Effect of Cell Density and Benzyl Amino Purine on the Growth of Somatic Embryo of Citrus Mandarin Batu 55 (Citrus Reticulata Blanco.) in Liquid Culture

Citrus mandarin Batu 55 (Citrus reticulata Blanco.) is one of Indonesian fruits commodities that have high economic value and consumers demand. The propagation of citrus mandarin by plant tissue culture generally was carried out on solid medium. The liquid culture system could increase cell multiplication therefore it became alternative method of plant propagation through somatic embryogenesis. The effect of initial cell density and Benzyl Amino Purin (BAP) concentration in liquid media were investigated. The initial cells density and right concentration of BAP given in media can increase cell proliferation of somatic embryo in liquid culture. Globular somatic embryo were cultured on Murashige and Tucker media with initial cell density 4, 6, 8 and 10 mgL-1 and BAP 0, 0.25, 0.5, and 0.75 mgL-1. Growth evaluation of somatic embryo were obtained by weighing fresh and dry weight every 2 weeks for 8 weeks for initial cell density treatment and 6 weeks of BAP treatment. The result of the research showed that cell density affect the growth of somatic embryo of citrus mandarin. Somatic embryo with low cell density showed slower growth compared than high cell density. Peak growth occured in 6th cultured with cell density 10 mgL-1. In addition to cell density, the growth of somatic embryo in liquid culture was affected by BAP. The growth of somatic embryo on the media containing BAP showed better results than without BAP. The highest BAP concentration on media showed fresh and dry weight of somatic embryo increased. In this research, growth of somatic embryo is not optimal yet because fresh and dry weights of somatic embryo still increase with high concentration 0.75 mgL-1 of BAP

Hubungan Keseimbangan dan Kekuatan Otot Lengan dengan Hasil Lempar Cakram pada Siswa Kelas VII Mts Al Yakin Pungpungan

The background of this research is the presence of eighth grade students of MTs Al Yakin Pungpungan who have difficulty in throwing discs, and the problem is whether there is a relationship between balance and strength of arm muscleswith discus throwing and whether discus throwing is influenced by balance and  strength of arm muscles. Therefore this study aims to determine the relationship of balance and arm muscle strength with discus throwing results in grade VII students of MTs Al Yakin Pungpungan in the 2018 school year. This research is a correlational study. The method used is a survey method and uses test and measurement techniques. Analysis of research data uses partial correlation and multiple regression. The population of this research is VII grade students of Al Yakin Pungpungan MTs in the 2018 school year with a total of 37 students. The instruments used were standing balance, push dynamometer and disc throwing test with stages from initial attitude to final throw attitude. The results of this study indicate that there is a significant relationship between balance and arm muscle strength with discus throwing results because r count = 0.369> r (0.05) (37) = 0.334. There is a significant relationship between balance with discus throwing because r count = 0.578> r (0.05) (37) = 0.334 and there is a significant relationship between arm muscle strength and discus throwing because Rhitung = 0.876> R (0.05) (37) ) = 0.334. The effective contribution of arm muscle strength by 26.6%, the ability of balance 50.2%, and the total effective contribution of arm muscle strength and balance ability to the results of discus throwing by 76.8% while the remaining 23.2% is determined by other factors or variables not examined in this study