Molecular breeding

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

Progress and Prospects of Breeding by Gene Design in Rice

Abstract: Progress in molecular markers,gene engineering and genomics are beneficial to direct selection and crop breeding by design.Breeding by design is a concept that aims to control all allelic variation for all genes of agronomic importance.This concept can be achieved through a combination of precise genetic mapping,high-resolution chromosome haplotyping and extensive phenotyping.Thanks to marker technology and software tools available today,and the fine-mapped/cloned genes in rice and their related GP data bank,this goal can now be achieved.Some related techniques concerning molecular breeding and breeding by gene-design,a highlight of breeding by gene-design and progress in functional research for key genes and their molecular utilization in rice breeding are presented in the paper.In addition,the prospects of rice gene-design breeding are discussed.

Seedling morphology in applied genetics and plant breeding

Abstract: Seedling Techniques 382 Seedlings in Genetical Experiments 388 Seedlings in Cytoplasmic Studies 394 Seedling M orphology and Changes of Ploidy . 396 Economic Applications of Seedling Morphology . 401 Seedling Morphology and Practical Plant Breeding 407 Conclusions ..... 415 Addendum . 416 Literature Cited 416

Development of the PARMS marker of the TAC1 gene and its utilization in rice plant architecture breeding

Abstract: The ideal plant architecture is a new strategy for super high yield breeding of rice. Tiller angle is an important plant architecture character of rice. A reasonable tiller angle is a key factor for the ideal plant architecture and achieving high-yield breeding. Molecular design breeding is the most potential new direction of crop breeding in the future. The development of accurate and efficient functional molecular markers of target trait genes is crucial for molecular design breeding. The TAC1 (Tiller Angle Controlling) gene is the primary gene that regulates tiller angle in rice. This gene can be used to improve the compact plant architecture of indica and japonica rice varieties. The SNP variation from A to G at the fourth intron 3′ splicing point in TAC1 changes plant architecture. Based on the SNP variation, PM-TAC1 was successfully developed as a fluorescent functional molecular marker, via the penta-primer amplification refractory mutation system. Ninety-three rice materials were genotyped using this marker, and the marker was effectively used in rice plant architecture breeding. The successful development of this marker will contribute to the molecular breeding of rice plant architecture.

Genomics-Assisted Breeding for Improving Stress Tolerance of Graminaceous Crops to Biotic and Abiotic Stresses: Progress and Prospects

Abstract: Advances in genomics research have led to the development of high-quality reference genome data, genome-wide molecular markers, quantitative trait loci (QTL), and high-throughput genotyping platforms for cereal crops. The availability of these genomic resources has facilitated the development of breeding technologies such as genomics-assisted breeding (GAB). GAB is an advanced form of marker-assisted breeding where genome-wide genetic selection and high-density genotyping are performed to generate elite varieties with better agronomic traits. Marker-assisted selection (MAS) is a genotypic variation based indirect selection method that reduces the time and cost of breeding. The different approaches of MAS include marker-assisted backcrossing (MABC) or introgression of agronomically important alleles or QTLs with relatively large effect, marker-assisted recurrent selection (MARS) for introduction of complex traits and genomic selection (GS) based on overall molecular markers distributed throughout the genome. In view of these, the present chapter discusses the application of genetic and genomic resources in identification and mapping of stress-tolerant genes/QTLs and their application in molecular breeding. In addition, the chapter also summarizes the current status of marker-assisted selection approach for improving tolerance to drought and virus infection in major graminaceous crops. The challenges and future prospects of GAB in enhancing crop productivity under stress conditions have also been summarized.

Innovative breeding methods to develop seedless citrus cultivars.

Abstract: Presence of a large number of seed contents in citrus fruits is a big restraint in consumer’s acceptability even if the fruit have premium organoleptic characteristics. Consumers are only willing to eat seeded fruits if seedless are not available. Seediness is also a major handicap restricting the use of large number of fruit in processing industries and increases the cost of juice or pulp production. Moreover, seed presence in the fruit may be related with bitterness and certain undesirable aromatic compounds. Various useful breeding approaches have been devised by researchers to reduce total number of seeds or create complete seedlessness in citrus fruits. These consist of both orthodox and modern molecular breeding tools. Conventional techniques used in the past encountered numerous problems due to specific reproductive physiology of citrus and was also time exhaustive. Modern molecular techniques like embryo rescue, protoplast fusion, cybrids, irradiation, inter specific or generic crosses, flow cytometry and citrus transformation are less time consuming and more productive as well as rapid results can be attained in short time period. Molecular techniques have further reduced the difficulties faced in conventional breeding to produce less seeded or completely seedless citrus cultivars.