Leymus chinensis (sheepgrass) is a key perennial forage grass for grassland restoration in northern China, but its complex genome and high genetic diversity hinder precise cultivar identification using traditional morphological methods. Recent advances in SNP-based molecular markers provide efficient and reliable tools for Distinctness, Uniformity and Stability (DUS) testing and cultivar-rights protection in this species. Using a custom-designed sheepgrass 50K whole-genome liquid-phase SNP array, we genotyped 223 individuals from 11 accessions, including nine cultivars, one breeding line, and one wild accession, with 15–30 individuals sampled per accession. After stringent quality control, 159,262 high-confidence SNPs were retained, with over 60

Leymus chinensis (Trin.) Tzvel. (sheepgrass) is an important forage species, yet the relationships between seed phenotypic traits, agronomic performance, and their underlying genetic mechanisms remain unclear. In this study, we utilized the AIseed high-throughput phenotyping platform to systematically analyze 54 image-based traits (i-traits)—encompassing morphology, color, and texture—in 262 dehusked seeds of sheepgrass. Coupled with 50K single nucleotide polymorphism (SNP) chip genotyping data, we performed a genome-wide association study (GWAS) to elucidate genetic correlations among seed phenotypic traits. Elastic net regression was employed to identify informative phenotypic predictors, revealing significant associations between seed size, seed coat texture, and color with hundred-seed weight (HGW), hundred-seed weight without glumes (HGWwg), and germination rate (GR). Additionally, a germplasm screening approach based on principal component analysis (PCA) achieved a 71% accuracy rate in predicting high-germination germplasm and identified 10 germplasm lines with superior comprehensive performance. GWAS identified several SNPs significantly associated with seed color and morphology, mainly on chromosomes Lc2Xm and Lc6Xm. KEGG analysis highlighted the roles of phenylpropanoid and flavonoid biosynthesis pathways, with candidate genes such as PAL, PER18, PER50, BGLU16, BACOVA_02659, and ANR implicated. This study offers effective phenotypic screening strategies and valuable genetic resources for the molecular breeding of sheepgrass.

Molecular breeding has revolutionized the improvement of forage crops by offering precise tools to enhance the yield, quality, and environmental resilience. This review provides a comprehensive overview of the current technologies, applications, and future directions in the field of forage crop molecular breeding. Technological advancements in the field, including Quantitative Trait Loci (QTL) mapping, Genome-Wide Association Studies (GWASs), genomic selection (GS), and genome-editing tools such as CRISPR-Cas9, have significantly advanced the identification and incorporation of beneficial traits into forage species. These approaches have dramatically shortened the breeding cycles and increased the efficiency of developing cultivars with improved yield, disease resistance, stress tolerance, and nutritional profiles. The implementation of these technologies has led to notable successes, as demonstrated by case studies on various forage crops, showcasing enhanced forage quality and adaptability to challenging environmental conditions. Furthermore, the integration of high-throughput phenotyping with advanced bioinformatics tools has streamlined the management of large-scale genomic data, facilitating more precise selection and breeding decisions. Looking ahead, this review explores the potential of emerging technologies, such as the application of artificial intelligence in predictive breeding, along with the associated ethical and regulatory considerations. While we stand to gain benefit from these innovations, the future of molecular breeding in forage crops must also confront the challenges posed by climate change and the imperative of sustainable agricultural practices. This review concludes by emphasizing the transformative impact of molecular breeding on the improvement of forage crop and the critical need for ongoing research and collaboration to fully realize its potential.

[Objective]Caladium bicolor is a foliage plant in the Araceae family,characterized by rich colors and diverse patterns on its leaves,making it widely used for indoor and outdoor ornamental purposes and possessing good economic value.C.bicolor is often cultivated in greenhouses without additional lighting measures,which limits the quality and efficiency of seedling production due to weather conditions,making it difficult to guarantee the production efficiency and standardization of commercial seedlings.Light is an important factor in the growth and pigment accumulation of C.bicolor.The study aims to explore suitable types of light quality for tissue-cultured C.bicolor seedlings,providing a theoretical basis for improving the production efficiency and seedling quality of C.bicolor plants.[Method]We used white fluorescent light as a control and employed 7 different light quality types including LED white light,LED red light,LED blue light,LED red-blue-white 1:1:1,LED red-blue-green 1:1:1 and LED red-blue-white-green 1:1:1:1 light to treat tissue-cultured regenerated plants of C.bicolor.Various growth indicators such as leaf size,leaf thickness,plant height,number of roots,and pigment content of C.bicolor after different light quality treatments were measured to evaluate and select effective light qualities that could enhance the quality of commercial C.bicolor seedlings.[Result]Compared to fluorescent light,LED red light treatment was detrimental to the increase in the number of leaves and the thickness of petioles in C.bicolor,which were 5.3 pieces and 3.42 mm,respectively;it hindered the accumulation of total chlorophyll content and relative anthocyanin content on the leaf surface,which were 2.0 mg/g and 1.0 U/g respectively;and it was also unfavorable for the maximum photochemical efficiency of PSII(Fv/Fm)and the actual quantum yield of photosystem Ⅱ[Y(Ⅱ)],with values of only 0.64 and 0.60,respectively.LED blue light treatment promoted the increase in plant height,petiole thickness and accumulation of relative anthocyanin content in C.bicolor,which were 21 cm,4.6 mm and 6.1 U/g,respectively.However,it was not beneficial for the increase in the number of roots in C.bicolor.For the light combination treatment,LED red blue white green 1:1:1:1 was beneficial for the increase of leaf area,reaching 98.8 cm2.The relative anthocyanin content on the leaf surface was highest under this treatment,reaching 8.23 U/g.LED red blue green 1:1:1 treatment was not conducive to increasing plant height,petiole thickness and leaf thickness,which were 10.6 cm,3.9 mm,and 0.70 mm,respectively.The relative anthocyanin content on the petioles of C.bicolor under LED red blue white 1:1:1,LED red blue green 1:1:1,and LED red blue white green 1:1:1:1 treatments was significantly lower than that under white fluorescent lamp light treatment.[Conclusion]Different light qualities influence the growth and pigment accumulation of regenerated plants of C.bicolor.LED blue light treatment is the most effective in increasing plant height,petiole thickness and relative anthocyanin content in C.bicolor.LED red blue white green 1:1:1:1 treatment is the most effective in increasing leaf area and relative anthocyanin content on the leaf surface.By selecting the appropriate light quality ratio based on actual conditions in production,the efficiency of standardized production of C.bicolorseedlings can be effectively improved.

As a crucial forage grass, Leymus chinensis plays significant roles in soil and water conservation owing to its robust stress resistance. However, the underlying molecular mechanisms of its stress tolerance remain unclear. In this study, a novel gene, designated as LcASR (Abiotic Stress Resistance in Leymus chinensis), imparting resilience to both high light and drought, was identified. Under normal growth conditions, heterologous overexpression of LcASR in Arabidopsis (HO lines) showed no significant difference in appearance compared to wild-type. Nevertheless, HO lines accumulate significantly higher chlorophyll content during the dark-to-light transition compared to the wild-type, indicating that the LcASR protein participates in chlorophyll synthesis during chloroplast development. Meanwhile, transgenic Arabidopsis and L. chinensis plants exhibited resistance to abiotic stresses such as high light and drought. Photosystem complexes analysis revealed that LHCII proteins remained stable within their respective complexes during high light stress. We hypothesize that LcASR may play a role in fine tuning of chlorophyll synthesis to enable plant adaptation to diverse stress conditions. Moreover, overexpression of LcASR in L. chinensis led to agronomically valuable traits such as deeper green color, higher biomass accumulation, prolonged withering period, and extended grazing durations. This study uncovers a novel gene in L. chinensis that enhances forage yield and provides valuable genetic resources for sheepgrass breeding.

Sugarcane (Saccharum spp. hybrid) cultivar Yuetang 03-373 is a hybrid with superior agronomic characteristics that was obtained from the cross between Yuetang 92-1287 (♀) and Yuetang 93–159 (♂). In this study, transversely cut discs of immature leaves were used to induce adventitious shoots for the first time. Embryonic callus was induced from leaf explants on Murashige and Skoog (MS) medium with 0.5 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.1 mg/l α-naphthaleneacetic acid (NAA). On MS medium containing 0.75 mg/l 6-benzyladenine and 0.1 mg/l NAA, 73.1

Caladium bicolor is widely used as an ornamental plant outdoors and indoors due to its rich colors, diverse combinations, and strange patterns. In the commercial production of Caladium bicolor , tissue culture technology can quickly reproduce seedlings with consistent genetic properties. In practice, there are still aspects that can be improved in terms of energy dissipation and ornamental value when using fluorescent lamps. In this experiment, the light intensity had no significant effect on the induction of callus and the germination rate, but from the number of buds per explant increased. Different light waves affect the occurrence of seedlings of Caladium bicolor . Among them, a single light source, LED-Red, is not conducive to callus differentiation, plant height, and carotenoid accumulation compared to other treatments; LED-Blue is beneficial for the formation of relative anthocyanin content and plant height.LED-White is beneficial for leaf size. Fluorescence is not conducive to increasing the total number of seedlings, which is important for production. Compared with fluorescence, the transplanting rate of LED-Blue increased by 94.92%. The results of this experiment suggest that LED light can replace florescent lamps in tissue culture for achieving low energy consumption and high efficiency.

紫花丹全草药用功能广泛,但其自然授粉率、种子萌发率和种苗存活率均非常低,自然种群分布越来越少.为保护紫花丹资源及满足未来的种苗需求,以紫花丹茎段为外植体,对其外植体消毒时间、芽增殖和壮苗生根培养基、移栽方式及基质进行研究.结果表明:利用 0.1％氯化汞对紫花丹新生枝条消毒 12 min效果较好;MS+6-BA 0.2 mg/L+IBA 0.1 mg/L可诱导茎段出芽,出芽后用MS+6-BA 2 mg/L+NAA 0.2 mg/L诱导芽增殖,增殖系数可达 32.52;最佳生根培养基为 1/2 MS+IBA 0.1 mg/L,15 d生根率可达 61.57％;最佳移栽基质为泥炭土∶珍珠岩 1∶1(V∶V),其生根率为 76.67％,黑茎率最低(4.00％),新叶萌发率最高(78.00％);移栽方式以盖膜培养最佳,其植株新根及新叶萌发率最高,分别为 76.67％和 78％.本研究初步建立了紫花丹的离体快繁体系,为其工厂化育苗提供技术参考.

以大花虎刺梅花朵为试材,采用组培快繁的方法,研究了取材部位、花朵的成熟程度、激素配比及浓度等因素对植株再生的影响,以期建立大花虎刺梅高效、适合工厂化生产的离体再生体系,为品种快繁和推广提供参考依据.结果表明:大花虎刺梅花序总苞上花芽经过生殖生长发育成二歧聚伞复状花序,组培培养使其经过营养生长诱导出再生植株.大花虎刺梅花朵的成熟度对出芽率影响比较明显,苞片半张开时的花序总苞是组培快繁的最佳取材部位.芽诱导的最佳培养基为MS+6-BA 1.0 mg·L-1+NAA 0.1 mg·L-1,出芽系数150.45％,芽体健壮,长势良好;丛芽增殖的最佳培养基为MS+6-BA 0.5 mg·L-1+NAA 0.2 mg·L-1,增殖系数4.03±0.43,植株健壮,叶片舒展墨绿,长势很好;生根培养的最佳培养基为MS+NAA 0.2 mg·L-1+IBA 0.4 mg·L-1,30 d后生根率达85％以上.移栽至消毒的珍珠岩∶泥炭土∶沙(1∶1∶1)的基质中定植,成活率85％.

少花蒺藜草(Cenchrus spinifex Cav.)原产于北美洲,上世纪80年代侵入科尔沁草原并在全国多地快速蔓延,成为科尔沁沙地的一大草害.本文通过羊草播种、刈割试验,旨在探索高效、经济控制少花蒺藜草的技术.结果表明:播种30 kg/hm2的中科1号羊草第1年对少花蒺藜草密度抑制率为26.96％;第2年两时期株高抑制率为25.00％、41.27％,第3年两时期株高抑制率为53.28％、90.91％,逐年提升;第2年两时期盖度抑制率为70.15％、78.01％,第3年两时期盖度抑制率为99.18％、100.00％,逐年提升;第2年对生物量抑制率达到87.79％.针对少花蒺藜草,中科1号羊草播种量为30 kg/hm2时已经可以在第3年完全控制少花蒺藜草,无须增大播种量.本研究为大面积利用羊草防除少花蒺藜草提供了科学依据,对保障草原生态安全具有重要意义.

Euryodendron excelsum H.T. Chang is a rare and endangered woody plant endemic to China. It is very important to conserve and propagate this species from extinction. In this study, leaves and petioles from the axillary shoots in vitro were used as explants to culture on the different plant growth regulator (PGR) woody plant medium (WPM) and establish an efficient shoot proliferation and plant regeneration system. WPM supplemented with 1.0 mg/L 2,4-D induced callus dedifferentiated into buds and somatic embryos on various media,including PGR-free WPM. However, only adventitious shoots formed on WPM with 1.0 mg/L of cytokinins such as 6-benzyladenine (BA), kinetin (KIN) or thidiazuron (TDZ). When another cytokinin, zeatin, was used, somatic embryos were induced directly from From cut surface of these explants. Adventitious roots could be induced from both explants on WPM with 1.0 mg/L α-naphthaleneacetic acid (NAA). Somatic embryos cultured in PGR-free WPM or WPM with 0.2 mg/L NAA developed roots. Plantlets derived from somatic embryos were transferred to a peat: sand (1:1, v/v) substrate, and showed survival rates of 64.3% at 30 days and 54.6% at 90 days. Callus clumps with adventitious shoot buds that were transferred to WPM containing 1.0 mg/L BA and 0.2 mg/L NAA generated a mean 3.3 multiple shoots. Callus-derived shoots regenerated and rooted successfully (100%) on agar-free vermiculite-based WPM with 0.5 μM NAA after 30 d. Plantlets transplanted to peat soil: vermiculite (1:1, v/v) displayed the highest survival (96.7%) after three months.

羊草是我国重要的牧草和生态草资源,具有耐盐碱、耐旱、耐低温等特性,是天然的抗逆基因资源库.CBF/DREB属于AP2转录因子家族,在植物抗逆中发挥着重要作用.本研究克隆得到羊草LcCBF6(Leymus chinensis C-repeat binding factor 6)基因,该基因含有AP2结构域,编码245个氨基酸.氨基酸序列比对发现,LcCBF6与蒙古冰草和黑麦的CBF6蛋白的同源性分别为92％和91％.组织特异性表达模式分析表明,LcCBF6基因在羊草根、叶、种子中均有表达,且受盐胁迫诱导表达.过表达LcCBF6能显著提高转基因拟南芥的抗盐性.在盐胁迫条件下,转基因株系的绿色子叶数、根长、植株生物量以及存活率等均明显高于野生型.上述结果表明羊草LcCBF6基因在提高植物盐胁迫抗性方面发挥了重要的作用,将为牧草及重要农作物抗逆分子育种提供优异的基因资源.

Sheepgrass is a perennial native grass species in China, and it can tolerate high levels of salt stress with an aggressive and vigorous rhizome system. Many salt-stress-responsive genes have been identified in sheepgrass. In this study, we report the cloning and characterization of a novel salt-induced gene, LcSAIN3 (Leymus chinensis salt-induced 3), from sheepgrass. Expression analysis confirmed that LcSAIN3 was induced by PEG, ABA, and salt treatments, and the expression of LcSAIN3 was significantly increased in salt-tolerant germplasms under salt treatment. Subcellular localization analysis indicated that the GFP-LcSAIN3 protein was mainly localized in the chloroplasts. The heterologous expression of LcSAIN3 in Arabidopsis increased the seed germination rate of transgenic plants under salt, ABA, and mannitol treatments. The seedling survival rate, plant height, and fresh weight of the transgenic plants were higher than those of WT plants under salt stress. The overexpression of LcSAIN3 caused a relatively high accumulation of free proline, enhanced SOD activity, and led to the upregulation of several stress-responsive genes such as AtRD26, AtRD29B, AtSOS1, and AtP5CS1. These results suggest that LcSAIN3 could be a potential target for molecular breeding to improve plants’ salt tolerance.

In vitro flowering and fruiting of Portulaca pilosa L were achieved for the first time. The ability of several factors to induce in vitro flowering, including plant growth regulators and carbon sources, were investigated. Initial in vitro flowering (12.1%) from stems, most likely from floral buds that had differentiated before stem sections were inoculated on MS medium supplemented with 30 g/L sucrose, 1.0 mu M BA and 0.1 mu M NAA, occurred within less than one month. Axillary shoots were subcultured multiple times on this medium. Secondary in vitro flowering (12.2%) and fruit setting from axillary shoots was possible on MS medium supplemented with 120 g/L sucrose without any plant growth regulators. Continuous culture on this medium for 12 days after flowering yielded fruits and produced a mean 58 normal seeds per fruit. Seeds germinated and developed seedlings in vitro without any additional treatment. (C) 2021 SAAB. Published by Elsevier B.V. All rights reserved.

南海珊瑚岛礁自然植被由于人类干扰和环境变化出现了退化现象,急需进行植被恢复重建.抗风桐作为南海珊瑚岛礁的优势种,在防风固沙以及植被生态恢复等方面发挥着重要作用.该文以抗风桐带腋芽茎段为外植体,研究不同基本培养基、激素对其不定芽增殖和活性炭对生根、移栽的影响,以便建立其种苗快速繁殖和植株再生体系.结果表明:(1)MS基本培养基适合于丛生芽的诱导和增殖,最佳继代培养周期为60 d,最佳的不定芽增殖培养基为MS+2.0 mg·L-16-BA+0.1 mg·L-1 NAA,培养60 d后增殖倍数达5.52;(2)不定芽在MS+1.0 mg·L-1 IBA培养基中生根率为96.0％,在生根培养基中添加1.6 g·L-1活性炭后其生根率下降至42.4％;(3)以添加活性炭生根培养获得的组培苗进行移栽成活率高达93.9％,而不添加活性炭生根培养的组培苗移栽成活率仅为78.3％.研究结果可为抗风桐种苗的离体快繁和珊瑚岛礁的植被恢复奠定技术基础.

Sheepgrass is a perennial native grass species with an aggressive and vigorous rhizome system, and it can tolerate high levels of salt stress. Many salt stress-responsive genes have been identified in sheepgrass. Here, we identified and characterized a novel salt-induced gene, LcSAIN3 ( L eymus chinensis salt-induced 3), from sheepgrass. Expression analysis confirmed that LcSAIN3 is induced by PEG, ABA and salt stress. Subcellular localization analysis indicated that the LcSAIN3 protein is mainly localized in the chloroplasts. The heterologous of LcSAIN3 in Arabidopsis increases seed germination under various stress conditions. More importantly, the seedling survival, plant height and weight of the transgenic plants are higher than those of the WT plants under salt stress. The overexpression of LcSAIN3 causes a relatively high accumulation of free proline; enhances SOD activity; and leads to the upregulated expression of several stress-responsive genes, such as AtRAB26 , AtRD29B , AtSOS1 and AtP5CS1 . Our results suggest that LcSAIN3 may be a useful gene for the molecular breeding to improve plants salt stress tolerance.

Background Sheepgrass ( Leymus chinensis (Trin.) Tzvel) is a perennial forage grass that can survive extreme freezing winters (− 47.5 °C) in China. In this study, we isolated an unknown function MYB transcription factor gene, LcMYB4 , from sheepgrass . However, the function of LcMYB4 and its homologous genes has not been studied in other plants. Results The expression of the LcMYB4 gene was upregulated in response to cold induction, and the LcMYB4 fusion protein was localized in the nucleus, with transcriptional activation activity. Biological function analysis showed that compared with WT plants, LcMYB4 -overexpressing Arabidopsis presented significantly increased chilling and freezing tolerance as evidenced by increased germination rate, survival rate, and seed setting rate under conditions of low temperature stress. Furthermore, LcMYB4 -overexpressing plants showed increased soluble sugar content, leaf chlorophyll content and superoxide dismutase activity but decreased malondialdehyde (MDA) under chilling stress. Moreover, the expression of the CBF1 , KIN1 , KIN2 and RCI2A genes were significantly upregulated in transgenic plants with chilling treatment. These results suggest that LcMYB4 overexpression increased the soluble sugar content and cold-inducible gene expression and alleviated oxidative damage and membrane damage, resulting in enhanced cold resistance in transgenic plants. Interestingly, our results showed that the LcMYB4 protein interacts with fructose-1,6-bisphosphate aldolase protein1 (LcFBA1) and that the expression of the LcFBA1 gene was also upregulated during cold induction in sheepgrass, similar to LcMYB4 . Conclusion Our findings suggest that LcMYB4 encodes MYB transcription factor that plays a positive regulatory role in cold stress.

This study established, for the first time, shoot proliferation and plant regeneration protocols via shoot organogenesis from leaf explants of a medical and ornamental plant, Portulaca pilosa L. The optimal proliferation of axillary shoots was 6.2-fold within 30 days on Murashige and Skoog (MS) medium supplemented with 3.0 µM 6-benzyladenine (BA). Shoots could be induced directly from leaf explants, forming an average of 3.8 adventitious shoots per explant, on optimal MS medium supplemented with 1.0 µM thidiazuron (TDZ) and 0.1 µM α -naphthaleneacetic acid (NAA). A higher concentration of TDZ (3.0 µM), alone or in combination with 0.1 µM NAA, induced somatic embryo-like shoot buds and then developed into real shoots. Rooting was easier since roots were induced on all rooting media within one month. Half-strength MS medium free of plant growth regulators was best for rooting. Rooted plantlets were transferred to a sand: perlite (1:1, v/v) substrate, resulting in highest survival (90%). Plantlets showed more robust growth, however, on substrates of yellow mud: perlite (1:1, v/v) or peat soil: vermiculite: perlite (1:1:1, v/v).

In the original article, some of the values in the fifth column of Table 2 and in the fifth and eighth columns of Table 4 are incorrect. The corrected values are in bold typeface in both tables below.

Euryodendron excelsum H. T. Chang is a single-type, rare and endangered woody plant unique to China. In this study, young stems were used as explants and cultured on Woody Plant Medium (WPM) supplemented with 5.0 μM 6-benzyladenine (BA), were subcultured for more than 15 times over a total of more than 3 years and finally an efficient axillary shoot proliferation and plantlet regeneration system was established in which one shoot could proliferate an average of 5.1 axillary shoots every 2 months on the medium supplemented with 5.0 μM BA and 0.5 μM α-naphthaleneacetic acid (NAA). Shoots rooted at a moderate frequencies (50.1%) on agarized WPM supplemented with 0.5 μM NAA but 100% of shoots rooted in agar-free vermiculite-based WPM after culture for 2 months. Plantlets, when transplanted to peat soil: vermiculite (1:1), showed the highest 95.1% survival within 1 month.