Search Results (444)

Liriope muscari is a medicinal and ornamental herbaceous plant with significant economic value, as its tuberous roots are used for medicinal purposes. However, the current production of medicinal plants is characterized by wasteful use of resources and ecological risks caused by the unreasonable application of nitrogen fertilizers. In this study, based on uniform application of phosphorus and potassium fertilizers, six nitrogen application levels were set in pot experiments (expressed as N): N0: 0 kg/ha, N1: 208.33 kg/ha, N2: 416.66 kg/ha, N3: 625 kg/ha, N4: 833.33 kg/ha, N5: 1041.66 kg/ha). The morphological characteristics, photosynthetic physiology, tuber yield and quality, and seven nitrogen fertilizer utilization indices of L. muscari were analyzed and measured. Correlation analysis and structural equation modeling (SEM) were employed to investigate the mechanism by which nitrogen influences its growth and development, photosynthetic characteristics, tuber yield and quality, and nitrogen fertilizer utilization efficiency. The results showed that (1) nitrogen significantly promoted plant height, crown width, tiller number, and chlorophyll synthesis, with the N3 treatment (625 kg/ha) reaching the peak value, and the crown width and tiller number increasing by 26.44% and 38.90% compared to N0; the total chlorophyll content and net photosynthetic rate increased by 39.67% and 77.04%, respectively, compared to N0; high nitrogen (N5) inhibited photosynthesis and increased intercellular CO₂ concentration; (2) Fresh weight of tuberous roots, polysaccharide content, and saponin C content peaked at N3 (34.67 g/plant, 39.89%, and 0.21%), respectively, representing increases of 128.69%, 28.37%, and 33.66% compared to N0; (3) Nitrogen uptake, nitrogen fertilizer utilization efficiency, agronomic utilization efficiency, and apparent utilization efficiency were optimal at N3, while high nitrogen (N4–N5) reduced nitrogen fertilizer efficiency by 40–60%; (4) SEM analysis indicated that tiller number and transpiration rate directly drive yield, while stomatal conductance regulates saponin C synthesis. Under the experimental conditions, 625 kg/ha is the optimal nitrogen application rate balancing yield, quality, and nitrogen efficiency. Excessive nitrogen application (>833 kg/ha) induces photosynthetic inhibition and “luxury absorption”, leading to source-sink imbalance and reduced accumulation of secondary metabolites. This study provides a theoretical basis and technical support for the precise management of nitrogen in Liriope-type medicinal plants. It is expected to alleviate the contradictions of “high input, low output, and heavy pollution” in traditional fertilization models. Full article

Agrobacterium-mediated transformation systems are extensively applied in japonica rice varieties. However, the adaptability of local rice varieties to existing transformation systems remains limited, owing to their complex genotypes, posing a substantial challenge to transformation. In this study, four local rice varieties were selected to optimize the effects of different culture media on callus induction, browning resistance, contamination resistance, callus tolerance, differentiation, regeneration, and root development, and then two varieties were selected to improve plant architecture and tiller development by CRISPR/Cas9-mediated gene editing, based on constructive transformation systems. The goal was to enhance the transformation efficiency of local varieties and innovate germplasms. The results demonstrated that japonica rice varieties XG293 and WD68 exhibited higher induction rates under the treatment of 2 mg/L 2,4-D (2,4-Dichlorophenoxyacetic acid) + 1 mg/L NAA (Naphthaleneacetic acid), whereas indica rice varieties H128 and E33 performed the best under 3 mg/L 2,4-D + 1 mg/L NAA. Severe browning in H128 was effectively mitigated by a carbon source of 20 g/L maltose supplemented with 40 mg/L ascorbic acid. Contamination after Agrobacterium infection was controlled by 300 mg/L Tmt (Timentin). Under a treatment of 200 µM/L acetosyringone +10 min infection duration, XG293 and WD68 exhibited higher callus tolerance, differentiation rates, and GUS staining rates, achieving transformation efficiencies of 43.24% and 52.38%, respectively. In contrast, H128 and E33 performed better under the treatment of 200 µM/L Acetosyringone + 5 min, with transformation efficiencies of 40.00% and 40.74%, respectively. The mutants after OsCCD7 gene editing in WD68 and H128 displayed a dwarfness of plant height, a significant increase in tiller numbers, and compact architecture. These findings demonstrate that an optimized combination of plant growth regulators and infection durations effectively improves transformation efficiency for local varieties, and the OsCCD7 gene regulates plant architecture and tiller development with variable effects, depending on the rice complex genotypes. This study provides a theoretical basis for the efficient transformation of local rice varieties and germplasm innovation. Full article

Sugarcane requires high doses of phosphorus to achieve high productivity. However, not all the phosphorus applied to crops is utilized. Therefore, it is believed that some remaining phosphorus can meet the nutrient demand of the ratoon crop. The objective of this study was to evaluate the effects of mineral fertilization with triple superphosphate (TSP) and organic fertilization with poultry litter (PL), applied to plant cane and the first ratoon, on the quality of second ratoon sugarcane. The experimental design was a randomized complete block design with a 5 × 5 factorial scheme with four replications. The treatments consisted of five TSP doses (0, 60, 120, 180, and 240 kg ha⁻¹) and five PL doses (0, 2, 4, 6, and 8 t ha⁻¹). Fertilization with TSP and PL applied in the two preceding cycles promoted an increase in plant height, stalk diameter, number of tillers, and productivity in the second ratoon. The doses of triple superphosphate and chicken litter applied in cycles preceding the second ratoon were able to increase the agronomic performance of the genotype IACSP95-5094. However, the highest subsequent combined doses of triple superphosphate and chicken litter resulted in a 27% increase in stalk productivity. In general, the preceding doses of chicken litter showed greater potential to enhance the technological attributes. Full article

Rice blast is one of the main diseases of rice, causing severe economic losses to agricultural production; thus, the search for blast resistance is a top priority for rice breeding. When challenged by the blast causal fungus Magnaporthe oryzae the expression level of OsMAPKKK69 gene in rice cultivar Nipponbar was found to increase significantly. Such an induction was also found in a different genetic material, cultivar Shufanggaonuo, indicating that OsMAPKKK69 plays an important role in blast disease response. However, the function of OsMAPKKK69 remains unclear. In this study, wild type ZH11 was selected as the background material to investigate the expression and functions of OsMAPKKK69 in rice disease resistance by constructing knockout mutants. The results showed that OsMAPKKK69 is mainly expressed in four-week-old shoots and localized in cell membrane, cytoplasm, and nucleus. The two allelic knockout mutants, osmapkkk69-1 and osmapkkk69-2, were more resistant to M. oryzae and bacterial blight Xanthomonas oryzae pv. Oryzae (Xoo). Further agronomic trait analysis revealed that the osmapkkk69-1 and osmapkkk69-2 mutants had reduced plant height, smaller grain size, a significant increase in tillering number, but also a significant increase in yield per plant. Our results show that OsMAPKKK69 is involved in the immune response of rice by negatively regulating the resistance to rice blast and blight diseases, and in regulating important agronomic traits. This study lays a foundation for revealing the molecular mechanism of OsMAPKKK69 in the immune response to rice diseases and provides novel genetic resources for rice breeding. Full article

Leaf morphology significantly impacts rice (Oryza sativa L.) plant architecture and yield. Here, we identified and characterized a novel narrow-leaf mutant, nal25, derived from indica rice cultivar ‘Huazhan’ using EMS mutagenesis. Phenotypic analyses revealed that nal25 exhibited significantly narrower leaves, reduced plant height, increased tiller number, and notably decreased grain size, seed setting rate, and thousand-grain weight compared to the wild type. Genetic analyses demonstrated that the narrow-leaf phenotype is controlled by a single recessive nuclear gene. Through precise localization analysis, the NAL25 gene was located within a region of approximately 103 kb on the long arm of rice chromosome 7. The sequencing results showed that the mutant nal25 had a T to C mutation at position 173 of the heat-shock protein gene LOC_Os07g09450 encoding the DnaJ domain in this interval, resulting in a change in amino acid 58 from leucine to proline. The qRT-PCR results showed that the expression level of NAL25 gene decreased in the mutant. The nal25 mutant obtained in this study exhibits stable mutant phenotypes, including dwarfism and excessive tillering, traits typically unfavorable for rice production. Nevertheless, it serves as valuable genetic material for forward genetics approaches to identify yield-related genes regulating leaf morphology and culm height. Thus, research on the nal25 mutant advances the development of rice varieties with ideal plant architecture, thereby stabilizing yield increases and safeguarding global food security. Full article

Astragalus sinicus, a key leguminous green manure widely cultivated in Southern China’s rice-based cropping systems, plays a pivotal role in sustainable agriculture by enhancing soil organic matter sequestration, improving rice yield, and elevating grain quality. The symbiotic nitrogen-fixing association between A. sinicus and its matching rhizobia is fundamental to its agronomic value; however, suboptimal inoculant efficiency and field application methodologies constrain its full potential. To address these limitations, we conducted a multi-phase study involving (1) rhizobial strain screening under controlled greenhouse conditions, (2) an optimized lyophilization protocol evaluating cryoprotectant (trehalose, skimmed milk powder and others), and (3) seed pelleting trails with rhizobial viability and nodulation assessments over different storage periods. Our results demonstrate that Mesorhizobium huakuii CCBAU 33470 exhibits a superior nitrogen-fixing efficacy, significantly enhancing key traits in A. sinicus, including leaf chlorophyll content, tiller number, and aboveground biomass. Lyophilized inoculants prepared with cryoprotectants (20% trehalose or 20% skimmed milk powder) maintained >90% bacterial viability for 60 days and markedly improved nodulation capacity relative to unprotected formulations. The optimized seed pellets sustained high rhizobial loads (5.5 × 10³ cells/seed) with an undiminished viability after 15 days of storage and nodulation ability after 40 days of storage. This integrated approach of rhizobial selection, inoculant formulation, and seed coating overcomes cultivation bottlenecks, boosting symbiotic nitrogen fixation for A. sinicus cultivation. Full article

Sulfur-containing fertilizers increase production costs, which leads to low utilization of this nutrient. Thus, evaluating how the absence of sulfur influences the early development of Urochloa brizantha is essential. Study was conducted in a greenhouse at the Federal University of Rondonópolis in a completely randomized design, with six treatments in a 3 × 2 factorial scheme, and eight replications. Three cultivars of U. brizantha (Marandu, Xaraés and Piatã) were evaluated under two fertilization strategies: with or without sulfur fertilization. Sufur presence increased the number of leaves and forage mass, in which cultivar Xaraés presented the greatest means. Piatã was the cultivar most sensitive to sulfur deficiency at establishment, which reduced forage mass, number of leaves and number of tillers by 42%, 32%, and 45%, respectively. Despite these differences between cultivars, sulfur efficiently increased the forage yield. Sulfur fertilization increased the concentrations of nutrients in the plants without significantly affecting the uptake of nitrogen, phosphorus, potassium, calcium and magnesium. Sulfur omission resulted in increased phosphorus uptake in all grass. In contrast, Marandu grass exhibited the greatest reduction in sulfur uptake. Therefore, the use of sulfur in the fertilization of grasses is recommended, it is important to evaluate the responses of each cultivar to better adjust the fertilization management. Full article

This study investigated the impact of nitrogen (N) fertilization on the yield and grain filling (GF) characteristics of two conventional japonica rice varieties with distinct panicle types: Yangchan 3501 (large-panicle: spikelets per panicle $> 150$) and Nangeng 46 (medium-panicle: $100 <$ spikelets per panicle $< 150$). Field experiments were conducted over two growing seasons (2022–2023) with three N application rates (T1: 225 kg ha⁻¹, T2: 270 kg ha⁻¹, T3: 315 kg ha⁻¹). Key measurements included tiller dynamics, panicle composition, GF parameters modeled using the Richards equation, and enzyme activities related to nitrogen metabolism (Fd-GOGAT, NR) and carbohydrate transport (α-amylase, SPS). Results showed that the yield increased with higher N levels for both varieties, with Yangchan 3501 achieving higher yields primarily through increased grains per panicle (15.65% rise under T3 vs. T1), while Nangeng 46 relied on panicle number (8.83% increase under T3 vs. T1). Nitrogen application enhanced Fd-GOGAT and NR activities, prolonging photosynthesis and improving GF rates, particularly in the inferior grains of Yangchan 3501 during middle and late stages. However, a high N reduced seed-setting rates and 1000-grain weight, with larger panicle types exhibiting a greater sensitivity to N-induced changes in branch structure and assimilate allocation. This study highlights that optimizing N management can improve nitrogen-metabolism enzyme activity and GF efficiency, especially in large-panicle rice, while medium-panicle types require higher N inputs to maximize panicle number. These findings provide actionable insights for achieving high yields and efficient nutrient use in conventional rice cultivation. Full article

The utilization of saline–alkali land for rice cultivation is critical for global food security. However, most existing studies on rice salt tolerance focus on the seedling stage, with limited insights into tolerance mechanisms during reproductive growth, particularly at the panicle initiation stage (PI). Leveraging precision salinity-control facilities, this study imposed four salt stress gradients (0, 3, 5, and 7‰) to dissect the differential response mechanisms of six rice varieties (YXYZ: Yuxiangyouzhan, JLY3261: Jingliangyou3261, SLY91: Shuangliangyou91, SLY138: Shuangliangyou138, HLYYHSM: Hualiangyouyuehesimiao, and SLY11:Shuangliangyou111) during PI. The results revealed that increasing salinity significantly reduced tiller number (13.14–68.04%), leaf area index (18.58–57.99%), canopy light interception rate (11.91–44.08%), and net photosynthetic rate (2.63–52.42%) (p < 0.001), accompanied by reactive oxygen species (ROS)-induced membrane lipid peroxidation. Integrative analysis of field phenotypic and physiological indices revealed distinct adaptation strategies: JLY3261 rapidly activated antioxidant enzymes under 3‰ salinity, alleviating lipid peroxidation (no significant difference in H₂O₂ or malondialdehyde content compared to 0‰ salinity) and maintaining tillering and aboveground biomass. SLY91 tolerated 7‰ salinity via CAT/POD-mediated lipid peroxide degradation, with H₂O₂ and malondialdehyde contents increasing initially but decreasing with escalating stress. These findings highlight genotype-specific antioxidant strategies underlying salt-tolerance mechanisms and the critical need for integrating phenomics–physiological assessments at reproductive stages into salt-tolerance breeding pipelines. Full article

To clarify the ecological mechanisms underlying the succession of artificial grasslands to native alpine meadows and systematically reveal the patterns of ecological restoration in artificial grasslands in the Qinghai–Tibet Plateau, this study provides a theoretical basis for alpine meadow ecological restoration. In this study, artificial grassland and degraded grassland (CK) with different restoration years (20 years, 16 years, 14 years, and 2 years) in the Qinghai–Tibet Plateau were taken as research objects. We focused on the tillering characteristics, patch number, community structure evolution, and soil properties of the dominant species, C. alatauensis, and systematically explored the ecological restoration law by comparing and analyzing ecological indicators in different restoration years. The results showed the following: (1) With the extension of restoration years, the asexual reproduction ability of C. alatauensis was enhanced, the patches became large, and aboveground/underground biomass significantly accumulated. (2) Community structure optimization meant that the coverage and biomass of Cyperaceae plants increased with restoration age, while those of Poaceae plants decreased. The diversity of four species in 20A of restored grasslands showed significant increases (10.71–19.18%) compared to 2A of restored grasslands. (3) Soil improvement effect: The contents of soil organic carbon (SOC), total phosphorus (TP), nitrate nitrogen (NN), and available phosphorus (AP) increased significantly with the restoration years (in 20A, the SOC content in the 0–10 cm soil layer increased by 57.5% compared with CK), and the soil pH gradually approached neutrality. (4) In artificial grasslands with different restoration ages (20A, 16A, and 14A), significant or highly significant correlations existed between C. alatauensis tiller characteristics and community and soil properties. In conclusion, C. alatauensis in artificial grasslands drives population enhancement, community succession, and soil improvement through patch expansion. Full article

Straw returning inhibits tillering at the early stage of rice growth and thus affects grain yield. Sulfur-coated urea (SCU) has been expected to increase nitrogen use efficiency (NUE) and yield, save labor input, and reduce environmental pollution in crop production. Nevertheless, the sulfur coatings of SCU are easy to break and then shorten the nutrient release cycle. Whether there was a complementary effect between straw returning and SCU in NUE and grain yield had remained elusive. To investigate the effects of straw returning combined with the application of SCU on NUE and rice yield, a two-year field experiment was conducted from 2022 to 2023 with three treatments (straw returning combined with conventional urea (SRU), no straw returning combined with SCU (NRS), straw returning combined with SCU (SRS)). We found that straw returning combined with the application of SCU increased rice yield and NUE significantly. Compared with SRU and NRS, SRS treatments significantly increased grain yield by 14.61–16.22%, and 4.14–7.35%, respectively. Higher effective panicle numbers per m² and grain numbers per panicle were recorded in NRS and SRS treatments than SRU. SRS treatment increased nitrogen recovery efficiency by 79.53% and 22.97%, nitrogen agronomic efficiency by 18.68% and 17.37%, and nitrogen partial factor productivity by 10.51% and 9.81% compared with SRU and NRS treatment, respectively. The enhanced NUE in SRS was driven by higher leaf area index, SPAD value, net photosynthetic rate, carbon metabolic enzyme (RuBP and SPS) activity, nitrogen metabolic enzyme (NR, GS, and GOGAT) activity, sucrose and nitrogen content in leaves, and nitrogen accumulation in plant during grain filling. Moreover, the improved yield in SRS was closely related to superior NUE. In conclusion, straw returning combined with application of SCU boosted grain yield and NUE via enhanced carbon–nitrogen metabolism during the late growth period in rice. Full article

Current rice cultivation relies on mechanical transplanting, which is costly and complex, and direct seeding, which suffers from poor quality and low efficiency. To address these issues, a double-press precision depth-control seeding method was developed in this study. Discrete element modeling (DEM) was employed to optimize key operational parameters—compaction force, soil covering cutter rotational speed, and penetration depth—using qualified seeding depth and missed seeding rates as performance metrics. Optimal results were achieved at a 60 kPa compaction force, a 300 rpm rotational speed, and a 7 cm penetration depth. A prototype seeder was manufactured and evaluated in three-year field trials against conventional dry direct seeders and mechanical transplanters. The double-press seeder demonstrated significantly superior performance compared to conventional direct seeding. It optimized the crop population structure by maintaining a high tiller number while increasing the productive tiller rate, resulting in stable annual yields exceeding 10.11 t·hm⁻². Although its yield was slightly lower than that of mechanical transplanting, the double-press seeder offers a compelling practical alternative due to its operational convenience and economic benefits. Full article

The extension of genetic diversity is the basis for yield and adaptability improvements of winter wheat varieties under climate fluctuations. In the present study, an international collection consisting of 96 winter bread wheat accessions from Russia, Germany, Finland, Kazakhstan, Bulgaria, Turkey, the USA, and the international programme (Turkey–CIMMYT–ICARDA) was analysed under the conditions of Western Siberia during three growing seasons. Yield and yield-related traits were recorded following standard agronomy practices. Genotyping of the germplasm panel was conducted using 55 KASP markers at the Institute of Plant Biology and Biotechnology (Kazakhstan). The yield had a high correlation with the number of fertile tillers per unit area (0.68), which indicates significant yield reduction in wheat accessions from different origins that are not adaptive to the conditions of Western Siberia. The main stable QTLs associated with yield-related traits during two growing seasons, ippb_ta_1147 (1A), ippb_ta_107 (4A), ippb_ta_239 (5D), and ippb_ta_283 (6A), can be used in MAS for the improvement of yield and related traits. The outperforming genotypes Zhiva, Zolushka, Doneko, Line K 18918, Line 2293; CO13D1299, KS13DH0030-32, Gondvana//HBK0935-29-15/KS90W077-2-2/VBF0589-1… are recommended to be included in hybridisation programmes and represent promising sources for breeding high-yielding and climate-resilient winter wheat. Full article

Plant-beneficial microbes are a perennial ally in an agroecosystems, providing multiple benefits to crop plants. The present study explored the potential of two microbial biocontrol agents (MBCAs), viz., Trichoderma asperellum and Pseudomonas fluorescens, against the bacterial blight pathogen of rice, Xanthomonas oryzae pv. oryzae. In vitro, MBCAs resulted in significant inhibition of X. oryzae pv. oryzae, as evidenced through the distortion of pathogen cell morphology and formation of a pathogen biofilm. Pot studies on the effect of MBCAs in rice showed increased germination, increased vigor index of seedlings, increased tiller numbers, a 10.29% reduction in percentage disease incidence (PDI), and low disease severity following individual inoculation. Activity of plant defense enzymes also increased with MBCA treatment (phenylalanine ammonia-lyase, 2.7-fold increase; peroxidase and polyphenol oxidase, 5-fold increase), establishing the priming effect of MBCAs on host defense. The quantitative polymerase chain reaction data revealed that pathogenesis-related genes (OsPR1a, OsPR1b, and OsPR10a) and X. oryzae pv. oryzae resistance genes (Xa1 and Xa26) were upregulated 4- to 14-fold in MBCA-treated rice plants over control plants. These results provide insights into the phenological, physiological, and molecular responses of rice crops treated with MBCAs in the presence of X. oryzae pv. oryzae and could be used to develop an effective field management strategy. Full article

Sulfur (S) fertilizer is routinely applied together with other macronutrients by farmers across all regions to improve grain yield and quality, but its distinct effects on grain yield and aroma intensity in fragrant rice remain inadequately studied, especially when applied under varying existing soil S levels. This study aimed to determine the effects of S fertilizer application on grain yield and aroma intensity (2-Acetyl-1-Pyrroline, 2AP) in fragrant rice grown under varying soil S levels (very low, low, and medium). The premium Thai fragrant rice cultivar KDML105 was grown under field conditions during two cropping seasons in 2021 and 2022 in Surin province, northeastern Thailand. Sulfur fertilizer in the form of (NH4)₂SO₄ was applied at 0, 30, 60, 90, and 120 kg S ha⁻¹ at one time with the basal fertilizers phosphorus (P) and potassium (K) under varying soil S levels, using the same protocol in both cropping seasons. Plant growth parameters were evaluated at the tillering stage, and grain samples were harvested at maturity to evaluate grain yield and aroma intensity. The results showed that applying S at rates between 60 and 90 kg ha⁻¹ to soils with very low and low S increased grain yield from 4 to 20% compared to no S application, while no effect of S application was observed for the medium soil S level. The results were primarily attributed to the number of tillers and panicles per hill and the 1000-grain weight in both cropping seasons. Dissimilar effects of S application rates and soil S level were found for grain 2AP content. There was a higher grain 2AP content in the low and medium soil S levels compared to very low S, but the pattern varied according to the S application rate. Applying the appropriate rate of S fertilizer can significantly improve rice productivity, especially when cultivated under S-deficient soil, and higher soil S levels can promote the grain 2AP content of fragrant rice. Full article