Molecular breeding

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

Methodological Advancement in Molecular Markers to Delimit the Gene(s) for Crop Improvement

Abstract: Molecular markers, in recent years, have accelerated plant breeding methods significantly with an objective of crop improvement. At present a variety of molecular markers are available and the choice of using a particular type of marker depends on the user. With the advances in the area of genomics, new type and gene-derived markers as well as novel approaches such as genetical genomics, linkage disequilibrium (LD)- based association mapping, etc. have been developed for identification of “perfect” markers for their use in breeding practices. The present article provides an overview on presently available but main type of molecular markers and their use in trait mapping, map-based cloning, estimation of diversity in germplasm collection to understand the population structure as well as in the area of comparative genomics. While dealing the above topics, major emphasis have been given on modern genomics tools and approaches such as functional molecular markers (EST-SSRs, EST-SNPs, SFPs), expression genetics or genetical genomics, high throughput approaches and automation technologies, public databases, etc. Utilization of modern genomics approaches such as functional genomics coupled with molecular marker technologies have a great potential to facilitate plant breeding practices and thus marker-assisted breeding seems to be evolved to genomics-assisted breeding in the near future.

Triticale (x Triticosecale Wittmack) Breeding

Abstract: Triticale (x Triticosecale Wittmack) is a man-made, self-pollinated cereal crop specie developed by crossing wheat (Triticum spp.) and rye (Secale cereale). The initial goal of creating triticale was to develop a new cereal crop that would combine the superior agro-morphological and end-use quality characteristics of wheat, and the adaptability, vigor and resistance/tolerance to abiotic and biotic stresses of rye. Triticale is well adapted to a wider range of environments where wheat is grown; moreover, under stress conditions, triticale performs better. Triticale has been grown worldwide mainly for grain and forage production, and recently for bioenergy production. Although the grain quality of triticale is unsatisfactory compared to other small grain crops such as wheat, it still possesses a good level of resistance to multiple diseases and pests and many useful genes have been successfully transferred to wheat from triticale. The majority of triticale breeding programs focus on the improvement of economically-important traits such as grain and biomass yield, diseases and pest resistance, quality and agronomic traits. Several studies have demonstrated that genetic diversity within triticale germplasm is low, which is not unexpected. Traditional breeding methods are most commonly used in triticale improvement. Currently, modern breeding approaches, such as marker-assisted selection (MAS), genomic selection, double-haploid (DH) and genetic transformations are being explored to improve triticale. Use of molecular breeding technology and molecular markers are limited in triticale but many molecular markers of wheat and rye are conserved in the triticale genome and therefore wheat and rye genomics can be used in triticale improvement. The objective of this chapter is to summarize the current status of triticale production worldwide and provide details on different breeding approaches being used to improve triticale cultivars.

Molecular breeding of transposable elements

Abstract: Methods for producing transposable elements with improved properties as vectors are provided. Directed evolution procedures are employed to improve characteristics of transposable elements, including transposons and insertion sequences as vectors. Methods for generating diversity in vivo and in vitro using transposable elements as vectors are provided.

Barley, Disease Resistance, and Molecular Breeding Approaches

Abstract: At present, the cultivated barley (Hordeum vulgare L.) is among the four major crops produced worldwide used for human food, stews, cattle feed, brewing, and malt production. There is a wide range of biotic variables which affect both quality and quantity components of the multi-nutrient crop. Among the biotic variables, phytopathogens are considered as the most negative constraint on the global barley production. In addition, the intensive monoculture of cultivars along with changing climate conditions has boosted the emergence of new virulent races and pathovars. The earlier conventional breeding efforts were focused mainly on simple genetics, selection, mutation breeding, and hybridization. However, they were ineffective in developing new varieties with durable and broad-spectrum resistance in a short span of time. As a result, the breeders have shifted their focus from conventional approaches to better molecular approaches for enhancing disease resistance in the last 20 years. These better molecular approaches include transgenic technology, VIGS (virus-induced gene silencing), marker-assisted selection (MAS), QTL mapping, gene mapping, and TILLING (targeting induced local lesions in genomes). These approaches have provided novel strategies for enhancing durability and broad-spectrum disease resistance in a short span of time. Furthermore, these technologies have shown tremendous potential to accelerate crop improvement efforts as well as sustained global production, especially for barley. In this chapter, we have focused on the widely employed molecular approaches for enhancing disease resistance in barley (Hordeum vulgare L.).