寡雄腐霉发酵液的动物安全性及其对黄瓜的防病促生效应

【目的】生物农药安全无害,环境友好。为了评价寡雄腐霉发酵液(Pythium oligandrum broth,POB)的动物安全性和防病促生效应,研制高效、无害的生物农药。【方法】试验利用自主分离的寡雄腐霉生防菌株(P.oligandrum CQ2010)制备POB,通过动物试验、拮抗试验、盆栽和生产试验,研究了POB的动物毒性,对黄瓜蔓枯病的防治作用,以及对黄瓜生长、产量和品质的影响。【结果】用大剂量的POB灌胃给药对小鼠体重增长无显著影响,其外观和行为均无异常,组织器官也未见病理改变。POB对甜瓜球腔菌的抑制率为51.95%,药效介于1∶800的百菌清溶液和1∶200的甲基托布津溶液之间。在黄瓜幼苗接种甜瓜球腔菌前后喷施POB,叶片丙二醛含量下降,过氧化物酶和超氧化物歧化酶活性增强,发病率和病情指数均显著降低,相对防治效果达到54.8%–64.1%,故POB能减轻病原菌对细胞膜的伤害,激发防御性生理反应,增强黄瓜植株的抗病能力。此外,POB处理提高叶绿素含量,增强根系活力,增加植株氮、磷、钾吸收量,促进黄瓜植株生长,生物量和果实产量分别提高81.10%和11.58%。POB还使黄瓜果实Vc和可溶性糖提高,硝酸盐含量降低。【结论】寡雄腐霉发酵液对动物安全无毒,能有效防治黄瓜蔓枯病,促进黄瓜生长,提高产量品质。     

寡雄腐霉施用时期对设施黄瓜霜霉病的防治试验

寡雄腐霉是一种对多种植物病害有很好防治效果的新型生物农药。本文通过田间试验明确了寡雄腐霉在黄瓜霜霉病不同发病时期使用时的防治效果。结果表明,寡雄腐霉对黄瓜霜霉病预防效果达到68.9%,发病初期防治效果达到61.9%,发病后期防治效果只有23.5%。因此,在使用寡雄腐霉防治黄瓜霜霉病时一定要在未发病或发病早期使用才能达到理想的防病效果。     

寡雄腐霉发酵液的动物毒性及其对柑橘果实贮藏期青、绿霉病的防治效果

摘要:【目的】研制安全、无毒、高效的生物保鲜剂,降低意大利青霉(Penicillium italicum,青霉)和指状青霉(Penicillium digitatum,绿霉)引起的柑橘烂果。【方法】试验利用自主选育的寡雄腐霉优良菌株(Pythium oligandrum CQ2010),制备发酵液,测试了对小鼠的急性毒性,并设置对照(液体培养基,CK)、寡雄腐霉发酵液(P． oligandrum Broth,POB)、咪鲜胺(Prochloraz,PC)、咪鲜胺+ POB(PC+POB)等4种处理,研究了它们对青、绿霉菌的抑制作用及其对柑橘防腐保鲜的作用。【结果】用大剂量的POB灌胃给药对小鼠体重增长无显著影响,供试动物的外观和行为均无异常,心、肝、肾、肺、肠等组织器官也未见病理改变。POB显著抑制青、绿霉菌丝生长和孢子萌发,抑制率分别为70.24%－93.74%(菌丝生长)和44.91%－87.82%(24 h孢子萌发)。柑橘果实接种青霉后,烂果率CK＞POB、PC＞PC+POB,防治效果PC+POB＞POB、PC。在模拟柑橘商品化贮藏保鲜试验中,青、绿霉发病率占总发病率的50%以上,CK、POB、PC和PC + POB的烂果率依次为26.40%、15.03%、16.61%和4.21%。此外,POB对果实品质无显著影响,但显著提高果皮中的超氧化物歧化酶、过氧化物酶和过氧化氢酶活性,有益于提高柑橘果实的抗病性和贮藏性。【结论】在柑橘贮藏过程中,POB对果实青、绿霉病有显著的防治作用,并与咪鲜胺的防病效果有叠加作用。     

生防真菌寡雄腐霉原生质体的制备及再生

寡雄腐霉Pythium oligandrum是一种对动、植物和环境无害,兼具杀菌和增产效果的生防真菌。本研究以0.8mol/L甘露醇与25mmol/L CaCl_2和10mmol/L Tris-HCl作为渗透压稳定剂,使寡雄腐霉菌丝体在含有裂解酶、纤维素酶、破壁酶的复合酶系中酶解得到其原生质体。此原生质体通过液体振荡培养的途径恢复再生1d后涂于平板上可生长为成熟菌体。本研究所述方法制备得到的寡雄腐霉原生质体数量超过1×10~9CFU/m L,活性超过80%;通过液体培养再生途径使得寡雄腐霉原生质体再生率达32.9%。此方法操作简便,稳定性好,获得的寡雄腐霉原生质体品质高、数量多,完全能够满足后期基因遗传转化、细胞融合培养等研究应用。     

云南的腐霉

本文报道迄今为止在我国云南省发现的腐霉属真菌19个种,其中1个新种,3个中国新记录,5个云南新记录。新种为下雄腐霉Pythium hypoandrum Yu ＆ Y.L.Wang sp.nov.; 云南新记录为:旋柄腐霉P.helicoides、长井腐霉P.nagaii、周雄腐霉P.periilum、喙腐霉P.rostratum和钟器腐霉P.vexans,前3者还是中国新记录。有分种检索表,对其中12个种进行了描述并附形态图。     

腐霉属的一个新种和二个新记录

本文报告作者1982—1983年在北京和广东一些地区土壤中用已知方法(余永年,1975)分离到的几种腐霉,其中1个新种(Pythium borealis sp.nov.)、2个国内未报道的种(P.oligandrum和P.myriotylum)和1个已知种的变异株(P.ultimum variant)。文中对以上各菌进行了形态学描述。     

农杆菌介导的携带egfp基因载体转化寡雄腐霉

【目的】寡雄腐霉(Pythium oligandrum Drechsler)是一种对动、植物和环境无害,兼具杀菌和增产效果的生防真菌。通过研究建立农杆菌介导的寡雄腐霉遗传转化体系。【方法】选用EHA105、AGL-1、LBA4404三种农杆菌菌株对寡雄腐霉进行遗传转化研究,通过对影响遗传转化效果的条件参数试验优化,确立适宜寡雄腐霉遗传转化的农杆菌菌株及转化条件,建立农杆菌介导的寡雄腐霉遗传转化体系。【结果】经研究发现,所选3种农杆菌菌株中EHA105菌株对寡雄腐霉的遗传转化效果最好,其次是AGL-1菌株,LBA4404菌株转化效果不好。EHA105菌株经IM(含300μmol/L AS)诱导培养至OD_(600)=0.6时,与浓度为10~6–10~7个/m L的寡雄腐霉孢子悬浮液以1–10:1的比例混合,在25–26°C以液体振荡的方式避光共培养72 h(pH 5.0,含300μmol/L AS),寡雄腐霉菌体液体振荡恢复培养24 h,涂布抗性选择平板筛选寡雄腐霉转化子,即可得到寡雄腐霉基因工程菌株,其转化率可达到130个转化子/106个孢子。【结论】本研究首次构建了农杆菌介导的寡雄腐霉遗传转化体系,研究结果可为寡雄腐霉的生防机制及分子育种研究提供技术支撑。     

芳樟醇对灰葡萄孢生长的影响及对番茄灰霉病的防控效果

通过平板抑菌试验和孢子萌发试验研究了芳樟醇对灰葡萄孢的生长抑制作用,并通过盆栽试验进一步验证了芳樟醇对番茄灰霉病的防控效果。结果表明: 芳樟醇能够显著抑制灰葡萄孢菌丝的生长,半最大效应浓度(EC₅₀)值为0.581 mL·L^-1。孢子萌发试验中,芳樟醇能够有效抑制灰葡萄孢孢子的萌发,并表现出浓度依赖性。芳樟醇处理提高了灰葡萄孢菌菌丝体的相对电导率和丙二醛(MDA)含量,说明芳樟醇可引起氧化损伤效应导致灰葡萄孢菌的膜系统被破坏;芳樟醇处理后灰葡萄孢菌中的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性较对照组分别下降了27.4%、68.9%和26.0%,说明芳樟醇抑制了灰葡萄孢菌体内的抗氧化系统。盆栽试验结果显示,芳樟醇处理的病斑直径较对照组显著降低;番茄叶片中的SOD、CAT、POD、多酚氧化酶和苯丙氨酸解氨酶活性均显著高于对照组;而MDA含量下降了41.5%,说明芳樟醇可减轻灰葡萄孢菌对番茄植株造成的氧化损伤以提高植物抗病性。综上,芳樟醇对灰葡萄孢的生长有显著抑制作用并对番茄灰霉病有较好的防治效果,研究结果可为开发新型植物源抑菌剂防控番茄灰霉病提供理论依据。     

葫芦岛市保护地番茄灰霉病的发生和防治

葫芦岛市保护地番茄灰霉病的发生和防治齐素芳,王宏,马宗超（葫芦岛市植保站,１２５０００）番茄灰霉病在保护地的番茄栽培中,已成为一个主要的病害。据我们调查,保护地番茄一般发病果率为２０％,重病果率高达８０％以上。该病流行年份发病面积约达５０－７０％,成...     

应用梧宁霉素防治番茄灰霉病的研究初报

应用梧宁霉素防治番茄灰霉病的研究初报王志,鲍秀芬,宗玉丽（辽宁省微生物研究所朝阳．１２２０００〕番茄灰霉病（灰葡萄抱,ＢｏｔｒｙｔｉｓＣｉｎｅｒｅａＰｅｒ’ｓ）是近年来温室、大棚番茄的一种主要病害,其发病率高、危害严重。目前防治该病主要应用化学农药,...     

Effect of a formulation of Bacillus firmus on root-knot nematode Meloidogyne incognita infestation and the growth of tomato plants in the greenhouse and nursery

Bacillus firmus, commercial WP formulation (BioNem) was evaluated against the root-knot nematode Meloidogyne incognita in a laboratory, greenhouse and under field conditions on tomato plants. In the laboratory tests, an aqueous suspension of BioNem at 0.5%, 1%, 1.5% and 2% concentration reduced egg hatching from 98% to 100%, 24-days after treatment. Treatment of second-stage juveniles with 2.5% and 3% concentration of BioNem, caused 100% inhibition of mobility, 24 h after treatment. In the green house trials, BioNem applied at 8 g/pot (1200 cc soil) planted with a tomato seedlings reduced gall formation by 91%, final nematode populations by 76% and the number of eggs by 45%. Consequently, plant height and biomass was increased by 71% and 50%, respectively, compared to the untreated control, 50-days after treatment application. Application of BioNem at 16 g/pot was phytotoxic to plants. In the field trails, BioNem applied at 200 and 400 kg ha⁻¹ was effective in reducing the number of galls (75-84%), and increased shoot height (29-31%) and weight (20-24%) over the untreated control, 45-days after treatment. Our results indicate that B. firmus is a promising microorganism for the biological control of M. incognita in tomato pots.     

南方根结线虫对不同砧木嫁接番茄苗活性氧清除系统的影响

采用盆栽人工接种方法,对番茄嫁接苗进行了抗性评价,研究了番茄嫁接苗叶片中抗氧化酶活性和活性氧代谢的动态变化。结果表明,接种南方根结线虫(J2)后,砧木嫁接苗表现为高抗,自根嫁接苗为高感。通过嫁接换根,与自根嫁接苗相比,砧木嫁接苗明显提高了接穗叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,降低了超氧阴离子(O.2-)产生速率以及过氧化氢(H2O2)和丙二醛(MDA)含量。表明番茄植株体内的活性氧水平和抗氧化酶活性的高低与其抗根结线虫的能力密切相关,较低的活性氧水平和较高的抗氧化酶活性有利于减轻对膜系统的伤害,提高番茄植株的抗根结线虫能力。     

Antitumor activity of sulfated extracellular polysaccharides of Ganoderma lucidum from the submerged fermentation broth

Water-soluble extracellular polysaccharides are known to possess weak or no in vitro antitumor activity. In this experiment, a mixture of extracellular Ganoderma lucidum polysaccharides (GLP) from the submerged fermentation broth was sulfated and studied on their antitumor activity. The sulfated GLP performed significant inhibition on the proliferation of assayed carcinoma cells in a dose-dependent manner, and present a degree of substitution-dependent suppressing to HepG2 cells. Meanwhile, the sulfated GLP presented remarkable but not dose-dependent inhibition on Heps hepatona in mice. With same degree of substitution, the sulfation protocol with aminosulfonic acid-pyridine yielded GLP sulfates with higher activity on HepG2 cells. In comparison, the native GLP showed no or little antitumor activity on the assayed cell lines but remarkable inhibition on suppressing the proliferation of rat Heps. The highest in vivo inhibition rate of 55.5% provided by sulfated GLP was observed on suppressing the proliferation of rat Heps.     

Inhibitory effects of leachate from Eupatorium adenophorum on germination and growth of Amaranthus retroflexus and Chenopodium glaucum

Amaranthus retroflexus L. and Chenopodium glaucum L. are two widely distributed destructive weeds. Their strong adaptability and massive seed production make them the hardest weeds to deal with. This present study intended to investigate the effect of leachate from Eupatorium adenophorum on the growth of these weeds and explore the potential to develop an environmental friendly strategy to use the leachate to control the weeds. Seeds of A. retroflexus L. and C. glaucum L. were soaked in solutions containing 0%, 0.6%, 1.25%, 2.5%, and 5% leachate from E. adenophorum leaves. A. retroflexus and C. glaucum seedlings grown in pots were sprayed with leachate solutions in the same concentration range. The effects of these leachate solutions on membrane permeability and germination of seeds, and growth and physiological characteristics of the seedlings were investigated. The highest concentration of leachate (5%) caused significant damage to the cell membrane of seeds of both weed species, whereas lower concentrations (0.6%) promoted repair of the membrane system, as reflected by higher and lower than control in relative conductivity (RC), respectively. Different concentrations of leachate showed distinct allelopathic inhibitory effects on the two weed species; lower concentrations showed weak inhibitory or even positive effects, whereas higher concentrations showed stronger inhibitory effects. Higher concentrations of leachate (2.5% and 5%) delayed germination and significantly decreased the emergence rate of the seeds, survival rate, and dry matter accumulation of the seedlings. When treated by 5% leachate, the emergence date of A. retroflexus was delayed by 3.6 d, emergence rate of the seeds and survival rate was 69.1% and 70.6% of the control, respectively, seedling dry matter was 48.6% less than the control; In the case of C. glaucum, the emergence date was delayed by 2.7 d, emergence rate of the seeds and survival rate was 45.1% and 58.6% of the control, respectively, seedling dry matter was 44.7% less than the control. There were significant interactions among the different concentrations of leachate and the length of treatment period with respect to activities of antioxidant enzymes, malondialdehyde (MDA) contents, and chlorophyll contents. Seedlings treated with 0.6%, 1.25%, or 2.5% leachate solution for 24–72 h showed increased superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities. When seedlings were treated with leachate solutions for 96 h, antioxidant enzyme activities and chlorophyll content decreased in A. retroflexus, but only CAT activity decreased in C. glaucum. When seedlings of the two weed species were treated with 5% leachate solution, CAT activity and chlorophyll content decreased and MDA content gradually increased with longer treatment times (from 24 to 96 h). The two weed species showed different allelopathic responses to E. adenophorum; A. retroflexus was more sensitive than C. glaucum. Based on the investigation, it could be speculated that the delayed germination and low germination rate of the weeds after treatment by leachate could be due to the fact that leachate damaged the membrane system of the seeds. By delaying germination, lowering the germination rate of the weeds and inhibiting seedling growth, leachate from E. adenophorum could provide an effective way of controlling the weeds.     

Influence of host plants on feeding, growth and reproduction of Papilio polytes (The common mormon)

We studied the feeding, growth and reproductive behaviour of Papilio polytes (common mormon butterfly) on five different host plants, Murraya koenigii, Toddalia asiatica, Glycosmis pentaphylla, Aegle marmelos and Citrus medica. The growth rate of P. polytes was fastest on M. koenigii followed by T. asiatica, C. medica, G. pentaphylla and A. marmelos. We related this to the nutrient contexts of the five plants. The plants T. asiatica and C. medica had higher water contents, which influenced the growth rate of the insect. M. koenigii was found to contain rich quantities of carbohydrate. M. koenigii, T. asiatica and C. medica were also rich in protein when compared to A. marmelos and G. pentaphylla. Total amino acid levels were comparatively higher in M. koenigii, T. asiatica, C. medica rather than A. marmelos and G. pentaphylla.     

土壤逐渐干旱对菖蒲生长及光合荧光特性的影响

在土壤逐渐干旱过程中,连续测定典型湿地植物菖蒲生长发育状况及叶片叶绿素荧光参数,结果表明:短期内(实验第O-3天)土壤水分含量下降(土壤含水率自53.86％下降至42.6％)有利于菖蒲生长,干旱组菖蒲叶片Fv/ Fm、Yield、qP显著高于对照组(实验期间土壤平均含水率为53.49±0.6％)(P＜0.05),qN则低于对照组;随着土壤进一步干旱(土壤含水率自42.6％下降至18.02％,实验第3-9天),菖蒲叶片qN值则由0迅速上升至0.403,显著高于对照组(P＜0.05),Fv/Fm值与对照相比无显著差异(P＞0.05),叶片保持较高的热耗散以维持光合结构PSⅡ保持正常,并能以降低叶片含水率、叶面积(叶片卷曲避光)减少水分蒸腾及降低根系含水率促进水分吸收的方式进行自我保护;随着土壤干旱程度加剧(土壤含水率自18.02％下降至4.5％、实验第9-12天),菖蒲叶片Fv/ Fm、yield、qP值显著低于对照组(P＜0.05),qN值降为0,光合结构PSⅡ受到损坏,第11天、12天,叶片含水率分别降至75.79％和68.78％,此时菖蒲也逐步以自小叶片至大叶片的顺序枯萎衰亡,表明在土壤水分快速下降过程中过高的生物量将不利于菖蒲保持水分,而80％左右的叶片含水率是维持菖蒲存活的临界值.     

盐胁迫下荒漠共生植物红砂与珍珠的根茎叶中离子吸收与分配特征

西北荒漠地区C3小灌木红砂(Reaumuria soongorica)和C4半灌木珍珠猪毛菜(Salsola passerina)在特定环境下混生在一起,分布面积广阔。以采自腾格里沙漠边缘荒漠地带的天然野生珍珠猪毛菜和红砂群落的幼苗为材料,经0、100、200、300、400mmol/L NaCl盐溶液共同胁迫10 d,检测它们的含水量、主要矿质离子在根茎叶的含量与分布,揭示二者耐盐的共生协同的离子平衡适应机制。试验结果发现,珍珠猪毛菜叶片具有"吸钾排钠的"的耐盐特征,红砂叶片具备"吸钠排钾"的特征,吸收利用无机矿质离子具备互补效应。二者耐盐Cl、Ca和Si离子吸收与累积能力存在很大差异:随着盐胁迫程度加剧,红砂的根茎叶中Cl离子含量持续增加,并且为珍珠猪毛菜的2—5倍;珍珠猪毛菜根中Ca离子含量为红砂的2—3倍,但含量变化不显著;红砂根中Si离子含量迅速降低后稳定,并且是珍珠猪毛菜根的3—5倍,其他器官变化差异较小。因此,红砂与珍珠猪毛菜的共培养盐胁迫下根中吸收的离子侧重不同,红砂以Na、Cl、Si为主,珍珠猪毛菜以K、Ca为主。随着盐胁迫的程度加强,离子选择吸收系数S k,Na的变化趋势降低,表明二者叶部对Na的选择性减小,K的选择性吸收积累增大,增强了它们的抗盐性,最终使叶片所受盐害减小。总之红砂与珍珠猪毛菜共生的耐盐离子稳态机制显著不同,离子吸收与分布具有互补互利的效应。