Response of Soybean Genotypes to Different Levels of Mutagens for Yield Related Attributes

Soybean ( Glycine max L ) is an annual legume of the pea belonging to family, Fabaceae and has eatable seed. It provides protein for masses of individuals and also used in many of the industrial products. The present experiment was conducted in the experimental area of the Department of Plant Breeding and Genetics, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi and Nuclear Institute for Agriculture and Biology(NIAB), Faisalabad, during kharif season, 2018.Five genotypes of the soybean were treated with chemical and physical mutagens at different levels of concentrations. The seeds were treated by two different doses of chemical mutagens like 0.04% and 0.06% of Sodium Azide (SA), and seeds were exposed to different amount of radiations like 30kr and 45kr of gamma rays at the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad. From the current study it is determined that the 0.04% 0f the chemical mutagens and 30kr of the gamma rays performed optimum for the yield and biochemical parameters. Moreover, the genotypes KY EXOTIC, NARC-2, AJMERI-2 performed well for all of the studied traits, hence these genotypes can further be exploited for yield improvement of soybean. Present study also enabled us to select desirable doses of the Sodium Azide and suitable amount of gamma rays for genetic variability Abstract


Introduction
Soybean (Glycine max L.) has a significant nutritional value.
It comprises around 40% protein and 20% oil content. Soybean protein has valuable amino acid lysine (5%). Additionally, it also includes a good number of vitamins like thiamine and riboflavin, salts and minerals [1] Pakistan is fronting a severe scarcity of edible oils. The native edible oil production does not complete the increasing needs of population. The entire accessibility of eatable oils in 2015-16 remained at 3.726 million tons. Home-grown production mounted at 0.85 million tons which accounts for 28% of whole accessibility. The lasting 72% was completed by import [2].
Edible oil is the major diet element being trade in in the country. produces ·OH and O 2 · and induces injury in cellular casings [4].

Preparation of Sodium Azide
Solution of sodium azide was prepared in the laboratory, Department of Plant Breeding and Genetics, NIAB, Faisalabad. 0.04grams of sodium azide were added in 100 ml H 2 O to prepare 0.04% and 0.06 grams of SA were added in 100ml of water to prepare 0.06% of SA.

Mutagenesis
In the first experiment the seeds of five Soybean genotypes, (PGRI-15, KY EXOTIC, NARC-, AJMERI-2, AJMERI) was subjected to mutation. The seed was treated at Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, with two different mutagenesis, Physical and Chemical mutagenesis. In physical mutation the seed was exposed to the gamma rays, 30KR and 45KR. In chemical mutagenesis the seed of equal size was subjected to 0.04% and 0.06%, SA. For each of the chemical treatment the seed was presoaked in the distilled water. After soaking with the distilled water, the seed was dried and treated with different concentrations (0.04% & 0.06%) of the chemical for 6 hours tracked by washing of seeds by tape water for 2 hours. Second experiment was conducted at the Glass house, at the research site of the, Department of Plant Breeding & Genetics, PirMehr Ali Shah Arid Agriculture University, Rawalpindi, following Randomized Block Design (RCBD). The seeds treated with the Chemical, Physical and untreated (control) were sown in the pots with two replications.

Morphological Traits
Data were recorded on the following morphological traits.
Germination Percentage: The emergence of the seed was recorded as germination percent. After sowing the seeds propagation percentage was intended by following method (Figure 1).

Number of Seeds per Pod
Number of seeds per pod was determined by calculating the seeds from irregularly particular pods from respectively genotype and their middling was calculated ( Figure 3).

Biochemical Traits
The data for soybean biochemical traits were recorded which are described below.

Statistical Analysis
The data thus composed were exposed to study of variance (ANOVA) procedure Steel et al., (1997) for entirely the characters deliberate to observe the significant variances among the genotypes.
Data were statistically investigated through (Statistix8.1) processor software. The difference among the treatment means was compared by the Fisher Least Significant Difference (LSD) test at 0.05 P-value and correlation coefficient, was also studied as described by [5] and determined the association between yield and yield component.

Results and Discussion
Soybean is an important oil seed crop. Pakistan is fronting the scarcity of edible oil because it is grown in a limited area. The  (Table 2), while germination percentage for the genotypes in which the physical mutagens applied were high as compared to control. The results showed that with the rise in concentration of the mutagens applied, itlead to the decrease in the germination percent. The findings of the existing study also commensurate [6] and [7] who also reported that the emergent percentage decreases with the increase in mutagens concentrations.
Among all the genotypes, the results (     [9] in which they reported that number of pods is high in mutant genotype as compare to the control. The findings (Table 1) revealed that all the genotypes presented significant differences for hundred grain weight. The products (Table 2) predicted that the genotypes, KY EXOTIC and NARC-2, showed highly significance for the hundred grain weight, 8.7900 g and 9.8847 g respectively. The results for the chemical mutation showed 8.3632 and 6.9357 at dosage of 0.04% and 0.06% SA respectively, while the results for physical mutation, gamma rays, the grain weight showed 8.1315 at amount of 30kr and 7.300 (g) grain weight for control [10] in which they reported that the grain weight increased due to induced mutation as compared with the control where mutation was not induced.
The results (Table 2) for protein content were observed highly significant for the genotypes, NARC-2, AJMERI-2, 27.343 and 27.900 respectively. The results (Table 2) coincided for Protein content showed that the genotypes on which mutagens applied, was highly significant compare with the control. The protein content for the genotype which was treated with the chemical mutagens showed high protein content 27.800 at dosage of 0.04%. The results were also supported by [1] in which they reported that the protein content was different for different dosage of the mutagens. The findings (Table 2)

Correlation Analysis
Estimation of phenotypic correlation between yield components and quality traits as well as among the components themselves is presented ( Table 3) the present study assembled with the results of the [11] in which they conveyed that number of seeds per pod positively correlated with the yield related traits. The outcomes also observed that the genotypic, phenotypic and environmental correlation was highly significant. The number of pods per plant correlation showed highly significant results with the hundred grain weight (0.8311), protein (0.8781) and oil content (0.8884).The present study is also supported by [11] in which they showed positively high correlation of pods/plant. The consequences of our study resembled with the [12] in which they revealed that the number of pods/plants definitely correlated with the plant height, Days to flowering, Days to maturity.
The hundred grain weight correlated with the protein and oil content, 0.9469 and 0.9523 respectively. The findings reported by [12] that Hundred grain weight, negatively correlated with other yield related traits. Observation of the present study showed positive correlation of the hundred grain weight, which may be because of genotypes, environmental effects or that may be because of the mutation induced. The results of the present study were supported by [11] in which they reported that hundred grain weight positively correlates with the yield related traits.
The protein content showed high correlation with the oil content is significant and positive correlated with oil content. The results (Table 3) showed that fat and oil contented was highly correlated with yield related traits. The results also intimated that the genotypic, phenotypic and environmental association for fats and oil content is highly significant. The outcomes of the current study resembled with the results of [1] who described that a confident correlation was found between oil content and grain yield and a negative significant correlation were found between oil content and protein content. But in the present study the effect might be due to genotypic, environmental effect or that may be because of mutation induced [13][14][15]. performed well for all of the traits studied hence these genotypes can further be exploited for yield improvement of soybean.