Search Results (65)

(1) The primary objective was to determine whether, within this taxonomically challenging group, the closely related European species and their subspecies exhibit distinct inflorescence characters that allow for unambiguous differentiation. This study focuses on two closely related species within the genus Hierochloë: Hierochloë hirta (Schrank) Borbás and Hierochloë odorata (L.) Beauv. (2) For four subspecies, data were collected from 15 inflorescences each, while for one subspecies, 10 inflorescences were examined. From each inflorescence, six spikelets were selected. The statistical analyses were non-parametric methods, the Kruskal–Wallis test, and principal component analysis. (3) Morphological traits showed consistent patterns within each subspecies, indicating their suitability for taxonomic differentiation. The most reliable diagnostic traits were the length of the outer glume of the first flower and the lengths of the awns. (4) The study concludes that while some subspecies can be clearly distinguished based on inflorescence morphology, no single trait is sufficient to completely separate all taxa. The authors recommend recognizing Hierochloë odorata subsp. praetermissa as a subspecies rather than a distinct species and affirm the validity of the species names Hierochloë hirta and Hierochloë odorata. Full article

To better understand the physiological mechanisms underlying the variation of Cadmium (Cd) accumulation in wheat, Cd absorption, translocation, and distribution in five low grain-Cd-accumulating wheat (LCA) and five high grain-Cd-accumulating wheat (HCA) were studied at four growth stages under three soil Cd concentrations. Grain Cd concentration of HCA was 2.92 times, 1.61 times, and 1.40 times more than that of LCA under the soil with 0.3 mg/kg,1.5 mg/kg, and 7.5 mg/kg Cd concentrations, respectively. LCA was more tolerant of Cd pollution than HCA. Consequently, dry matter in LCA roots, stems + leaves, glumes, grains, and the entire plant was significantly higher than that of HCA at all growth stages under all three soil Cd concentrations, and the most pronounced difference was observed during the maturity stage. The critical period governing the disparity in Cd uptake between LCA and HCA primarily occurred before jointing and the maturity stage. LCA absorbed more Cd than HCA under the three Cd soil concentrations before the jointing stage, during which Cd uptake of LCA was 1.92 times, 1.86 times, and 1.46 times that of HCA under 0.3, 1.5 and 7.5 Cd soil concentrations. But LCA absorbed less Cd than HCA at the maturity stage, during which Cd uptake of LCA was 50%, 50%, and 49% of HCA under 0.3,1.5 and 7.5 mg/kg soil Cd concentrations, respectively. Cd uptake or accumulation per plant in LCA was significantly lower than that of HCA throughout the entire growth period, but the difference between them becomes increasingly smaller as the concentration of Cd contamination increases. Early absorption and accumulation of Cd played a limited role in grain Cd accumulation, and Cd transport played a critical role in determining grain Cd content at maturity. In addition, tolerance to Cd was higher, and grain Cd concentration was lower. Full article

Establishing an accurate high-moisture corn ear fragmentation model using the Discrete Element Method is crucial for studying the processing and fragmentation of high-moisture corn ears. This study focuses on high-moisture corn ears during the early harvest stage, developing a fragmentable corn ear model and calibrating its bonding parameters. First, based on the Hertz–Mindlin method in the Discrete Element Method, a three-layer corn cob bonding model consisting of pith, woody ring structure, and glume was established. Through a combined experimental and simulation calibration approach, the bonding parameters of the cob were determined using Plackett–Burman tests, the steepest ascent tests, and Box–Behnken tests. Subsequently, the same method was applied to establish a corn kernel bonding model, with the kernel bonding parameters calibrated through the steepest ascent and Box–Behnken tests. In order to arrange the kernel models on the cob model to achieve the construction of a complete ear model, this paper proposes a “matrix coordinate positioning method”. Through calculations, this method enables the uniform arrangement of corn kernels on the cob, thereby accomplishing the establishment of a composite model for the high-moisture corn ear. The bonding parameters between the cob and kernels were determined through compression tests. Finally, the reliability of the model was partially validated through shear testing; however, potential confounding variables remain unaccounted for in the experimental analysis. While this study establishes a theoretical framework for the design and optimization of machinery dedicated to high-moisture corn ear fragmentation processes, questions persist regarding the comprehensiveness of variable inclusion during parametric evaluation. This analytical approach exhibits characteristics analogous to incomplete system modeling, potentially limiting the generalizability of the proposed methodology. Full article

In recent years, the problem of Cd (cadmium) contamination in cultivated soils has grown worse, endangering food security and human health and impeding agricultural sustainability. The application of foliar fertilizer can effectively prevent and control the accumulation of Cd in crops, but the related effects of foliar fertilizer application on the accumulation of Cd in wheat and the risk to human health are not clear. On the Cd-polluted farmland, five foliar fertilizers (multi-element compound fertilizer (Me), manganese-zinc micro-fertilizer (MZ), sodium dihydrogen phosphate (P), water-soluble organic fertilizer (WO) and foliar silicon fertilizer (Si)) and CK (the fresh water was used as the control) were sprayed on wheat at different growth periods (spraying once at the tillering stage and spraying twice at the tillering stage and the booting stage) to investigate the effects of foliar fertilizer on wheat yield and the content of Cd in grains and human health risks. The results showed that the application of five types of foliar fertilizers can lead to an increase in wheat yield, an inhibition of the transfer of cadmium to the edible parts of wheat, and a reduction in the human health risk (THQ). Compared with the CK (the fresh water was used as the control), the impact of Cd stress on the yield of spring wheat was alleviated by the MZ treatment, and the largest yield increase of 24.2% was achieved when MZ was sprayed once. When compared with one application, two applications of foliar fertilizers were shown to effectively reduce the content of Cd in the leaves, glumes, and grains of wheat, while increasing the content of Cd in the roots and stems. Among all foliar fertilizers, the cadmium content in wheat grains was most effectively decreased using MZ2 (spraying twice at the tillering stage and the booting stage), with a reduction of 36.6%. At the same time, the target hazard coefficient (THQ) of foliar spraying was reduced, and using two bouts of foliar fertilizer spraying was more effective in reducing the health risks. In conclusion, MZ fertilizer sprayed twice was a desirable choice for wheat, which was conducive to the safe production of wheat on Cd-contaminated farmland and for contributing to the sustainable development of agriculture. Full article

Wheat growth is highly sensitive to temperature fluctuations, and with the intensification of global climate change, low-temperature stress has become more frequent during various growth stages of wheat, severely affecting its growth and reducing wheat yield. An experiment examined the effects of low-temperature (daytime 8:00–20:00/nighttime 20:00–next day 8:00: 16 °C/8 °C, 12 °C/4 °C, 8 °C/0 °C, and 4 °C/−4 °C) and exposure durations (1, 3, and 5 days) on winter wheat yield during the anthesis stage. Compared to exposure duration, temperature was the main factor affecting dry matter accumulation, distribution, and transport. Temperature had an average influence of 79.7%, 57.5%, 61.9%, and 79.0% on dry matter distribution in the stem-sheath, leaf, spike axis+glume, and grain, respectively. It also affected pre-anthesis translocation amount, the contribution of pre-anthesis translocation to grains, post-anthesis accumulation amount, and the contribution of post-anthesis accumulation to grains by 48.3%, 55.1%, 44.2%, and 48.2%, respectively. Conversely, exposure duration mainly influenced grain-filling parameters, with an average effect of 43.8%, 44.0%, 83.3%, and 43.8% on the maximum filling rate, average filling rate, filling rate in the fast-increasing period, and filling rate during the slow growth period, respectively. Low-temperature duration also significantly altered the fast-increasing period, slow growth period, and grain weight per spike by 79.9%, 79.9%, and 51.3%, respectively. Low-temperature stress alters the accumulation and distribution of dry matter in wheat, and the duration of exposure further affects the grain-filling process, ultimately resulting in a decrease in yield. Full article

The key flavonoid biosynthesis-related genes and their molecular features in rice have not been comprehensively and systematically characterized. In this study, we investigated the glumes of OsCSN1 mutants and OsCSN2 mutants and found the changes in the total flavonoid contents of the OsCSN2 mutants to be more pronounced than those of the OsCSN1 mutants and the changes in the anthocyanin contents of the OsCSN1 mutants to be more pronounced than those of the OsCSN2 mutants. In addition, key genes related to flavonoid synthesis, OsCHI, showed a more pronounced up-regulation trend, and the OsDFR gene, which encodes a precursor enzyme for anthocyanin synthesis, showed a clear down-regulation trend. And yeast two-hybrid experiments showed that OsCSN1 and OsCSN2 had the ability to interact with OsCUL4. In summary, OsCSN1 and OsCSN2 may regulate the metabolism of flavonoids in rice through CUL4-based E3 ligase, and the two subunits play different roles, laying a foundation for the study of the mechanism of flavonoid metabolism in monocotyledonous plants. Full article

The timely and accurate identification of invasive species is a critical first step in recognizing the threats that they present in their new habitats. The accurate identification of an invasive species, however, can prove difficult if that species displays taxonomic complexity in its native range, i.e., it consists of morphologically similar subspecies. Across its native range, the grass Taeniatherum caput-medusae (medusahead) exhibits taxonomic complexity: three subspecies have been recognized. As part of our ongoing research to better understand the invasion of T. caput-medusae in the western United States, the accurate identification of these three subspecies is a requisite first step. Plants from each native population were grown in a greenhouse common garden, harvested at maturity, and measured using five previously described morphological characteristics. Three characteristics, glume length, glume angle, and palea length, were found to be statistically significant, and are diagnostic in differentiating the three subspecies. The results for the two other characteristics were not significantly different, although conical cell prominence was only slightly non-significant (p = 0.0532). Genetic differentiation among native populations of T. caput-medusae was assessed using allozymes as molecular markers. Results of an UPGMA cluster diagram based on allozyme data indicate that subspecies crinitum is genetically differentiated from the other two, some populations of subspecies caput-medusae and asperum co-occur within a cluster, and subspecies asperum is the most variable. Results of the analysis of multilocus genotypes are generally consistent with the UPGMA diagram (e.g., subspecies caput-medusae and asperum share six multilocus genotypes). Our findings confirm the need for a better understanding of the taxonomic complexity that can be found within the native ranges of invasive species. Full article

Wild emmer wheat (Triticum turgidum ssp. dicoccoides) is the ancestral species of cultivated tetraploid wheat with BBAA genomes. Because of its full interfertility with domesticated emmer wheat, this wild species can serve as one of the most important genetic resources to improve durum and bread wheat. To clarify the magnitude of genetic diversity between and within populations of Turkish wild emmer wheat, 169 genotypes of ssp. dicoccoides selected from the 38 populations collected from the three sub-regions (East-1, West-1, and West-2) of the Southeast Anatolia Region of Turkey were molecularly and morphologically characterized. The populations showed significant variation in plant height, heading date, flag leaf area, spike length and number, spikelet, peduncle, lemma, palea, glume and anther lengths, glume hull thickness, anther width, and days to maturity. According to the results of nuclear-SSR analysis, the populations collected from the sub-regions East-1 and West-2 were the most genetically distant (0.539), while the populations collected from the sub-regions West-1 and West-2 were the most genetically similar (0.788) populations. According to the results of AMOVA, there was 84% similarity within the populations studied, while the variation between the populations of the three sub-regions was 16%. In the dendrogram obtained by using nuclear-SSR data, the populations formed two main groups. The populations from the sub-region East-1 were in the first group, and the populations from the sub-regions West-1 and West-2 were in the second group. From the dendrogram, it appears that the populations from the sub-region East-1 were genetically distant from the populations from the sub-regions West-1 and West-2. The results highlight the potential diversity in Southeast Anatolia for wild emmer discovery and utilization. Full article

Using male sterile (MS) lines instead of normal inbred maternal lines in hybrid seed production can increase the yield and quality with lower production costs. Therefore, developing a new MS germplasm is essential for maize hybrid seed production in the future. Here, we reported a male sterility gene ms*-N125, cloned from a newly found MS mutant ms*-N125. This mutant has an underdeveloped tassel that showed impaired glumes and shriveled anthers without pollen grains. The MS locus of ms*-N125 was mapped precisely to a 112-kb-interval on the chromosome 5. This interval contains only three candidate genes, Zm958, Zm959, and Zm960. Sequencing results showed that only candidate Zm960 harbored a 548-bp transposable element (TE) in its 9th exon, and the two other candidate genes were found to have no genetic variations between the mutant and wild type (WT). Thus, Zm960 is the only candidate gene for male sterility of the mutant ms*-N125. In addition, we screened another recessive MS mutant, ms*-P884, which exhibited similar male sterility phenotypes to ms*-N125. Sequencing Zm960 in ms*-P884 showed a 600-bp TE located in its 2nd exon. Zm960 encodes an ATP-binding cassette in the G subfamily of ABC (ABCG) transporters, ZmABCG2a, with both mutants which harbored an Ac/Ds-like transposon in each. To verify the function of ZmABCG2a for male sterility further, we found an ethyl methanesulfonate (EMS) mutant, zmabcg2a*, which displayed male sterility and tassel phenotypes highly similar to ms*-N125 and ms*-P884, confirming that ZmABCG2a must be the gene for male sterility in maize. In addition, the results of lipid metabolome analysis of ms*-N125 young tassels showed that the total lipid content of the mutant was significantly lower than that of the WT, with 15 subclasses of lipids, including PE (phosphatidylethanolamine), PC (phosphatidylcholine), DG (digalactosyldiacylglycerols), and MGDG (monogalactosyldiacylglycerol) which were significantly down-regulated in the ms*-N125 mutant versus its wild type. In summary, we identified alternate mutations of the ZmABCG2a gene, which may be a potential germplasm for hybrid seed production in maize. Full article

Glume-opening of thermosensitive genic male sterile (TGMS) rice (Oryza sativa L.) lines after anthesis is a serious problem that significantly reduces the yield and quality of hybrid seeds. However, the molecular mechanisms regulating the opening and closing of rice glumes remain largely unclear. In this study, we report the isolation and functional characterization of a glum-opening mutant after anthesis, named gom1. gom1 exhibits dysfunctional lodicules that lead to open glumes following anthesis. Map-based cloning and subsequent complementation tests confirmed that GOM1 encodes a receptor-like kinase (RLK). GOM1 was expressed in nearly all floral tissues, with the highest expression in the lodicule. Loss-of-function of GOM1 resulted in a decrease in the expression of genes related to JA biosynthesis, JA signaling, and sugar transport. Compared with LK638S, the JA content in the gom1 mutant was significantly reduced, while the soluble sugar, sucrose, glucose, and fructose contents were significantly increased in lodicules after anthesis. Together, we speculated that GOM1 regulates carbohydrate transport in lodicules during anthesis through JA and JA signaling, maintaining a higher osmolality in lodicules after anthesis, which leads to glum-opening. Full article

Jasmonate ZIM-domain (JAZ) acts as the repressor of the JA signaling pathway and plays a significant role in stress-inducible defense, hormone crosstalk, and the regulation of the growth-defense tradeoff. The aim of this study is to systematically survey and analyze the JAZ gene family in Coix lacryma-jobi and unveil its expression profiles in diverse organs under high-temperature stress using transcriptome. The results identified a total of 20 JAZ family proteins randomly mapped on four chromosomes and encoding 159–409 amino acids. They were clustered into six groups and were mainly located in the nucleus. The conserved motifs, gene composition, and secondary structure of ClJAZ members within the same subtribes were similar. Multitudinous cis-regulating elements employed in hormone responsiveness and stress responsiveness were displayed before the promoter sequences of ClJAZ1-ClJAZ20. ClJAZ1-ClJAZ20 were differentially distributed across diverse organs (the roots, shoots, leaves, kernels, glumes, and flowers), exposed to high-temperature stresses, and treated using ABA or MeJA. A total of 29115 DEGs were identified under heat stress, which were mainly involved in biological regulation and the metabolic process. Intriguingly, ClJAZ15 was highly expressed in the leaves of C. lacryma-jobi, down-regulated by MeJA, but up-regulated by heat stress and ABA, inferring that ClJAZ15 might be associated with ABA-inducible heat stress. The results laid a foundation for in-depth study of the role of ClJAZ family genes in C. lacryma-jobi. Full article

Wheat hybrids have been widely demonstrated to have remarkable heterosis or hybrid vigor in increasing yield potential and stability since the 1960s. Two-line hybrid wheat can achieve higher yields than local varieties, especially in marginal environments. However, the commercial application of hybrid wheat is hindered by higher seed costs, primarily due to lower yields in hybrid seed production. Stigma exsertion has been verified as a decisive factor in increasing rice’s hybrid seed yield, but more investigation is needed in hybrid wheat breeding and production. In this study, four thermo-photo-sensitive genic male sterile lines, including K41S, K64S, K66S, and K68S, with different stigma exsertion rates (SERs) were used to compare the differences in floral architecture relative to stigma exsertion over two growing seasons. The results revealed that the K41S and K64S exhibited a relatively higher SER at 21.87% and 22.81%, respectively. No exserted stigma was observed in K66S, and K68S had an SER of only 0.82%. This study found that the stigma length, glume width and the length–width ratio of the glume were significantly correlated with the SER, with correlation coefficients of 0.46, −0.46 and 0.60, respectively. Other stigma features such as the branch angle, stretch width and hairbrush length, as well as the glume length, also had a weakly positive correlation with SER (r = 0.09–0.27). For K41S and K64S, the SER was significantly affected by the differences in the stigma branch angle and stigma stretch width among florets. A cross-pollination survey showed that the out-crossing ability of florets with an exserted stigma was about three times as high as that of florets with a non-exserted stigma. As a result, the stigma-exserted florets that accounted for 21.87% and 22.81% of the total florets in K41S and K64S produced 46.80% and 48.53% of the total cross-pollinated seeds in both sterile lines. These findings suggest that a longer stigma combined with a slender glume appears to be the essential floral feature of stigma exsertion in sterile wheat lines. It is expected that breeding and utilizing sterile lines with a higher SER would be a promising solution to cost-effective hybrid wheat seed production. Full article

Archaeological excavations led by Yung-jo Lee and Jong-yoon Woo were carried out twice at the Sorori paleolithic site, Cheongju, in the Republic of Korea, at the upper stream of the Geumgang river, the Miho riverside. A total of 127 rice seeds were excavated, including 18 ancient rice and 109 Quasi-rice, in 1998 and 2001. At the first excavation, eleven short japonica-type ancient rice and one slender smooth ancient rice with two kinds of Quasi-rice were excavated. The average length of the 11 short rice grains obtained from the first and second excavation was 7.19 mm and the average width was 3.08 mm, respectively. The Quasi-rice are apparently different from the rice and do not have bi-peak protuberances on their glume surface. At the second excavation, six short ancient rice chaffs and some Quasi-rice 2 were found. These short-grained ancient rice were comparable to the ancient rice that were excavated at the Illsan Neolithic site. Geologists and radiologists confirmed that the peat layer in which the rice found was older than 15,000 years. In this study, the morphological characteristics, crushing, and DNA band patterns related to the genetic polymorphism of rice grains in Cheongju Sorori were compared and analyzed for genetic similarities and differences with wild rice, weed rice, and modern rice. The morphological, ecological, and physiological variations in rice grains excavated from the Sorori site were presumed to denote the origin of rice domestication in Korea. It is also suggested that the results of the DNA sequencing of excavated rice are very important clues in estimating the origin of the early domestication of rice. Full article

The changes in biomass (including yield), copper (Cu) concentration, and the accumulation of wheat (Triticum aestivum. L) in response to soil Cu pollution under nighttime warming had still not been explored. Hence, this study was carried out, and these variations were analyzed from a physiological perspective. Pot trials were performed at two levels of ambient temperatures (no-warming (NT) and average nighttime warming of 0.28 °C (WT)) and two levels of soil Cu concentrations (control check without Cu application (CK) and 100 mg/kg Cu application (Cu)). Soil was collected from the carbonate cinnamon soil region of central China. The warming effects of the passive nighttime warming system were prominent, and the average increment was 0.28 °C. Antioxidant enzyme activities were promoted by warming (p < 0.05) and Cu. The highest yield was achieved in NT-Cu, mainly attributed to relatively strong root activity and photosynthesis caused by supplemental Cu, but the Cu concentration in its grains was close to the threshold (10 mg/kg) for Cu concentration in foodstuff and could present a potential food safety risk. Though nighttime warming did not increase the total biomass and yield of wheat, it decreased the Cu accumulation of wheat grown in Cu-contaminated soil, especially in grains. Moreover, WT-CK and WT-Cu increased the Cu concentration in the roots and glumes and reduced the Cu concentration in grains by 13.09% and 55.84%, respectively, probably because of a lower transpiration rate. Among them, the Cu concentration of grains in WT-Cu was the lowest and significantly lower than other applications. Our findings reveal that nighttime warming has the potential to reduce the Cu risk of grains in wheat grown in the Cu-contaminated carbonate cinnamon soil region of central China and could then provide a theoretical reference for risk assessment of food quality for wheat subjected to dual stress from nighttime warming and Cu pollution. Full article

Low-cadmium (Cd) accumulating wheat cultivars (LAWC-Cds) can effectively reduce the total Cd content in wheat grains (Grain-Cd). Thirteen LAWC-Cds were planted in three fields to study the enrichment, transport, and accumulation patterns of Cd in LAWC-Cds. Compared with the soil properties before planting, the soil pH and the total Cd content in the soil decreased, while the Cd content in the diethylenetriaminepentaacetic acid extract, soil conductivity, and soil organic matter increased at wheat maturity. The Cd enrichment capacity of the different organs of wheat decreased in the following order: root > leaf > rachis > stem > glume > grain. The dynamics of Cd accumulation in roots affected Grain-Cd, and these factors were negatively correlated. The Cd content and Cd accumulation in all organs of LAWC-Cds showed strong negative correlations with the lengths of the first and second internodes and highly significant positive correlations with both grains per spike and awn length. Structural equation modeling showed that the Cd content of wheat organs had the most direct effect (0.639) in determining Grain-Cd, and soil properties had the largest effect (0.744) in influencing Grain-Cd. This study is important for screening wheat cultivars with stable low Cd-accumulation characteristics. Full article