Chromosome aberration assays in Pisum for the study of environmental mutagens.

From a literature survey, 117 chemicals are tabulated that have been assayed in 179 assays for their clastogenic effects in Pisum. Of the 117 chemicals that have been assayed, 65 are reported at giving a positive reaction (i.e. causing chromosome aberrations), 30 positive with a dose response, five borderline positive. Seventeen chemicals gave a negative response. Eighty-one percent of the chemicals gave a definite positive response. A c-mitotic effect was detected from treatment with 17 chemicals. In addition to the above tabulation of chemicals, 39 chemicals have been reported with an antimitotic effect. Thirteen assays have been recorded for five types of radiation, which with the exception of ultrasound reacted positively. The results of assays with 38 chemicals and/or radiations in combined treatments, as well as 15 chemicals and three types of radiations that induce somatic mutations are tabulated. The Pisum sativum (2n=14) bioassay has been shown to be a very good plant bioassay for assessing chromosome damage both in mitosis and meiosis for somatic mutations induced by chemicals, radiations, and environmental pollutants. For some chemicals, the Pisum assay is not as sensitive in assessing clastogenicity as the Allium assay, although this should be considered in relative terms. Pisum fulvum (2n=14) has been used in clastogenic studies also, but to a much lesser extent.

Chromosome aberration assays in Crepis for the study of environmental mutagens.

Crepis capillaris (2n=6) is an excellent plant for the assay of chromosome aberrations after chemical treatment. C. tectorum (2n=8) has been used also in mutagenic studies, but to a much lesser extent. A protocol has been given for using root tips to study the cytological endpoints, such as chromosome breaks and exchanges, which follow the testing of chemicals in somatic cells. Meiotic endpoints have not been used in C. capillaris for testing potential chemical mutagens but should be considered, especially a meiotic micronucleus assay. From a literature survey, 81 chemicals are tabulated that have been assayed in 162 Crepis assays for their clastogenic effects. Of the 162 assays that have been carried out, 40 are reported at giving a positive reaction (i.e., causing chromosome aberrations), 97 positive and with a dose response, 7 borderline positive, and 17 negative. Eighty-five percent of the chemicals gave a definite positive response. Assays for one chemical gave contrary results, and were not included in the above tabulation. The Crepis bioassay has been shown to be an excellent plant bioassay for assessing chromosome damage induced by chemicals and environmental pollutants.