Reaction Of Sweetpotato Genotypes to Botryodiplodia Theobromae Pat. and Macrophomina Phaseolina Tassi

Crisanta  E. Sajise,; Carlito  Palermo,

Reaction Of Sweetpotato Genotypes to Botryodiplodia Theobromae Pat. and Macrophomina Phaseolina Tassi

Abstract:

Sweetpotato genotypes were screened for resistance to Botryodiplodia theobromae Pat. and Macrophomina phaseo/ina Tassi, the two major postharvest pathogens found infecting sweetpotato roots during storage.in the Philippines. The effect of different stages of maturity of sweetpotato plants on host resistance and the nature of postharvest disease development were also investigated, Assessment of 437 genotypes for resistance to B. theobromae infection showed that 0.7% and 15% were highly resistant and resistant, respectively. Out of 434 genotypes evaluated for resistance to M phaseolina only 0.2% and 6% were noted to be highly resistant and resistant, respectively. Majority of the genotypes screened against both pathogens were found to be moderately susceptible to susceptible. Roots taken from 3 months old plants were more resistant to infection by either B. theobromae or M phaseolina than those taken from 4 and 5 months old plants. The resistant, moderately resistant, and susceptible lesion types were categorized based on visual and histological examinations. Ipomeamarone was detected in inoculated resistant, moderately resistant and moderately susceptible sweetpotato roots but not in susceptible roots. No visible formulation of ipomeamarone was noted in healthy uninoculated roots.

References:

AKASAWA, T. and URITANI, I. 1961. Influence of environmental temperatures on metabolic alteration related to disease resistance in sweet potato root infected by black rot. Phytopath. 51:668-674.
AVINZE, A.F., NAQVI, SH. Z. and EXUNDAYO, J.A. 1975. Storage rot of sweet potato (Ipomoea batatas) and effect of fungicides. Int. Biodeter. Bull. 11:41-47.
CENTER FOR OVERSEAS RESEARCH. 1978. Pest control in tropical root crops. PANS Manual No. 4235 pp.
DALISAY, R.F., DIVINAGRACIA, G.G., and MENDOZA, E.M.T. 1987. Screening sweet potato roots for resistance to Java Black Rot caused by Diplodia tubericola (Ell. and Ev.) Taubenn. Phil. J. Crop Sci. 12(1):33-37.
GRAINGER, J. 1968. Cp/Rs and the disease potential of plants. Hort. Res. 8:1-40.
JENKINS, P.D. 1981. Difference in the susceptibility in the sweet potatoes (Ipomoea batatas) to infection by storage fungi in Bangladesh. Phytopath. 2(102):247-256.
KOJIMA, M. and URITANI, I. 1976. Possible involvement of furanoterpenoid phytoalexins in establishing host-parasite specificity between sweet potato and various strains of Ceratocystis fimbriata. Physio. Plant Path. 8:97-111.
MARTIN, W.J. 1971. Evaluation of fungicides for effectiveness against the sweet potato black spot fungus, Ceratocystis fimbriata. Plant Dis. Rep. 55:523-526.
MARTIN, W.J., HASLING, V.C., CATALANAO, E.A. and DUPUY, H. 1978.Effect of sweet potato cultivars and pathogens on Ipomeamarone content of diseased tissues. Phytopath. 68:863-865.
NORKRANS, B. 1963. Degradation of cellulose, Ann. Rev. Phytopath. 7:325-350.
OGUNDANA, S.K. 1971. The postharvest decay of young tubers and its preliminary control in Nigeria. In: Biodeterioration of Materials. E.H. Walter and E.H. Huck vander Plas (eds.). 2:481-492.
PALOMAR, M.K., SOLIS, A.D. and BANDALA, H.S. 1980. Sweet potato tuber rot disease in the Philippines. Ann. Trop. Res. 2:11-121.
SARDSUD, V. 1979. Ingress, internal spread of some factors affecting pathogenecity of Diplodia tubericola (E. and E.) Taub. in sweet potato. M.S. Thesis, UP at Los Baños.
STAHMAN, M.A., CLAIRE, B.C. and WOODBURG, W. 1966. Increased disease resistance and enzyme activity induced by ethylene production by black rot infected sweet potato tissue. Plant Physio. 41-1512.
TUITE, J. 1969. Plant pathological methods: fungi and bacteria. Burgess Publ. Co., USA. 239 р.
URITANI, I. 1965. Molecular pathology in the plant field with special regard to defense action of the host. Biochemische Problems der Kranken Pflanze, Vortrage Lines Symposium. Inst. Phytopath. Aschersloban, Desch. Akad. Landdw. Wiss. Berlin. pp. 201-218.