Sudhir Chandra

The nutrition of Colletotrichum gloeosporioides Penz

Colletotrichum gloeosporioides could grow and sporulate on a wide range of pH (viz., from 3.0 to 8.5). The best growth was obtained at pH 6.0. Mannitol proved to be the best carbon source. Good growth and sporulation were also observed on maltose, glucose, galactose and sucrose. Nitrates supported better growth than ammonium compounds. Glutamic acid was found to be the best amino acid. Nitrites inhibited the growth completely at acid pH values but they supported growth at alkaline pH. Mannitol-glutamic acid was most suitable carbon-nitrogen combination for growth. Magnesium sulphate was the only sulphur source which was good both for growth and sporulation. The organism could not grow on media lacking carbon, nitrogen or sulphur.

Three new leaf-infecting fungi from allahabad

The fungi described in this paper were isolated during the course of a detailed survey of leaf-spot diseases of Allahabad and adjacent regions. A comparative s tudy indicated the forms reported here viz., Colletotrichum sp. from Sapindus lauri/olius VAHL., Pyrenochaeta sp. from Gardenia florida L. and Phoma sp. from Ehretia acuminata BR., to be distinct from the hitherto described species of the respective genera. They are thus reported here as new species. 1. Colletotrichum sapindi sp. nov. On living leaves of Sapindus lauri/olius VAHL., Alfred Park, Allahabad, September 1963, leg. S.C. (Fig. 1). Symptoms of the disease: the infection started near the margin where a small area of lamina turned light cinnamon drab. This area gradually increased inwards and its colour changed to cinnamon drab. Very minute acervuli appeared after a few days on the

Studies on the pectolytic enzymes ofaspergillus terreus Thom

Aspergillus terreus, the causal organism of fruit-rot of apples produced pectin methylesterase (PME) and depolymerase (DP) on a number of substrates. The production of polygalacturonase (PG) was restricted to few substances only and appeared to be adaptive. PME as well as hydrolytic activities were maximum when cultures were incubated at 25°C. The pH of the substrate for maximum PME and hydrolytic activities was 5.5 and 5.0 respectively.

Effect of organic soil amendments on the rhizosphere microflora of tomato

Effect of organic amendments on the microbial population of rhizosphere and non-rhizosphere soils was studied taking a number of dry and green plant materials. All the amendments had marked stimulatory/inhibitory effects on the population of fungi and bacteria in the rhizosphere but the magnitude varied with the amendment as well as variety and age of the plant. They also affected the relative population of different fungi in the rhizosphere. A number of them suppressed the population of Fusaria and stimulated that of Aspergilli.

Incidence of Aspergillus flavus in Rice and Rice Products in Uttar Pradesh, India

One hundred and thirteen samples of rice and rice products collected from different places in thirty-three districts of Uttar Pradesh were screened for their associated mycoflora employing standard techniques. In addition to forms belonging to Penicillium, Alternaria, Curvularia, Cladosporium, Fusarium, Helminthosporium, Rhizopus and Trichoderma species, a number of Aspergilli were found associated externally and internally with the samples, represented by A. flavus, A. fumigatus, A. niger, A. flavipes, A japonicus, A terreus, A parasiticus, A. tamarii and A ochraceous. Many of the samples especially those collected from damp areas of the state were heavily infested with A. flavus.