Mutation techniques through gamma ray irradiation is useful to support breeding programs for genetic improvement of wheat. Genetic improvement on tolerance to high temperatures is necessary for development of wheat in Indonesia. The purpose of this study was to determine the level of radiosensitivity to be used as the basis for the induction of mutations by gamma ray irradiation on embryogenic callus to obtain putative mutants with high temperature tolerance. Explants used were embryogenic callus cultured on MS medium containing 30 g L-1 sukrosa, 2 g L-1 gelrite, 2 mg L-1 2.4D and 1 mg L-1 picloram. Culture incubated for 6 weeks with temperature 20±4 oC in the room culture. Five irradiation doses (10, 20, 30, 40 and 50 Gy) were used in radiosensitivity testing. A factorial, completely randomized design was applied to the experiment. The first factor was selection temperature with three levels (25, 30 and 35 oC), and the second factor was doses of gamma ray iradiation with three levels (10, 20, and 30 Gy). The result showed that radiosensitivity levels varied among varieties, LD20: 7.79 to 18.96 Gy and LD50: 24.29-33.63 Gy. Selayar variety which has highest sensitivity value compared with Dewata and Nias. Increasing doses of iradiation and temperature decrease survival of embryogenic callus, number of embryos, and percentage of germinated plantlets. Based on in vitro selection using high temperature (25, 30, and 35 oC), the obtained 19 putative mutants were derived from embryos that appear on the surface of embryogenic callus survival after irradiation and high temperature selection.<br />Keywords: in vitro selection, putative mutant, radiosensitivity, somatic embryo

One of the efforts to increase domestic production is improving superior soybean through plant breeding techniques. Improving superior soybean cannot be separated from the regeneration process. Regeneration via somatic embryo induction has the advantage of being bipolar. Types of explants, genotypes, media composition, and growth regulators play an important role in plant in vitro regeneration. This study aims to obtain a regeneration protocol for two varieties of soybeans, namely, Derap I and Devon I, through induction of somatic embryos. This research was conducted at Tissue Culture Laboratory of the Faculty of Agriculture, Andalas University, Padang, from July to November 2020. This study used a completely randomized design (CRD) that was carried out separately in one experiment with 4 levels of 2,4-D, namely, 10 ppm, 20 ppm, 30 ppm, and 40 ppm, which were repeated 5 times. The results showed that the concentration of 2,4-D 20 ppm was the best concentration for percentage of explants that produced somatic embryos in Derap I (35%), and Devon I (95%).

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Clonal propagation using in vitro techniques to provide good quality seedling of coffee requires technological establishment, especially about the determinant factor for regeneration success. Therefore the study of regeneration methods in vitro in coffee plants needs to be done either through somatic embryogenesis or organogenesis. The purpose of this research was to obtain the optimal concentration of plant growth regulators and incubation temperatures to induce the embryogenic callus of coffee. The basic medium was used MS [Murasige and Skoog] with the addition of 1 g/L of active charcoal and 7 g/L of bactoagar. The experiment used a factorial completely randomized design. The first factor is the concentration of plant growth regulators consisting of 6 levels : 0.5 mg 2.4D L−1 + 1 mg TDZ L−1; 0.5 mg 2.4D L−1 + 2 mg TDZ L−1; 1 mg 2.4D L−1 + 1 mg TDZ L−1; 1 mg 2.4D L−1 + 2 mg TDZ L−1; 2 mg 2.4D L−1 + 1 mg TDZ L−1; 2 mg 2.4D L−1 + 2 mg TDZ L−1. The second factor is the incubation of temperature is consisting of 2 levels: 18°C and 26°C. Variables observed included: time of callus induction, percentage of callus induction, callus texture and callus color. The results showed that all medium tested only media with a concentration of 2 mg 2.4D L−1 + 2 mg TDZ L−1 which gave an optimal response to the percentage of callus induction which reached 100% with friable texture and yellowish-white. Based on observations it is also known that the incubation temperature of 26°C can induce callus faster than the incubation temperature of 18°C.

Moringa (Moringa oleifera) has the potential to be an ingredient of superfood and biopharmaceutical because it is rich in nutrients, vitamins, and other secondary metabolites. Moringa leaves contain antioxidants to neutralize and stabilize free radicals in the body. Moringa exploration is important for the purpose of finding trees to be used as sources of superior seeds. This study aimed to obtain a Moringa tree with the highest antioxidant content. An exploration had been carried out from June to July 2021 in four cities/regencies in West Sumatra, namely Padang City, Solok City, Pesisir Selatan Regency, and Solok Selatan Regency. Coordinate data were analyzed using ArcGIS, and antioxidant activity test results were analyzed using the DPPH method. From the exploration, 36 Moringa trees were found with different characters. The results of the testing of the antioxidant activity of leaf extracts showed that there were 3 parent trees that had high antioxidant activity, marked by the lowest IC50 values, namely those in Padang City (0.17%), Solok City (0.17%), and Solok Selatan Regency (0.19%).