Genomics Approaches to Crop Improvement in the Rosaceae [chapter]

Cameron Peace, Jay Norelli
2009 Genetics and Genomics of Rosaceae  
Genomic research in Rosaceae crops is commonly directed at understanding the genetic control of important agronomic traits with the aim of improving product quality and reducing production costs. Genomic knowledge can be used for genetic improvement of cultivars through breeding or genetic engineering. Genomic knowledge can also be used for the development of new cultural practices and the tailoring of existing production practices according to genetic categories of cultivars. The translation
more » ... genomic data and fundamental discoveries into practical results with real world applications is often termed "translational genomics". However, this term is also used to describe the transfer of genomic knowledge from model organisms, such as Arabidopsis, to crop species, with practical application sometimes only implied. Many crop attributes are limited by the underlying genetics of the cultivars at hand. Breeders seek to raise the bar with each generation, and provide new genetic possibilities. New cultivars are designed to possess improved potential for horticultural performance, whether as incremental gains over previous cultivars, or with novel attributes that set them apart. Decisions regarding parent selection for crossing and progeny selection for advancing potential cultivars are based on knowledge, as well as educated guesses and hunches, of how controlling genes combine and are expressed in breeding populations. Genomics can shortcut or enhance the scope of genetic studies to elucidate the genetic architecture of traits by identifying, quantifying, and validating important genomic regions. It can also identify the genes that control trait variation and determine their strength of expression under varying production conditions. Armed with such knowledge, breeders can more efficiently manipulate germplasm over generations to produce optimum genetic combinations and novel genetic possibilities in the form of new cultivars that perform better for C. Peace (B) growers and produce superior products for handlers, processors, marketers, and ultimately, consumers. Breeders are therefore genetic architects, designing new products from the manipulation of genetic components. Genomics can also impact the production of established plantings. In horticultural production, many crop attributes are readily influenced by cultural practices. However, some cultivars may respond poorly to treatments or respond differently across different environments and seasons. Knowledge of the genetics underlying the performance of each cultivar could lead to genetic "diagnostics" that allow cultural practices to be tailored to a specific functional genetic group of cultivars. Another approach is genomic-based crop "therapeutics", or "chemical genomics", an emerging field of research that also allows improvement of plants already under cultivation. Where specific genes are known to influence important traits, compounds can be designed that enhance or interfere with their expression to improve a crop's performance or product quality. New genomic technologies are also valuable for more fundamental studies. Basic biological research has traditionally avoided Rosaceae species, and numerous organismal systems are much more tractable to studying many basic biological mechanisms. However, certain biological phenomena in Rosaceae crops such as perenniality, dormancy, extended juvenility, scion-rootstock interaction, complex polyploidy, and diverse plant, flower, and fruit form are usually absent in model organisms. The genetic systems of one or more species in the Rosaceae family can offer useful platforms for uncovering the genomic networks underlying these attributes, mechanisms, and processes. In this approach, the rosaceous species is the model organism. Ultimately, fundamental genomic studies in this plant family can be turned to practical use by providing the valuable knowledge that aids in understanding and manipulating existing cultivars, and breeding the next generation.
doi:10.1007/978-0-387-77491-6_2 fatcat:f5dstznamzbipa52rguh3qejyq