Hepatic differentiation of mesenchymal stem cells derived from rats in three-dimensional microenvironment formed by hanging drops

AIM: To establish an optimal differentiated three-dimensional microenvironment formed by hanging drops for the high efficiency of hepatic differentiation from rat mesenchymal stem cells(rMSCs).METHODS: rMSCs were cultured in the hanging drops, which provided a three-dimensional microenvironment, for 21 days in the presence of hepatocyte growth factor(HGF, 20 μg/L). The expression of albumin(ALB), alpha-fetoprotein(AFP) and cytokeratin-18(CK-18) was detected by RT-PCR and immunofluorescence staining at 7th, 14th and 21st days. The secretion of albumin in the culture supernatants was measured by ELISA. RESULTS: rMSCs were aggregated in spheroid with a tubiform medium altitude in the center. In rMSCs cultured in the hanging drops with HGF, the expression of albumin, AFP and CK-18 was all detectable by RT-PCR and immunofluorescence staining at 7th day. The production of albumin in the cells cultured in the hanging drops with HGF was 50.25±5.32, 55.03±7.45 and 54.92±3.18(ng·dish^-1·d^-1) at 7th, 14th and 21st days, respectively, significantly higher than that in the cells in the plate cultivation with or without HGF induction at corresponding time points(P<0.01).CONCLUSION: In the presence of HGF, rMSCs are induced to differentiate into hepatocyte-like cells cultured in the hanging drops, where the three-dimensional spheroidal cultures are promising microenvironment for hepatic transdifferentiation of MSCs.     

草石蚕块茎腐烂病病原菌鉴定(英文)

Identification of tuber rot pathogen on Stachys sieboldii Miq. was carried out with morphological and molecular methods for the first time. Though the observation of morphology and color of the colonies,morphology of macroconidia, microconidia and chlamydospores, it was preliminarily identified as Fusarium oxysporum. The fungus DNA was amplified by PCR with the universal primers of fungal rDNA ITS1 and ITS4, and sequenced. The sequencing results were logged in GenBank to BLAST, and all of the molecular detections and morphologic observations showed that the pathogen was F. oxysporum.     

芦笋茎枯病拮抗菌KJ-1的筛选及其对土壤微生物区系的影响

为探索芦笋茎枯病的生物防治技术,本文从设施芦笋土壤中分离筛选到1株性状稳定的拮抗性菌株,经形态学、生理生化和分子生物学特征的综合鉴定,将该菌株归为Bacillus cereus,命名为KJ-1。KJ-1发酵液对芦笋茎枯病菌丝生长有较强的抑制作用,稀释4倍时对菌丝生长抑制率达65%。将KJ-1发酵液灌根施于设施芦笋地,明显提高了土壤可培养微生物数量,微生物总数为CK的1.38倍,细菌、真菌数量均为CK的1.52倍,B/F值比CK有略微上升;同时,土壤微生物代谢类群多样性也有一定的变化,AWCD值和物种丰富度（S）都高于CK,其中AWCD值与CK的差异达极显著水平（P<0.01）,说明施用KJ-1发酵液提高了设施芦笋土壤的微生物数量和生物多样性,对土壤健康有利。     

欧洲甜樱桃的组织培养与快速繁殖技术

以欧洲甜樱桃当年萌生嫩枝为外植体,研究不同种类和不同浓度生长调节物质对初代、增殖和生根培养的影响。结果表明：MS＋6-BA1．5mg／L＋IAA0．3mg／L为欧洲甜樱桃最佳初代培养基,茅诱导率达89％,在MS培养基中分别添加0．2mg／L细胞分裂素（6-BA）和0．1mg／L生长素（IAA）增殖效果最佳;组培苗在1／2MS＋IBA0．2mg／L培养基上根诱导效果最好。     

有效积温对中华常春藤生长的影响

通过调查中华常春藤的生境和测量茎的生长情况,总结了中华常春藤的种植特点和分枝方式,同时利用SPSS软件的回归分析建立回归模型,并根据建立的模型用Excel软件绘制坐标图。结果表明:中华常春藤主枝生长完毕所需的有效积温为2 718.34℃/d;茎伸长量随有效积温延续的变化呈"S"形曲线,而茎伸长速度变化趋于钟罩型单峰曲线。再利用此结果估算出:在理想的生长条件下采用三角形定植方式定植中华常春藤为宜,并且植株与植株之间的最佳定植密度为510 mm×510 mm。     

70%代森联DF对桃褐腐病防治效果

以不同浓度代森联DF处理花后10 d的桃树,调查其对桃褐腐病的防治效果。结果表明:在桃树花后10 d到果实成熟前3周喷施70%代森联DF对桃树生长期和贮藏前期的褐腐病有明显的防治作用,以875～1 166.7 mg/kg为宜。在供试药剂量内对桃树安全。     

无籽西瓜茎段组织培养与嫁接育苗技术研究

以无籽西瓜(Citrullus lantus)墨童无菌苗的茎段为外植体,对组织培养与嫁接育苗技术研究进行了研究。结果表明：不同消毒剂对种胚萌发有一定影响,其中消毒剂二氧化氯250mg/L 处理有利于种胚萌芽,萌发率达82.5%;子叶芽诱导的最佳培养基配方为1/2MS +IAA0.2 mg/L+蔗糖30g/L+琼脂7g/L;不同激素浓度对芽丛增殖和单芽生根也有一定影响,其中MS +6-BA0.4 mg/L +IAA0.2 mg/L +蔗糖30g/L+琼脂7g/L继代培养增殖率最高;MS+NAA0.5mg/L生根率最高(96.2%)。     

大豆根腐主要病原菌毒素致病作用的初步研究

研究了4种大豆根腐主要病原菌毒素毒性大小,毒素对大豆幼根细胞膜透性的影响,不同病原菌毒素与毒素互作以及毒素与病原菌共同作用对大豆根部发病的影响。结果表明：4种病原菌中,尖镰孢菌毒素毒性最强,并随着浓度增加,对大豆根细胞膜透性的影响增强。四种毒素互作对大豆幼根毒害作用的正交试验得出,尖镰孢菌毒素在其过程中起着重要的作用。病原菌与毒素共同接种时,尖镰孢菌毒素处理的发病加重,病情指数比不接毒素处理的上升10%左右。     

Characterization of a new fungal antagonist of Phytophthora capsici

The capacity of many microorganisms for antagonism towards pathogens is unknown and previously uncharacterized species may be potentially useful in this respect. This work presents the evaluation of the capacity of a previously uncharacterized Ascomycete, denominated here as UA to protect chili pepper (Capsicum annuum) against Phytophthora capsici, and other soil-borne plant pathogens and establishes the role of UA as a biocontrol agent. Inoculation of UA 2 days before the inoculation of P. capsici led to 77.8% survival of pepper plants. Simultaneous confrontation of both microorganisms in vitro led to 53.1% growth inhibition of P. capsici, while the inoculation of P. capsici 3 days after the inoculation with UA improved growth inhibition up to 73%. Simultaneous confrontation in vitro of UA with Fusarium oxysporum and Fusarium solani led to 41.2 and 50% growth inhibition, respectively, but had no effect on Rhizoctonia solani or a binucleate Rhizoctonia isolate. Moreover, formation of zoosporangia and the germination of zoospores were completely inhibited by exposure to undiluted filter sterilized filtrate. UA produces septate mycelia, but could not be classified in detail due to a lack of spores or reproductive structures. However, sequencing of Internal Transcribed Spacer 1, 2 and the 5.8S genes indicated that this fungus is a member of the Ascomycetes.     

诱抗剂对切花百合生长、抗病性及相关酶活性的影响

分别用DL-β氨基丁酸(DL-β-aminobutyric acid,BABA)、移栽灵(Isolane,有效成分:10%稻瘟灵,10%噁霉灵)、表油菜素内酯(epibrassino1ide,epi-BR)、水溶性壳聚糖(hydrosoluble chitosan,OS)、苯并噻二唑(acibenzolar,BTH)、脱落酸(abscisic acid,ABA)、MgO和NH4Cl浸泡切花百合种球根部与鳞片,通过盆栽、田间种植和鳞片包埋,测定其生长指标,POD、PAL、PPO等防御酶活性以及根腐病的病情指数。结果表明,各种试剂处理后,植株叶片防御酶活性增加,株高、叶片数、茎粗等生长性状得到改善,子球鳞片数增加,病情指数减小。其中OS400mg·L-1处理的百合在各个生理指标以及抗病性上明显高于对照。