Konstitusi Genetik dan Karakter Fenotipik Galur-galur Padi Pup1 Turunan Varietas Situ Bagendit

Acidity, phosphorus deficiency, and drought stress are major problems in Indonesia’s Ultisol rice farming. Development of rice lines tolerant to those stresses is expected to be able to reduce the consumption of P fertilizer. The objectives of the research were to evaluate genetic constitutive of rice lines (BC2F6 population) derived from Situ Bagendit x Kasalath and Situ Bagendit x NIL-C433 crossings, and to evaluate responses of those lines to Yoshida nutrient solution under P deficiency and Al stress condition. The research was conducted at Molecular Biology Laboratory and Greenhouse of ICABIOGRAD, from November 2011 to May 2013. The result of foreground analysis showed that Pup1 locus has been integrated into the genome of BC2F6 rice lines, eventhough some lines (SK5, SK6, SK7, SK8, SK9, SK10, SK19, and SK20) showed incomplete integration. Background analysis indicated that majority (95.7%) of the Situ Bagendit background has been recovered in BC2F6 rice lines. Al stress evaluation showed SN lines were more tolerant to P deficiency and Al stress than that of SK lines. Pup1 locus showed good expression under low P and no Al stress. Based on genome proportion and Yoshida nutrient solution experiments, a total of three lines, namely SK13, SN2, and SN9, have potential good characteristics. Molecular analysis within a marker-assisted backcrossing (MAB) experiment should be carried out at each generation of lines for gaining fully gene segment in advanced generations.