peak marker. Three minor QTLs were found on chromosomes 3B and 7B. Two markers coding for resistance proteins co-segregate with the major QTL on chromosome 2B and the minor QTL on chromosome 3B, representing potential candidate genes for the two resistance loci. Microsatellite markers flanking the major QTL were evaluated on a set of 25 durum wheat genotypes that were previously characterized for SBCMV resistance. The allelic composition of the genotypes at these loci, together with pedigree data, suggests that the old Italian cultivar Cappelli provided the SBCMV-resistance determinants to durum cultivars that have been independently bred in different countries over the last century

Sixth Symposium of the International Working Group on Plant Viruses with Fungal Vectors

Dal 5 al 7 Settembre presso l\u2019Aula Prodi (P.zza S. Giovanni in Monte) si \ue8 svolto il sesto congresso internazionale del Working Group on Plant Viruses with Fungal Vectors (IWGPVFV). IWGPVFV \ue8 un gruppo internazionale di ricerca sui virus delle piante trasmessi dal terreno mediante vettori fungini e protozoi. Virus questi ultimi che sono responsabili di numerose malattie nelle colture cerealicole, industriali e orticole a livello mondiale. Durante i tre giorni del convegno, a cui hanno partecipato circa 130 relatori provenienti dall\u2019Europa, dall\u2019Asia, dall\u2019America, dall\u2019Africa e dall\u2019Australia, sono state discusse una settantina di ricerche riguardanti la caratterizzazione e tassonomia dei virus delle piante trasmessi da funghi e protozoi, la caratterizzazione biologica e molecolare dei vettori di tali virus, l\u2019epidemiologia e il controllo delle malattie con particolare riguardo allo studio dei meccanismi di interazione ospite - patogeno e le fonti di germoplasma nell' ambito della resistenza alle virosi. Il Convegno, patrocinato dall\u2019Universit\ue0 di Bologna e sponsorizzato da UniboCultura e Promega Italia, \ue8 organizzato dalla Dott. ssa Concepcion Rubies Autonell, del DiSTA della Facolt\ue0 di Agraria dell\u2019Universit\ue0 di Bologna e dal Dr Victor Vallega, C.R.A. Istituto Sperimentale per la Ricerca Cerealicola di Roma. All\u2019organizzazione del convegno hanno collaborato la Dott.ssa Annamaria Pisi e il Dr. Claudio Ratti del DiSTA della Facolt\ue0 di Agraria dell\u2019Universit\ue0 di Bologna. Ulteriori informazioni possono riscontrarsi nei siti: www.agrsci.unibo.it/iwgpvfv/ e www.rothamsted.bbsrc.ac.uk/ppi/Iwgpvfv/index.htm