The coexistence of cereal cyst nematode (CCN) species Heterodera avenae and H. filipjevi, often involving multiple pathotypes, is a limiting factor for wheat production in China. Some of the known genes for resistance to CCN are not effective against both nematode species, hence complicating breeding efforts to develop CCN-resistant wheat cultivars. Here, we demonstrate that the CCN resistance in wheat cultivar Madsen to both Heterodera spp. is controlled by different genetic loci, both of which originated from Aegilops ventricosa. A new quantitative trait locus (QTL), QCre-ma7D, was identified and localized in a 3.77-Mb genomic region on chromosome arm 7DL, which confers resistance to H. filipjevi. QCre-ma2A on chromosome arm 2AS corresponds to CCN resistance gene Cre5 and confers resistance to H. avenae. This QTL is a new locus on chromosome arm 7DL and is designated Cre9. Three Kompetitive allele-specific PCR markers (BS00150072, BS00021745, and BS00154302) were developed for molecular marker-assisted selection of Cre9 and locally adapted wheat lines with resistance to both nematode species were developed. QCre-ma2A on chromosome arm 2AS corresponds to CCN resistance gene Cre5 and confers resistance to H. avenae. The identification of different loci underlying resistance to H. filipjevi and H. avenae and the development of adapted resistant entries will facilitate breeding of wheat cultivars that are resistant to these devastating nematodes in China.

Triticale (× Triticosecale Wittmack) is a valuable dual-purpose crop due to its adaptability to marginal environments and its potential for both high-quality grain and forage production. However, a comprehensive evaluation of its forage quality characteristics and agronomic performances is still needed. This study evaluated the grain and forage yield potentials and nutritional compositions of 11 triticale genotypes over two consecutive years in a semi-arid region located in Shanxi province, China. Forage quality was assessed using several key parameters, including nutrient composition, fiber digestibility, mineral content, and energy density, while grain quality parameters, including nutrient composition as well as carbohydrate and fiber characteristics, were also analyzed. Significant genetic variation was observed in these traits, indicating the influence of genotype–environment interactions on these traits. The tested genotypes exhibited grain yields ranging from 4.83 to 6.92 t ha⁻¹ and fresh forage biomass yields between 20.06 and 29.78 t ha⁻¹, demonstrating their potential for sustainable forage and grain production under semi-arid conditions. Genotypes from our breeding programs, including Shengnongsicao 1 and Jinsicao 1, demonstrated superior adaptability, maintaining stable forage and grain yield potentials under adverse conditions. Their favorable nutritional characteristics further enhance their suitability for semi-arid livestock systems. High levels of essential minerals, particularly calcium and potassium, further enhanced the nutritional value of these genotypes. These results provide valuable insights for triticale breeding programs and suggest triticale’s potential as a reliable crop in semi-arid regions, where maximizing land productivity is essential.

Perennial wheat is considered to be a practical way to increase the flexibility and profitability of sustainable agricultural system, as it can be either a forage grass or a grain crop. Four perennial wheat lines SX12-480, SX12-787, SX12-1150, and SX12-1269 were developed from a series of interspecific crosses between common wheat (Triticum aestivum, 2n = 42) or durum wheat (T. turgidum var. durum, 2n = 28) and the intermediate wheatgrass (Thinopyrum intermedium, 2n = 42). These lines were characterized by the vigorous regrowth for at least 3 years. The one- and 2-year-old plants had higher grain yield potential than the 3-year-old perennial plants. The decline of grain yield was associated with plant age-related effects on yield components. The perennial wheat lines were all resistant to both Heterodera avenae and H. filipjevi, the two distinct cereal cyst nematode species that occur in China, except that line SX12-787 exhibited moderate resistance only to H. avenae. The dual-purpose perennial wheat lines were evaluated for quality values of both defoliated grass and harvested grains in the form of amino acid profile, mineral concentration, and contents of protein and fiber. Difference in the quality profile was observed between the perennial lines. These perennial lines had an overall improved quality levels over those of the perennial wheat control Montana-2 (T. turgidum × Th. intermedium) and the annual wheat cultivar Jinchun 9. The amplification profiles of the molecular markers provided molecular evidence for the introgression of alien chromatin. Genomic in situ hybridization detected 16, 14, 14, and 12 Th. intermedium chromosomes in lines SX12-480 (2n = 48), SX12-787 (2n = 56), SX12-1150 (2n = 56), and SX12-1269 (2n = 54), respectively, in addition to either 32 or the complete set of wheat chromosomes. The four perennial wheat-Th. intermedium lines described here provide valuable sources of perennial wheat for the dual-purpose application of both grain and forage.

Wide hybridization between wheat and wild relatives such as Thinopyrum intermedium is important for broadening genetic diversity and improving disease resistance in wheat. We developed 30 wheat-Th. intermedium derivatives. Here, we report assessments of their resistance to different pathogens including cereal cyst nematode (CCN; Heterodera spp.), Puccinia striiformis f. tritici Erikss. causing stripe rust, and Blumeria graminis f. tritici (DC.) Speer inciting powdery mildew. Under natural field infection, all the wheat-Th. intermedium lines were resistant to at least one of the pathogens, and four lines were resistant to multiple pathogens. Twenty-nine of 30 tested lines exhibited resistance to H. avenae, a dominant CCN species in wheat fields. Twenty-four lines were resistant to H. filipjevi, an emerging threat to wheat production. Tests of phenotypic responses in the naturally infected field nurseries identified six stripe rust-resistant lines and 13 powdery mildew-resistant lines. Mitotic observation demonstrated that these newly developed wheat-Th. intermedium derivatives included not only octoploid but also chromosome addition, substitution, and translocation lines. Chromosome compositions of the four lines resistant to multiple pathogens were analyzed by genomic in situ hybridization and fluorescence in situ hybridization. The octoploid lines Zhong 10-68 and Zhong 10-117 carried both intact Th. intermedium chromosomes and translocated chromosomes. Line Zhong 10-149 had 42 wheat chromosomes and two wheat ditelosomes plus a pair of T3BS·J translocated chromosomes. Line Zhong 10-160 carried 41 wheat chromosomes plus one pair of the J genome chromosomes of Th. intermedium. The multiple disease-resistant wheat-Th. intermedium derivatives, especially lines with chromosome counts close to that of common wheat, provide valuable materials for wheat resistance breeding programs.

A total of 159 wheat–Thinopyrum intermedium derivatives, originating from six Zhong partial amphiploids, were evaluated for resistance to powdery mildew (Blumeria graminis f. sp. tritici) at both seedling and adult-plant stages, as well as for field resistance to wheat aphids, together with key agronomic traits. Adult-plant resistance to powdery mildew was common across three years: 34 lines (21.4%) exhibited stable resistance, and 27 (17.0%) were moderately resistant. Resistance frequencies differed among pedigree backgrounds, with Zhong 2 & 5 derivatives showing the highest proportion of stable resistant lines (35.7%). Seedling resistance was detected in 63 lines (39.6%). Aphid resistance was less frequent, with 61 lines (38.4%) classified as resistant, including two highly resistant lines derived from Zhong 3 and Zhong 1 & 3 backgrounds. Combined resistance traits were comparatively rare. Thirty-two lines exhibited resistance to powdery mildew at both seedling and adult-plant stages, while nine lines displayed combined resistance to seedling mildew, adult mildew, and aphids. Analysis of agronomic traits indicated that environmental effects accounted for a substantial proportion of the observed phenotypic variation, whereas pedigree background and resistance responses contributed comparatively little. Correlation analyses revealed generally weak associations between resistance responses and agronomic traits, suggesting that resistance was not a major determinant of agronomic performance within the evaluated population. The identified resistant materials, therefore, represent valuable pre-breeding resources for the incorporation of resistance to multiple biotic stresses in wheat. Further genetic characterization and multi-environment evaluation will facilitate their effective utilization in wheat improvement programs.