The affecting factors and developing prospect of marker-assisted selection;

This project used the strategy of discarding susceptible individual Plants and keeping resistance ones by resistance identification in breeding populations and Planted resistant plants next in earlier generations (F1 - F3), and performing marker-assisted selection combining resistance identification in later generation (F4 generation) for pyramiding powdery mildew resistance.

In order to improve the precision of marker-assisted selection for fragrance gene in rice, a functional marker GRFM04 has been developed based on the deletion of 8 bp in DNA sequence of BAD2 gene, namely the fragrance gene, in the fragrant rice varieties.

The broad-spectrum blast resistance gene Pi-1,from the donor line BL122,was introduced into a thermo-sensitive genic male sterile(TGMS)line GD-8S,which possessed good grain quality but high susceptibility to rice blast,by using backcross breeding and molecular marker-assisted selection.

Two bacterial blight(BB)resistance genes, Xa21 and Xa4,from IRBB24 were introduced into hybrid rice restorer line Mianhui 725, which is highly susceptible to BB by using hybridization and molecular marker-assisted selection technology.

Molecular marker-assisted selection (MAS) provides a very efficient tool for backcross breeding because it can offer rapid and precise selection of the targeted gene.

This paper showed the application of QTL mapping in genetic mapping, building saturate genetic map and molecular marker assisted selection of crop breeding.

Rice bacterial blight resistance molecular breeding includes:the identification and cloning of resistance genes,molecular marker assisted selection,gene engineering breeding and creation and improvement of resistance gene resource.

Advances in MAS Technique;

With almost equal cost,Silver-staining detection in strongly alkaline situation had higher efficiency and adaptation especially in MAS than traditional method in alkalescent situation without the consideration of instrument investment.

Its restorer line Zhonghui 8006 with Xa21 gene resistant to bacterial leaf blight (BLB) was developed by way of the molecular marker-assisted selection (MAS) technique.