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

Induced mutagenesis by gamma rays plays a potent promising technology to be applied for crop improvement through breeding methods, especially in tiny florets possessing self- pollinated plants such as cereals. Finger millet (Eleusine coracana (L.) Gaertn.) which always ensured for valuable nutrients, as well as famine tolerant crop to supply food for global population throughout the year. The present study was performed to assess the spectrum and frequency of macro mutants induced by gamma radiations in M2 generation finger millet. The chlorophyll mutants viz., albina, xantha, chlorina and viridis and morphological mutants such as tall, dwarf, bushy, brittle stalk and broad leaf were recorded in different doses. Among the mutagen doses 600 Gy dose induced maximum increase in mean values and phenotypic and genotypic coefficients of variation for the plant height (cm), number of leaves per plant, leaf length (cm), number of tillers per plant, number of panicles per plant, panicle length, days to 50% flowering, and 1000 seeds weight. Except for panicle number/plant and 1000 seed weight, all traits showed high heritability in all doses. The results revealed a progressive decrease in mean values of quantitative traits with the increase in doses. The present study provides an idea about the optimum dose of gamma rays from a pool of doses that could be employed in future breeding programmes.

Section: Discussionsupporting

confidence: 93%

Gamma ray induced positive alterations in morphogenetic and yield attributing traits of finger millet (Eleusine coracana (L.) Gaertn.) in M2 generation

Latha

Dhanarajan²,

Raina³

et al. 2022

“…Except for days to first flowering, gamma irradiation suppressed changes in morphological and quantitative features in the M1 generation of cowpea. In our previous studies, the quantitative traits such as plant height, number of branches per plant, number of leaves per plant, number of fruit clusters per plant, number of pods per plant, pod length, number of seeds per pod, hundred seed weight and seed yield per plant were gradually decreased in all concentrations compared to the control (7). In M2 generation, gamma radiation induced phenotypic alteration of traits leads to obtained new mutants.…”

Section: Discussionmentioning

confidence: 82%

“…The availability of genetic diversity is the basis for crop development, but since cowpea are predominantly selfpollinated, there is a dearth of genetic variability. Induced mutations offer a means of generating unique genetic variations for cowpea breeding programmes (7).…”

Section: Introductionmentioning

confidence: 99%

60Co gamma ray induced mutants of cowpea and assessment of genetic variability by SCoT marker

Sankar

Dhanarajan²,

Gurunathan³

et al. 2022

Mutagenesis is a well-known technique for introducing new variants into crop plants. In the present study, M2 populations were generated in the cowpea (Vigna unguiculata (L.) Walp.) variety CO7 using gamma irradiation. The M2 progeny were used to investigate the effectiveness of the gamma irradiation doses and examined for the agronomic traits. The genomic variation present in the mutants and their parents was analysed using five SCoT markers. Marker analysis revealed a total of 87 amplicons and among these, 20 amplicons showed polymorphism. The highest numbers of amplicons were observed at SCoT10 (39), while the lowest number of amplicons was produced by SCoT09 (07). The percentage of polymorphism ranged from 18.18% to 28.57%, with an average of 21.12%. Polymorphic information content (PIC) values ranged from 0.197 to 0.345. Analysis of Molecular Variation (AMOVA) showed 12% and 88% between the genotypes and within the genotypes respectively. The constructions of 4 clusters were identified through Unweighted Pair Group Method with Arithmetic Mean (UPGMA) dendrogram tree based on the genetic distance deduced from SCoT marker analysis. Analysis of the genetic relatedness between parent and mutants through Principal Coordinate Analysis (PCoA) revealed two main groups. The present study concludes that the genetic variability induced by gamma irradiation and inherited in the next generations. This research investigation supports that gamma irradiation alters the growth and yield traits, which is helpful for generating the cowpea improvement.

“…Groundnuts are mainly self-pollinated plants with limited genetic variation because of the cleistogamous nature of flowers. Therefore, inducing mutations play an important role in developing desired traits and the generation of variations in plants (4).…”

Section: Introductionmentioning

confidence: 99%

Effect of gamma irradiation on quantitative traits and post harvesting analysis of groundnut (Arachis hypogaea L.) seed in M1 generation

Aswini

Arulbalachandran²,

Latha³

2022

Groundnut (Arachis hypogaea L.) is a member of family Fabaceae. It is an important monoecious annual legume, mainly grown for oilseed. Gamma irradiation is a powerful tool to induce genetic alteration and improvement in crops with beneficial mutants. The study was undertakenn to evaluate the quantitative traits of gamma rays on groundnut. Genetically healthy, dried and uniform size seeds of groundnut variety of Dharani were treated with six doses viz., 100, 200, 300, 400, 500 and 600 Gy of gamma rays. The biological damage based on lethality and injury was estimated in the M1 generation. The present investigation reveals that seed germination LD50 value recorded at 300 Gy and highest survival percentage value was obtained at 100 Gy compared to control and other treatments. In M1 generation, the morphological and quantitative traits were decreased as the dose increases. The maximum reduction was observed at 600 Gy. In general, the higher doses showed increasing plant damage compared to control. The amino acid content was high in 500 Gy doses of gamma irradiation. The lipids, protein and carbohydrate content were high in 400 Gy compared to control and other doses. Gas chromatography-mass spectrometry (GC-MS) was used to analyse the lipid substances and the results showed that significantly more compounds were found in seeds that had received 400 Gy radiation than in untreated seeds. The current study found that gamma irradiation changes the morphology, quantitative characteristics and biochemical composition of groundnut seeds in the M1 generation.