Identification and linkage mapping of complementary recessive genes causing hybrid breakdown in an intraspecific rice cross

K. Matsubara, T. Ando, T. Mizubayashi, S. Ito, M. Yano
Theoretical and Applied Genetics, 2007, 115(2): 179-186  DOI: 10.1007/s00122-007-0553-x;      追溯原文......本站官方QQ群:62473826
Oryza sativa; Poor growth; Epistatic interaction; Linkage mapping; QTL mapping

One outcome of hybrid breakdown is poor growth, which we observed as a reduction in the number of panicles per plant and in culm length in an F2 population derived from a cross between the genetically divergent rice (Oryza sativa L.) cultivars 'Sasanishiki' (japonica) and 'Habataki' (indica). Quantitative trait locus (QTL) analysis of the two traits and two-way ANOVA of the detected QTLs suggested that the poor growth was due mainly to an epistatic interaction between genes at QTLs located on chromosomes 2 and 11. The poor growth was likely to result when a plant was homozygous for the 'Habataki' allele at the QTL on chromosome 2 and homozygous for the 'Sasanishiki' allele at the QTL on chromosome 11. The results suggest that the poor growth found in the F2 population was due to hybrid breakdown of a set of complementary genes. To test this hypothesis and determine the precise chromosomal location of the genes causing the hybrid breakdown, we performed genetic analyses using a chromosome segment substitution line, in which a part of chromosome 2 from 'Habataki' was substituted into the genetic background of 'Sasanishiki'. The segregation patterns of poor growth in plants suggested that both of the genes underlying the hybrid breakdown were recessive. The gene on chromosome 2, designated hybrid breakdown 2 (hbd2), was mapped between simple sequence repeat markers RM3515 and RM3730. The gene on chromosome 11, hbd3, was mapped between RM5824 and RM1341.

  杂种衰退;酪蛋白激酶 hbd2; OsCKI1; LTG1; LTRPK1
  杂种衰退 hbd-3