Effects of IAA with maleic hydrazide and colchicine on root tip mitosis.

Abstract

Mutachromosomic chemicals not only cause structrual changes in the chromo somes but also affect the rate of mitosis (Darlington and McLeish 1951, Bowen and Wilson 1954, Rossi 1955, Kihlman 1956, McManus 1959, Davidson 1964, Prasad and Das 1977. These active chemicals belong to divergent groups and vary in their action. Continuous attempts are being made to discover certain general principles of action among these numerous and divergent chemicals. A fruitful method in this field is to study their comparative effects under similar conditions. This paper reports the results of an experiment designed to study the effects of three chemicals of varying concentration and duration on the mitotic behaviour of Atlium cepa Linn. root tips. While the literature on MH and colchicine is large, work with IAA is still scanty. A comparative study of the effects of IAA with MH and col chicine was thus thought to be fruitful. Materials and methodsThree chemicals namely, maleic hydrazide, MH (an antiauxine), indole-3 acetic acid, IAA (a growth substance) and colchicine (a mitoitc poison) were used for the treatment. The bulbs of Allium cepa Linn. were placed on the mouth of the specimen tubes filled with the aqueous solution of each chemical of 25, 50 and 75 ppm concentrations for 4, 8 and 12 hours and it was ensured that the base and roots of bulbs were dipping in the solution during the treatment. After this treat ment the bulbs were allowed a recovery period of 24 hours in distilled water. The root tips were fixed in 3:1 alcohol-acetic acid and stored in 70per cent alcohol in a refrigerator. For cytological preparations 0.5per cent haematoxylin was used. ResultsThe effects were studied in two groups namely, the effects on mitotic index and the induction of abnormalities in dividing nuclei.The mitotic index and cell metabolism were greatly affected by all the three chemicals.

Genotoxic effects of some organophosphorus pesticides. III. In vivo chromosomal aberration bioassay in root meristems of Allium and Hordeum.

“…These were observed with the treatment of phorate in barley while with ekatin in A. cepa. Interphase cells with micronuclei were observed in Allium cepa following treatment with different pesticides and chemicals (Chaurasia 1979, Shantnhamurthy and Rangaswamy 1979, Singh 1982. These have also been reported in Vicia faba by a number of workers (Amer and Ali 1969, Mohandas and Grant 1972, Amer and Farah 1976.…”

Dose Response of Viola odorata on Meiotic and Mitotic Chromosomes of Vicia faba

“…These observations may be due to nucleotoxic action of extracts or the disturbance of the formations of spindle fibers during cell division, which leads to chromosomal aberration. Numerical and structural changes in chromosomes were attributed to spindle failure, leading to fragmentation, lagging chromosomes [17] (Fig. 2.…”