Molecular breeding

About: Molecular breeding is a research topic. Over the lifetime, 2120 publications have been published within this topic receiving 56908 citations.

Prospects for application of breakthrough technologies in breeding: The CRISPR/Cas9 system for plant genome editing

Abstract: Integration of the methods of contemporary genetics and biotechnology into the breeding process is assessed, and the potential role and efficacy of genome editing as a novel approach is discussed. Use of molecular (DNA) markers for breeding was proposed more than 30 years ago. Nowadays, they are widely used as an accessory tool in order to select plants by mono- and olygogenic traits. Presently, the genomic approaches are actively introduced into the breeding processes owing to automatization of DNA polymorphism analyses and development of comparatively cheap methods of DNA sequencing. These approaches provide effective selection by complex quantitative traits, and are based on the full-genome genotyping of the breeding material. Moreover, biotechnological tools, such as doubled haploids production, which provides fast obtainment of homozygotes, are widely used in plant breeding. Use of genomic and biotechnological approaches makes the development of varieties less time consuming. It also decreases the cultivated areas and financial expenditures required for accomplishment of the breeding process. However, the capacities of modern breeding are not limited to only these advantages. Experiments carried out on plants about 10 years ago provided the first data on genome editing. In the last two years, we have observed a sharp increase in the number of publications that report about successful experiments aimed at plant genome editing owing to the use of the relatively simple and convenient CRISPR/Cas9 system. The goal of some of these experiments was to modify agriculturally valuable genes of cultivated plants, such as potato, cabbage, tomato, maize, rice, wheat, barley, soybean and sorghum. These studies show that it is possible to obtain nontransgenic plants carrying stably inherited, specifically determined mutations using the CRISPR/Cas9 system. This possibility offers the challenge to obtain varieties with predetermined mono- and olygogenic traits.

Construction of a high-density genetic map of Ziziphus jujuba Mill. using genotyping by sequencing technology

Abstract: The Chinese jujube (Ziziphus jujuba Mill., 2n = 2 × = 24), one of the most popular fruit trees in China, is widely cultivated and utilized in Asia. High-density genetic linkage maps are valuable resources for molecular breeding and functional genomics; however, they are still under-developed for the jujube. The genotyping by sequencing (GBS) strategy could be an efficient and cost-effective tool for single nucleotide polymorphism (SNP) discovery based on the sequenced jujube genome. Here, we report a new high-density genetic map constructed using GBS technology. An F1 population with 145 progenies and their parents (‘Dongzao’ × ‘Zhongningyuanzao’) were sequenced on the Illumina HiSeq 4000 platform. In total, 79.8 Gb of raw data containing 256,708,177 paired-end reads were generated. After data filtering and SNP genotyping, 40,372 polymorphic SNP markers were developed between the parents and 2540 (1756 non-redundant) markers were mapped onto the integrated genetic linkage map. The map spanned 1456.53 cM and was distributed among 12 linkage groups, which is consistent with the haploid chromosome number of the jujube. The average marker interval was 0.88 cM. The genetic map allowed us to anchor 224 Mb (63.7 %) of scaffolds from the sequenced ‘Junzao’ genome, containing 52 newly anchored scaffolds, which extended the genome assembly by 7 Mb. In conclusion, GBS technology was applied efficiently for SNP discovery in this study. The high-density genetic map will serve as a unique tool for molecular-assisted breeding and genomic studies, which will contribute to further research and improvement of the jujube in the near future.

Quantitative Genetic Principles in Plant Breeding

Abstract: Quantitative genetics refers to the study of inheritance of traits whose phenotypes show more or less continuous distributions. There is no compelling reason for distinguishing among related terms such as ‘biometrical genetics’, ‘statistical genetics’, nor, in some cases, ‘population genetics’. All are concerned with the study of how genes affect important characteristics, how they interact with environmental factors, and how they can be manipulated to give improved plant or animal strains.