Rye (Secale cereale L.) is an exceptionally climate-resilient cereal crop, used extensively to produce improved wheat varieties via introgressive hybridization and possessing the entire repertoire of genes necessary to enable hybrid breeding. Rye is allogamous and only recently domesticated, thus giving cultivated ryes access to a diverse and exploitable wild gene pool. To further enhance the agronomic potential of rye, we produced a chromosome-scale annotated assembly of the 7.9-gigabase rye genome and extensively validated its quality by using a suite of molecular genetic resources. We demonstrate applications of this resource with a broad range of investigations. We present findings on cultivated rye’s incomplete genetic isolation from wild relatives, mechanisms of genome structural evolution, pathogen resistance, low-temperature tolerance, fertility control systems for hybrid breeding and the yield benefits of rye–wheat introgressions.

Simple sequence repeats (SSRs) are highly versatile markers in genetic diversity analysis and plant breeding, making them widely applicable. They hold potential in lentil (Lens culinaris) breeding for genetic diversity analysis, marker-assisted selection (MAS), and linkage mapping. However, the availability and diversity of SSR markers in lentil is limited. We used next-generation sequencing (NGS) technology to develop SSR markers in lentil. NGS allowed us to identify regions of the lentil genome that contained SSRs. Illumina Hiseq-2000 sequencing of the lentil genotype “Karacadağ” resulted in 1,727,734 sequence reads comprising more than 48,390 Mb, and contigs were mined for SSRs, resulting in the identification of a total of 8697 SSR motifs. Among these, dinucleotide repeats were the most abundant (53.38%), followed by trinucleotides (30.38%), hexanucleotides (6.96%), tetranucleotides (6.59%), and pentanucleotides (3.19%). The most frequent repeat in dinucleotides was the TC (21.80%), followed by the GA (17.60%). A total of 2000 primer pairs were designed from these motifs, and 458 SSR markers were validated following their amplified PCR products. A linkage map was constructed using these new SSRs with high linkage disequilibrium (209) and previously known SSRs (11). The highest number of SSR markers (43) was obtained in LG2, while the lowest number of SSR markers (19) was obtained in LG7. The longest linkage group (LG) was LG2 (86.84 cM), whereas the shortest linkage group was LG7 (53.46 cM). The average length between markers ranged from 1.86 cM in LG1 to 2.81 cM in LG7, and the map density was 2.16 cM. The developed SSRs and created linkage map may provide useful information and offer a new library for genetic diversity analyses, linkage mapping studies, and lentil breeding programs.

Cadmium (Cd) is a non-essential heavy metal having toxic effects on all living organisms. Durum wheat (Triticum durum Desf.) is widely used in human diets but has the potential to accumulate Cd. It also has a high level of genetic diversity, which may be exploited to develop cultivars with low Cd content. We aimed to perform marker-assisted selection and validate previously identified Cd markers in durum wheat germplasm for use in the investigation of accessions that accumulate low grain Cd content. We assessed 130 durum wheat accessions phenotypically and using three different molecular markers. Grain Cd contents of the studied germplasm varied 4.91-fold (26.2–128.7 μg/kg) with an average of 58.2 μg/kg. Landraces showed lower average values of grain Cd content than cultivars. Three molecular markers (usw47, Cad-5B and KASP marker Cad-5B) were used to differentiate high and low Cd accumulating lines. Results showed high correlation and successfully classified the accessions to the expected high or low Cd level; 87 accessions showed the low Cd alleles, and 43 accessions the high Cd alleles, except for five accessions with the usw47 marker that showed heterozygous status. A significant correlation coefficient (r = 0.944*) was observed among the three molecular markers. Based on molecular markers, 96.2% of the accessions were classified accurately. The KASP assay was highly effective in successfully separating low from high Cd content accessions and could be used as a molecular tool in durum wheat breeding programs, with less cost and time, targeting reduced grain Cd levels. The results of this study will allow durum wheat breeders to accelerate their progress to select suitable genotypes with the desired alleles.

Genotypes with longer coleoptiles can be sown in deep soil layers to reach the underground moisture needed for germination in dry areas. Developing new varieties with longer coleoptiles and shorter plant heights would be novel for wheat breeding and production. In this study, coleoptile lengths of a panel of durum wheat (Triticum turgidum ssp. durum) genotypes were determined, and 14,255 DArTseq (SNP and Silico‐DArT) markers were used to identify coleoptile length‐associated markers by genome‐wide association study (GWAS). A wide genetic variation was accounted for both coleoptile length and plant height. The genetic relationships between coleoptile length and plant height were evaluated using plant height values from five different environments. Two environmentally stable MTAs were identified, one for coleoptile length (QCol.su.4BS) and one for plant height (QPh.su.4BS). These MTAs were located on the short arm of chromosome 4B, with LOD scores up to 12.00 and 17.00, respectively. A relatively high LD (r² = 0.71) was accounted for between QCol.su.4BS and QPh.su.4BS. The LD block intervals of the MTAs overlapped with some genes with roles in plant growth and development. The functions of plausible candidate genes tell us that QCol.su.4BS may be controlling coleoptile length, whereas QPh.su.4BS may be regulating plant height. The combination of the two loci would be desirable. In conclusion, this study sheds light on the genetic control of coleoptile length and its relationship with plant height in durum wheat.

The black point is a discoloration that shows up on the embryos of wheat and barley, and it is becoming an important problem in many wheat-growing areas. In this study, 200 commercially important bread wheat varieties that were cultivated between 1931 and 2017 in Turkey were screened in terms of black point, and the effect of black point was observed on thousand grain weight in all cultivars. The trials were conducted in accordance with the augmented block trial design in three environments during the 2016-17 growing season. A high variation was observed among the cultivars for black point and thousand grain weight. Twelve varieties (6% of populations) showed no discoloration (0.00%) in any environment, whereas 44 varieties (22% of population) showed discoloration rate more than 10.00%. The first three most susceptible cultivars showed black point percentages of 38.76, 32.08, and 27.5, respectively. In the remaining cultivars, eighty-eight showed discolorations up to 5.00%, whereas the rest demonstrated discoloration from 5.00% to 24.00%. Interestingly, a positive correlation was observed between black point damage and thousand grain weight (r=0.32). The reasonable interpretation is that the larger seed surfaces may have increased the effect of black point causes, such as pathogens and oxidative reactions. This screening enabled us to determine black point susceptible and tolerant cultivars in well-known bread wheat cultivars growing in Turkey. Hence, the results will be useful for wheat production and wheat breeding approaches in Turkey and around the world.