The breeding companies and laboratories involved in this article cover a wide range of crops grown in the temperate climate zone: small grain cereals, oilseed crops, forage crops, turf, vegetables and potato. Speed and efficiency are becoming increasingly important in variety breeding and doubled haploids (DH) and genetic markers are important biotechnological tools to accelerate materials to market. Collaborative research between universities, research institutions and breeding companies has resulted in the routine use of DH technology and molecular markers in practical breeding of barley, wheat and rapeseed. DH populations have been established not only for barley, wheat and rapeseed, but for rye, oat and triticale, where DH technology is less developed.

SUMMARYThe current study aimed to evaluate breeding effect on nitrogen use efficiency (NUE), its components and some agronomic traits and disease resistance in barley by using extensive germplasm covering 72 landraces and 123 cultivars released since 1910. Trials were established in southern Finland with a modified strip-plot experimental design. Prior to sowing, blocks were placement fertilized with compound nitrogen : phosphorus : potassium (NPK) fertilizer (N-P-K: 20–3–8) at the rate of 35 and 70 kg N/ha and unfertilized plots were placed at the other end of the fertilization block. The germplasm collection was genotyped with 1536 single nucleotide polymorphism (SNP) markers and phenotyped during a 2-year field experiment in 2011/12. Independent of row type, a positive breeding effect was evident in NUE and for other plant N traits, except that grain N slightly decreased. Breeding has improved NUE by 0·08 kg/year (26% over the century). Nitrogen utilization and N uptake efficiencies were also improved by breeding as were straw length, lodging tolerance, grain yield and yield components, without any sign of levelling-off. Bred cultivars were more resistant to leaf-damaging diseases, especially to net blotch. The SNP data indicated no reduction in overall genetic diversity. However, genetic diversity differed along the barley chromosomes showing either reduced or increased diversity in certain regions when landraces were compared with modern varieties.

Genetic diversity was studied in a collection of 61 accessions of Brassica rapa, which were mostly oil-type turnip rapes but also included two oil-type subsp. dichotoma and five subsp. trilocularis accessions, as well as three leaf-type subspecies (subsp. japonica, pekinensis, and chinensis) and five turnip cultivars (subsp. rapa). Two-hundred and nine SNP markers, which had been discovered by amplicon resequencing, were used to genotype 893 plants from the B. rapa collection using Illumina BeadXpress. There was great variation in the diversity indices between accessions. With STRUCTURE analysis, the plant collection could be divided into three groups that seemed to correspond to morphotype and flowering habit but not to geography. According to AMOVA analysis, 65% of the variation was due to variation within accessions, 25% among accessions, and 10% among groups. A smaller subset of the plant collection, 12 accessions, was also studied with 5727 GBS-SNPs. Diversity indices obtained with GBS-SNPs correlated well with those obtained with Illumina BeadXpress SNPs. The developed SNP markers have already been used and will be used in future plant breeding programs as well as in mapping and diversity studies.

To prevent lodging and sprouting damage in rye, a dominant dwarfing gene, Ddw1, has been incorporated into breeding lines to reduce plant height in Finland. However, the inability to identify heterozygous plants makes it difficult to purify breeding lines. Doubled haploidy (EM-1 9 Voima) and bulked segregant analysis were used to search for an efficient PCR-based tool to identify homozygous short plants. In addition, SNP (single nucleotide polymorphism) markers were created from the endosperm-specific b-amylase gene and the microsatellite locus REMS1218 expressed in rye and known to be located near Ddw1. The best marker was a combination of the microsatellite REMS1218 and the SNP created from it, located 13 cM from the QTL corresponding to Ddw1. However, for a rye breeder, the SNP alone is an adequate tool to identify plants homozygous for the EM-1 allele and it can be used in selection for the desirable growth habit in rye.

Doubled haploid (DH) plants were produced using anther culture from out-crossing rye, including breedersÕ lines, cultivars and F 1 plants with DH parents, to examine the feasibility of using the DH technique for breeding and specifically for developing mapping populations. Only 10-36% of green regenerants produced via anther culture were suitable for research or breeding purposes because of low survival rate or low fertility. Spontaneously arising DH regenerants were more often fertile compared with the colchicine-treated ones. The fertility of spontaneous DHs varied from sterile to half that found in a normal rye population, which has implications for the design of a crossing scheme and subsequent anther culture. In the reciprocal crosses within one DH population, fertility was the lowest observed, probably because of selfincompatibility factors, whereas in the DH crosses with normal heterozygous cultivars fertility was the highest. Two mapping populations using DHs were established, the first for out-crossing rye it would seem. These populations will be used for mapping two important traits, the semi-dwarf growth habit and preharvest sprouting resistance in rye.