Gamma-rays induced mutations increase soybean oil and protein contents.

Mutation breeding is one of the effective techniques used for improving desired traits such as yield quality and quantity in economic crops. The present study aims to develop oil and protein contents in addition to high yield attributes in soybean using gamma rays as a mutagen. Seeds of the soybean genotypes Giza 21, Giza 22, Giza 82, Giza 83 and 117 were treated with gamma rays doses 50, 100, 200 and 300 Gy. Plants were then scored based on morphological parameters correlated with yield quantity including plant height, seed weight and valuable protein and oil contents. Mutant lines exhibiting the highest yield attributes were selected and used as parents for M2 generation. The M2 progeny was further assessed based on their ability to maintain their yield attributes. Twenty mutant lines were selected and used as M3 lines. The yield parameters inferred a positive effect of gamma irradiation on the collected M3 mutant lines compared to their parental genotypes. 100 Gy of gamma rays gave the highest effect on the number of pods, branches and seeds per plant in addition to protein content, while 200 Gy was more effective in increasing plant height, number of pods per plant, and oil content. Six mutant lines scored the highest yield parameters. Further assessment inferred an inverse relationship between oil and protein content in most of the tested cultivars with high agronomic features. However, four mutant lines recorded high content of oil and protein besides their high seed yield as well, which elect them as potential candidates for large-scale evaluation. The correlation among examined parameters was further confirmed via principal component analysis (PCA), which inferred a positive correlation between the number of pods, branches, seeds, and seed weight. Conversely, oil and protein content were inversely correlated in most of yielded mutant lines. Together, those findings introduce novel soybean lines with favorable agronomic traits for the market. In addition, our research sheds light on the value of using gamma rays treatment in enhancing genetic variability in soybean and improving oil, protein contents and seed yield.

Improvement of German Chamomile (Matricaria recutita L.) for Mechanical Harvesting, High Flower Yield and Essential Oil Content Using Physical and Chemical Mutagenesis.

Chamomile (Matricariarecutita L.) is one of the most important medicinal plants with various applications. The flowers and flower heads are the main organs inthe production of essential oil. The essential improvement goals of chamomile are considered to be high flower yield and oil content, as well asthe suitability for mechanical harvesting. The present study aimed to improve the flower yield, oil content and mechanical harvestability of German chamomile via chemical and physical mutagens. Three German chamomile populations (Fayum, Benysuif and Menia) were irradiated with 100, 200, 300 and 400 Gray doses of gamma rays, as well as chemically mutagenized using 0.001, 0.002 and 0.003 mol/mL of sodium azide for 4 h. The two mutagens produced a wide range of changes in the flowers' shape and size. At M3 generation, 18 mutants (11 from gamma irradiation and 7 from sodium azide mutagenization) were selected and morphologically characterized. Five out of eighteen mutants were selected for morphological and chemical characterization for oil content, oil composition and oil quality in M4 generation. Two promising mutants, F/LF5-2-1 and B/HNOF 8-4-2, were selected based on their performance in most studied traits during three generations, as well as the high percentage of cut efficiency and a homogenous flower horizon, which qualify them as suitable candidates for mechanical harvesting. The two mutants are late flowering elite mutants; the F/LF5-2-1 mutant possessed the highest oil content (1.77%) and number of flowers/plant (1595), while the second promising B/HNOF 8-4-2 mutant hada high oil content (1.29%) and chamazulene percentage (13.98%) compared to control plants. These results suggest that the B/HNOF 8-4-2 and F/LF5-2-1 mutants could be integrated as potential parents into breeding programs for a high number of flowers, high oil content, oil composition and oil color traits for German chamomile improvement.