Shamsher Singh

Influence of pigweed mosaic virus on free amino acids of pigweed (Amaranthus viridis L.)

An increase in the number of amino acids inAmaranthus viridis plants infected with pigweed mosaic virus was found.

Trianthema portulacastrum — Local lesion host for brinjal mosaic and tobacco mosaic viruses

Summary This paper deals with the first record of virus infections (brinjal mosaic virus and tobacco mosaic virus) on Trianthema portulacastrum L., a common weed in India. Trianthema portulacastrwn L., locally known as “Bishkhapra”, is a common weed with medicinal properties, and grows extensively in summer everywhere. It is a succulent, prostrate, glabrous or slightly pubescent herb with many branched, angular stems, leaves broader towards the tip, fruits small like flowers, concealed in the base of the leaf stalk. Experiments were carried out to determine the utility of T. portulacastrum as a local lesion host. The culture of mosaic disease of brinjal (Seth et al. 1967) and SK strain of tobacco mosaic virus (Verma et al. 1972) were maintained on Nicotiana glutinosa L. and N. tabacum cv. White Burley, respectively. The test plants of T. portulacastrum were raised in 4 inch pots, filled with sterilized soil, and kept inside the insect-proof glasshouse. For inoculations, the conventional method of macerating the infected leaf material in a mortar and pestle and rubbing the test seedlings by means of a cotton wool swab was employed. The plants were maintained on glasshouse benches at a temperature of 29 to 30°C. Within 6”7 days of inoculation, distinct countable chlorotic local lesions appeared which turned necrotic with a yellow halo over a period of 10”12 days. The lesions produced by both these viruses on T. portulacastrum were slightly different in their size and necrotic reaction on this host. Leaves of T. portulacastrum developed at first a few local lesions, followed by mosaic mottling of the newly emerging leaves in case of brinjal mosaic virus. Systemic infection, however, does not occur by tobacco mosaic virus in this host. A perusal of literature suggested that this constitutes the only record of a virus infection on Φ in India and is the first record as a local lesion host for brinjal mosaic virus and tobacco mosaic virus SK strain. Kristensen (1955) reported T. portulacastrum a systemic host of Beet yellows virus from Denmark.

Effect on protein content by viral infections in seeds of wheat, bajra, and urid

Summary Increased percentage of protein in diseased wheat and bajra seeds was observed compared to healthy ones while in the protein content of diseased and healthy urid seeds there was no difference at all. This increase in percentage of protein content may be due to faster rate of metabolism in diseased ones but in case of urid the reason is not known.

Association of mycoplasmalike bodies with Launaea nudicaulis phyllody.

Summary Mycoplasma-like organisms were observed in thin sections cut from parts of Launaea nudicaulis plants with phyllody. It appears that they may be the causal agents of this malady, as no such bodies were observed in tissues from normal plants.

An Electron Microscope Study on the Size of Launaea Mosaic Virus

Summary Launaea Mosaic Virus has along thread-like particles, measuring from 750–930 nm. in length and 16–18 nm. in width.

Tissue culture cultivation ofLaunaea nudicaulisHook f. infected with a mosaic virus disease

Healthy and mosaic infected leaves ofL. nudicaulis have been cultivated onMS and modifiedMS media (MC). Profuse growth and differentiation of tissue have been obtained onMS medium in diseased tissues as compared to the modified medium. It has been found on bioassay that although there is no difference between the concentration of the virus in tissue culture and glasshouse material yet the incubation period of the virus is decreased in tissue cultures.AbstractZdravé a infikované listyLaunaea nudicaulis byly kultivovány na mediu podleMurashige aSkoog-a bez (MS) a ś příměsí 15% kokosového mléka a 4 ppm 2,4-D (MC). Mohutnějšího růstu a diferenciace infikovaných pletiv bylo dosaženo na mediuMS ve srovnání sMC. Biologickým testem bylo zjištěno, že inkubační doba viru se v tkáňové kultuře zkracuje, ačkoli koncentrace viru v tkáňové kultuře a ve skleníkovém materiálu byla stejná.