Effect of Mutagens on Quantitative Characters in M₂ and M₃ Generation of Sesame (<i>Sesamum indicum</i> L.)

Abstract

The mutagenic effects of different dose/concentrations of gamma rays (30, 40 and 50 KR) and ethyl methane sulphonate (1.0, 1.5 and 2.0 mM) on sesame (Sesamum indicum L.) varieties VRI-1 were investigated. The characters studied include; days to first flower, plant height, number of branches per plant, number of capsule per plant, number of seeds per capsule and seed yield per plant in M 2 and M 3 generations. Both negative and positive shifts in mean values were recorded as a result of the physical and chemical treatments. The results indicate the possibilities of evolving higher yield variants through proper selection. Thus, economic traits like number of capsule per plant, number of seeds per capsule and hundred seed weight in M 3 generation offer scope for selection and improvement. INTRODUCTIONSesame plays an important role in human nutrition. Most of the sesame seeds are used for oil extraction and the rest are used for edible purposes (El Khier et al., 2008). Sesame is grown primarily for its oil-rich seeds. Before seeds were appreciated for their ability to add nutty flavour or garnish foods, they were primarily used for oil and wine (Ghandhi, 2009). Sesame seed is rich in fat, protein, carbohydrates, fibre and some minerals. The oil seed is renowned for its stability because it strongly resists oxidative rancidity even after long exposure to air (Global Agri Systems, 2010).Mutation breeding is one possible alternative to conventional breeding for crop improvement. Exposing plant genetic material to mutagens enhances the chance of isolating unique genetic material. In the past, induced mutations have effectively been utilized in development of new and valuable alterations in plant characteristics that have contributed to increased yield potential. Induced mutations can rapidly create variability in quantitatively and qualitatively inherited traits in crops (Maluszynski et al., 1995;Muduli and Mishra, 2007). Mutation breeding not only creates variability in crop species, but also shortens the time taken for the development of cultivars via induced mutation compared to those via hybridizations. The average time elapsed from initial mutation treatment to the release of the mutant cultivars was approximately 9 years, while the time was more than 9 years for cultivar arising from crossing programmes (Brock, 1977). Moreover mutations induced both qualitative and quantitative characters in a short time altering new alleles of known and previously unknown genes, and modify the linkages (Konzak et al., 1977). The present investigation was undertaken study the effect of mutagens on quantitative characters in M 2 and M 3 generation of sesame and results are discussed.

Effect of recurrent mutagenesis on some induced genotypes in safflower (Carthamus tinctorious L.)

“…The genotypes 12 and 6 exceeded the untreated plants with 38.73% with percentage (14.94 and 14.85 %), respectively. Our results were in agreement with those obtained by Dhole et al (2003), Sheeba et al (2005), Mensah andObadoni (2007), Nuraet al (2013), Gopinath and Pavadai (2015), Ravichandran and Jayakumar (2015), Okaz et al (2016 a) and Ahmad (2019). The results showed that all treatments of chemical mutagen (h 1 , h 2 and h 3 ) gave low estimates of variation coefficient (c.v), Table (1) indicated that these three treatments induced low amount of genetic variability in the studied genotypes for seed oil content.…”

Induced polygenic variability in sesame by combining hybridization and recurrent mutagenesis in F3M3 generation

“…The increase in variability for these characters had arisen from induced micro mutations and that resulting from segregation and recombination of polygenes in hybrid populations are cumulative. Similar results have been reported by Ravichandran and Jayakumar (2018) for number of capsules per plant and single plant yield and for plant height, number of branches per…”

“…Increased mean values in the present investigation, denoted the occurrence of more favorable mutations and breaking up of undesirable linkages with enhancing recombination. Similar results of an increase in mean value have been reported by Begum and Dasgupta (2015) and Ravichandran and Jayakumar (2018) for number of capsules per plant and seed yield per plant.…”

Effects of gamma radiation on quantitative traits and genetic variation of three successive generations of cowpea (Vigna unguiculata (L.) Walp.)

“…It is noteworthy that the increasing mean values of quantitative traits are due to the incidence of polygenic mutation with cumulative effects (54). After the mutagenic treatment, the mean values changed in legumes such as urdbean (55), mungbean (56)(57)(58), lentil (59) and sesame (60).…”

“…A hundred seeds per set were packed for each dose in a paper cover to subject irradiation such as 200, 400, 600, 800, 1000 and 1200 Gy and non-irradiated seeds used as control. The source of gamma irradiation 60 Co (Cobalt) was emitted 28 Gy/min dose rate in every seed and the facility was used in Radiological Safety Division, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, Chennai, Tamil Nadu, India. In the present study, the raising of M1, M2 and M3 generations was carried out from 2016-2019 with respective seasons in Botanical Garden, Department of Botany, Periyar University, Salem, Tamil Nadu, India.…”