<p>Aluminum Tolerance Improvement of Rootstock Citrus<br />through Repeated In Vitro Selection. Mia Kosmiatin,<br />Rosa Yunita, and Ali Husni. National orange productivity<br />was trend to decrease because of pathogen attack and<br />reducing of planting area. One of alternative ways to<br />preserve and increase orange productivity was using<br />marginal soil mainly acid soil. This matter pushed the<br />breeder to prepare tolerant rootstock and stable in the acid<br />soil. In vitro culture technique was effective and efficient<br />methods to produce tolerant and stable rootstock in acid soil<br />through simulation of acid soil with addition of high<br />aluminum and low pH in the medium. By the simulation the<br />selection could be done in cell level, so cell was selected<br />after induction of variation. A rootstock which high<br />compatibility with scion, useful rooting, and aluminum<br />tolerance could be increased orange productivity through<br />acid soil development. The research was conducted in 3<br />phase: (1) induction of embryogenic calli, (2) improvement<br />of genetic variation through mutation, and (3) In vitro<br />selection with AlCl3.6H2O for aluminum and low pH tolerant.<br />Immature embryos of rootstock were use as explant. The<br />result showed that the best embryogenic calli were induced<br />on MS basal medium with MW vitamin + NAA 7,5 mg/l +<br />kinetin 0,5 mg/l. Before selection, 1.000 rad dosage was the<br />most tolerant dosage to growth embryogenic calli. After<br />selection, 2.000 rad dosage was the best dosage to produce<br />shoots which stable tolerant to aluminum. Selected 88<br />mutant shoots were produced after three times selection on<br />the same medium which AlCl3.6H2O added at low pH.</p>
Selection methods for maize seedlings in greenhouse as related to aluminum tolerance