Judul: Induksi embriogenesis somatik dan seleksi in vitro empat genotipe kedelai untuk toleransi terhadap cekaman aluminium
Abstrak: Soybean (Glycine max (L.) Merr.) is an important source of protein for many Indonesian and the demand of soybean for food is increasing year by year. The increasing demand of soybean is not met by national production mainly due to decreasing harvest area. Therefore, expansion of soybean harvested area should be the main priority in the effort to increase soybean production. However, the targeted area should not be in competition with the other more profitable crops such as corn and rice. Dry acid soil, the main marginal lands in Indonesia, can be developed as an expansion of soybean planting areas because of the area reach 102.8 million hectares. Efficient crop improvement programs should be targeted to generate high yielding soybean varieties grown in acid soil. Currently, more than sixty varieties of soybean have been released by the Ministry of Agriculture, however, few are tolerant to acid soil. The constraint in developing soybean varieties for adaptation to adverse environmental condition is low genetic variability. Genetic variability can induced by conventional and non conventional plant breeding. In vitro selection is one strategy from non conventional plant breeding to produce plants that can be use as a source of variation in a breeding program. The use of somatic embryo for in vitro selection program is very valuable since the selected traits will be inherited in the progenies. Embryogenesis somatic was reported to be genotype specific for soybean. The general objective of this research was to obtain soybean promising lines tolerant to Al toxicity. Specifically, this study was aimed to obtain the optimum medium for induction and proliferation of somatic embryo, and to regenerate embryogenic callus of four soybean genotypes; and to obtain tolerant Al somaclones (putative). This study consisted of two experiments, which was induction of somaclonal variation of four soybean genotypes via somatic embryogenesis and in vitro selection of four soybean genotypes using AlCl3 to generate a putative somaclone acid soil tolerant. Embryogenic callus was obtained from the experiment of optimation of embryogenic callus induction medium. Induced callus had morphological differences, color and diameter in each type of media being used and the type of genotypes. The morphology of the formed callus can be classified into six groups. Callus can be induced at 6 weeks after treatment (WAT) on MS medium with the addition of 10 mg/l 2,4-D and 10 mg/l NAA in all soybean genotypes. Callus induced on medium with 5 mg/l NAA had callus morphology that tends to be green and then rooted. Callus induced on MS medium with the addition of 40 mg/l 2,4-D tends to had compact callus. In MS medium containing 40 mg/l 2,4-D, 54.5% of the Tanggamus genotype callus was embryogenic. Tanggamus genotypes was the only genotype that successfully formed somatic embryo (globular, torpedo and cotyledonary stages) after cultured for 4 weeks in medium containing 40 ppm 2,4-D and subcultured for another 4 weeks in the same media. The other genotype (Willis) formed only preembryonic mass (PEM) and failed to form somatic embryo after cultured in four different induction mediums. In order to increase the number of somatic
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