Breeding method for directed improvement of tobacco black shank resistance by molecular marker-assisted selection

Abstract

The invention discloses a breeding method for directed improvement of tobacco black shank resistance by molecular marker-assisted selection. The breeding method includes the steps: acquiring a molecular marker; performing molecular marker-assisted selection for five times. Existing excellent characteristics of Honghua Dajinyuan can be completely preserved, black shank resistance is enhanced, field growth is regular, and genetic characters are stable. A progressive two-step method assists in background selection, so that the workload of background molecular marker-assisted selection can be effectively decreased. The background recovery ratio of single plants with backcross 3-generation BC3F1 subjected to molecular marker-assisted selection can reach 97.5% or more and is greatly increased, and the breeding process is shortened. The harmful or adverse effect of foreground linkage drag on improved varieties is decreased by selection, and the excellent characteristics of improved initial varieties are effectively and comprehensively preserved. Large-scale field planting for phenotype screening is omitted in the whole directed improvement process, field workload is low, most of work is less affected by environments, and results are more accurate.

Description

technical field [0001] The invention belongs to the technical field of tobacco disease-resistant breeding, and in particular relates to a breeding method for directional improvement of tobacco black shank resistance by molecular marker-assisted selection. Background technique [0002] The development of molecular biology technology, especially molecular marker technology, provides an effective means for variety improvement. Molecular marker-assisted selection breeding is to select target traits with the help of molecular markers closely linked to target genes during the breeding process. The major project of the China Tobacco Genome Project launched in 2010 has drawn a set of high-quality genome maps centered on the whole genome sequence maps of Nicotiana tomentosa, tobacco forest, and cultivated tobacco, tobacco molecular genetic linkage maps, and tobacco haplotype maps. Laid a solid foundation for molecular marker-assisted breeding; [0003] The flue-cured tobacco variet...

AI Technical Summary

Problems solved by technology

For more than 20 years, Chinese tobacco breeders have tried to use conventional breeding techniques to improve the resistance of Honghua Dajinyuan to black shank, but they have not been successful. The selected offspring materials cannot maintain the characteristics of Honghuadajinyuan varieties. characteristics and the loss of blackleg resistance; and in traditional backcross breeding, it often takes five generations of backcrossing to achieve a high genetic background recovery rate, and the breeding process is long; moreover, large-scale field planting is required type screening, the workload in the field is large, and it is greatly affected by the environment, and even the results are inaccurate.

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