Computer-Simulated Evaluation of the Hybrid Weakness Gene System as a Means of Preventing Genetic Contamination of Rice Cultivars |
| |
| Authors: | K Yonezawa Y L Sato T Nomura H Morishima |
| |
| Institution: | Drs. K. Yonezawa;and T. Nomura, Kyoto Sangyo University, Kyoto 603 (Japan) Drs. Y. L. Sato;and H. Morishima, National Institute of Genetics, Mishima 411 (Japan) |
| |
| Abstract: | Effectivness of the hybrid-weakness caused by a complementary interaction of two dominant genes Hwc1 and Hwc2 to suppress the spread of the red-grain gene into ordinary white-grained rice cultivars was investigated using the Monte Carlo computer simulation method. It was shown that the weakness genes, as far as being capable of reducing the fitness of the carrier by 80 percent or more, work quite effectively to suppress the genetic contamination of white-grained cultivars due to inflow of pollen from red-grained cultivars due to inflow of pollen from red-grain gene once the gene has been incorporated in to the population in the form of red-grained progeny produced as a result of the imperfect lethality of the initial hybrid between red-and white-grained cultivars. The weakness genes have little or no effect cultivars. The weakness genes have little or no effect either, when the contamination is initiated by an inflow of seeds or seedlings from ed-grained cultivars in these situations, removal (selection)of red grained plants Is the only countermeasure to exterminate the red-grain gene. The removal of red grained plants need not be intensive if carried out continuously. The spread of the red-grain gene after initial contamination is suppressed if the red-grain gene and weakness genes are linked. The suppressing effect of the linkage, however, is not substantial when the outcrossing rate is around or smaller than 0.01 as can be assumed in most rice cultivars. |
| |
| Keywords: | Oryza sativa complementary weakness genes hybrid weakness outcrossing genetic contamination computer simulation |
|
|
