Uncovering the dispersion history, adaptive evolution and selection of wheat in China

Wheat was introduced to China approximately 4500 years ago, where it adapted over a span of time to various environments in agro-ecological growing zones. We investigated 717 Chinese and 14 Iranian/Turkish geographically diverse, locally adapted wheat landraces with 27,933 DArTseq (for 717 landraces) and 312,831 Wheat660K (for a subset of 285 landraces) markers. This study highlights the adaptive evolutionary history of wheat cultivation in China. Environmental stresses and independent selection efforts have resulted in considerable genome-wide divergence at the population level in Chinese wheat landraces. In total, 148 regions of the wheat genome show signs of selection in at least one geographic area. Our data show adaptive events across geographic areas, from the xeric northwest to the mesic south, along and among homoeologous chromosomes, with fewer variations in the D genome than in the A and B genomes. Multiple variations in interdependent functional genes, such as regulatory and metabolic genes controlling germination and flowering time were characterized, showing clear allelic frequency changes corresponding to the dispersion of wheat in China. Population structure and selection data reveal that Chinese wheat spread from the northwestern Caspian Sea region to south China, adapting during its agricultural trajectory to increasingly mesic and warm climatic areas

Genome-Wide Association Study for Adult-Plant Resistance to Stripe Rust in Chinese Wheat Landraces (Triticum aestivum L.) From the Yellow and Huai River Valleys

Stripe rust (also known as yellow rust), caused by the pathogen Puccinia striiformis f. sp. tritici (Pst), is a common and serious fungal disease of wheat (Triticum aestivum L.) worldwide. To identify effective stripe rust resistance loci, a genome-wide association study was performed using 152 wheat landraces from the Yellow and Huai River Valleys in China based on Diversity Arrays Technology and simple sequence repeat markers. Phenotypic evaluation of the degree of resistance to stripe rust at the adult-plant stage under field conditions was carried out in five environments. In total, 19 accessions displayed stable, high degrees of resistance to stripe rust development when exposed to mixed races of Pst at the adult-plant stage in multi-environment field assessments. A marker–trait association analysis indicated that 51 loci were significantly associated with adult-plant resistance to stripe rust. These loci included 40 quantitative trait loci (QTL) regions for adult-plant resistance. Twenty identified resistance QTL were linked closely to previously reported yellow rust resistance genes or QTL regions, which were distributed across chromosomes 1B, 1D, 2A, 2B, 3A, 3B, 4A, 4B, 5B, 6B, 7A, 7B, and 7D. Six multi-trait QTL were detected on chromosomes 1B, 1D, 2B, 3A, 3B, and 7D. Twenty QTL were mapped to chromosomes 1D, 2A, 2D, 4B, 5B, 6A, 6B, 6D, 7A, 7B, and 7D, distant from previously identified yellow rust resistance genes. Consequently, these QTL are potentially novel loci for stripe rust resistance. Among the 20 potentially novel QTL, five (QDS.sicau-2A, QIT.sicau-4B, QDS.sicau-4B.2, QDS.sicau-6A.3, and QYr.sicau-7D) were associated with field responses at the adult-plant stage in at least two environments, and may have large effects on stripe rust resistance. The novel effective QTL for adult-plant resistance to stripe rust will improve understanding of the genetic mechanisms that control the spread of stripe rust, and will aid in the molecular marker-assisted selection-based breeding of wheat for stripe rust resistance

Leaching of valuable metals from cathode active materials in spent lithium-ion batteries by levulinic acid and biological approaches

Recycling of valuable metals from spent lithium-ion batteries (LIBs) is of paramount importance for the sustainable development of consumer electronics and electric vehicles. This study comparatively investigated two eco-friendly leaching methods for recovering Li, Ni, Co, and Mn from waste NCM523 (LiNi0.5Co0.2Mn0.3O2) cathode materials in spent LIBs, i.e., chemical leaching by a green organic solvent, levulinic acid (LA) and bioleaching by an enriched microbial consortium. In chemical leaching, mathematical models predicting leaching efficiency from liquid-to-solid ratio (L/S; L/kg), temperature (°C), and duration (h) were established and validated. Results revealed that LA of 6.86 M was able to achieve complete leaching of all target metals in the absence of reductants at the optimal conditions (10 L/kg, 90 °C, and 48 h) identified by the models. The evaluation of direct one- and two-step and indirect bioleaching indicated that the latter was more feasible for metal extraction from waste NCM523. L/S was found to impact the indirect bioleaching most significantly among the three operating variables. Pretreatment of waste NCM523 by washing with 1 vol% methanesulfonic acid significantly improved indirect bioleaching. The side-by-side comparison of these two leaching approaches on the same cathode active material (CAM) thus provided the technical details for further comparison with respect to cost and environmental impact

Genome-wide association study of pre-harvest sprouting resistance in Chinese wheat founder parents

Abstract Pre-harvest sprouting (PHS) is a major abiotic factor affecting grain weight and quality, and is caused by an early break in seed dormancy. Association mapping (AM) is used to detect correlations between phenotypes and genotypes based on linkage disequilibrium (LD) in wheat breeding programs. We evaluated seed dormancy in 80 Chinese wheat founder parents in five environments and performed a genome-wide association study using 6,057 markers, including 93 simple sequence repeat (SSR), 1,472 diversity array technology (DArT), and 4,492 single nucleotide polymorphism (SNP) markers. The general linear model (GLM) and the mixed linear model (MLM) were used in this study, and two significant markers (tPt-7980 and wPt-6457) were identified. Both markers were located on Chromosome 1B, with wPt-6457 having been identified in a previously reported chromosomal position. The significantly associated loci contain essential information for cloning genes related to resistance to PHS and can be used in wheat breeding programs

Effects of the 1BL/1RS translocation on 24 traits in a recombinant inbred line population

The 1BL/1RS translocation is widespread in a large number of wheat varieties. In this study, we comprehensively evaluated the efects of the 1BL/1RS translocation on 24 traits in a recombinant inbred line population derived from the cross between 20828 and Chuannong16. The phenotypic data was from multiple environments and major loci for a given trait were excluded to avoid their interference with the efects of 1BL/1RS translocation. Comparison results showed that 1RS chromosome arm carried lines had positive efect on increasing maximum root length and spike density. While 1BS chromosome arm carried lines had positive efects on increasing plant height, grain number per spike, efective tiller, root tip number, and resistance to stripe rust. The stripe rust resistance genes, Yr15 detected on 1BS in this study and QYr.sicau-1B.1 identifed previously on 1BL were both derived from 20828. These results revealed the genetic mechanism of near-immune resistance to stripe rust in 20828 that has been utilized as a breeding parent for over a decade, and thus possibly accelerate its breeding utilization. This study combined with previous studies indicated that 1BS chromosome arm is likely benefcial to yield increase, while 1RS is more helpful for drought tolerance improvement

Increasing the Grain Yield and Grain Protein Content of Common Wheat (Triticum aestivum) by Introducing Missense Mutations in the Q Gene

Grain yield (GY) and grain protein content (GPC) are important traits for wheat breeding and production; however, they are usually negatively correlated. The Q gene is the most important domestication gene in cultivated wheat because it influences many traits, including GY and GPC. Allelic variations in the Q gene may positively affect both GY and GPC. Accordingly, we characterized two new Q alleles (Qs1 and Qc1-N8) obtained through ethyl methanesulfonate-induced mutagenesis. Compared with the wild-type Q allele, Qs1 contains a missense mutation in the sequence encoding the first AP2 domain, whereas Qc1-N8 has two missense mutations: one in the sequence encoding the second AP2 domain and the other in the microRNA172-binding site. The Qs1 allele did not significantly affect GPC or other processing quality parameters, but it adversely affected GY by decreasing the thousand kernel weight and grain number per spike. In contrast, Qc1-N8 positively affected GPC and GY by increasing the thousand kernel weight and grain number per spike. Thus, we generated novel germplasm relevant for wheat breeding. A specific molecular marker was developed to facilitate the use of the Qc1-N8 allele in breeding. Furthermore, our findings provide useful new information for enhancing cereal crops via non-transgenic approaches

Rescuing ocular development in an anophthalmic pig by blastocyst complementation

Abstract Porcine‐derived xenogeneic sources for transplantation are a promising alternative strategy for providing organs for treatment of end‐stage organ failure in human patients because of the shortage of human donor organs. The recently developed blastocyst or pluripotent stem cell (PSC) complementation strategy opens a new route for regenerating allogenic organs in miniature pigs. Since the eye is a complicated organ with highly specialized constituent tissues derived from different primordial cell lineages, the development of an intact eye from allogenic cells is a challenging task. Here, combining somatic cell nuclear transfer technology (SCNT) and an anophthalmic pig model (MITFL247S/L247S), allogenic retinal pigmented epithelium cells (RPEs) were retrieved from an E60 chimeric fetus using blastocyst complementation. Furthermore, all structures were successfully regenerated in the intact eye from the injected donor blastomeres. These results clearly demonstrate that not only differentiated functional somatic cells but also a disabled organ with highly specialized constituent tissues can be generated from exogenous blastomeres when delivered to pig embryos with an empty organ niche. This system may also provide novel insights into ocular organogenesis

Analysis of the starch properties in tetraploid wheat–Aegilops sharonensis amphidiploid

In this study, we investigated the starch properties of Aegilops sharonensis (R7), tetraploid wheat (Z636), and their amphidiploid (Z636 × R7). The results of protein electrophoresis showed that waxy protein of Ae. sharonensis (R7) and tetraploid wheat (Z636) is expressed in the amphidiploid (Z636 × R7). The total starch content and amylose content of the amphidiploid (Z636 × R7) were higher than Ae. sharonensis (R7) and lower than tetraploid wheat (Z636). The amphidiploid (Z636 × R7) exhibits an intermediate type of starch granules morphology that the ratio of A/B-type starch granules and their shapes ranged between Ae. sharonensis and tetraploid wheat. The gelatinization parameters showed that the concluding temperature (Tc) and enthalpy change (ΔH) of Ae. sharonensis (R7) were significantly lower than those of tetraploid wheat (Z636) and the amphidiploid (Z636 × R7), while the values of onset temperature (To) and peak temperature (Tp) were similar among the Ae. sharonensis (R7), tetraploid wheat (Z636), and the amphidiploid (Z636 × R7). For the aging properties, the ΔH values of Ae. sharonensis (R7) and the amphidiploid (Z636 × R7) were close but lower than that of tetraploid wheat (Z636), whereas the parameters of To, Tp, and Tc did not differ significantly among three materials. The amphidiploid (Z636 × R7) possesses varied starch properties from wheat, which may be useful in wheat quality improvement