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Fungicides have been used widely to control fungal diseases. In plant disease control these compounds are of unquestionable economic importance. Interest in the effects of fun gicides has increased considerably with the knowledge that fungi may become resistant to the application of fungicides and that the use of fungicides has many secondary non-target effects ranging from poor germination and stunting of plants (George et al. 1970) to genetic changes including chromosomal and gene mutations leading to hereditary alterations (Prasad and Pramer 1968, Wuu and Grant 1960, 1966a, 1966b). Among benzimidazole fungicides, benomyl has been tested for its clastogenic effects. Boyle (1973) reported benomyl induced production of fragments and laggards in somatic cells of onion. Spasojeric (1974) found that benomyl blocked mitosis in maize root tip cells. Treatment of root-lets at 0.5% for 5hr in activated the root spindle and disoriented the chromosomes. Changes in crop genotype as a result of fungicide treatment could have serious repurcussions from the breeders' point of view. The present study reports the clastogenic effects of carbendazim seed treatment in somatic and reproductive cells of pearl millet and sunflower plants.

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Material and methodsFor meiotic stduies, young buds were collected between 11.30A. M. and 1.00P. M. and fixed in acetic alcohol (1:3). Anther smears were prepared in propiono-carmine to study the chromosomal associations at metaphase I and distribution of chromosomes at anaphase I. Stainability of pollen grains with propiono-carmine was used as an index for pollen fertility.Degree of self-incompatibility was determined on the basis of percentage seed set under self-pollination.Plants having 0-10 per cent seed set were classified as self-incompatible, those with 11-30 per cent seed set as partially compatible and the others having higher seed set were regarded to be in the self-compatible group. Results Morphology.The polyploid plants, in general, showed a slower rate of growth in the earlier stage but later on exhibited more vigour as compared to the diploids. There was an increase in plant height and stem was thicker. The leaves were broader, dark green in colour and with larger stomata. The flowers were larger and occasionally more than four petals were present (Fig. 1). These plants were late in maturity and continued flowering even when not a single flower was seen in the diploids. Seeds from the tetraploids were significantly bolder as compared to the diploids (Fig. 2) and the seed set was quite normal.An observation of interest was that the polyploids were comparatively more resistant to frost and aphid attack.Cytology. Meiosis in diploids was normal with formation of 10 Its (Fig. 3) and regular separation of 10 chromosomes at anaphase I (Fig. 4). All the tetraploid plants studied had 40 chromosomes showing various types of as

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