Triticale is tolerant of many environmental stresses, especially highly resistant to salt stress. However, the molecular regulatory mechanism of triticale seedlings under salt stress conditions is still unclear so far. In this study, a salt-responsive transcriptome analysis was conducted to identify candidate genes or transcription factors related to salt tolerance in triticale. The root of salt-tolerant triticale cultivars TW004 with salt-treated and non-salt stress at different time points were sampled and subjected to de novo transcriptome sequencing. Total 877,858 uniquely assembled transcripts were identified and most contigs were annotated in public databases including nr, GO, KEGG, eggNOG, Swiss-Prot and Pfam. 59,280, 49,345, and 85,922 differentially expressed uniquely assembled transcripts between salt treated and control triticale root samples at three different time points (C12_vs_T12, C24_vs_T24, and C48_vs_T48) were identified, respectively. Expression profile and functional enrichment analysis of DEGs found that some DEGs were significantly enriched in metabolic pathways related to salt tolerance, such as reduction–oxidation pathways, starch and sucrose metabolism. In addition, several transcription factor families that may be associated with salt tolerance were also identified, including AP2/ERF, NAC, bHLH, WRKY and MYB. Furthermore, 14 DEGs were selected to validate the transcriptome profiles via quantitative RT-PCR. In conclusion, these results provide a foundation for further researches on the regulatory mechanism of triticale seedlings adaptation to salt stress in the future.

To clarify the compensatory effect of increasing density on the yield of extremely late-sown wheat and screen the best combination of the sowing date and density of extremely late-sown wheat in the wheat area of northern Xinjiang, this study set three extremely late-sown dates of October 25 (D1), November 4 (D2), and November 14 (D3) and four densities of 337.5 (M1), 450 (M2), 562.5 (M3), and 675 kg·hm⁻² (M4). Additionally, the effects of the sowing date and density combinations on the formation process of the yield element spike number, spike grain number, and 1000-grain weight were analyzed in detail using the local conventional sowing date and density (25 September, 270 kg·hm⁻²) as the control (CK). The results showed that compared to the CK, increasing the planting density of extremely late-sown wheat compensated for the reduction in the number of harvested spikes due to low emergence rates. The young spikes were stunted due to a reduction in the number of grains per spike, and the grain grouting rate caused a reduction in the defects of the 1000-grain weight in order to increase the number of harvested spikes to improve yield. Under extremely late sowing conditions, D2M2 had the highest post-spring emergence rates, the highest number of harvested spikes, better development of young spikes and grain-filling, and non-significant declines in the number of grains per spike and 1000-grain weight, which balanced the contribution of the number of harvested spikes, number of grains per spike, and 1000-grain weight to the yield and gave the highest yield. After comprehensive yield factor analysis, sowing 450 kg·hm⁻² (1.00 × 10⁶ seeds·hm⁻²) on 4 November (pre-winter cumulative temperature of 47.5 °C) was determined to be the best combination for planting extremely late-sown wheat in the northern Xinjiang wheat area, and the results of this study can provide important theoretical and technical references for guaranteeing the yield of winter wheat in extremely late-sown winter wheat areas.

Grain size is a key trait associated with bread wheat yield. It is also the most frequently selected trait during domestication. After the phenotypic characterization of 768 bread wheat accessions in three plots for at least two years, the present study shows that the improved variety showed significantly higher grain size but lower grain protein content than the landrace. Using 55K SNP assay genotyping and large-scale phenotyping population and GWAS data, we identified 5, 6, 6, and 6 QTLs associated with grain length, grain weight, grain area, and thousand grain weight, respectively. Seven of the 23 QTLs showed common association within different locations or years. Most significantly, the key locus associated with grain length, qGL-2D, showed the highest association after years of multi-plot testing. Haplotype and evolution analysis indicated that the superior allele of qGL-2D was mainly hidden in the improved variety rather than in landrace, which may contribute to the significant difference in grain length. A comprehensive analysis of transcriptome and homolog showed that TraesCS2D02G414800 could be the most likely candidate gene for qGL-2D. Overall, this study presents several reliable grain size QTLs and candidate gene for grain length associated with bread wheat yield.

Soil microbes are crucial in shaping the root-associated microbial communities. In this study, we analyzed the effect of the soil–root niche gradient on the diversity, composition, and assembly of the bacterial community and co-occurrence network of two cotton varieties. The results revealed that the bacterial communities in cotton soil–root compartment niches exhibited a skewed species abundance distribution, dominated by abundant taxa showing a strong spatial specificity. The assembly processes of the rhizosphere bacterial communities were mainly driven by stochastic processes, dominated by the enrichment pattern and supplemented by the depletion pattern to recruit bacteria from the bulk soil, resulting in a more stable bacterial community. The assembly processes of the endosphere bacterial communities were determined by processes dominated by the depletion pattern and supplemented by the enrichment pattern to recruit species from the rhizosphere, resulting in a decrease in the stability and complexity of the community co-occurrence network. The compartment niche shaped the diversity of the bacterial communities, and the cotton variety genotype was an important source of diversity in bacterial communities within the compartment niche. We suggest that the moderate taxa contribute to significantly more changes in the diversity of the bacterial community than the rare and abundant taxa during the succession of bacterial communities in the cotton root–soil continuum.

Wheat leaf rust, caused by Puccinia triticina, is a severe fungal disease threatening global wheat production. The rational application of genetic loci controlling wheat resistance to leaf rust in breeding practice is still the best choice for disease control. A previous study indicated that the Argentinean wheat cultivar “Klein Proteo” might carry leaf rust resistance (Lr) genes Lr3a and Lr10, as well as an unknown Lr gene. In this study, seedlings of “Klein Proteo” showed high resistance to all the 20 Pt pathotypes isolated in China. Using bulked segregant RNA sequencing (BSR-seq) and developed CAPS markers, the single-dominant gene LrKP was initially mapped to a 114–168 Mb region on chromosome 2BS. Using gene-specific primers of a previously cloned chromosome 2BS-located Lr13 gene, we found that “Klein Proteo” also carried the Lr13 gene. Moreover, the expression of Lr13 in the resistant bulk was significantly higher than that in the susceptible bulk. Nevertheless, “Klein Proteo” showed a much broader and higher resistance compared with the near isogenic line and “ZhouMai 22” carrying Lr13. In conclusion, the wheat cultivar “Klein Proteo” showed great potential in the genetic improvement of wheat resistance to leaf rust in China and the genetic bases controlling the broad-spectrum resistance were initially revealed.