Inbred Development

Abstract

Inbred lines are nearly homozygous due to long inbreeding by forced self-pollination or sib-mating. These inbred lines can be used in genetic research (e.g., mapping genes and quantitative trait loci), allele discovery, and directly as cultivars in selfing species or as parents of hybrids and synthetic cultivars. Microsatellites and single-nucleotide polymorphisms are today among the most widely used DNA marker systems, while new generation sequencing starts providing access to more DNA landmarks for plant breeding. DNA markers allow us selecting genes directly or indirectly rather than solely based on phenotypes, and may reduce the time for assembling favorable alleles in doubled haploids (DHs), near-isogenic lines, or recombinant-inbred lines. DHs along with DNA marker-aided breeding offer a shortcut for backcrossing because they are fertile and homozygous at all loci in a single step. Model species such as Arabidopsis thaliana provides genetic resources to find genomic sites related to climatic adaptation, whose genetic basis remains mostly unknown. Plant breeding for local adaptation seems to be best in stressful environments where stable genotypes derived from broad-based germplasm can be selected. Local adaptation by various genetic mechanisms will also facilitate a flexible response to the changing climate. Decentralized and end-user participatory plant breeding provides further means to ensure impacts, particularly for low-input agriculture and farming systems in marginal environments.