Molecular Cytogenetic Identification of a Novel Wheat–Thinopyrum ponticum 1JS (1B) Substitution Line Resistant to Powdery Mildew and Leaf Rust

Thinopyrum ponticum (2n = 10x = 70) is a wild relative of wheat with high tolerance to both biotic and abiotic stresses; it has been wildly used in wheat genetic improvement. A disomic substitution line named SN19647 was derived from a cross between Triticum aestivum and the wheat–Th. ponticum partial amphiploid SNTE20 (2n = 8x = 56). It was evaluated for disease resistance and characterized via sequential fluorescence in situ hybridization (FISH)-genomic in situ hybridization (GISH) and molecular markers. The results showed that SN19647 carried resistance to both powdery mildew and leaf rust. It contained 42 chromosomes with a pair of wheat chromosome 1B replaced by a pair of JS chromosomes from Th. ponticum. In addition to chromosomal substitution events, structural variation also occurred on wheat chromosomes 2A, 5A, 6B, and 7B. Based on marker analysis, 19 markers specific to the JS chromosome were obtained, of which seventeen markers belonged to homoeologous group one. These results indicated that SN19647 was a 1JS (1B) substitution line. Compared with the known 1JS (1D) substitution line CH10A5, it was found that 17 markers generated different specific bands to Th. ponticum, confirming the novelty of the 1JS chromosome in SN19647. Therefore, SN19647, resistant to powdery mildew and leaf rust, was a novel 1JS (1B) substitution line that can be used in wheat genetic improvement.

Molecular cytogenetics and St-chromosome-specific molecular markers development of novel stripe rust resistant wheat–Thinopyrum intermedium as well as wheat–Thinopyrum ponticum substitution lines

Background Owing to the excellent resistance to abiotic and biotic stress, Thionpyrum intermedium (2n = 6x = 42, JJJsJsStSt) and Thinopyrum ponticum (2n = 10x = 70) are both widely utilized in wheat germplasm innovation programs. Disomic substitution lines (DSLs) carrying one pair of alien chromosomes are valuable bridge materials for novel genes transmission, FISH karyotype construction and specific molecular marker development. Results Six wheat–Thinopyrum DSLs derived from crosses between Abbondanza nullisomic lines (2n = 40) and two octoploid Trititrigia lines (2n = 8x = 56), were characterized by a sequential fluorescence in situ hybridization (FISH)–genome in situ hybridization (GISH), a multicolor GISH (mc-GISH), and an analysis of wheat 15K SNP array combined with molecular marker selection. ES-9 (DS2St (2A)) and ES-10 (DS3St (3D)) are wheat–Th. ponticum DSLs, while ES-23 (DS2St (2A)), ES-24 (DS3St (3D)), ES-25(DS2St (2B)), and ES-26 (DS2St (2D)) are wheat–Th. intermedium DSLs. ES-9, ES-23, ES-25 and ES-26 conferred higher thousand-kernel weight and stripe rust resistance at adult stages, while ES-10 and ES-24 performed highly resistant to stripe rust at all stages. Furthermore, cytological analysis showed that the alien chromosomes (2St/3St) belonging to the same homoeologous group derived from different donors carried the same FISH karyotype and could normally form a bivalent. Based on specific-locus amplified fragment sequencing (SLAF-seq), two 2St-chromosome-specific markers (PTH-005 and PTH-013) and two 3St-chromosome-specific markers (PTH-113 and PTH-135) were developed. Conclusions The six wheat–Thinopyrum disomic substitution lines conferring stripe rust resistance will be used as bridging parents for valuable resistant genes transmission. And the utility of PTH-113 and PTH-135 in a BC1F2 population showed the newly developed markers could be useful tools for efficient identification of St chromosomes in a common wheat background.

Molecular Cytogenetics of Chromosome 2St as Well as Chromosome 3St Derived from Thinopyrum Intermedium and Thinopyrum Ponticum

Owing to the excellent resistance to abiotic and biotic stress, Thionpyrum intermedium (2n = 6x = 42, JJJsJsStSt) and Thinopyrum ponticum (2n = 10x = 70) are both widely utilized in wheat germplasm innovation programs. Disomic substitution lines (DSLs) carrying one pair of alien chromosomes are valuable bridge materials for novel genes transmission. In this study, six wheat-Thinopyrum DSLs were derived from crosses between Abbondanza nullisomic lines (2n = 40) and two octoploid Trititrigia lines (2n = 8x = 56), characterized by a sequential fluorescence in situ hybridization (FISH)-genome in situ hybridization (GISH), a multicolor GISH (mc-GISH), and an analysis of wheat 15K SNP array combined with molecular marker selection. ES-9 and ES-10 were two wheat- Th. ponticum disomic substitution lines, DS2St (2A) and DS3St (3D). While ES-23, ES-24, ES-25, and ES-26 were four wheat- Th. intermedium disomic substitution lines, DS2St (2A), DS3St (3D), DS2St (2B), DS2St (2D). The FISH karyotypes of Th. ponticum 2St/3St chromosomes were well coincident with the ones of Th. intermedium. The chromosome configurations of F1 hybrids derived from crosses between ES-23 and ES-9, as well as ES-24 and ES-10 were mostly formed 21Ⅱ. Four St-chromosome-specific markers were developed by specific-locus amplified fragment sequencing (SLAF-seq). Additionally, the substitution lines containing chromosome 2St conferred higher thousand-kernel weight and stripe rust resistance at adult stages, while the substitution lines containing chromosome 3St were highly resistant to stripe rust at all stages. Therefore, these six substitution lines could serve as useful bridging parents for wheat genetic improvement.

Long-Term Effects of TBBPA-Contaminated Pyrogenic Organic Matters under The Abiotic Aging: Insights on Immobilization Capacity, Surface Functionality Correlation, and Phytotoxicity to Thinopyrum Ponticum

A large amount of annual global carbon input is reported from pyrogenic organic matters (POMs) production, motivating numerous research studies. Given to Tetrabromobisphenol A (TBBPA) can be frequently exposed to...

Продуктивность и хлебопекарные свойства ×Trititrigia cziczinii

Многолетняя пшеница — трититригия, несущая гены своих родительских видов, в качестве которых использовали виды пырея Agropyron elongatum (Host) P. Beauv. [syn. Thinopyrum ponticum (Podp.) Zhi W. Liu et R. R.-C. Wang] и A. glaucum (Desf. ex DC) Roem. and Schult. [syn. Thinopyrum intermedium (Host) Barkworth et D. R. Dewey] и сорта мягкой и твердой пшеницы (Triticum aestivum L. и T. durum Desf.) в различных комбинациях, унаследовала много положительных свойств своих родителей (многолетность, способность к отрастанию после уборки, более высокий показатели качества зерна — содержание белка, клейковины и т.д., устойчивость к неблагоприятным почвенно-климатическим условиям, ряду болезней). Для установления объективной оценки качественных показателей зерна трититригии в условиях центрального региона России в зоне рискованного земледелия изучены технологические и хлебопекарные показатели некоторых образцов данной культуры. При обычных условиях для роста и развития растений многолетняя пшеница накапливает в зерне значительное количество белка — 18 – 19 %. Анализ хлебопекарных достоинств трититригии показал, что основные показатели такие как внешний вид, пористость, объем хлеба, превышают показатели сорта озимой пшеницы Московская 39, используемого в качестве стандарта. Исследуемые образцы многолетней пшеницы (М 3202, ЗП 26,548, Памяти Любимовой) имели высокую хлебопекарную оценку — от 3,8 до 4,0 баллов соответственно, тогда как у стандарта Московская 39 общая оценка — 3,7 балла.

Development of Specific Thinopyrum Cytogenetic Markers for Wheat-Wheatgrass Hybrids Using Sequencing and qPCR Data

The cytogenetic study of wide hybrids of wheat has both practical and fundamental values. Partial wheat-wheatgrass hybrids (WWGHs) are interesting as a breeding bridge to confer valuable genes to wheat genome, as well as a model object that contains related genomes of Triticeae. The development of cytogenetic markers is a process that requires long and laborious fluorescence in situ hybridization (FISH) testing of various probes before a suitable probe is found. In this study, we aimed to find an approach that allows to facilitate this process. Based on the data sequencing of Thinopyrum ponticum, we selected six tandem repeat (TR) clusters using RepeatExplorer2 pipeline and designed primers for each of them. We estimated the found TRs’ abundance in the genomes of Triticum aestivum, Thinopyrum ponticum, Thinopyrum intermedium and four different WWGH accessions using real-time qPCR, and localized them on the chromosomes of the studied WWGHs using fluorescence in situ hybridization. As a result, we obtained three tandem repeat cytogenetic markers that specifically labeled wheatgrass chromosomes in the presence of bread wheat chromosomes. Moreover, we designed and tested primers for these repeats, and demonstrated that they can be used as qPCR markers for quick and cheap monitoring of the presence of certain chromosomes of wheatgrass in breeding programs.

Assessing the Ability of Durum Wheat-Thinopyrum ponticum Recombinant Lines to Suppress Naturally Occurring Weeds under Different Sowing Densities

The use of synthetic chemicals in cropping systems is becoming more controversial and highly debated worldwide, owing to its impacts on the environment, food safety, and human health. For this reason, sustainable crop management strategies are gaining increasing interest. In this perspective, agronomic practices and use of disease-resistant and competitive genotypes represent valuable tools in the hands of farmers. The competitive ability of two durum wheat-Thinopyrum ponticum recombinant lines (named R5 and R112), carrying effective resistance genes towards main rust diseases and enhanced yield-related traits in their alien chromosome segments, was investigated in comparison with that of a widely grown commercial cultivar (Tirex), under two sowing densities (250 and 350 seeds m−2), in the presence or absence of weeds. Yield-related traits and specific attributes that confer competitive ability were recorded in two subsequent seasons. R5 was the most weed-suppressive genotype, whereas Tirex was the least competitive. R112 was the best yield performer under favorable weather conditions (5.6 t ha−1), while it suffered the presence of weeds in the drier year (−38% grain yield). Although 350 seeds m−2 appeared to be the most effective sowing density for suppression of weeds (−16% weed biomass), adoption of the lower density can optimize grain yield and limit weed infestation in dry seasons. A suitable combination of sowing density and genotype choice can improve yield performance. R112 required the higher sowing rate to maximize grain yield (+43% as compared to the lower sowing rate), while R5 proved to be a density-neutral genotype.