紫花苜蓿耐羟脯氨酸变异体的筛选及抗性研究

以紫花苜蓿Medicago sativa（敖汉苜蓿和龙牧801苜蓿）种子为材料,培养无菌幼苗。以无菌苗的茎段为外植体,诱导愈伤组织,并用叠氮化钠（NaN3）200 mg/L对愈伤组织进行诱变,以脯氨酸类似物L 羟脯氨酸（L Hyp）作为选择压力,通过在含半致死浓度的L Hyp（8 mmol/L）选择培养基及无L Hyp培养基上交替培养,分离出抗L Hyp的愈伤组织变异体。该变异体以高脯氨酸含量为特征,其脯氨酸含量分别比原型高2.84倍（敖汉）和3.17倍（龙牧801）,同时进一步测定其生理生化指标,发现变异体的可溶性糖含量是对照的1.56（敖汉）倍和1.76倍（龙牧801）,过氧化物酶（POD）活性与原型相比差异极显著。分别对2种苜蓿愈伤组织进行聚乙二醇（PEG）（敖汉）和低温（龙牧801）胁迫处理,结果显示,变异体具有更强的抗逆性（抗旱、抗寒）,能更好的适应恶劣（干旱、寒冷）的生长环境。     

藜营养器官水浸提液对紫花苜蓿的化感作用研究

采用纸培法研究不同稀释倍数的藜营养器官水提液对苜蓿种子萌发及幼苗生长的影响,以探明藜对紫花苜蓿种子萌发的影响.结果表明:藜营养器官水浸提物低浓度处理时,紫花苜蓿种子发芽率均有所提高,但与对照差异不显著(P＞0.05),随着浓度的增加,抑制作用加强,发芽率明显下降,与对照和低浓度差异极显著(P＜0.01),各浓度间差异显著或极显著(P＜0.05,或P＜0.01),浓度达到0.1000g/ml完全受到抑制,种子不能萌发.藜水浸提物对紫花苜蓿幼苗胚根、胚芽生长和根芽比的影响表现出浓度效应,藜根、茎水浸提物在相同浓度下对苜蓿胚根和胚芽生长的影响也存在差异,且均是胚根敏感性强于胚芽的敏感性.叶水浸提物对胚根、胚芽的作用与根、茎不同,浓度≤0.0125g/ml时,对胚根和胚芽生长均无显著影响(P＞0.05),浓度≥0.0250g/mL均表现为抑制作用(P＜0.01,或P＜0.05),各处理与对照根芽比无显著差异(P＞0.05).     

草地早熟禾农杆菌介导法基因转化条件

以大青山草地早熟禾(Poapratensis L.cv.Daqingshan)和超级伊克利草地早熟禾(PoapratensisL.cv.Totaleclipse)成熟种子诱导产生的胚性愈伤组织为材料,比较抗生素及筛选剂对愈伤组织生长和绿苗分化的影响.结果表明:500mg/L的羧苄青霉素或头孢霉素对愈伤组织的生长与对照间差异不显著;羧苄青霉素可提高愈伤组织绿苗分化率,而头孢霉素则有抑制作用;2个供试品种G-418的筛选浓度分别为50和70mg/L时,愈伤组织的褐化率达100%;在幼苗分化期,G-418浓度为20mg/L时,2个供试品种的试管苗均为白化苗;在观察到愈伤组织周围的培养基上显现菌落时,立即转移到筛选培养基上为宜.用农杆菌介导法获得了转苏云金芽孢杆菌杀虫晶体蛋白(B.t)基因植株.     

不同活力种子的萌发与出苗特性

摘要：研究测定了老化处理后几种禾本科牧草种子的萌发、幼苗以及出苗期的相关指标,进一步分析其相关性。结果表明,1）除羊草（Leymus chinensis）种子外,老化处理显著降低其他参试种子的发芽势、发芽率、发芽指数、活力指数,胚根、胚芽以及幼苗长度,出苗率、出苗速率;2）牧草种子的耐老化能力因种而异,休眠可显著提高种子自身的耐老化能力,如羊草;3）除羊草种子外,其他种子的发芽势、发芽率、发芽指数、活力指数,胚根、胚芽以及幼苗长度与出苗率、出苗速率极显著正相关(P<0.01);4) 相比其他萌发指标,发芽率用于种子活力批次的划分在所有物种中表现相对较好。     

硒对不同品种紫花苜蓿发芽阶段物质转化和形态建成的影响

为了探究外源硒对不同品种紫花苜蓿种子萌发阶段糖、氮物质转化，发芽指标和形态建成的影响，以甘农3号、DS310FY及中苜5号紫花苜蓿为对象，设置5个亚硒酸钠浓度（0、0.3、0.6、1.2、2.4 mg·L-1），培养10 d后测定苜蓿种子的发芽率，表型及生理指标和硒含量，并运用综合分析和相关性分析探究各生理指标与表型的关系，以筛选出最适宜的硒浓度和潜在的硒营养强化材料。结果表明：施硒处理4 d,DS310FY和甘农3号苜蓿幼苗的还原糖含量、可溶性糖含量及发芽势均在0.6 mg·L-1硒处理下显著高于对照（P<0.05）；施硒处理10 d,0.3、0.6 mg·L-1硒处理下DS310FY和甘农3号苜蓿幼苗的还原糖含量、硝酸还原酶活性、发芽率及发芽指数都显著高于对照（P<0.05）；而甘农3号苜蓿幼苗的胚芽长及DS310FY苜蓿幼苗的总氨基酸含量、活力指数、胚芽长、胚根长及单株鲜重，施硒后的最大值相比对照均显著提高（P<0.05）；另外，0.3 mg·L-1硒处理下相比对照也显著提高了中苜5号苜蓿幼苗的蔗糖含量、发芽率及胚根直径（P<0.05）。相关性分析和各指标...     

γ射线对沟叶结缕草愈伤组织再生和耐盐性的影响

以沟叶结缕草匍匐茎诱导的胚性愈伤组织为材料,分别进行0Gy(对照)和10Gy的⁶⁰Coγ射线辐照处理,比较愈伤组织的再生能力以及再生植株的过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性和脯氨酸含量,并对辐射材料进行不同浓度(0%,0.5%,1.0%,1.5%和2.0%)的NaCl筛选。结果表明,10Gy⁶⁰Coγ射线处理对愈伤组织的再生分化有显著的促进作用,分化形成3个以上小苗的外植体比率提高11.25%,但是愈伤组织再生率下降8.75%;再生植株的CAT活性提高16.02%,脯氨酸含量提高1.20倍;同对照相比,10Gyγ射线处理的愈伤组织获得的再生植株中SOD和POD活性没有显著变化。10Gy⁶⁰Coγ射线辐射处理能显著提高愈伤组织对NaCl的抗性;外植体的生长速度和存活率随着NaCl浓度的提高而下降;愈伤组织经过10Gy⁶⁰Coγ射线处理后,在含1.0%NaCl的再生培养基上获得最多的耐盐植株(成苗率为9.60%),这些植株转移到含1.0%NaCl的生根培养基上后保持旺盛生长。     

溶磷菌对3种牧草种子发芽和幼苗生长的影响

为了探究促生微生物对植物种子萌发和幼苗生长的影响,本研究选用前期从牧草根际分离获得的枯草芽孢杆菌和菌株编号为191、92、59、170的促生溶磷细菌,制备接菌剂,对3种优良牧草(老芒麦Elymus sibiricus L.、燕麦Avena sativL.、紫苜蓿Medicago sativa L.)种子进行接菌处理,并采用培养箱纸床发芽试验和盆栽试验,研究各菌株对牧草种子的发芽和幼苗生长的影响。结果表明:各菌株对3种牧草种子的发芽率、发芽势和发霉率的影响显著差异(P0.01),与对照相比能显著提高种子的发芽率、发芽势和降低种子的发霉率。各菌株对3种牧草幼苗生长的影响差异显著(P0.05),各菌株处理较对照都能显著提高牧草幼苗的株高、根长和根粗,但各菌株对不同牧草种子萌发和幼苗生长的影响各不相同,不同菌株间也存在一定差异。本研究供试的各菌株对植物种子的萌发和幼苗的生长均有一定的促进作用,各菌株可作为微生物肥料开发的菌株资源,菌株的其他特性及对不同植物促生影响不同的机理有待进一步研究。     

苜蓿抗乙硫氨酸（ETH）变异体的初步筛选

用高胚性细胞系Ｔｒｅｋｌ作为筛选材料，进行了抗乙硫氨酸（ＥＴＨ）变异体的初步筛选，愈伤组织经２，４，６ＫＲγ射线照射后，转到含不同浓度的ＥＴＨ固体和液体选择培养基中，继代筛选三个月后，抗性愈伤组织中内硫氨基到量比对照提高１．０５～１．８４倍，并在０．０２～１．０ｍＭＥＴＨ范围同表现出有随ＥＴＨ浓度升高而逐渐提高的趋势，从０．０２，０．０１ｍＭＥＴＨ的抗性愈伤组织获得了一批再生植株，植株体内含硫氨基     

苜蓿抗性愈伤组织诱导的初步研究

以硫酸二乙酯（DES)和紫外线(UV)对准格尔苜蓿愈伤组织进行诱变处理，筛选其半致死浓度和剂量。对诱变处理后的材料进行脯氨酸含量测定。结果表明，脯氨酸含量明显高于对照。筛选出具有抗性的苜蓿愈伤组织，为苜蓿抗性育种提供基础材料。     

紫穗槐幼苗不同生长阶段叶水势对干旱胁迫与复水的响应特征

为揭示紫穗槐（Amorpha fruticosa）幼苗叶水势对土壤干旱与复水环境的响应特征，本研究通过盆栽试验，研究了土壤干旱胁迫及复水对紫穗槐幼苗不同生长阶段叶水势的影响。结果表明：土壤水分、干旱历时和生长阶段3个因素以及各因素间的相互作用对紫穗槐幼苗叶水势均有极显著影响（P<0.01）；随着干旱程度加剧，幼苗叶水势呈下降趋势，水分胁迫指数呈上升趋势；40.00%土壤相对含水量下的幼苗叶水势下降幅度达到最大，其中干旱15 d的生长初期和生长中期以及干旱30 d的生长后期的叶水势分别比对照下降了0.71 MPa，1.12 MPa和0.58 MPa；复水后，叶水势出现补偿效应，随着复水后时间的延长，幼苗3个生长阶段叶水势逐渐恢复，恢复速率与干旱程度、干旱历时和生长阶段密切相关，但均在复水72小时后恢复到接近对照水平。     

5个小黑麦新品系的种子产量及产量构成因素分析

本文研究了5个小黑麦新品系(Triticale Wittmack)的物候期、田间抗病性、株高、种子产量,以及产量构成因素(穗长,小穗数,穗粒数,穗粒重)对种子产量的贡献。结果表明,P2的实际和预测的种子产量均最高,抗锈病能力最强,为最好品系;在种子产量构成因素中,穗粒重对种子产量的正向直接效应最大,在小黑麦育种中应首先考察穗粒重这一性状,同时考虑穗长与穗粒数、穗粒重与穗粒数之间关系的协调均衡。     

黑龙江省玉米穗腐病致病镰孢菌分离鉴定及产毒基因型分析

为全面阐明黑龙江省玉米穗腐病的主要致病镰孢菌种类及其分布特征,制定科学合理的防治措施,以控制真菌毒素对玉米籽粒的危害。2018年在黑龙江省21个玉米主产区县采集玉米穗腐病病样143 份,采用种子健康检测法进行镰孢菌分离,根据形态学和分子生物学特征进行鉴定,并对分离的镰孢菌进行产毒基因型检测。结果表明,共分离到200株镰孢菌分离物,鉴定出12种镰孢种,其中禾谷镰孢和拟轮枝镰孢的分离频率分别为30.00%和16.00%;亚粘团镰孢和层出镰孢的分离频率均为13.00%;布氏镰孢分离占比12.50%;温带镰孢分离占比7.50%;新知镰孢分离占比2.50%;变红镰孢分离占比2.00%;拟枝孢镰孢、梨孢镰孢和居群镰孢分离频率均为1.00%;亚洲镰孢占比0.50%。产毒素类型分析发现,亚洲镰孢菌为雪腐镰刀菌烯醇(NIV)产毒类型,禾谷镰孢与布氏镰孢含3种产毒类型,其中15-乙酰基-脱氧雪腐镰刀菌烯醇(15-AcDON)产毒类型最多,3-乙酰基-脱氧雪腐镰刀菌烯醇(3-AcDON)稍次之,NIV型最少;拟轮枝镰孢、层出镰孢、亚粘团镰孢、新知镰孢、变红镰孢、拟枝孢镰孢和梨孢镰孢均含有产伏马毒素的关键基因fum1,具备产伏马毒素能力,温带镰孢和居群镰孢不含有fum1基因。黑龙江玉米穗腐病致病镰孢种类较多,其中禾谷镰孢和拟轮枝镰孢为优势致病镰孢,亚粘团镰孢、层出镰孢和布氏镰孢亦分布较广,温带镰孢和新知镰孢呈现小范围分布,拟枝孢镰孢、变红镰孢、梨孢镰孢以及居群镰孢是首次在黑龙江省玉米穗腐病中分离得到,丰富了黑龙江地区玉米穗腐病致病镰孢菌的种类。     

不同饲草型小黑麦基因型的光合生理差异

为筛选光合性能强的饲草型小黑麦种质及探讨光合性能主要影响因素,采用差异分析和主成分分析法研究了6个饲草型小黑麦基因型在不同生育时期的叶绿素含量及光合生理指标的变化。结果表明,随着生育时期推移,饲草型小黑麦的光合性能指标(除气孔限制值)均为先增加后减少,叶绿素含量、蒸腾速率、光合速率、胞间二氧化碳浓度在抽穗期达到最高值,水分利用效率在开花期达到最高值;随着生育时期推移,饲草型小黑麦的气孔限制值先减少后增加,抽穗期最低。通过生育时期×小黑麦种质间光合性能指标差异分析可知,C31和C19在整个生育时期光合性能都较强,可达到高产的目的,而饲草型小黑麦C19的优势是水分利用效率较高,可进一步作为抗旱种质资源。主成分分析可知,影响饲草型小黑麦光合性能的主要因素有蒸腾速率和与气孔有关的因素。     

苜蓿花药愈伤组织胚状体诱导因素的研究

以7个基因型的苜蓿花药愈伤组织为材料,进行了基因型、愈伤组织生长率、培养温度、培养基碳源等因素对苜蓿花药培养诱导胚状体影响的研究.结果表明:不同基因型苜蓿花药愈伤组织生长率、胚状体诱导率都存在显著性差异,两者的相关系数r=-0.326 1(P＜0.01),两者没有明显的相关性;低温处理可促进花药愈伤组织的分化,4℃低温...     

Effects of graded levels of Fusarium toxin-contaminated wheat and of a detoxifying agent in broiler diets on performance,nutrient digestibility and blood chemical parameters

1. A growth experiment was carried out with male broilers from d 1 to d 35 of age in order to evaluate the effects of the addition of a detoxifying agent (Mycofix Plus, Biomin GmbH, Herzogenburg, Austria) at different dietary proportions of wheat (0, 16.5, 33, 49.5 and 66%) contaminated with Fusarium mycotoxins (21.2 mg of deoxynivalenol and 406 microg of zearalenone, ZON, per kg of wheat) on growth performance, nutrient and zearalenone balance and clinical-chemical parameters. 2. An increase in dietary mycotoxin concentration resulted in a linearly related decrease in feed intake, a slight decrease in weight gain and an improvement in feed to gain ratio. 3. Apparent protein digestibility and net protein utilisation were higher in diets containing exclusively Fusarium toxin-contaminated wheat than control diets. 4. The proportions of beta-zearalenol, alpha-zearalenol and ZON of total ZON metabolites in excreta of broilers fed on the diets containing the Fusarium toxin-contaminated wheat were approximately 3, 21 and 76%. 5. Serum antibody titres to Newcastle disease virus decreased in a linear fashion with increasing mycotoxin concentration in the diets, whereas other clinical-chemical serum parameters (liver cell and muscle cell necrosis indicating enzymes, haemoglobin, haematocrit, magnesium, inorganic phosphate) were not influenced by increasing Fusarium toxin concentrations. 6. Supplementation of the diets with Mycofix Plus decreased performance in a manner independent of mycotoxin concentration. Moreover, some clinical-chemical serum parameters were significantly altered due to Mycofix Plus but also independently of the dietary mycotoxin concentration.     

In Vitro Metabolism of Fumonisin B1 by Ruminal Microflora

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium moniliforme and F. proliferatum. Little is known of its metabolic fate after oral ingestion in ruminants, but these animals are reported to be tolerant towards FB1. The metabolism of this mycotoxin was evaluated following incubation (1 g/ml) in ruminal fluid for up to 72 h, in the presence or absence of alfalfa as a substrate for microbial growth, using a model rumen (sealed flask, anaerobic conditions, exclusion of light, gentle agitation, 39°C). The decrease in FB1 concentration and the production of short-chain fatty acids were determined. FB1 had no effect on SCFA production. After 72 h incubation, FB1 depletion was 12% and 18% in samples with and without alfalfa, respectively. No hydrolysed metabolites (aminopolyols or aminopentol) were detected. These results indicate that FB1 is poorly metabolized in the rumen and suggest that such metabolism is not the cause of the tolerance to this toxin displayed by ruminants.     

Rejection by pigs of mouldy grain containing deoxynivalenol

SUMMARY: Weaner pigs on a farm near Beaudesert in south eastern Queensland refused to eat feed comprised largely of wheat and barley. Older pigs consumed small amounts and some prepubertal gilts subsequently displayed enlarged and reddened vulvas. Wheat, barley and triticale were grown on the farm during 1983, which was unusually and persistently wet. The wheat and triticale were harvested and stored for about 3 weeks with moisture contents above 14% before being fed. Samples of the wheat and triticale contained pale pink grains, which can indicate infection by the fungus Fusarium graminearum Schw. On analysis 2 mycotoxins known to be produced by F. graminearum were detected, deoxynivalenol (vomitoxin) which causes feed refusal and vomiting, and zearalenone which causes oestrogenic effects. Concentrations of deoxynivalenol in the wheat, triticale and barley were 34, 10, and < 0.1 mg/kg respectively. Concentrations of zearalenone were 6.2, 2.8 and 0.1 mg/kg respectively. Subsequently, F. graminearum was isolated from grains and crop residues. Although the wet weather contributed to F. graminearum infection of the crops before harvest, most of the toxins probably developed during storage.     

草坪褐斑病菌和镰刀枯萎病菌拮抗木霉菌的筛选及效果研究

通过木霉属5个菌株与草坪禾草褐斑病菌、草坪禾草镰刀枯萎病菌的对峙培养试验,发现哈茨木霉1、哈茨木霉2、深绿木霉、钩状木霉及桔绿木霉的抑菌效果很好,可以作为草坪镰刀枯萎病菌的生物防治拮抗菌加以利用。在这5株木霉中以哈茨木霉对草坪镰刀枯萎病菌的拮抗作用最强。     

In vitro analysis of antiangiogenic activity of fungi isolated from clinical cases of equine keratomycosis

OBJECTIVE: The goal of this project was to explore the possibility that fungal organisms produce metabolites that inhibit angiogenesis. Procedures Fungal cultures were obtained from cases of keratomycosis, grown in Sabouraud's dextrose broth, and sterile filtered for use in experiments. The Matrigel assay was used to screen the filtrate samples for antiangiogenic activity. Matrigel is a basement membrane matrix that supports the differentiation of human umbilical vein endothelial (HUVE) cells into a capillary-like network of tubules. HUVE cells were cultured using standard techniques and passaged at confluence, with all cells being used at passage 3-6. HUVE cells (40 000 cells) were pipetted into each well of a 24-well tissue-culture plate coated with Matrigel. An aliquot of fungal media filtrate was added to each well and the plates allowed to incubate for 18 h, at which time they were evaluated for tubule formation. RESULTS: Two fungal isolates showed inhibition of tubule formation. The addition of 100, 200 and 400 &mgr;L of the fungal media filtrate from the first isolate (Fusarium sp. 99A34574) produced a consistent and dose-dependent inhibition of tubule formation. The second isolate (Aspergillus sp. 271599) did not show inhibition of tubule formation with 100 or 200 &mgr;L added to the wells, however, it did show inhibition at 400 &mgr;L/well. The remaining three isolates did not cause inhibition at any concentration. CONCLUSIONS: Our findings suggest that certain fungal organisms produce metabolites that inhibit tubule formation in vitro, and that these metabolites may play a significant role in altering the host vascular response to fungal infections of the cornea.     

甘肃中部地区禾谷镰孢的变异研究

为掌握禾谷镰孢在甘肃中部地区的分布及变异情况,从根部表现有坏死和叶鞘发褐的小麦幼苗的不同部位、小麦地土壤及玉米籽粒、玉米茎秆上分离禾谷镰孢,并以形态学为基础,参照Nelson分类系统进行鉴定。结果表明,在分离到的43个镰刀菌菌株中,有14个菌株经鉴定为禾谷镰孢,均从玉米茎秆上分离到,小麦根部、小麦叶鞘、小麦地土壤、玉米籽粒中分离到的镰刀菌中未见禾谷镰孢。将禾谷镰孢在特定条件下培养后,发现14个禾谷镰孢菌株产生子囊壳的数量不同,为2～90个。在以Fg16为引物的PCR反应中,随机选取的11个禾谷镰孢菌株都产生0.41kb的PCR产物,而6个对照菌株都产生0.50kb的片段,证明引物Fg16可以区分禾谷镰孢菌株群体的遗传多态性。以Tri13为引物的PCR反应显示,11个禾谷镰孢菌株以及3个中国对照菌株都产生脱氧雪腐镰刀菌烯醇(DON)毒素,而3个澳大利亚对照菌株产生雪腐镰刀菌烯醇(NIV)毒素。