To study the effect of long-term successive subculture on pear somaclonal variation, so as to provide a theoretical basis for the control and utilization of variation in vitro culture and reproduction. Here, we compared newly established (3‑month) tissue‑cultured plantlets of the dwarfing rootstock ‘Qingzhen D1’ ( Pyrus communis × P. bretschneideri ) with those subcultured for five years, using an integrated approach that combined phenotypic and anatomical evaluation, endogenous hormone quantification, flow cytometry (FCM), whole‑genome resequencing (WGS), and functional validation of candidate mutations. Long-term subcultured plantlets exhibited notable phenotypic changes, with approximately 20% of individuals developing lobed leaves; the shoot proliferation coefficient increased from 2.7 to 5.4, and the rooting rate rose from 75% to 100%. Plant growth regulator and endogenous hormone quantification revealed elevated 6-benzylaminopurine (6-BA), indole-3-butyric acid (IBA), and zeatin (ZT), and decreased indole-3-acetic acid (IAA) in long-term subcultured plantlets. FCM confirmed that no ploidy variation occurred during subculture. WGS identified 452,432 SNPs and 44,892 Indels, yielding a mutation frequency of approximately 5.0 × 10⁻⁴ per base pair. Based on the KEGG enrichment results and the observation that long-term subcultured plantlets exhibited elevated endogenous ZT levels, we selected the cytokinin oxidase/dehydrogenase ( CKX ) gene ( pycom07g02010 ) located on chromosome 7 for functional validation. A non-synonymous SNP was identified in this gene, corresponding to a T‑to‑C transition on the coding strand, which results in a leucine-to-proline substitution at position 34 (L34P). Transient expression in tobacco demonstrated that the L34P variant partially impaired the ability of CKX to degrade ZT. Overall, long-term successive subculture altered morphological and physiological traits linked to shifted growth regulator and endogenous hormone levels, while maintaining relatively stable genetic integrity. These findings suggest a mechanistic link between somaclonal variation and cytokinin homeostasis, providing a scientific basis for optimizing pear micropropagation strategies.

Melatonin is increasingly recognized as a multifunctional signaling molecule involved in plant growth regulation and stress adaptation. Recent studies have revealed that melatonin plays a pivotal role in shaping root system architecture (RSA) by modulating root growth dynamics, lateral root formation, and root-microbe interactions. This review highlights emerging evidence that melatonin regulates RSA through complex crosstalk with phytohormones, reactive oxygen species, and stress‐responsive signaling pathways, rather than acting solely as a growth regulator. Importantly, accumulating evidence indicates that melatonin functions as an integrative regulator of RSA by coordinating multiple hormone signaling pathways, including auxin, jasmonic acid, ethylene, cytokinins, salicylic acid, and abscisic acid, in a concentration‐ and context‐dependent manner. We further distinguish the regulatory effects of melatonin on root growth and root architectural remodeling and summarize the dose‐dependent actions of melatonin under abiotic stress conditions. Beyond hormonal regulation, melatonin enhances root nutrient acquisition by modulating ion transporters, maintaining ion homeostasis, and optimizing root system architecture, thereby improving nitrogen, phosphorus, potassium, and micronutrient uptake under stress conditions. Emerging evidence also suggests that melatonin may indirectly influence root-microbe interactions by reshaping root physiology, redox status, and hormonal balance, contributing to improved stress resilience. By integrating molecular, physiological, and developmental perspectives, this review provides a conceptual framework for understanding melatonin‐mediated root system plasticity and positions melatonin as an integrative regulator of root system architecture that links hormonal crosstalk, nutrient acquisition, and stress adaptation, offering insights into its potential applications in crop stress resilience improvement.

Pear trees typically exhibit a prolonged juvenile period, which significantly restricts the breeding process. Additionally, the increasing prevalence of soil salinization further constrains pear production. The nuclear factor Y (NF-Y) represents a crucial family of transcription factors that play vital roles in plant development and responses to abiotic stress. However, research on NF-Y members in Pyrus is currently limited. In this study, utilizing the released genome assembly, we identified a total of 41 PbNF-Y encoding genes in Chinese white pear (Pyrus bretschneideri Rehd), comprising 11 PbNF-YAs, 20 PbNF-YBs, and 10 PbNF-YCs, which were named according to the standardized nomenclature in Arabidopsis. Phylogenetic analysis, gene structure evaluation, and sequence alignments indicated the conservation of PbNF-Ys throughout the evolutionary process in Pyrus. Based on previous reports and transcriptome database analyses related to the juvenile-adult phase transition, NF-YA4a was identified as a candidate gene for further investigation. Quantitative PCR (qPCR) results revealed that the expression of NF-YA4a increased during ontogeny, reaching a peak at the adult phase. Furthermore, NF-YA4a exhibited a rapid response to NaCl and ABA treatments, and was also induced by dehydration, but showed no response to low temperature. Overexpression of NF-YA4a in Arabidopsis led to earlier production of abaxial trichomes and flowering phenotypes, as well as enhanced salt stress tolerance compared to the wild-type phenotype. These findings suggest that NF-YA4a positively regulates the juvenile-adult phase transition and salt stress tolerance in Pyrus. This research may provide a foundational basis for future studies on the regulatory mechanisms involved in juvenile-adult phase changes and salt stress responses in Pyrus trees.

The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia) 'PY-9' was identified and used as the material for anatomical analysis. 'PY-9' grew to half the tree height of the normal cultivar 'Zhengdu', along with fewer internodes and shorter length. Significant differences in growth rate between 'PY-9' and 'Zhengdu' were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar. 'PY-9' showed a higher photosynthetic rate than 'Zhengdu'. Anatomical analysis showed that 'PY-9' had higher area ratios of both phloem and xylem and more developed vascular tissues than 'Zhengdu'. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity in 'Zhengdu' than in 'PY-9', which could contribute to the more vigorous growth of 'Zhengdu'. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity.

This experiment was conducted to study the effects of different lactic acid bacteria treatments on nutritional quality,fermentation characteristics and aerobic stability of hybrid Broussonetia papyrifera silage,and to provide technical reference for the development and utilization of hybrid Broussonetia papyrifera. There were7 treatments as follows:the CK treatment was supplemented 10 mL/kg deionized water,the LP treatment was supplemented 5×106CFU/g FM Lactobacillus plantarum,the LB treatment was supplemented 5×106CFU/g FM Lactobacillus brevis,the EF treatment was supplemented 5 × 106CFU/g FM Enterococcus faecalis,the LP+EF treatment was compound supplemented 5×106CFU/g FM Lactobacillus plantarum and Enterococcus faecalis（1∶1）,the LP+LB treatment was compound supplemented 5×106CFU/g FM Lactobacillus plantarum and Lactobacillus brevis（1∶1）,and the LP+LB+EF treatment was compound supplemented 5×106CFU/g FM Lactobacillus plantarum,Lactobacillus brevis and Enterococcus faecalis（1∶1∶1）,each treatment contained 5replicates,fermentation for 60 days. The results showed as follows:1)the dry matter content of LP and LP+LB+EF treatments was significantly higher than that of CK treatment（P＜0.05）. The neutral detergent fiber content of LP,LB,EF,LP+LB and LP+LB+EF treatments was significantly lower than that of CK treatment（P＜0.05）. The crude protein content of EF and LP+LB+EF treatments was significantly higher than that of CK treatment（P＜0.05）. The water-soluble carbohydrates content of LP,LB and EF treatments was significantly lower than that of CK treatment（P＜0.05）. 2)The pH of LP and LP+LB+EF treatments was significantly lower than that of CK treatment（P＜0.05）. The ammoniacal nitrogen content of CK treatment was significantly higher than that of other treatments（P＜0.05）. The lactic acid content of LP treatment was significantly higher than that of EF,LP+LB and CK treatments（P＜0.05）. The acetic acid content of LB and LP+LB treatment was significantly higher than that of other treatments except LP+LB+EF treatment（P＜0.05）.The propionic acid content of LP,LB and LP+LB treatment was significantly lower than that of CK treatment（P＜0.05）. The lactic acid bacteria population of LP+LB treatment was significantly higher than that of other treatments（P＜0.05）. 3)After 5 days of aerobic exposure,the mold population of LP+LB treatment was the lowest,and the aerobic bacteria population of LP+LB+EF treatment was the lowest. The aerobic stability order from high to low was LB treatment ＞ LP+LB treatment ＞ LP+LB+EF treatment ＞ CK,LP,EF and LP+EF treatments. To sum up,adding epiphytic lactic acid bacteria to hybrid Broussonetia papyrifera silage obviously improve the nutritional quality,fermentation characteristics and aerobic stability.[Chinese Journal of Animal Nutrition,2023,35（4）:2702-2710]

This study explored the effects on the P content of various organs and parts of alfalfa and soil available P content, of inoculation with arbuscular mycorrhizal fungi（AMF） and phosphorus-solubilizing bacteria（PSB） in different proportions with and without phosphorus（P） application. The ultimate aim of this research was to provide a theoretical basis for improving the efficiency of phosphorus fertilizer utilization for the production of high-quality, high-yielding alfalfa by formulating a scientifically based and appropriate fertilization system. A pot experiment was conducted with a randomized block design. There were 10 treatments in total, consisting of five inoculation ratios（AMF∶PSB） treatments [3∶7（J 1 ）, 4∶6（J 2 ）, 5∶5（J 3 ）, 6∶4（J 4 ） and 7∶3（J 5 ）] and two phosphorus（P 2 O 5 ） application levels [0（P 0 ） and 150 mg·kg -1 soil（P 1 ）]. The plant P content, soil P content, dry matter yield of alfalfa and P use efficiency were measured. Correlation analyses were conducted to clarify the relationship between the alfalfa plant P content, soil P content, dry matter yield, and P use efficiency. The best combination of bacteria and phosphorus conditions for promoting alfalfa growth was identified using a membership function analysis. It was found that, under the same inoculation conditions, the contents of plant P, stem P, leaf P, flower P, root P, upper 1/3 plant P of aboveground part, middle 1/3 plant P of aboveground part, lower 1/3 plant P of aboveground part, rhizosphere soil available P, non-rhizosphere soil available P and the dry matter yield were all significantly greater in the P 1 treatments than in the P 0 treatments（P＜0. 05）. Under the same P application conditions, the plant P, stem P, leaf P, flower P, root P, upper 1/3 plant P of aboveground part, middle 1/3 plant P of aboveground part, lower 1/3 plant P of aboveground part were all significantly greater in the J 5 treatment than in the J 1 , J 2 , J 3 and J 4 treatments（P＜0. 05）, and the dry matter yields of J 1 , J 2 , J 3 and J 4 treatments were significantly greater than that of the J 5 treatment（P＜0. 05）. The P content of each organ of alfalfa ranked: flower＞leaf＞root＞stem; the P content of each plant fraction ranked: upper 1/3 plant of aboveground part＞middle 1/3 plant of aboveground part＞lower 1/3plant of aboveground part and the soil available P content ranked: rhizosphere soil＞non-rhizosphere soil. Across the bacterial-P coupling treatments, the total dry matter yield and P use efficiency of alfalfa both reached their maximum values(49. 31 g·pot -1 and 27. 23%, respectively) in the J 4 P 1 treatment. Correlation analysis showed that the P content of alfalfa plants, rhizosphere soil P content, non-rhizosphere soil P content, P use efficiency and total dry matter yield were positively correlated with each other. Among these, total dry matter yield was highly significantly positively correlated with rhizosphere soil available P content and P use efficiency（P＜0. 01）, and was significantly positively correlated with non-rhizosphere soil available P content（P＜0. 05）. According to the ranking of membership function values, the top three were J 1 P 1 , J 3 P 1 and J 4 P 1 . Therefore, a phosphorus application rate of 100mg·kg -1 P（P 2 O 5 ） and double inoculation of AMF and PSB in the ratio 3∶7 can greatly improve alfalfa P nutrition level, thereby increasing the dry matter yield.

[目的]探究连续3年施用磷肥后对紫花苜蓿叶片养分吸收量、光合色素含量、气孔开度及抗氧化系统的影响,为紫花苜蓿高效生产提供科学施肥方法.[方法]2019-2021年,以'WL366HQ,紫花苜蓿为试验材料,在石河子大学牧草试验站连续开展为期3年的田间试验.试验设置磷肥添加量分别为0(对照,CK)、50 kg·hm-2(低磷,LP)、100kg·hm-2(中磷,MP)和150kg·hm-2(高磷,HP),共4个磷肥处理.于苜蓿初花期进行取样,测定干草产量、叶片氮磷含量、色素含量、气孔开度、抗氧化酶活性以及氧化物质等指标.[结果]连续施加磷肥3年后,叶片的氮磷含量、光合色素含量及气孔开度显著增加(P＜0.05),其中叶片氮磷含量在中磷处理下最高,分别为54.74和2.99 g·kg-1;叶绿素a和叶绿素b的含量均在中磷处理下最高,类胡萝卜素含量在低磷或中磷处理下最高,且均在CK最低;气孔开度在中磷处理下达到最大,且显著高于CK(P＜0.05).因此,磷肥对苜蓿叶片的形态和生理特性有不同的影响,且中磷处理显著影响苜蓿叶片的光合生理特性(P＜0.05).合理添加磷肥可以提高苜蓿叶片抗氧化酶的活性并降低氧化物质的含量,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性均在中磷处理达到最高,分别为162.55、406.40和147.13 U·g-1,且显著高于CK(P＜0.05);丙二醛(MDA)、过氧化氢(H202)和脯氨酸(Pro)含量均在中磷处理下最低,分别为2.38和1.04μmol·g-1以及56.85μg·g-1.根据Pearson相关性分析可知,苜蓿叶片全氮和全磷含量与叶绿素含量、类胡萝卜素含量、气孔开度、SOD和POD活性显著正相关(P＜0.05),与MDA和H2O2含量呈显著负相关(P＜0.05).综合评价表明,施磷处理的主成分得分排序为:中磷＞高磷＞低磷＞对照.[结论]合理施加磷肥增加苜蓿叶片的营养特性及光合生理特性,从而避免其他环境因子带来的胁迫作用,增强苜蓿的适应能力,使苜蓿更好地适应外界环境变化.综合考虑紫花苜蓿的叶片形态、光合生理特性及抗氧化酶和氧化物质等因素,本试验施磷量为100kg·hm-2较为适宜.

The aim of this study was to investigate the effect of arbuscular mycorrhizal fungi inoculation under different levels of phosphorus application on the aboveground biomass and nutritional quality of alfalfa, and to identify the optimal phosphorus inoculation mode for alfalfa. A two-factor completely randomized design was used, with four levels of phosphorus application（P 2 O 5 ）: 0, 50, 100 and 150 mg/kg, and four treatments under each level of phosphorus application: single inoculation with Funneliformis mosseae, Glomus etunicatum, mixed strains, and uninfected fungus.The results showed that, within the same fungal treatment, the aboveground biomass, plant height, stem diameter, growth rate, crude protein content, relative feeding value and soluble sugar content of alfalfa initially increased and then decreased with increasing phosphorus application rates. These parameters reached their highest values in the P 2 treatment, and P 1 , P 2 and P 3 treatments were significantly better than P 0 （P＜0.05）. Within the same phosphorus application, the aboveground biomass, plant height, stem diameter, growth rate, crude protein content, relative feeding value and soluble sugar content of alfalfa in the simultaneous inoculation of F. mosseae and G. etunicatum and the single inoculation of either F. mosseae or G. etunicatum were significantly greater than those of non-inculcated alfalfa（P＜0.05）. However, the contents of neutral detergent fiber and acid detergent fiber in alfalfa were opposite to the above indicators. In conclusion, under the conditions of aphosphorus application rate of 100 mg/kg, simultaneous inoculation with F. mosseae and G. etunicatum significantly increased the dry matter yield of alfalfa and improve its nutritional quality.

为探讨不同施磷水平下接种丛枝菌根真菌(AMF)和解磷细菌(PSB)对紫花苜蓿光合特性及生物量的影响,提高紫花苜蓿的磷肥利用效率及优质高产研究、制定科学合理的施肥制度提供理论依据.采用随机区组设计进行盆栽试验,设置4个接菌处理[未接菌对照组(CK,J0)、单接巨大芽孢杆菌(Bm,J1)、单接摩西管柄囊霉(Fm,J2)和双接菌(Bm×Fm,J3)]和4个施磷(P2O5)水平[0(P0)、50(P1)、100(P2)和150 mg·kg-1(P3)],共计16个处理.通过对紫花苜蓿的叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、胞间CO2浓度(Ci)、光能利用效率(LUE)、水分利用效率(WUE)、叶绿素[Chl(a+b)]含量和生物量进行测定,并通过相关性分析明确紫花苜蓿各光合指标与生物量之间的关系,通过隶属函数分析筛选出有利于促进紫花苜蓿生物量形成的最佳菌磷耦合模式,明确施磷和接种解磷菌对紫花苜蓿光合特性及生物量的影响.结果表明:相同接菌处理下,紫花苜蓿叶片Pn、Tr、Gs、LUE、WUE、Chl(a+b)和生物量均随施磷水平的提高而呈先升高后降低的趋势,在P2处理达到最大值,且施磷处理均显著大于未施磷处理(P<0.05),而Ci则随施磷水平的提高呈逐渐降低的趋势,且施磷处理均显著低于未施磷处理(P<0.05);相同施磷处理下,紫花苜蓿叶片的Pn、Tr、Gs、LUE、WUE、Chl(a+b)和生物量均为接菌处理显著大于未接菌处理(P<0.05),且除Chl(a+b)外,Pn、Tr、Gs、LUE、WUE、Chl和生物量均为在J3处理达到最大值,而Ci显著低于未接菌处理(P<0.05),在J3处理达到最小值.相关性分析表明,Ci与Pn、Tr、Gs、LUE、WUE、Chl(a+b)和生物量均呈显著负相关(P<0.05),其余各指标间均两两呈显著正相关(P<0.05).根据隶属函数值大小排序,排名前3位的分别为J3P2、J2P2和J3P1.双接种丛枝菌根真菌与解磷细菌,并施磷100 mg·kg-1的菌磷耦合模式,能够显著提高紫花苜蓿叶片的光合特性并增加叶绿素含量,进而有利于促进紫花苜蓿生物量的形成.

以紫花苜蓿WL354HQ为对象,采用施磷和接种芽孢杆菌双因素完全随机设计,设置单接种胶质芽孢杆菌(J1)、单接种巨大芽孢杆菌(J2)、混合接菌(J3)和不接菌(J0)4个施菌处理以及不施磷(P0)和施100 mg/kg磷(P1)2个施磷处理,共8个处理,探究同一施磷条件下接种解磷细菌对紫花苜蓿生长及光合特性的影响,以筛选紫花苜蓿优质高产的最优菌磷配施模式.结果表明,在相同接菌条件下,施磷提高了苜蓿的株高、茎粗、生长速度、地上生物量、叶绿素含量、叶片净光合速率(Pn)、叶片气孔导度(Gs)和叶片蒸腾速率(Tr),降低了苜蓿的茎叶比和叶片胞间CO2浓度(Ci).在相同施磷条件下,接菌处理提高了苜蓿的株高、茎粗、生长速度、地上生物量、叶绿素含量和光合参数(Pn、Gs、Tr、Ci).隶属函数分析表明,8个处理9个指标的综合评价值为J3P1＞J1P1＞J2P1＞J3P0＞J2P0＞J0P1＞J1P0＞J0P0,且在同一施磷条件下双接菌处理＞单接菌处理＞不接菌处理,J3P1处理模式得分最高.综上所述,双接胶质芽孢杆菌、巨大芽孢杆菌和施磷100 mg/kg能够有效提高紫花苜蓿的光合性能并促进其生长.

The effects of compound starter on nutrient quality， fermentation quality and rumen degradation rate of sunflower by-product micro-storage were studied. The experiment was divided into two treatments， namely control （CK） and compound fermentation agent （SY）. The compound fermentation agent was: Lactobacillus plantarum 9.3×10 5 cfu·g -1 ， molasses 3.57%， urea 0.3%， cellulase 0.14%， respectively. After 60 days of fermentation， the bags were opened for nutrition， fermentation quality， microbial quantity and rumen degradation rate analysis. The results showed as follows :（1） the contents of WSC， DM， CP， LA and NH 3 -N and the number of LAB in SY treatment were significantly higher than those in CK treatment （P＜0.05）; The content of NDF and ADF， pH value and quantity of Mold and Yeast were significantly lower than those of CK treatment （P＜0.05）. （2） DMD and OMD of SY treatment at 24 and 48 h were significantly higher than those of CK treatment （P＜0.05）. Conclusion: Adding compound starter to sunflower by-product silage can significantly improve fermentation quality and promote utilization of ruminants.

以昆仑山沙区紫花苜蓿(Medicago sativa)根际与非根际(0-40 cm)土壤为研究对象,基于高通量测序技术分析真菌群落结构及多样性与土壤理化性质的关系,以揭示紫花苜蓿种植对该区域土壤生态的潜在影响.土壤理化性质分析结果表明:根际土壤含水量、全氮、碱解氮、速效钾和有机质含量整体均显著高于非根际(P＜0.05).通过对20 个土壤样品进行高通量测序,共检测到 12 门 40 纲 91 目 190 科 384 属 625 种 1487 个操作性分类单元(OTUs).根际土壤群落丰富度和多样性整体低于非根际.子囊菌门(Ascomycota)和担子菌门(Basidiomycota)为共有优势菌门;赤霉菌属(Gbberella)、Filobasidiu和Naganishia为共有优势菌属.枝孢属(Cladosporium)、链格孢属(Alternaria)和刺孢属(Phaeomycocentrospora)是非根际真菌群落的关键类群;Naganishia、Vishniacozyma、Cystofilobasidium、赤霉菌属和镰孢菌属(Fusariella)是根际真菌群落的关键类群.冗余分析表明土壤有效磷、有效钾、碱解氮和电导率是影响土壤真菌群落分布的关键因素.赤霉菌属与土壤电导率和土壤有机质具有显著相关性(P＜0.05),Naganishia、Vishniacozyma和Cystofilobasidium与土壤有机质、速效钾和碱解氮具有显著相关性(P＜0.05),链格孢属与枝孢属与土壤全磷、有效磷、土壤含水量和全氮具有显著相关性(P＜0.05).综上,昆仑山沙区紫花苜蓿种植通过提高土壤养分在根际的富集以及促进有益真菌丰度,以达到促进土壤生态环境的稳定.

Cork spot is a common physiological disorder in pear fruits, which has been found in some pear cultivars. Mineral nutrition imbalance in fruit is regarded as the principal influence factor for disorder incidence, with some ongoing confusion and controversy. In our research, we explored the cork spot characteristics in Japanese pear 'Akizuki' (Pyrus pyrifolia Nakai), adopted metabolome and mineral content analysis for healthy and disordered fruits, and made a correlation analysis of mineral and metabolites. Cork spots are mainly distributed on the outer flesh beneath the fruit peel. In cork spotted tissues, superoxide (SOD) and peroxidase (POD) activities, as well as malondialdehyde (MDA) content, increased. A total of 1024 known metabolites were identified from all the samples and more changes in metabolism were detected between normal and cork spotted flesh tissues. Correlation analysis displayed that Ca, especially the Mg/Ca in fruits, could be used to predict whether an orchard will develop cork spot disorder; Mg and B were associated with the appearance of symptoms, and the contents of Zn, Fe, and Mg, as well as Mg/B and Zn/B, might be strongly tied to the formation of cork spots in pears. This research provides insights into the occurrence of pear cork spot disorder and clarifies the role of minerals.

本研究对麻叶荨麻(Urtica cannabina)青贮饲料中优势乳酸菌进行分离鉴定,为改善麻叶荨麻青贮品质提供理论依据.经传统微生物和分子生物学鉴定,结果表明:麻叶荨麻青贮中共分离得到 11 株优势乳酸菌,其中 1 株为格氏乳球菌(Lactococcus garvieae,QM7),1 株为粪肠球菌(Enterococcus faecalis,QM16),1 株为鹑鸡肠球菌(Enterococcus gallinarum,QM35),2 株为铅黄肠球菌(Enterococcus casseliflavus,QM13、QM32),3 株为类肠膜魏斯氏菌(Weissella paramesenteroides,QM6、QM8、QM10),3 株为戊糖片球菌(Pediococcus pentosaceus,QM9、QM11、QM12).分离出的乳酸菌均能在 4～45℃以及 3.0％和 6.5％的 NaCl条件下良好生长;而所有菌株在 pH为 3 时不生长,在 pH为3.5～9 呈现生长或微弱生长.研究结果表明菌株QM7 和QM11 在培养至 24 h时pH可下降到 3.82 和 3.78,OD600 值为2.12 和 2.06,表现出最强的产酸能力和生长速率,可作为后期调控麻叶荨麻青贮的菌剂应用.

为了明确 2,3-二羟基苯甲醛与异丙甲草胺混用的除草增效效果,以稗(Echinochloa crusgalli)和反枝苋(Amaranthus retroflexus)为供试植物,采用琼脂处理法通过等效果线和共毒系数测定了 2,3-二羟基苯甲醛与异丙甲草胺混用的联合效应.结果表明,2,3-二羟基苯甲醛 5 个浓度(0、3.125、6.25、12.5、25 mg/L)与异丙甲草胺 5个浓度(0、0.8、4、20、100 mg/L)两两混配共 25 个处理对两种杂草幼苗胚根(种子根)和胚轴(胚芽鞘)的生长均有很好的抑制增效作用,抑制率为 90%时的等效果点均在相加线的下方.异丙甲草胺与 2,3-二羟基苯甲醛质量比为28∶1 对稗胚芽鞘和种子根的共毒系数分别为 155.07 和 188.13,异丙甲草胺与 2,3-二羟基苯甲醛质量比为 39∶1对反枝苋胚轴和胚根的共毒系数分别为 164.95 和 147.34,均表现为很好的增效效果.

The quality of seedlings is an important factor for development of the pear industry. A strong seedling with few branches and suitable internodes is ideal material as a rootstock for grafting and breeding. Several branching mutants of pear rootstocks were identified previously. In the present study, 'QAU-D03' (Pyrus communis L.) and it's mutants were used to explore the mechanism that affects branch formation by conducting phenotypic trait assessment, hormone content analysis, and transcriptome analysis. The mutant plant (MP) showed fewer branches, shorter 1-year-old shoots, and longer petiole length, compared to original plants (OP), i.e., wild type. Endogenous hormone analysis revealed that auxin, cytokinin, and jasmonic acid contents in the stem tips of MP were significantly higher than those of the original plants. In particular, the jasmonic acid content of the MP was 1.8 times higher than that of the original plants. Transcriptome analysis revealed that PcCOI1, which is a transcriptional regulatory gene downstream of the jasmonic acid signaling pathway, was expressed more highly in the MP than in the original plants, whereas the expression levels of PcJAZ and PcMYC were reduced in the MP compared with that of the original plants. In response to treatment with exogenous methyl jasmonate, the original plants phenotype was consistent with that of the MP in developing less branches. These results indicate that jasmonic acid negatively regulates branch growth of pear trees and that jasmonic acid downstream regulatory genes play a crucial role in regulating branching.

为探讨施磷条件下不同比例接种丛枝菌根真菌(AMF)与解磷细菌(PSB)对紫花苜蓿生长及生产性能的影响,明确苜蓿农艺性状、地上生物量与营养品质的关系,筛选出适合苜蓿生长的最佳接菌比例.接菌比例(AMF∶PSB)设置 5 个梯度,分别为 3∶7(J1)、4∶6(J2)、5∶5(J3)、6∶4(J4)和7∶3(J5),设置2个施P2O5梯度:0(P0)和100mg/kg(P1),共计10个处理,采用随机区组设计,对紫花苜蓿农艺性状、地上生物量及营养品质进行测定.结果表明:相同接菌条件下,紫花苜蓿的株高、茎粗和粗蛋白含量为P1处理大于P0处理,生长速度和总地上生物量为P1处理显著大于P0处理(P＜0.05),而茎叶比则表现为P1处理显著小于P0处理(P＜0.05).P0条件下,苜蓿各茬次茎粗、生长速度、总地上生物量和中性洗涤纤维均表现为J1、J2、J3和J4处理显著大于J5处理(P＜0.05);P1条件下,苜蓿各茬次生长速度和总地上生物量均为J1、J2、J3和J4处理显著大于J5处理(P＜0.05).相关性分析表明,株高、茎粗、生长速度和地上生物量四者中两两互为极显著正相关(P＜0.01),中性洗涤纤维与酸性洗涤纤维呈极显著正相关(P＜0.01).根据模糊相似优先比排序,排名前三的处理分别为J1P1、J2P1和J4P1.在100mg/kg的施磷(P2O5)条件下,以3:7的比例复合施入AMF和PSB能够有效提高苜蓿的生产性能.

[目的]研究新疆北疆地区规模化牧场全株玉米青贮饲料品质及生产水平,分析全株玉米青贮饲料品质,为推动新疆北疆地区青贮饲料高效生产提供依据.[方法]采集新疆北疆地区18个不同规模牧场中窖贮全株玉米青贮饲料,分析营养品质、发酵品质、霉菌毒素含量,运用模糊相似优先比法综合价值评定各规模化牧场全株玉米青贮饲料品质.[结果]各牧场青贮营养品质及发酵品质整体水平达到国家二级标准,所有牧场的霉菌毒素含量均符合国家限量标准.排名前三位的牧场为R＞I＞Q(存栏量在1 000头以上的牧场),排名后三位的牧场为N＞L＞H(存栏量在500头以下的牧场).[结论]新疆北疆地区规模化牧场全株玉米青贮品质整体水平良好,但不同规模牧场之间存在差距,存栏量在1 000头以上的牧场整体水平优于存栏量在500头以下的牧场;各牧场全株玉米青贮品质主要受青贮玉米品种、地区气候特性、牧场规模的影响.

The aim of this experiment was to explore the bacteria agent adding methods for improve the grape branch and leaf silage fermentation quality,and then prepare the wrapped package grape branch and leaf silage,clear the grape branch and leaf silage replacing part of corn silage and corn straw on the growth performance,slaughter performance,serum biochemical indexes and economic benefits of Kazakh sheep,provide the basis for the rich straw resources. Four treatments were used in the fermentation experiment,CK treatment（without adding any bacterial agent）,EH treatment（supplemented with 5×10~6CFU/g FM Enterococcus hirae）,M treatment（supplemented with 3% FM molasses）,EHM treatment（combined supplemented with 5×10~6CFU/g FM Enterococcus hirae and 3% FM molasses）,after 60 days of fermentation at room temperature,the bag was opened to detect the nutritional composition,fermentation quality and main microbial number. In the feeding experiment,twenty 3-month-old Kazakh sheep with similar body weight[（30.0±0.7）kg]were randomly divided into 2 groups with 10 sheep per group. Sheep in 2 groups were fed corn silage and corn straw type total mixed ration（CY group）and grape branch and leaf silage type total mixed ration（SP group）,respectively. The pre-experimental period lasted for 7 days,and the experimental period lasted for 60 days. The results showed as follows:1)compared with the grape branch and leaf raw material,the contents of neutral detergent fiber（NDF）,acid detergent fiber（ADF）and pH and mold number of EHM treatment were significantly decreased（P＜0.05）,the lactic acid content and lactic acid bacteria number were significantly increased（P＜0.05）,and the silage effect of EHM treatment was optimal. 2)There were no significant differences on growth performance,slaughter performance and serum biochemical indexes between CY group and SP group（P＞0.05）. 3)Compared with CY group,the feed cost of SP group was significantly decreased（P＜0.05）,and the fattening profit was significantly increased（P＜0.05）. In conclusion,the combined addition of Enterococcus hirae and molasses can effectively improve the fermentation quality of grape branch and leaf silage,inhibit the growth of Escherichia coli and mold,and promote the propagation of lactic acid bacteria and the content of lactic acid. In addition,the grape branch and leaf silage replacing part of corn silage and corn straw in the diet of fattening Kazakh sheep can save the feed cost and increase economic benefits.[Chinese Journal of Animal Nutrition,2023,35（3）:1771-1780]

In order to investigate the effects of phosphorus application and inoculation with arbuscular mycorrhizal fungi on dry matter yield,phosphorus content and soil alkaline phosphatase activity （AKP） of alfalfa,the soil available phosphorus and total phosphorus of alfalfa under different inoculation and phosphorus application regimes were analyzed.The relationship between alfalfa dry matter yield and inoculation and phosphorus application and the relationship between yield and various other indicators were further clarified.In this experiment,a two-factor completely randomized design was adopted.Four inoculation treatments were included:Single inoculation with Funneliformis mosseaes （Fm,T 1 ）,Glomus etunicatum （Ge,T 2 ）,double inoculation （Fm×Ge,T 3 ） and no fungal treatment （CK,T 0 ）.As the second factor,four phosphorus application levels were included:P 2 O 5 0 （P 0 ）,50 （P 1 ）,100 （P 2 ）,150 （P 3 ） mg·kg -1 making a total of 16 treatments defining the fungus-phosphorus interaction.Each treatment was repeated 10 times.It was found that:1) With the same inoculation treatment,the dry matter yield,phosphorus content of leaves,stems and roots,soil pH value and alkaline phosphatase activity of alfalfa all initially increased first and then decreased with increasing phosphorus application.All reached the maximum value in the P 2 treatment,and the yield of the alfalfa P fertilization treatment was significantly greater than the no P fertilization treatment （P＜0.05）.The content of available phosphorus and total phosphorus in rhizosphere and non-rhizosphere soil increased gradually with increasing phosphorus application rate,and the agronomic efficiency of alfalfa phosphorus fertilizer showed a decreasing trend with increase in phosphorus application rate.2) With the same inoculation treatment,dry matter yield,phosphorus content of plant leaves,stems and roots,rhizosphere and nonrhizosphere soil available phosphorus,total phosphorus content,phosphorus use efficiency,soil alkaline phosphatase activity was significantly greater than that of uninoculated treatment （P＜0.05）,and the soil total phosphorus and available phosphorus contents were maximised in the T 3 treatment.The pH value of soil in the double inoculation treatment was significantly lower than that in the uninoculated treatment （P＜0.05）,and reached the minimum value in the T 3 treatment.Based on these results,the phosphorus application （P 2 O 5 ） treatment of 100 mg·kg -1 ,coupled with the mixed inoculation of the two arbuscular mycorrhizal fungi could could be recommended and this treatment effectively promoted the absorption of available phosphorus in the soil by the roots of alfalfa plants,improved the efficiency of phosphorus use,and enhanced dry matter yield in alfalfa.