Exotic invasive plants are frequently targeted by introduced insects as a strategy for biological control. The idea behind this approach is that herbivore damage reduces a plant’s fitness and competitive ability. Although some studies have explored the consequences of invasive plants re-associating with their enemies, little is known about the allelopathic potency of re-association with co-evolved generalist enemies, such as dodder. We investigated whether Cuscuta gronovii alters the metabolite profile of Solidago canadensis and modifies its allelopathic effects. We prepared aqueous extracts of S. canadensis with and without C. gronovii parasitism and tested their effects on the seed germination success of ten species co-occurring with Solidago in China, comprising five native and five invasive species. The aqueous extracts of S. canadensis negatively affected seed germination in both native and alien species. The invasive species were more strongly affected than the native species. Although responses varied among species to S. canadensis extracts with or without C. gronovii infection, C. gronovii had no significant overall effect on S. canadensis for either the native or the invasive test species. Subsequently, metabolomic analysis revealed that C. gronovii infection significantly up-regulated the tyrosine, flavone, and flavonol biosynthesis pathways while down-regulating the anthocyanin biosynthesis pathway. Our results indicated that S. canadensis infected with C. gronovii appears to sacrifice the less critical pigment anthocyanin to fuel the synthesis of compounds that are crucial for structural reinforcement (e.g., tyrosine-derived lignin) as well as direct chemical defense and antioxidant activity (e.g., flavonoids).

Abstract The dominance of alien invasive plants may be restricted by enemies, such as insect herbivores and parasitic plants. A fundamental assumption is that plants exposed to such antagonists produce less biomass and have weakened competitive ability. Here we tested experimentally whether the growth, metabolome and allelopathic effects of the invasive plant Solidago canadensis are affected by simulated herbivory (using jasmonic acid, JA) and Cuscuta australis parasitism. We found that biomass production of Solidago was decreased by JA application and by Cuscuta parasitism, but less so when both were applied simultaneously. In line with the latter, metabolome analysis indicated that growth-related pathways were upregulated under simultaneous JA application and Cuscuta parasitism. Solidago had negative allelopathic effects on germination of one native species and seedling root growth of two other native species, and these effects tended to become weaker when Solidago was either subjected to JA or Cuscuta parasitism, but not when both were applied simultaneously. Metabolome analysis indicated that Solidago down-regulated its accumulation of secondary metabolites when there was only a single stress (i.e. simulated herbivory or Cuscuta parasitism). Correlation analysis between allelopathic effects and differently accumulated metabolites indicated that coumarins (Esculin, Daphnin and Esculetin-7-O-glucoside) and phenolic acid (2-O-p-Cumaroylglycerol) may play an important role in Solidago allelopathy. Overall, our results suggest that Solidago regulates its metabolic pathways related to growth and defence chemistry differently in response to single and dual stresses.

Plants are increasingly exposed to simultaneous warming, drought, and herbivory, yet how invasive and native species regulate carbon allocation under these interacting stressors remains poorly understood. We conducted a full-factorial greenhouse experiment manipulating temperature (+3 °C), soil water availability, and herbivory to compare carbon allocation responses in the invasive Solidago canadensis and its native congener S. decurrens. Drought emerged as the dominant driver of carbon reallocation, shifting investment away from biomass production and photosynthetic function toward belowground allocation, osmotic adjustment, defense, and structural reinforcement. Herbivory imposed additional carbon demands and modified drought-induced responses, particularly by constraining phenolic accumulation under combined stress, whereas warming had comparatively weaker and largely context-dependent effects. Our results showed that the two species differed in how carbon was distributed under stress: S. canadensis maintained greater biomass, chlorophyll, soluble sugars, and hemicellulose, whereas S. decurrens showed stronger investment in structural components. Structural equation models further revealed contrasting pathways linking physiological, defensive, and structural traits to biomass, supporting species-specific strategies of carbon allocation under multiple stressors. These findings suggest that the greater carbon-allocation flexibility observed in S. canadensis may contribute to maintaining performance under increasingly variable environmental conditions. However, because S. canadensis was raised directly from field-collected seeds without a refresher generation, potential maternal environmental effects cannot be completely excluded. Overall, our findings identify coordinated redistribution of carbon among competing functional pools as a potential mechanism underlying contrasting stress responses in these two congeneric species.

Microplastic pollution and herbivory are increasingly recognized as significant stressors in terrestrial ecosystems, yet their interactive effects on native and invasive plants remain poorly understood. In this study, we investigated the individual and combined effects of polyethylene microplastics (PE-MPs) and herbivory by Helicoverpa armigera on the growth and functional traits of twelve plant species (six invasive and six native). Exposure to PE-MPs significantly reduced biomass accumulation, with larger reductions in shoot, root, and total biomass for native plants than for invasive ones. Herbivory also significantly reduced biomass accumulation. When combined, PE-MPs and herbivory produced antagonistic effects on shoot, root, and total biomass. No significant three-way interaction was found among PE-MPs, herbivory, and plant status. Both PE-MPs and herbivory significantly reduced the root mass fraction and root-to-shoot ratio (RSR) while increasing the shoot mass fraction, with the PE-MP-induced reduction in RSR being stronger in native plants. Our findings suggest that multiple anthropogenic stressors can act as ecological filters, reshaping plant competitive dynamics and accelerating community shifts toward stress-tolerant species.

Crop diversification has been acknowledged as a means of lowering the environmental impact of agriculture without sacrificing agricultural output in recent years due to the growth of intensive agriculture. Crop rotation and intercropping—the methodical growing of two or more crops on one plot—are promising practices in this regard. Therefore, we conducted a quantitative bibliometric analysis of observed data between 2014 and 2024 to identify current research hotspots and future research trends in intercropping and crop rotation. A further secondary search for research advances in four key sub-areas (soil physicochemical properties, microbial diversity, greenhouse gas emissions (CO2, N2O, or CH4) and crop yield) was conducted based on keyword clustering. Our findings suggest that a crop diversification strategy can significantly increase soil nutrient content, optimize soil physicochemical properties, and regulate microbial community structure. In addition, this strategy can help to reduce greenhouse gas emissions (CO2, N2O, CH4), which will have a positive impact on the atmospheric environment. Crop diversification improves crop yield and quality, which in turn increases farmers’ economic returns. In order to maximize the effective production methods of crop rotation and intercropping, and to increase the efficiency of resource usage, this paper examines the development of research and practice on two cropping patterns worldwide.

Continuous tobacco monocropping leads to soil degradation and yield reduction. To address this, we evaluated the effects of tobacco (Nicotiana tabacum L.)-woad (Isatis tinctoria L.) rotation (A2, A4) compared to tobacco monoculture (A1) and woad monoculture (A3) on soil health and crop quality over a multi-year period. Methods involved comparative analysis of soil nutrients, enzyme activities, microbial community structure, and crop chemical composition and economic value. Key results demonstrated that tobacco-woad rotation significantly improved soil fertility. The tobacco-woad rotation could increase the content of organic matter, alkaline available nitrogen, available phosphorus, and available potassium in the soil, which were increased by 1.44%, 17.96%, 4.61%, and 16.20%, respectively, compared to tobacco monoculture. Soil urease and catalase activities, particularly urease (increased by 2.31 times), were significantly enhanced during the tobacco pre-growth period under rotation. Soil microbial communities were significantly restructured under tobacco-woad rotation versus monocropping. Bacterial phyla Acidobacteria, Gemmatimonadota, and Methylomirabilota were enriched in tobacco-woad rotation (A2) relative to tobacco monoculture (A1), while Chloroflexi, Methylomirabilota, and Verrucomicrobiota increased in woad-tobacco rotation (A4) versus woad monoculture (A3). Fungal shifts featured decreased Ascomycota and Basidiomycota with increased Mortierellomycota in both rotations, alongside reduced Chytridiomycota in A4. Rotation enriched key bacterial genera (MND1, Nitrospira, Subgroup-10, and RB41) and fungal taxa (Mortierella, Saccharomyces, and Saitozyma). Crucially, rotation harmoniously improved the chemical composition of both tobacco and woad leaves, increasing reducing sugars, total sugars, nicotine, potassium, and the sugar ratio in tobacco. The proportion of high-quality tobacco leaves post-curing increased by 10.24% (A2), contributing to a significantly higher total crop production value. In conclusion, tobacco-woad rotation effectively alleviates soil degradation associated with continuous tobacco cropping by enhancing soil nutrient availability, boosting key enzyme activities, and optimizing the structure and interactions of the soil microbial community. These soil improvements collectively drive superior crop quality and economic returns, supporting their adoption as a sustainable agricultural practice.IMPORTANCE(i) The effects of rotation of tobacco with woad on the quality of tobacco production were clarified using physiological and biochemical analyses. (ii) The effects of rotating tobacco with woad on soil microorganisms were revealed by microbiome sequencing of tobacco soils. Tobacco-woad rotation significantly improved the relative abundance of soil-dominant bacteria and decreased the relative abundance of harmful fungi. (iii) An efficient cultivation model of tobacco and woad suitable for Shandong was established by combining soil microbiomics with tobacco plant growth and development. Rotation of tobacco to woad gave the best results.

There is increasing evidence that patterns of local adaptation to abiotic conditions in plants may be mediated by soil microbes. The alien plant Solidago canadensis increasingly invades riparian habitats, where it can even grow in waterlogged areas. However, whether S. canadensis is locally adapted to waterlogging in its non-native range, and whether soil microbes mediate this, has not yet been investigated. We measured the size of S. canadensis plants in riparian and non-riparian habitats at three locations in China. Then we grew offspring of these plants for 52 days in a full factorial greenhouse experiment under waterlogged, drought or intermediate conditions, and with soil microbes that either came from the riparian or non-riparian habitat. In the field, riparian S. canadensis plants grew less tall and had thinner stems than non-riparian ones. In the greenhouse experiment, riparian plants produced on average less biomass than non-riparian plants, and biomass production was on average higher at intermediate water availability than under drought and waterlogged conditions. Moreover, plants produced on average more biomass when grown with riparian instead of non-riparian soil microbes. However, the positive effect of riparian soil microbes was not found for riparian plants in the waterlogging treatment, and for non-riparian plants in the drought treatment. In conclusion, although our results indicate that riparian and non-riparian S. canadensis plants are genetically differentiated with regard to biomass production during the 52 days of our experiment, these data do not provide support for local adaptation to waterlogged conditions. Furthermore, as riparian soil microbes increased biomass production of both the riparian and non-riparian S. canadensis plants, there was also no evidence for local adaptation to the local soil microbes.

IntroductionMicroplastic pollution has emerged as a significant global change factor, with the potential to alter the biological, physicochemical properties of soil and to subsequently affect plant growth. Despite growing recognition of the impacts of microplastic pollution, the mechanisms by which microplastics modify plant leaf chemistry and influence allelopathic interactions among co-existing plant species remain unclear.MethodsWe used the native perennial forb Achyranthes bidentata and the invasive annual forb Amaranthus spinosus as focal species. We grew the two species with and without competition with each other. This setup was further combined with a treatment involving the addition of polyethylene (PE). We then testd the effects of aqueous extract on seed germination and seedling growth for five invasive and five native species. Subsequently, metabolomic analysis was conducted on the aqueous extracts, in which significant allelopathic effects were observed on test species.Results and discussionThe presence of PE microplastics enhanced the biomass of both Achyranthes and Amaranthus under competitive and non-competitive growth conditions. Furthermore, PE microplastics were found to induce a negative allelopathic effect for the native plant Achyranthes on co-occurring plants, which appeared to be mediated through changes in leaf chemistry. Bisdemethoxycurcumin, ethylparaben, salicin 6’-sulfate and 5-hydroxy-3’,4’,7-trimethoxyflavone glucoside were proven important compounds for allelopathic enhancement. Overall, these results suggest that microplastic pollution has the capability to influence the co-existence of invasive and native plants by altering their allelopathic potential. This insight into the interactions between microplastics and plant allelopathy provides a novel perspective on how microplastic pollution could modify plant species interactions and ecosystem dynamics. Future studies could aim to answer how microplastics might affect plant root exudates and whether this process would mediate biological invasion.

Plant investment in secondary metabolites can be driven by abiotic factors such as nitrogen (N) availability and variation in biotic factors such as root-associated microbes. However, few studies have tested their combined effect on allelopathy. Here, we test whether and how N addition (i.e. eutrophication) and soil microbes modify allelopathic effects of the invasive plant Solidago canadensis on germination of the native plant Crepidiastrum sonchifolium. We first grew Solidago at three N levels with a live or sterilized soil inoculum. Then we exposed seeds of Crepidiastrum to aqueous extracts made of the Solidago plants. We analysed the biomass, soil microbiome (bacteria and fungi), and flavonoid, phenolic and saponin contents of Solidago, and the effects of the aqueous extracts on germination of Crepidiastrum. We found that Solidago produced 67

To integrate the harmless treatment and resource utilization of piled distillers' grains waste (DGW) is a great challenge. Thus, the DGW was industrially composted, and a three-year field experiment was conducted to investigate the agronomic and environmental performances of the compost in maize cultivation. It was well composted to organic fertilizer (OF) within 42 days by the addition of lime, microbial starter, and adjuvant with ventilation and pile-turning. Compared with synthesized fertilizer application (SF), SF+OF increased maize yield, N uptake, utilization efficiency, and economic benefits. OF slowly released N in the early growing stage, which synchronized less N uptake by the young maize seedlings and thus significantly reduced inorganic N (NH4+-N and NO3--N) levels in the soil. SF behaved oppositely, increasing NH3 and N2O emissions. Total CO2 emissions from the soils varied little between SF and SF+OF, and CH4 emission was very low in all treatments. These results suggested more organic matter depletion in the soil fertilized with only SF than that with SF+OF, and CH4 emission could be overlooked in the maize field. Moreover, SF+OF greatly decreased the emissions of NH3 and greenhouse gases for producing each unit of maize grains, showing better agronomic and environmental performances.

To reduce tobacco production suggested by the Chinese government, a 12-year field experiment was established by planting other crops in a traditional tobacco growing system every 2 years. Thus, tobacco-wheat, tobacco-canola, tobacco-wheat-maize, and tobacco-canola-maize rotations were implemented to compare the changes in soil properties. Compared to the initial soil, available N, P, and K increased or changed little after 12-year cropping except for decreased available N in the tobacco-wheat rotation soil. Compared with two-crop rotations, soil organic matter, available N, microbial biomass, enzyme activities (urease, phosphatase, and dehydrogenase), and bacterial community indexes (16S rDNA sequences, operational taxonomic units (OTUs), and richness and diversity indexes) increased in the three-crop rotations. The return of voluminous maize stubble should be the important reason for the change of these soil properties. All cropping soils were dominated by five bacteria (Proteobacteria, Acidobacteria, Firmicutes, Actinobacteria, and Bacteroidetes) accounting for 53.5-62.3% of the 16S rDNA sequences. Among the top 20 predominant bacteria, 10 were commonly found in all soils and only 2-5 were unique. Therefore, maize incorporation into the traditional two-crop systems increased stubble return and improved soil properties. However, bacterial community composition was more influenced by the soil itself than cropping systems.

AIMS:Green bean (Phaseolus vulgaris L.) is a popular vegetable worldwide. The use of beneficial fungi is a simple and effective way to improve the biological nitrogen fixation (BNF) of this leguminous vegetable. METHODS AND RESULTS:A micro-plot was conducted to investigate the enhancement of BNF using 15N natural abundance technology and agronomic performances of green bean caused by wood-rot fungus Ceriporia lacerata HG2011. The results showed the soil for frequently growing green bean featured abundant native rhizobia, and newly inoculated rhizobia may have to compete with them in nodulation and only highly competitive rhizobia can succeed. The addition of C. lacerata HG2011 to the soil increased the population of ammonia oxidizers, nitrifiers, and phosphorus (P)-mobilizing microbes in rhizosphere, accelerated nitrification and P mobilization, creating a favorable soil environment with high P and low ammonia for BNF. Green bean received C. lacerata HG2011 had higher dehydrogenase activity in roots and higher nodulation rate and large nodules. These phenomena implied abundant supplies of adenosine triphosphate, nicotinamide adenine dinucleotide hydrogen, or nicotinamide adenine dinucleotide phosphate hydrogen for BNF in the roots, a large proportion of N2 fixation tissues, and a greater sink for receiving photosynthates. As a result, C. lacerata HG2011 considerably increased the percentage of N derived from the atmosphere, BNF, and plant nutrient uptake (including N, P, and potassium), leading to 15.58%-28.51% of biomass increasment and 9.82%-17.03% of peapod yield increasment along with quality improvement compared with non-fungal application. CONCLUSIONS:C. lacerata HG2011 increased the nodulation and BNF of green bean, accelerated the nutrient uptake (NPK) and therefore improved the yield and peapod quality of green bean. SIGNIFICANCE AND IMPACT OF STUDY:The study demonstrates that C. lacerata HG2011 could be used as a biofertilizer for BNF improvement of legumes.

The improvement of biological nitrogen fixation (BNF) is beneficial to improving legume yield and soil fertility. Thus, the potential of a white-rot fungus Ceriporia lacerata HG2011 in promoting soybean BNF and yield along with the mechanisms was investigated. Fungal metabolites and the effects of C. lacerata HG2011 on rhizobial growth, chemotaxis, and biofilm formation were investigated through pure culture. Soybeans inoculated with this fungus were grown in the climatic cabinet, greenhouse, and field for measuring nodulation parameters, BNF-related enzyme activity, BNF, and yield. Although C. lacerata HG2011 had no significant influence on the growth of the rhizobium Ensifer fredii S2-1, the rhizobial chemotaxis and biofilm formation were improved by this fungus broth in pure culture. C. lacerata HG2011 dwelled on the root surface, increased root tips and surface area, produced the nodulation-associated metabolites (phytohormones, flavonoids, and low-molecular-weight organic acids) and hydrolases (cellulase, pectinase, protease, and phosphatase), mobilized soil P and Fe, and stimulated the activities of plant BNF-related enzymes (nitrogenase, glutamine synthetase, and dehydrogenase). Compared with fungus-free control plants, C. lacerata HG2011 improved nodulation and increased

Overuse of fungicides to control crop diseases results in ecological damage, environmental pollution, and human health risks. Biocontrol is an increasingly popular alternative in plant disease management due to sustainability and environmental friendliness. Herein, antagonistic tests and greenhouse experiments were conducted to investigate the antagonism of a self-isolated white-rot fungus Ceriporia lacerata HG2011 against phytopathogens in vitro, the underlying mechanism exerted by this fungus, and disease control efficiency in the greenhouse. The results demonstrated that both soluble and volatile substances produced by this fungus suppressed the growth of all test phytopathogen fungi and oomycetes in vitro, with the inhibitory rates of 10.4-60.6% for soluble metabolites and 30.3-52.9% for volatiles. C. lacerata HG2011 could grow in and gradually spread on living phytopathogenic colonies, concurrently deformed and lysed pathogenic hyphae in dual culture, which were associated with the release of hydrolase (cellulose, chitinase, β-glucanase, and protease) from this biocontrol fungus for the use of the pathogens as nutrient sources. The chitinolytic and cellulolytic production by C. lacerata HG2011 presents the specific response to the cell wall of pathogenic fungi and oomycetes, and β-glucanase was triggered by carbon competition. Consequently, C. lacerata HG2011 successfully controlled eggplant stem blight and cucumber vine blight (control efficacy 67.9-70.9%) in the greenhouse experiments. C. lacerata HG2011 showed multiple antagonistic mechanisms against the phytopathogenic fungi and oomycetes concurrently. Our results provided information about a new potential use of this fungus as a biocontrol agent to control plant diseases in modern agriculture beyond medical purposes, wastewater treatment, and biofuel production.

Background and Aims Some plant species suppress competitors through release of chemical compounds into the environment. As the production of allelochemicals may be costly, it would be beneficial if their production would only be induced when plants experience competition. We tested whether two plant species that frequently co-occur show evidence for induced allelopathy in response to intra- and interspecific competition. Methods We used the annual forb Crepidiastrum sonchifolium and the perennial forb Achyranthes bidentata, which are native to China and predominantly occur in ruderal communities, as focal species. We first grew the species without competition, with intraspecific competition and in competition with each other. We chemically analysed aqueous extracts made from these plants to test for evidence that the competition treatments affected the metabolomic profiles of the species. We then tested the effects of the aqueous extracts on seed germination and seedling growth of both plant species. Key Results Metabolomic analysis revealed that competition treatments modified the chemical profiles of the two study species. The root lengths of A. bidentata and C. sonchifolium seedlings were reduced by the aqueous plant extracts. For seedling root length of A. bidentata, heterospecific allelopathy was more negative than conspecific allelopathy, but for germination of C. sonchifolium seeds, the reverse was true. Moreover, conspecific allelopathic effects on germination of A. bidentata seeds and on seedling root length of both species were most negative when the aqueous extracts were made from plants that had experienced competition. In the case of seedling root length of A. bidentata, this effect was most negative when the plants had experienced interspecific instead of intraspecific competition. Conclusions We showed that plants change their metabolomic profiles in response to competition, and that this correlated with allelopathic inhibition of conspecific seed germination and seedling growth. We suggest that autoallelopathy for seed germination could function as a mechanism to avoid strong competition by keeping the seeds in a dormant state.

采集遵义市15年长期施肥定位试验的土壤,包括撂荒地(对照)、烤烟连作—单施化肥、烤烟连作—化肥有机肥配施、烤烟玉米轮作—单施化肥和烤烟玉米轮作—化肥有机肥配施等处理,通过土壤悬浊液与培养液混合培养技术、微生物高通量测序及常规分析,研究长期施肥对土壤无机磷活化的影响.结果表明,烤烟玉米轮作、施用有机肥和撂荒地的土壤可培养微生物(细菌、真菌、放线菌和无机磷细菌)数量增多,种群多样性增加,说明土壤生态环境改善.将土壤悬浊液接种至微生物培养液中,培养期间混合液中的有效磷含量以烤烟玉米轮作高于烤烟连作,化肥有机肥配施和撂荒地高于单施化肥,其中以烤烟玉米轮作—化肥有机肥配施最高,烤烟连作—单施化肥最低,说明合理种植和科学施肥有益于土壤无机磷的活化,在遵义烟区提倡烤烟玉米轮作—化肥有机肥配施很有必要.在混合液中,氢离子与溶解钙磷、有机酸与溶解铁磷和铝磷显著相关.与溶磷微生物的纯培养技术相比,土壤悬浊液培养既能反映微生物的溶磷特征,又更接近土壤微生物菌群复杂的溶磷状况.在供试土壤微生物中,存在柠檬酸合酶、蛋白葡萄糖脱氢酶和苹果酸合酶等的合成通路,处理间的差异可从分子生物学角度解释合理轮作和化肥有机肥配施促进土壤无机磷活化的原因.

Ageratina adenophora originated from central America has flooded forests, pastures, and farmland in more than 40 tropical and subtropical countries, causing huge ecological disasters and economic losses. In this paper, we intended to use a complex inoculum composed of Pseudomonas putita and Clostridium thermocellum to in-situ compost A. adenophora debris and then to compare the phytotoxicity of extracts from uncomposted and composted A. adenophora (UCA and CA respectively) to barley seed germination and young seedling growth. A field experiment was finally conducted to reveal the effects of UCA and CA on barley yield and grain quality. UCA extracts showed negative influences on seed germination performances (germination rate, as well as germination and vigor indexes). The mechanism employed by UCA extracts involved in this process may be the inhibition of bio-macromolecules hydrolysis (including proteins, starch, and phytin) in endosperms and their hydrolysates for forming new plants. However, CA extracts promoted seed germination and seedling growth, increased chlorophyll levels in leaves, and stimulated dehydrogenase and nitrate reductase activities in plants, probably due to the presence of rich available nutrients and humic acid, a phytohormon-like substance. Compared with chemical fertilizers, application of CA in combination with chemical fertilizers significantly improved plant nutrient uptake (nitrogen, phosphorus, and potassium), yield, and grain quality in contrast to UCA which behaved otherwise. Taken together, the use of the microbial agent to in-situ compost A. adenophora may be an effective approach for agricultural use of A. adenophora debris as a plant-friendly organic fertilizer, being undoubtedly worth advocating.

[目的]系统研究火龙果的水肥耦合效应,制定适宜的灌水施肥方案,为其高产优质和可持续发展提供技术依据.[方法]以紫红龙(Hylocereus polyrhizus,Zihonglong)为试验材料,以田间持水量、施氮量和施钾量为试验因素,采用3因素5水平二次回归通用旋转组合设计,共设20个处理,进行2018—2019连续2年的定株水肥耦合试验,统计火龙果周年产量和各批次单果重,测定果实可溶性糖、可溶性蛋白等品质指标并进行综合评分,探究水、氮、钾对火龙果产量和品质的调控作用,采用频率分析法对产量和品质数学模型进行优化分析,以获取高产优质下的灌水施肥方案.[结果]不同处理水氮钾的供应对火龙果果实可溶性蛋白、糖酸比等品质指标影响显著(P<0.05,下同),处理10(田间持水量40％、N 300 kg/ha、K2O 375 kg/ha)和处理15(田间持水量60％、N 300 kg/ha、K2O 375 kg/ha)的果实蛋白质含量相对于其他处理有所提升,处理4(田间持水量72％、N 122 kg/ha、K2O 152 kg/ha)相对于其他处理明显降低火龙果果实中可滴定酸含量,提升糖酸比值,改善果实风味,但也降低果实中总酚含量.整体来看,产量和综合品质均随田间持水量、施氮量和施钾量的增加表现为先增后减的变化趋势;因素对产量和综合品质的影响程度均表现为田间持水量>施氮量>施钾量,田间持水量、施氮量和施钾量对于火龙果产量的交互效应存在差异,其中田间持水量与施氮量对产量的交互作用显著.在田间持水量52.43％～70.86％、N 215.17～511.00 kg/ha、K2O 148.99～565.47 kg/ha时,火龙果产量可达22500 kg/ha以上;在田间持水量48.25％～64.68％、N 247.89～404.48 kg/ha、K2O 247.30～581.51 kg/ha时,火龙果综合品质评分达80分以上.[结论]田间持水量、施氮量和施钾量水平显著影响火龙果的产量和主要品质指标,适宜的灌水和充足的氮钾供应可提高火龙果的产量和品质,增加其商品性和经济效益,综合考虑三者对火龙果产量和品质的影响,滴灌条件下,火龙果高产优质的灌水施肥方案为:田间持水量52％～65％,N 247.89～404.48 kg/ha,K2O 247.30～565.47 kg/ha.该优化方案可供同等肥力水平火龙果园水肥一体化模式下的管理参考.

Elton’s classic diversity-invasibility hypothesis posits that diversity of resident communities increases resistance against invaders. We tested whether the diversity-invasibility relationsip might be mediated by allelopathic effects of the resident species. In a large germination experiment, we exposed seeds of six alien and six native test species to leachates of one, three, six or twelve species. The leachates tended to slightly delay germination, and almost all single-species leachates reduced the proportion of germinated seeds. Nevertheless, the overall effect of the plant leachate mixtures on the proportion of germinated seeds was not significant. This was because a higher diversity of the leachates increased the proportion of germinated seeds, particularly for native test species. Among the six alien test species, it was only the most invasive one that benefited from increased diversity of the leachates, just like the natives did. Overall, our findings suggest that allelopathy of diverse communities does not provide resistance but could actually facilitate the germination of invaders.

[目的]为中、低肥力果园火龙果科学施肥提供技术和理论依据.[方法]2018-2020年在贵州省火龙果典型产区罗甸县进行定株施肥试验,设置5个施钾肥处理:CK(仅施有机肥)、K0(0 g/桩)、K1(150 g/桩)、K2(300 g/桩)、K3(450 g/桩),统计火龙果周年产量,测定植株养分浓度和果实品质指标,分析不同施钾水平火龙果的养分分配与产量品质.[结果]火龙果各器官氮、磷、钾养分积累均随施钾量的增加呈先升后降趋势,茎蔓、果肉和果皮中的养分含量均表现为钾＞氮＞磷.中肥力果园,随施钾量增加火龙果产量呈先升后降趋势,且随时间推移,肥料效应更为显著;低肥力果园,施钾肥较不施钾肥产量增加显著,但钾肥用量对产量影响不明显.中、低肥力果园连续3年施钾肥,各施钾处理(K1～K3)产量较未施钾肥的处理(K0)分别提高4.8％～21.66％、20.72％～26.35％.施用钾肥能够促进火龙果维生素C含量的积累、提高果实的可溶性糖含量.[结论]中、低肥力果园施钾肥能保证火龙果较高的产量和果实品质,适宜的钾肥施用量为300 g/桩.