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Biomedical subjects

M Prasad

Publications and source records attributed to M Prasad.

At least 109 records · Page 6Linked to original sources
PubMed1978

Serologic studies of the maize stalk rot pathogen Erwinia carotovora f. sp. zeae.

With the help of serological techniques, namely microprecipitin, agglutination, and gel diffusion, sixteen isolates of maize stalk rot pathogen were proved to be identical. Serological techniques have thus been utilized as an additional tool for identifying the pathogen Erwinia carotovora f. sp. zea. It was also established that the pathogen does not perpetuate in the seed, either externally of internally. It could, however, be found through serological tests that infected ears carried the pathogen and transmitted it as a contaminant to the healthy seeds.

Agglutination Tests↗
PubMed1978

Effect of C.C.C. [2-(chloroethyl)] trimethyl ammonium chloride on growth and sporulation in Fusarium oxysporum f. udum (butl.) Sn. et H.

In Fusarium oxysporum f. udum sporulation of macroconidia was completely inhibited due to the influence of C.C.C. [2-(Chloroethyl)] trimethyl ammonium chloride). Microconidial proliferation, on the other hand, was adversely affected and with increase in concentration of this compound a parallel and proportional decrease in the amount of microconidia was found. Size of microconidia, too, showed a concomitant decline. Although the size of the chlamydospores was also reduced, a tremendous increase in its population was evident, showing a positive response in favour of C.C.C. addition. Fungal mat accumulation, another important aspect of growth, did not evince any inhibitory pattern, compared to the progressive increase in C.C.C. amoung in younger cultures. In older cultures (15-day old), an initial depressing shock of C.C.C. addition could be seen. However, after stepwise and gradual adjustment to the new environment the same positive response of mycelial growth was discernible, although in a less degree than that of the young cultures.

Fusarium↗
PubMed1978

Systemic lupus erythematosus presenting as chorea.

A child presenting with chorea developed the full clinical and laboratory findings of systemic lupus erythematosus after hospitalisation. He responded dramatically to haloperidol. 6 months after diagnosis he began to manifest renal involvement.

Child↗
PubMed1977

Application and standardization of various procedures for inoculation of maize by Erwinia carotovora f. sp. zeae.

Hypodermic syringe and toothpick methods were best for evaluating pathogenicity of the maize plant against Erwinia carotovora f. sp. zeae, both in glass house and in the field. The portion of the stalk above the ground was best suited for reproducing the disease symptoms. Leaf and leaf whorl did not show any rotting hero. Seed inoculation showed least mortality percentage. Root inoculation was suitable only for young seedlings. Cotyledons, as an organ for inoculation for getting best reproducible infection, were not at all suitable.

Bacteriological Techniques↗
PubMed1977

Bacterial stalk rot of Maize, its symptoms and host-range.

Stalk rot of maize, caused by Erwinia carotovora f. sp. zeae Sabet (re-designated as Pectobacterium chrysanthemi pathovar. zeae by KELMAN 1974) showed first premature withering and drying up of the uppermost leaves which was soon followed by the lower leaves. The rot either extended from the base upwards (basal rot) or from the top downwards (top rot). In the case of basal rot, the leaves become yellow and the infected tissue becomes brown, soft, and water soaked. Internally, the stalk turns into a soft mass of disintegrated tissue. At this stage the plants usually topple over. A foul odour, accompanied with the presence of dipterous larvae on and in decaying tissues, are the characteristic symptoms of this disease. With the advance of the disease the stalk finally dries up into a conglomeration of dry and shredded or disjointed fibrous tissue. The top rot begins with wilting and drying up ot the tips of middle leaves of the whorl. A decay that continues rapidly spreads downwards throughout the stalk and the affected plants soon droop. The host range studies were suggestive of the fact that the maize pathogen, apart from causing the disease on maize, could produce soft rot in potato, carrot, onion, sugarbeet, sweet potato, papaya, cabbage, and many other plants and could also infect Sorghum vulgare, Pennisetum typhoidium, tobacco, and tomato.

Ecology↗
PubMed1977

Studies on certain aspects of chemical control of bacterial stalk rot disease of maize.

Sandoz seed dressing 6335 showing high efficacy in checking the growth of the maize stalk rot pathogen Erwinia carotovora f. sp. zeae Sabet in culture. Brestan, Antracol, Difolatan, Aratan, Duter, Ceresan wet, Flit-406, Cuman, Blitox-50, Streptocycline, Agrimycin, Terramycin, Actidione, Aureomycin, Chloromycetin, Penicillin G, and Streptomycin were moderately effective. The rest of the 35 chemicals was negligible in its influence. 15 different chemicals, namely Agrimycin, Streptocycline, Chloromycetin, Sodium penicillin G, Actidione, Terramycin, Aureomycin, Sandoz seed dressing 6335, Antracol, Aratan, Blitox-50, Diflotan-80, Ceresan wet, Cuman and Brestan 60 could also control the disease, but only when the plants were treated in vivo immediately after inoculation. They could not show any effectiveness, however, after 24, 48, and 72 hours of inoculation, showing their failure to control, once the infection has taken place by the pathogen.

Anti-Bacterial Agents↗
PubMed1977

Microbial society and its activity in the soil.

In this study, with the help of the buried slide method, a qualitative observation of the microsociological association in the soil was assessed. Fungal mycelium cohabiting with bacterial forms, rods as well as cocci, individual colonies of Azotobacter-type cells, and certain algae of Hantzschia species were recorded in a central European typical garden soil. The use of CHOLODNY-STRUGGER combination method was helpful in ascertaining the decaying nature of a soil nematode and also fungal mycelium which, during the process of decomposition, served there as a substrate for bacterial multiplication. Colony of Clostridium-type rod-shaped bacteria existed between the soil particles, acting as living bridges. When examined under fluorescent microscope, the bacterial forms emitted shining fluorescence of green colour which in effect presented them as lighted objects, prominent against the dull red background of soil objects and other decaying substances.

Azotobacter↗
PubMed1977

Effect of different concentrations of dl-isoleucine, dl-valine, and dl-alanine on growth and sporulation in Fusarium oxysporum f. udum (Butl.) Sn. et H.

D1-alanine and dl-valine, when added as an extra nitrogen for fortifying the already present inorganic nitrogen source, actually acted as growth retardant for F. oxysporum f. udum (Butl.) Sn. et H. Sporulation of microconidia was indifferently affected by these two amino acids. DI-valine stimulated microconidial formation in young cultures only. In both young and old cultures the lowest concentration of dl-valine depressed macronidial sporulation. In old cultures the lowest concentration of valine stimulated chlamydospore differentiation rapidly, higher concentrations being less effective. D1-alanine, as an additional nitrogen source, depressed both macro- and microconidal sporulation. It did not even invigorate chlamydospore formation. D1-isoleucine, on the other hand, belongs to the category of growth promoters and profuse and stimulative sporulators of macro- and microconidia. This pathogen needs very specific and preferential doses of the three amino acids, if these are used as a booster in addition to the already present nitrogen source. The response, both in terms of mycelial growth and sporulation of the three spore forms, was also conditioned by the age of the culture.

Alanine↗