Shahnawaz Khursheed

Effect of gamma radiation and EMS on mutation rate: their effectiveness and efficiency in faba bean (Vicia faba L.)

ABSTRACT Faba bean is one of the most important grain legumes in the world because of its multiple uses and its ability to grow over a wide range of climatic conditions. The objective of this study was to evaluate the effectiveness and efficiency of single and combination doses of gamma rays and ethyl methanesulphonate (EMS) on two different varieties of faba bean. Studies on induced mutagenesis in faba bean involving EMS and gamma rays are sparse. Genetically pure, uniform, dry and dormant seeds of Vicia faba varieties Vikrant and PRT-12 were treated with four different doses of gamma rays (100, 200, 300 and 400 Gy) and of EMS (0.01, 0.02, 0.03 and 0.04%). However, the utility of a mutagenic agent is determined by its ability to induce a high frequency of desirable mutations as compared to undesirable ones; thus, it is necessary to assess the effectiveness and efficacy of mutagens. The results indicated that EMS is more effective in inducing mutations than gamma rays, with the following trend: EMS > gamma rays+EMS > gamma rays. However, with regard to mutagenic efficiency measured based on seedling injury, gamma rays were more efficient than EMS, with the following trend: gamma rays > gamma rays+EMS > EMS. Both mutagenic effectiveness and efficiency were found to be higher at lower doses of both the mutagens. The possible reason for decrease in mutagenic efficiency and effectiveness with increase in dose may be the higher dose of mutagens and less damaging effect of lower doses of mutagens.

Quantitative analysis of genetic parameters in the mutagenized population of faba bean (Vicia faba L.)

Faba bean (Vicia faba L.) is a rich source of dietary proteins, minerals and nutrients particularly in India and a feed crop in the world. Successful crop breeding programmes require the recognition and understanding of different genetic parameters like genotypic coefficient of variation, heritability and genetic advance. In this backdrop, a field experiment was conducted to study the genetic parameters in M2 generation of faba bean using 60Co source gamma irradiation and ethyl methanesulphonate (EMS) as physical and chemical mutagens. The mutagens were used both individually and in combination. Genotypic coefficient of variation (GCV), heritability (h2) and genetic advance (GA) were calculated for total seed yield per plant (g) and its associated components like seeds per pod and pods per plant. Gradual increase in mean values for all quantitative characters was observed at lower doses/concentrations of gamma rays and EMS employed alone or in combination. Genotypic coefficient of variation and heritability increased considerably in the mutagenized population for all the traits in both the varieties suggesting the possibility of more genetic progress of these traits in subsequent generations which could lead to the overall improvement of these varieties.

Diff erential genotypic response of two varieties of Hordeum vulgare L. in response to hydrazine hydrate alone and in combination with dimethyl sulfoxide

Induced mutation has been an important tool for a man in bringing desirable changes in plants since times immemorial. Cereals form an integral part of human diet along with pulses, especially in India. Cereals contain a high percentage of carbohydrates along with the considerable amount of proteins. The present experiment was carried out to induce the variability in Hordeum vulgare L. variety RD-2035 and BH-393. The mutagen used in this experiment was hydrazine hydrate (Hz). The mutagen was used singly and in combination with dimethyl sulfoxide (DMSO). Usually, the DMSO is considered as a carrier for a mutagen to enhance the mutagenic activity of that particular mutagen used in combination. The two varieties of seeds were treated with individual concentrations of Hz along with combination treatments with DMSO. The seeds were sown to raise the M1 generation. Cytology of both control and treated plants was observed in the M1 generation. The control plants showed normal meiosis, whereas the treated plants showed different chromosomal abnormalities. The different chromosomal abnormalities were laggard, bridge, micronucleus, and univalents. The meiotic abnormalities were low at lower concentrations of both individual and combination treatments while as the percentage abnormalities increased with increasing concentrations of both individual and combination treatments. M1 seeds were sown to raise the M2 generation. Quantitative characters of both control and treated plants were observed. The lower concentrations of both individual and combination treatments induced desirable changes in quantitative characters while as the higher ones induced negative effects.