Proceedings Volume 2010 (format .pdf) - SimpBTH

All the biological material (positive and negative controls) was obtained from thevirus collection of our institute. The potato varieties tested in our research were thefollowing:- Christian, Romano, Roclas, Dacia, Ruxandra (roumanian cv.)- Ostara, Desiree, Hermes, Sante, Koretta (foreign cv.)Our researches regarding the behaviour of these varieties were done in green houseconditions. From each variety, 8 pots (with 1 eye pieces) were planted. Plants weregrown in 18 cm pots and were maintained at 18-22 o C with 14 hour day length.After emergence, plants have been mechanicaly inoculated, using an Y NTN isolate(Vital variety). After the inoculation, disease symptoms were observed and ELISAtests have been made. The infection of this material was confirmed by usingantiserum from Bioreba (Switzerland) and antiserum obtained in our laboratory(Cojocaru et al., 2009). The percentage of tubers with necrotic symptoms wasestimated at harvesting time and later (after 3 months).2.3.ELISA testA press with smooth roles was used for preparation leaf samples. For the tubertesting, the sap was extracted, diluted and dispensed directly into the plate usingthe extractor Microlab 500B/C (Hamilton). We tested sprouting tubers after naturalbreak of dormancy, when the sprouts were 2-3mm long. The antiserum andconjugated used for viruses detection were obtained in our laboratory (Cojocaru etal., 2009). Microplates-NUNC microplates were coated with antibodies forovernight incubation in the refrigerator. The analysis was performed followingessentially the protocol described by Clark and Adams (1977). We used 100 µlfrom each reactives solutions in each well of the plate (Clark and Adams 1977,Badarau et al. 2009, 2010). All experiments were repeated four times. Rinsedmicroplates were filled with substrate solution (p-nitrophenylphosphate) incubated60 minute and the absorbance values were estimated at 405 nm (A 405 ) on PR1100reader. The samples having A 405 values exceeding the cut-off (two times theaverage of healthy control samples) were considered virus infected.2.4.Quality characteristicsDry matter (thermoventilated oven at 105 o C), total protein content (Kjeldalmethod) were determined on healthy tubers before planting them in the pots. Wechoosed a representative sample of tubers per plot. The sample for these analysiswere choosed from each 2 tubers (2 tubers/sample). The quality characteristicsdetermination was made in four repetitions.2.5.Statistical interpretationEach set of comparable assay was conducted at the same time and with the samebulk sample. Analysis of variance (ANOVA) and Duncan’s multiple range testwere used to analyze the data. In the aim to illustrate the precision of the mean weuse confidence interval (CI).11