Molecular breeding

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

Genetic markers for improving farm animals

Abstract: Molecular breeding has been heralded as a powerful tool that can ameliorate the economically important traits of livestock species. Genetic markers like microsatellite and single nucleotide polymorphism have been experimentally identified and often validated. These markers have been successfully used in bovines, small ruminants, swine, and chicken with an aim to improve the productive, reproductive, and growth traits, as well as disease resistance. The present chapter discusses the discovery of these genetic markers for various economically important traits in bovines, caprine, and chicken.

Genetic Improvement of Basmati Rice—The Journey from Conventional to Molecular Breeding

Abstract: Marker-assisted breeding provides a great opportunity to the present-day researchers for breeding new crop varieties by design through precise transfer of desirable gene(s). Among the molecular breeding approaches, marker-assisted backcross breeding (MABB) is an attractive proposition for breeders as it can help in improving an already popular variety for specific target traits such as resistance to disease/pest/improvement in quality. MABB has been successfully employed in transferring genes (xa13 and Xa21) governing resistance to diseases such as bacterial blight (BB), blast (Pi54, Pita, Pi1, Pi9, Pib, Piz5 and Pi5), sheath blight (qSBR 11-1), and brown plant hopper (BPH; Bph18, Bph20 and Bph21) into a number of Basmati rice varieties, namely Pusa Basmati 1, Pusa Basmati 1121, and Pusa Basmati 6 as well as long slender grain aromatic rice varieties such as Pusa Sugandh 5. Further, a major QTL for salt tolerance (Saltol) has been transferred to Pusa Basmati 1121 and Pusa Basmati 1, which are widely grown in northwestern India. Genetically enhanced donor sources in the form of near-isogenic lines (NILs) carrying major gene(s)/QTLs for resistance to biotic (BB, blast, sheath blight, and BPH) and abiotic (salt tolerance) stresses in the background Pusa Basmati 1, the first semi-dwarf, high-yielding Basmati rice variety, have been developed. QTL mapping using recombinant inbred line (RIL) population has unveiled several novel QTLs for different agronomic, grain and cooking quality traits. Besides their effective use in Basmati rice improvement, molecular markers are also utilized in basic studies as well as in maintenance breeding of Basmati rice varieties, which is discussed in the present chapter.

SNP (Single Nucleotide Polymorphism) molecular marker chained with pumpkin peel color gene and application thereof

Abstract: The invention discloses an SNP (Single Nucleotide Polymorphism) molecular marker chained with a pumpkin peel color gene and an application thereof. A molecular marker 63809 and a molecular marker 30774 obtained by screening are tightly chained with the pumpkin peel color gene, and the genetic distance between the two markers is 1.04cM; the SNP molecular marker can be directly applied to building of a peel color gene molecular marker assisted breeding system. A dCAPS amplification primer designed according to the two molecular markers can be used for improving molecular assisted breeding of pumpkin varieties easily, conveniently and rapidly at a high flux, technical support is provided for pumpkin appearance quality molecular breeding, and meanwhile the conventional gene mapping time is shortened greatly.

Genome Editing: Advances and Prospects

Abstract: There is an urgent need to develop quality crop with improved productivity and wider tolerance to the environmental (biotic and abiotic) stresses for addressing different issues including global water crisis, food security, and climate change effect on agriculture. Traditional lengthy procedures for crop improvement including classical breeding and random mutagenesis will not be able to fulfill growing crop demand in near future. Gene targeting technology is a powerful transformative procedure that permits accurate genetic modification in any genome which relies on a variety of molecular editors. Formation of directed DNA cleavage by ZFNs, TALENs, and CRISPR/Cas9, followed by restoration via the DNA repair system either by NHEJ (non-homologous end joining) or by HDR (homology directed recombination), provides a useful insight of gene function and trait modification. In this chapter, we have described the four available types of genome editing tools; meganucleases, ZFNs, TALENs, and CRISPR systems, and discussed their revolutionary applications in precision molecular breeding and functional genomics research of crops. Furthermore, specific challenges in the plant genome editing and prospects were also reviewed.

Targeted Epigenome Editing of Plant Defense Genes via CRISPR Activation (CRISPRa)

Abstract: Crop protection plays a central role in maintaining and increasing crop productivity. Many pathogens continue to affect crop production, however, and losses generated by pests must be halted. Thus, if farming is to support the human population, additional viable strategies for crop production and improved integrated pest management systems must be developed. Genome editing is an alternative to conventional breeding that can facilitate the molecular breeding of crops with desired properties. We propose here the implementation of targeted modification of epigenetic marks (epigenome editing via CRISPR activation or CRISPRa) to activate plant defense genes to confer resistance against pathogen attack. Work on CRISPRa in plants is lacking, although its potential application to crops is one of the greatest challenges in the field. Future exploitation of this approach in crop improvement programs will reduce important economic losses and benefit society.