| dc.description.abstract | The main problem faces the expansion of rice plants in acid soils are A1 toxicity and low pH. The best approach to solve it is to produce tolerance varieties through genetic improvement. It is stable and enviroment friendly. One of the method was conducted through somaclonal variation and gamma ray irradiation. The aims of the recearch is to get rice plant genotypes which is tolerant to Al and low pH through somaclonal variation and gamma ray irradiation. Three stages of experiments were conducted : 1) in vitro culture experiment consists of callus induction, gamma ray irradiation, in vitro selection and regeneration, 2) plant selection grown on nutrient culture, and 3) plant selection in acid soils in green house. The first experiment proved that : 1) the best media composition for embryogenic callus induction is : MS + 2.4-D2 + CH3 for Jatiluhur dan Gajah mungkur genotype, LS + 2.4-D2 + Kin 1 for Cirata and MS + 2,4-D0.5 mg/l + NAAl mg/l + BA1.5 mg/l for T309, 2) the LD 50 from Jatiluhur dan Gajah mungkur genotype 1.5 krad, for as Cirata and T309 respectively 1 and 2 krad, and 3) the highest variation are from Jatiluhur genotype 838.68 (LD 47.92), Gajah mungkur 874.98 (LD SO), Cirata 713.42 (LD 52.08) and T309 1062.76 (LD 50). The second experiment proved that : 1) somaclonal plantlet from callus induction, treated with gamma ray irradiation and followed with in vitro selection are more tolerant then their parents, 2) test in nutient solution (Al 45 ppm) produced 28 tolerant genotype. The third experiment proved that test of plantlet in acid soil in green house with saturation of Al 74.98 %, pH 4.28 and Aldd 11.56 me1100 g soils resulted : 1) plants tolerant to Al and low pH grown in acid soil are also tolerant (78.57) if grown in nutient solution, 2) planlets from in vitro culture are more varied then their parents (controls), 3) the result are 18 genotypes tolerant and 4 rather tolerant : 8 Jatiluhur genotypes are tolerant 53, 517, J15, 521, 522, 526, 533, 536 and 1 genotype is rather tolerant J5; 6 Gajah mungkur genotype are tolerant G2, G4, G10, G19, G22, G28 and 2 genotypes are rather tolerant G14, G31; 4 Cirata genotypes are tolerant C5, Cl, C23, C29 and 1 genotype is rather tolerant C16, and 4) the tolerant genotype are productive seedling, more seed number per panicle, and low persentage of seedless. | id |
