Volume 27, Issue 6
June 1948, pages 153-193
pp 153-160 June 1948
pp 161-173 June 1948
A species ofPythium with filamentous sporangia was isolated from rotting fruits ofHibiscus esculentus L. collected at Podanur, Coimbatore District, South India. A detailed study of the fungus showed it to be a form related toPythium indigoferœ,P. deliense andP. aphanidermatum but possessing certain characteristics which mark it as different from these three species. On account of these differences, it is considered a new species and namedP. indicum. Inoculation experiments showed it to have a wide host range. Only one other species of Pythium—P. de Baryanum Hesse—has been so far recorded onHibiscus esculentus.
pp 174-193 June 1948
The morphology of four isolates ofPiricularia fromOryza sativa Linn.,Eleusine coracana Gaertn.,Setaria italica Beauv., andDigitaria marginata Link., has been studied. No appreciable difference in the morphological characters of the isolates was noticed.
The physiology of the isolates was studied. A study of their growth on different media, the optimum temperature and pH range for their growth was made. The effect of different sources of carbon and nitrogen and their different ratios in the medium on the growth of the isolates was investigated. The enzymes produced by the isolates were qualitatively tested for.
Cross-inoculation studies were conducted under optimum conditions for infection of the hosts.
The studies reported in this paper have established the importance of attacking problems of classification of fungal parasites from three angles, namely, morphology, physiology and pathology and these aspects considered interdependenty and not independently. With the results obtained an attempt has been made to classify the isolates within the genus.