Genotoxic Effects Induced by Methyl Methane Sulphonate in 2 Cultivars of <i>Capsicum annuum</i> L.

Abstract

Summary Seeds of Capsicum annuum L. cv. Pusa jwala and G 4 were treated with varying concentrations of methyl methane sulphonate (MMS), and the effect of various concentrations of MMS on each stage of meiosis has been studied in M1 generation. Various types of meiotic abnormalities and reduction in chiasma frequency were observed in treated populations. However, MMS treatment were found to be more effective in inducing meiotic abnormalities and reduction in chiasma frequency in Pusa jwala as compared to G 4 . Moreover, a co-linear relationship between increasing concentrations of MMS and reduction in chiasma frequency was also observed. Taking the percentage of meiotic abnormalities and reduction in chiasma frequency as an index of sensitivity of genotype to MMS, Pusa jwala was found to be more sensitive than G 4 . Key words Capsicum annuum, Chiasma frequency, Meiotic aberrations, MMS.Mutagenesis is an important method of inducing variations in a number of plant characters from time to time, and has a great relevance for raising superior plant types in different crop plants. Mutagenesis is a potential tool for the selection of efficient mutagens and their treatment doses are prerequisite for obtaining the potential mutations.Cytological studies are necessary to obtain information regarding the effect of the mutagens and in elucidating the response of various genotypes to a particular mutagen. Chemical mutagens provide a very good tool for creating alterations in the genotypes and enhancing the variability of characters. Keeping in view the economic importance of C. annuum (2n=24), as a vegetable as well as a spice crop, the present study was under taken to asses the effect of MMS on 2 cultivars of C. annuum. Materials and methodsFresh and healthy seeds of C. annuum cv. Pusa jwala and G 4 , obtained from the Indian Agriculture Institute New Delhi, were presoaked in distilled water for 12 h under laboratory conditions and then treated with different concentrations of MMS i.e., 0.01%, 0.02%, 0.03%, 0.04% and 0.05% for 7 h. The controls were maintained separately. After each treatment seeds were thoroughly washed in tap water and sown in earthen pots to raise the M 1 generation. After 30 days of showing, the seedlings were transplanted into the field. At the flowering stage young flower buds were collected and fixed in freshly prepared Carnoy s fixative for 24 h and preserved in 70% ethanol to study the chromosomal behavior at different stages of meiosis in the pollen mother cells (PMCs) of both control and treated plants. Squashes were made in 2% acetocarmine and the data was recorded at each stage of meiosis.

Comet and cytogenetic tests as tools for evaluating genomic instability in seeds of Oryza sativa L. and Phaseolus vulgaris L. from gene banks

“…The fact that no significant increase in chromosome lagging and chromosome aberrations was seen in periods later than those observed, at concentrations of 10 and 15 mg/L in accession GF004 of bean (p ≥ 0.05), may be explained as being due to mitotic inhibition for an exposure period of 24 h, because the chromosome aberrations evaluated in this study require cells that are undergoing division to be noticed ( Rank, 2003 ). MMS is a clastogenic agent, and thus promotes chromosome breaks and the induction of chromosome lagging in plants, as previously reported in Capsicum annum L. ( Gulfishan et al , 2011 ; 2012 ) and Vicia faba L. ( Sharma et al , 2009 ) and also observed in the present study. In accession GF007, MMS did not produce a significant increase in the frequency of chromosome aberrations in the meristematic root cells, when compared with the control ( Table 4 ).…”

Genotoxic effects of 5-bromouracil on cytomorphological characters of Cichorium intybus L.

“…In this investigation, pollen fertility decreased with the increase in concentrations of the 5-BU. Similar decrease in pollen fertility was reported earlier in Vicia faba , Capsicum annuum (Gulfishan et al, 2010) and C. intybus . Reduction in pollen fertility also supports a decrease in seed production due to the meiotic anomalies.…”

Comparative mutagenicity of EMS and HZ in Hordeum vulgare L. var. RD2052

“…Jayabalan and Rao (1987) suggested that stickiness might be due to disturbances in the cytochemically balanced reaction. Precocious movement of chromosome as observed during the present investigation, probably caused by spindle disfunction (Gulfishan et al 2010). Non-orientation and scattering of chromosomes at metaphase I was observed in the present investigation which may be due to either the inhibition of spindle formation or the destruction of spindle fibers (Kumar and Rai 2007).…”