Studies on soft rot Erwinias infecting potato in Mauritius
| MSI99P0035 | |
| Dookun, A. | |
| University of Newcastle-upon-Tyne, Newcastle, GB | |
| Studies on soft rot Erwinias infecting potato in Mauritius | |
| Thesis, M.Sc. | |
| Thesis | |
| 1986 | |
| 197 p.: 37 tbls., 6 figs., 38 pl. | |
| En | |
| En | |
| A detailed study of Erwinia spp. causing soft rot in potato was carried out for the first time in Mauritius. Using cultural, morphological, biochemical, and physiological characteristics, Erwinia carotovora subsp. carotovora (Ecc), Erwinia carotovora subsp. atroseptica (Eca) and Erwinia chrysanthemi (Echr) were identified. Out of 104 isolates from potato and various hosts, 74, 22 and 2 were Ecc, Eca, and Echr respectively and the remaining 6 had intermediate properties. All the isolates were further characterised by serological tests. Antisera produced against glutaraldehyde fixed cells of Ecc, Eca and Echr isolates from potato proved to be specific to their homologous antigens in immuno-diffusion tests. The viability and population density of erwinias on tubers were found to decrease markedly in storage at 4°C after 4 months and were almost undetectable after eight months. Among four potato varieties tested against Ecc and Eca, variety Mariline was highly susceptible while varieties Spunta, Up-to-date and Delaware were found to be slightly susceptible. In the same varieties, Ecc was more virulent than Eca. No difference in syndrome was found among Ecc, Eca and Echr when inoculated in glasshouse and in field under natural conditions of infection. Under field conditions no difference in disease uptake was obtained on inoculation of tubers by pricking with undiluted bacteria from pure cultures or by dipping in a bacterial suspension. However, best disease expression was obtained on inoculation at the middle part of stems from six weeks old plants. Tests carried out on tubers of commercial varieties showed that latent infection was widespread. No depressing effect on yield was found in the varieties inoculated with Ecc, Eca and Echr. It appears that the erwinias are of wide occurence in Mauritius, but have little economic importance except in humid and warm conditions prevailing in early and late summer. | |
| POTATOES ERWINIA ERWINIA CAROTOVORA ERWINIA CHRYSANTHEMI BACTERIAL DISEASES DISEASES SOFT ROT MARILINE DELAWARE UP-TO-DATE SPUNTA | |
| MAURITIUS | |
| Potatoes: Diseases and disease management | |
| Bacterial diseases: Soft rot | |
| 633.491:632.3 | |
| 1991-10-24 | |
| En | |
| Mauritius Sugar Industry Research Institute | |
| LIB | |
| CAT | |
| 1 | |
| PATH |