| dc.description.abstract | Potato is one of the world most important crops after rice, wheat, and maize. One of the major constraints to potato production is yield losses due to bacterial wilt (Ralstonia solanacearum). Planting resistant potato cultivars is an effective measure to control the disease, but resistant potato cultivars are lacking. Genetic resistance to bacterial wilt were found in wild potato species, such as Solanum chacoense. A research was carried out from January to September 2007 with objectives: (1) to find clones of wild potato Solanum chacoense that are resistant to the bacterial wilt, both in vitro and in the field; (2) to obtain an effective inoculation in vitro technique for evaluation of resistance to the disease, and (3) to identify an in vitro technique that give comparable results to that from the field trial. The research activities consisted of an in vitro trial and a field trial. Nineteen S. chacoense clones were evaluated for their resistance to bacterial wilt, and one susceptible potato cultivar Atlantic was used as a susceptible check. In the in vitro trial, two inoculation techniques were evaluated, i. e., the flooding and the leaf clipping techniques. The trial was arranged in a Factorial Experiment using a Completely Randomized Design with three replications. In the field trial, which was carried out in Pasir Sarongge, Cianjur, West Java (+1100 m above sea level), a Randomized Block Design with five replications was used to evaluate resistances of the potato clones. The trial was carried out in a homogenous heavily infested soil. Results of the trials showed that resistances of the 19 S. chacoense clones varied. These were indicated by the incubation period and incidence of the disease of each clones. Two of the clones (Pi230580 no. 01 and 03) were resistant to the disease both in vitro and in the field. Another clone (Pi230580 no. 04) was found resistant to the disease in the evaluation using the flooding technique. Among the clones in the field trial, four clones were moderately resistant, 6 clones were moderately susceptible, and 7 clones were susceptible. Both the flooding and leaf clipping techniques were effective for in vitro evaluation of the potato clones for resistance to the bacterial wilt, and the results was comparable to that from the field trial. The leaf clipping technique is preferably chosen for the in vitro evaluation of potato clones for resistance to bacterial wilt, since it showed results comparable to that of the field trial. Besides, comparing to the flooding technique, the leaf clipping technique was more effective in inoculum spreading and more efficient in time and number of inoculum used. | id |
