Cytogenetic Effects of Gamma Rays and Ethyl Methane Sulphonate in Chilli Pepper (Capsicum annuum L.).

Abstract

Summary Seeds of Capsicum annuum L. var. G-4 Bhagyalakshmi were subjected to 15, 25, 35 kR doses of gamma ray, and 0.8% and 1% ethyl methane sulphonate (EMS). Effects of mutagenic treatments of meiosis viz. chromosomal anamolies, pollen sterility, seed sterility and survival percentage in M2 generation have been reported. EMS was found more effective in inducing meiotic irregularities than gamma ray treatment. A dose dependent increase in meiotic anomalies was obtained with all the mutagenic treatments.Mutations can be beneficially utilized for tailoring better varieties of crop plants. But in general, ionizing radiations and chemical mutagens like ethyl methane sulphonate (EMS) effects a wide range of chromosomal alterations resulting in to abnormal behaviour during meiosis, leading to various degree of sterility. Further, the cytological abnormalities during meiosis has also been regarded as one of the dependable parameters for estimating mutagenic sensitivity of a species. Though considerable work has been done on induced mutation studies in red pepper (Bansal and Dalmirsingh (1972), Han (1974), Auni et al. (1978), Lakshmi and Bapa Rao (1978), Kumar et al. (1986), Meshram et al. (1992)), there was no current report available on physical and chemical mutagen effect on meiosis in the existing promising varieties of Capsicum annuum L. Hence, the present study is undertaken to assess the meiotic consequences of chromosomal aberrations induced by separate and combined application of gamma rays and EMS. Materials and methodsDry seeds of Indian popular chilli variety G-4-Bhagyalakshmi were subjected to mutagenic treatment with gamma rays and ethyl methane sulphonate (EMS). Seeds were irradiated with 15, 25, 35 kR doses of gamma rays from 6°Co source. A second set of seeds were soaked in 0.8% and 1.0% solution of EMS for 12 h at 23 -± 1°C. Another set of seeds were also subjected to combined doses of gamma rays and EMS in the following combinations; i) 15 kR+ 0.8% EMS ii) 15 kR+ 1% EMS iii) 25 kR+ 0.8% EMS iv) 25 kR+ 1% EMS v) 35 kR+ 0.8% EMS iv) 35 kR+ 1% EMS The control seeds were soaked in distilled water for 24 h at room temperature. After treatments seeds were throughly washed and sown in the nursery beds along with control seeds. Forty-five old day seedlings were transplanted in the field. For meiotic studies, young flower buds were fixed in Carnoy's fluid (6 : 3 : 1) for 24 h and then transferred to 70% ethyl alcohol. Squash preparations were made with 2% acetocarmine. Results and discussionsThe pollen mother cells (PMC's) of control plant showed regular 12 bivalent uniformly at

EMS, sodium azide and gamma rays induced meiotic anomalies in Delphinium malabaricum (Huth) Munz

“…The percentage of meiotic abnormalities was higher under EMS than in the SA and gamma ray treatments. Different types of chromosomal abnormalities observed in the present study have been reported for other plant systems after treatment with physical and chemical mutagens (Kumar & Dubey 1998;Dhanayanth & Reddy 2000;Bhat et al 2005).…”

Comparative genotoxic potential of <i>γ</i> rays in two varieties of Isabgol (<i>Plantago ovata</i> Forsk.)

“…The induced chromosomal variations have been extensively investigated from the point of view of understanding the damaging effects of the mutagen on the concerned plant. Different types of chromosomal aberrations as noticed in the present study have also been reported earlier by many workers in different plants after physical or chemical mutagenic treatments (Ahmad and Godward 1981;Dhamyanthi and Reddy 2000;Kumar and Singh 2003;Basi et al 2006;Khan et al 2009;Das et al 2010;Chatterjee et al 2011). Dose dependent increase in the chromosomal abnormalities was also reported by Singh and Chaudhary (2005) in Capsicum annuum L., Basi et al (2006) in Indica rice, Radha-4, Khan et al (2009) and Sharma et al (2009) in Vicia faba L. and Chatterjee et al (2011) in Papaver somniferum L. Induction of cytological disturbances in the mitotic as well as meiotic cells is of great value, as it results in the genetic damage that is handed over to the next generation (Kumar and Rai 2007).…”

Nuclear Blebs Assay for Genome Instability in <i>Phaseolus vulgaris</i> L.

“…The mutagenic effect of EMS could be related to its ability to induce nuclear alterations in the form of nuclear buds, micronuclei, irregular nuclei, etc., as well as various types of chromosomal aberrations such as stickiness, precocious movement of chromosomes, unorientation, univalents and multivalent at metaphase I/II, and laggards and bridges at anaphase I/II in the pollen mother cells of Phaseolus vulgaris L. There has been a significant enhancement in chromosomal anomalies along with increasing concentrations of EMS. Similar results have been obtained by other workers in different plants with different chemical and physical mutagens (Ahmad 1993, Dhamayanthi and Reddy 2000, Bhat et al 2005, Kumar and Rai 2007.…”