Effects of Material Physical Properties on White-rot Fungi Mycelial Growth

[ Objective] The research aimed to study effects of material physical properties on white-rot fungi mycelial growth and provide theoretical basis for further expanding the application range of white-rot fungi. [ Method Four common species of white-rot fungi were cultivated by wood meal fowl dung mixture in test tube and culture dishes. The relationship between physical properties of culture material and the growth of these mycelials were studied. [Result] The results showed the water retention capacity of culture material was decreased with the increasing of its grain size and porosity, but the decrease of its specific gravity reduced the material water retention. And the dehydration rate of medium prepared with these materials at the same moisture conditions tended to increase. These physical properties of material, such as grain size, specific gravity, porosity, water retention and water drainage, influenced the growth of white-rot fungi mycelial by affecting the moisture and ventilation condition of media. The results hinted that above material physical properties had feedback effects on the growth of white-rot fungi mycelia. [ Conclution] Physical properties of culture material have significant effects on the growth of white-rot fungi mycelial.

Mycelial Growth of <i>Paecilomyces hepiali</i>in Various Agar Media and Yield of Fruit Bodies in Rice Based Media

Growth of?Paecilomyces hepiali?in various agar media and yield of fruit bodies in rice based media were?studied. The best growth in agar media was obtained at 25℃?(61.86 mm colony diameter in 14 days). The initial agar media pH range?from?6 to 8 was found to be?the?most favourable for mycelial growth. This study found that agars made with powders of cereal grains alone do not support good mycelial growth of?P. hepiali. Addition of peptone improved mycelial growth significantly. The most favourable carbon sources were Mannose, Fructose and Glucose. Organic nitrogen sources were found to be?the?most preferred. The results demonstrated that brown rice is better than polished rice in yield of fruit bodies. Addition of peptone was found to be quite significant in enhancing yield of fruit bodies. Peptone, as a supplement, gave a better yield than addition of egg yolk, albumen and a mixture of the two. The medium with?40 g brown rice, 0.325 g glucose, 0.65 g sucrose, 2 g peptone and 65 ml corn steep liquor was found to be?the?most favourable and it yielded 19.3 g of fresh fruit bodies.

Inhibitory Effects of Sixteen Fungicides on Mycelial Growth and Spore Germination of Monilinia fructicola

[Objective]The paper was to compare the indoor toxicities of sixteen fungicides on mycelial growth and spore germination of Monilinia fructicola,to screen out effective fungicides and to discuss use characteristics of various types of fungicides.[Method]The inhibitory activities of 16 fungicides on mycelial growth and spore germination were determined by mycelial growth rate method and spore germination method.[Result]The EC50 values of 16 fungicides against mycelial growth ranged from 0.0184 to 61.5305 mg/L.Prochloraz,tetramycin,fenbuconazole and fludioxonil had strong inhibitory activities on mycelial growth,and their EC50 values were 0.0184,0.0456,0.0531 and 0.0814 mg/L,respectively,significantly lower than those of other 12 fungicides.The EC50 values of 16 fungicides against spore germination ranged from 0.0084 to 189.3938 mg/L.Tetramycin and chlorothalonil had strong inhibitory activities on mycelial growth,and their EC50 values were 0.0084 and 0.0378 mg/L,respectively,significantly lower than those of other 14 fungicides.[Conclusion]The 16 fungicides had great value in preventing and controlling peach brown rot.Benzimidazoles,diformimides and ergosterol inhibitors had good inhibitory activities on mycelial growth.Strobilurins,succinate dehydrogenase inhibitors and multiple-site protective fungicides had good inhibitory activities on spore germination.The agricultural antibiotics tetramycin,phenazine-1-carboxylic acid and pyrrole fungicide fludioxonil had good inhibitory activities on mycelial growth and spore germination.

Effect of Lead Stress on Growth Characteristics and Physiological Indexes of Alternanthera philoxeroides

[Objective] The paper aimed to discuss effects of different concentrations of lead stress on Alternanthera philoxeroides growth and physiological indices,to explore phytoremediation methods for removal of lead pollution. [Method] A. philoxeroides in water culture was treated with different concentration of lead,and then,its external injury was observed,its growth and physiological indexes were measured. [Result] A. philoxeroides biomass and chlorophyll content decreased; conductivity and malonaldehyde （MDA ） content were increased; the SOD,POD and CAT activities showed a trend of first increase and then decrease with increase in concentration of lead stress. [Conclusion] With increase in lead concentration,the cell membrane permeability increased and MDA had a higher accumulation,antioxidant enzymes activity decreased,the normal oxidative metabolism of A. philoxeroides was severely affected,leading it to wilt.

Effect of Different Preservation Conditions on Mycelia Growth of Morcllhea conica

[Objective] This study aimed to investigate the effect of different short-term preservation conditions on mycelial growth of Morchella conica, and search for opti- mum preservation conditions. [Method] M. conica strains in tubes were preserved at two temperature treatments 10 ℃/5 ℃ （day/night） and 15℃/10 ℃（day/night） in scat- tered light or dark for 30 or 60 d. The strain preserved at 4 ℃ dark for 90 d was the control （CK）. So, a total of nine treatments were prepared in this study. [Result] Mycelial growth of M. conica preserved at 10 ℃/5 ℃ was better than that at 15 ℃/10 ℃ and control. The colony color and aerial hyphae of strains preserved in scattered light was also better than that in dark. Additionally, the preservation time showed no distinct effect on mycelial growth at 10 ℃/5 ℃. So the time could be lengthened. But the maximal preservation time was 60 d at 15 ℃/10 ℃. Therefore, preserved under the appropriate conditions of 10 ℃/5 ℃, scattered light for 30 d, the strain had the neat colony edge, moderate aerial mycelia, dense mycelia, lower sectoral variation, uniform mycelial growth rate and high dry weight of mycelia.

Wheat growth, photosynthesis and physiological characteristics under different soil Zn levels

In recent years,heavy metal hazards in the soil have seriously affected agricultural production.This study aims to examine the effects of different levels of heavy metal Zn on the growth,photosynthesis and physiological characteristics of wheat,and provide a theoretical basis for the diagnosis and control of heavy metal pollution in agricultural production.The field test method was used to explore the changes of wheat agronomic traits,photosynthetic capacity,chlorophyll fluorescence parameters,spectral characteristic curve,active oxygen metabolism system,cell ultrastructure,and yield,under different Zn levels(0,250,500,750,and 1000 mg kg^(-1)).The results show that,low-level Zn treatments can effectively promote the synthesis of wheat chlorophyll,improve photosynthetic capacity,and increase yield.The yield of ZnL1(250 mg kg^(-1))was the highest in the two-year test,which increased by 20.4%in 2018 and 13.9%in 2019 compared with CK(0 mg kg^(-1)).However,a high Zn level had a significant stress effect on the photosystem of wheat.PIabs(reaction center performance index)and Fv/Fm(maximum photochemical efficiency)were significantly reduced,the active oxygen metabolism system was damaged,and the photosynthetic capacity was reduced,which in turn led to reduced yield.Among them,the yield of ZnL4(1000 mg kg^(-1))was the lowest in the two-year test,which was 28.1 and 16.4%lower than CK in 2018 and 2019,respectively.The green peak position of ZnL3 and ZnL4 had"red shift"to the long wave direction,while the red valley position of ZnL4 had"blue shift"to the short wave direction.Under ZnL4,some wheat leaf organelles began to decompose,vacuoles increased,cytoplasm decreased,cell walls thickened,chloroplast basal lamellae were disordered,and mitochondrial membranes disintegrated.Stepwise regression and Path analysis showed that Pn(net photosynthetic rate)played a leading role in the formation of yield.Redundancy(RDA)analysis showed that the optimal Zn level for wheat growth was about 250 mg kg^(-1),and wheat would be stressed when the soil Zn level exceeded 500 mg kg^(-1) in the test condition of this study.Findings of this study provide a theoretical basis for the diagnosis and prevention of heavy metal(Zn)pollution in the soil.

Effect of Culture Parameters on the Growth of Sparassis crispa Mycelium

The effect of carbon and nitrogen sources, pH, temperature and substrate water content on the growth and vigor of Sparassis crispa mycelium was evaluated. Mycelial growth rates were highest when rice starch served as the carbon source and when peptone, yeast extract or soybean meal were adopted as the nitrogen source. The optimum pH and substrate water content values were 5.25 and 62.5% respectively. Mycelial growth was optimal at 20.2 ℃ and inhibited at 35 ℃, and temperatures of 40 ℃ and above killed the fungus.

Biological Characteristics of the Pathogen Phyllosticta capitalensis Causing Banana Freckle Disease in Hainan Province

[Objectives]This study was conducted to clarify the biological characteristics of the pathogen Phyllosticta capitalensis,the causal agent of freckle disease on Cavendish banana in Hainan Province,China.[Methods]The impact of various nutritional and environmental factors,including media,carbon sources,nitrogen sources,temperature,pH and light on the growth and sporulation of P.capitalensis was assessed using two distinct methods:mycelium growth rate and blood counting chamber.[Results]The mycelial growth and sporulation of P.capitalensis on different media exhibited notable differences.The use of banana leaf extract dextrose agar(BLEAD)and carrot agar(CA)was observed to facilitate rapid mycelial growth.The potato dextrose agar(PDA)and potato sucrose agar(PSA)were conducive to the production of conidia.The utilization of distinct carbon and nitrogen sources exerted a pronounced influence on the growth of P.capitalensis.Maltose,dextrose,fructose,and casein acid hydrolysate were the preferred substrates for mycelial growth.The tested carbon and nitrogen sources did not significantly stimulate conidial production,whereas dextrose and NaNO 3 were found to favor sporulation.The optimal temperature for mycelial growth and conidial production was determined to be 28 and 32℃,respectively.No mycelial growth was observed at 5℃.Active mycelial growth was observed at pH 6-10,with pH 6-7 being particularly conducive to sporulation.Complete darkness was conducive to mycelial growth and sporulation.[Conclusions]It is recommended that BLEDA and PDA should be incubated at 28℃for 14 d in the dark for the purpose of mycelial growth and sporulation of P.capitalensis,respectively.

Vegetative Development of <i>Sparassis crispa</i>in Various Growth Conditions and Effect of Electric Pulse Simulation on Its Fruit Body Production

This study was carried out to detect the favorable mycelial growth conditions and effect of electric pulse stimulation on fruit body production of SC-1 strain of Sparassis crispa. The optimum growth in PDA was found at 25°C (67 mm colony diameter in 28 days) followed by 20°C (63 mm colony diameter in 28 days). There was no mycelial growth at 35°C. The most favourable initial media pH range was found to be 5 - 7 and colony diameter measurements were not statistically different among these pH values (p > 0.05). However, the highest growth was obtained at pH 6 (57 mm colony diameter in 28 days). A basal medium composed of 0.05 g MgSO4, 0.46 g KH2PO4, 1.0 g K2HPO4, 120 μg thiamine-HCl, 20 g agar and 1000 ml of distilled water was used to investigate growth response of S. crispato different carbon and nitrogen sources. In 28 days, fructose and glucose exhibited best growth (49.4 mm and 31.6 mm colony diameters respectively) and there was no growth on the basal medium supplemented with galactose. Basal medium supplemented with glycine and alanine as nitrogen sources resulted in best growth, 54.4 mm and 50.5 mm colony diameters respectively. There was no mycelial growth in culture medium supplemented with ammonium acetate, ammonium phosphate, arginine and histidine. Electric pulse stimulation improved the fruiting body production. The yields obtained from all bottles in which electric pulse was applied were significantly higher than the yields from the bottles in which electric pulse was not applied. The percent increases of fresh weight yield from control on 100, 120, 130, and 170 kilovolts were 36%, 44%, 75% and 81% respectively. As regard to dry weight yield, the percent increases from control on 100, 120, 130, and 170 kilovolts were 27%, 54%, 63% and 67% respectively.

落叶型棉花黄萎病的生物学特征及药剂防治分析

【目的】比较研究新疆昌吉市和沙湾市落叶型棉花黄萎病病原菌的生物学特性,分析的多菌灵、乙蒜素、唑酮乙蒜素、枯草芽孢杆菌和哈茨木霉菌5种农药对棉花黄萎病的防治效果,筛选出高效的药剂用于指导棉花病害防治。【方法】采用菌丝生长速率法,通过不同离子、pH值、碳源及温度生长的适应,分析各病原菌的主要生物学特性,并对5种农药进行室内毒力测定。【结果】昌吉市和沙湾市各病原菌生长最适温度为20~25℃,最适离子培养基为Ca^(2+),最适pH值5~7,最适碳源是蔗糖。5种供试药剂均对各病原菌具有明显的抑制效果。多菌灵、枯草芽孢杆菌、哈茨木霉菌对病原菌的抑制作用极强,昌吉市多菌灵、枯草芽孢杆菌、哈茨木霉菌其抑制中浓度EC_(50)值仅分别为0.2923~0.8193μg/mL、0.01661~0.02695μg/mL和0.1015~0.8846μg/mL,沙湾市EC_(50)值分别为0.3588~5.694μg/mL、1.813×10^(-2)~2.727×10^(-2)μg/mL和0.1810~0.6088μg/mL;而乙蒜素、唑酮乙蒜素对病原菌的防效最差,其EC_(50)在昌吉市分别高达71.04、111.6μg/mL,沙湾市分别为79.22、171.7μg/mL。【结论】昌吉市、沙湾市的各病原菌最适生长的温度为25℃,含Ca^(2+)培养基为最适离子培养基。各病原菌在pH值5~7时生长速率最快,最适生长环境为酸性环境,对偏碱性环境也有较好的耐受性。微菌核在偏碱性的环境下更易形成,在以蔗糖为碳源的培养基上的生长速率最快。多菌灵、枯草芽孢杆菌、哈茨木霉菌对棉花黄萎病菌有强抑菌作用,可在昌吉市和沙湾市用于防治棉花黄萎病。

无机盐、维生素及生长调节剂对卵孢长根菇菌丝的影响

以卵孢长根菇菌株“Chang-202001”为供试菌株,采用平板培养法,在培养基中加入不同种类和质量浓度的无机盐、维生素和生长调节剂,研究了不同无机盐、维生素和生长调节剂对卵孢长根菇菌丝生长的影响,以期为高质量卵孢长根菇菌种的生产提供参考依据。结果表明:供试无机盐中,适量浓度的磷酸二氢钾、硫酸镁对卵孢长根菇菌丝生长有促进作用,而氯化钠、氯化钾、氯化钙、硫酸锌、硫酸锰、硫酸铜抑制卵孢长根菇菌丝的生长。当磷酸二氢钾质量浓度为2.0 g·L^(-1)时,卵孢长根菇菌丝生长速率最大,为5.06 mm·d^(-1)。供试维生素(维生素B1、维生素B_(2)、维生素B6、维生素C、叶酸和烟酸)在一定范围内均促进卵孢长根菇菌丝的生长,其中当烟酸质量浓度为4 mg·L^(-1)时,卵孢长根菇菌丝生长速率最大,为6.97 mm·d^(-1)。供试生长调节剂中,6-BA、2,4-D、GA_(3)抑制卵孢长根菇菌丝的生长,适量浓度的NAA促进卵孢长根菇菌丝的生长,当NAA浓度为1.0 mg·L^(-1)时,卵孢长根菇菌丝生长速率最大,为5.41 mm·d^(-1)。

植物生长剂对高温胁迫后黑木耳菌丝生长的影响

以黑木耳品种‘89-1’为试材,在40℃高温胁条件下,测定添加FA、NAA、6-BA、GA和IAA植物生长剂不同培养基的黑木耳菌丝长势和生长速度,研究了5种植物生长剂对高温胁迫后黑木耳菌丝生长及显微结构的影响,以期为黑木耳品种选育和生产实践提供参考依据。结果表明:不同植物生长剂对黑木耳菌丝长势和生长速度均有一定的影响,其中添加了GA的培养基,在25℃和40℃高温培养环境下,对黑木耳菌丝生长均有促进作用,当浓度配比为15×10^(-7)mg·mL^(-1)时,对高温胁迫后的黑木耳菌丝修复效果最佳。

不同药剂与施药时期对辣椒炭疽病防治效果的影响

【目的】探明贵州辣椒炭疽病的适宜防治药剂和防治时期,为辣椒炭疽病化学防控提供依据。【方法】选取已登记的15种辣椒炭疽病防治药剂单剂(25%咪鲜胺EC、80%波尔多液WP、50%肟菌酯WG、22.7%二氰蒽醌SC、70%代森锰锌WP、40%百菌清SC、30%琥胶肥酸铜WP、80%克菌丹WG、22.5%啶氧菌酯SC、85%三氯异氰尿酸SPX、40%苯醚甲环唑SC、500 g/L氟啶胺SC、50%咪鲜胺锰盐WP、250 g/L嘧菌酯SC和25%吡唑醚菌酯SC)和1个混剂(40%苯甲•吡唑酯SC)为药剂处理,选取贵州辣椒炭疽病的3个主要致病菌菌株(C.scovillei GL 17-25、C.gloeosporioides GL 17-42和C.fructicola GL 17-147)为防治对象,采用菌丝生长抑制法和离体果实接种法对药剂进行初筛,通过田间试验进一步验证适宜的药剂和防治时期。【结果】25%咪鲜胺EC、50%咪鲜胺锰盐WP、70%代森锰锌WP对3种辣椒炭疽病菌的菌丝生长抑制率均为100.00%;离体果实接种试验表明,除70%代森锰锌WP外,各药剂的平均预防效果均高于治疗效果,25%咪鲜胺EC对3个菌株的预防和治疗效果最好,平均值分别为72.48%和60.01%,其次为25%吡唑醚菌酯SC(43.53%和30.36%)。相比发病中期用药,发病初期用药的病情指数低、防效高,25%吡唑醚菌酯SC和40%苯甲•吡唑酯SC的防效显著(P<0.05)高于25%咪鲜胺EC,前两者发病初期用药的防效分别为86.99%和88.59%,发病中期用药防效分别为50.87%和45.48%。【结论】25%吡唑醚菌酯SC和40%苯甲•吡唑酯SC能有效防治辣椒炭疽病,防治时期以发病初期为佳。

不同竹笋加工废弃物配方对大球盖菇菌丝生长及产量的影响

【目的】分析不同竹笋加工废弃物栽培配方对大球盖菇菌丝生长及产量的影响,为竹笋加工废弃物栽培大球盖菇提供参考依据。【方法】以全木屑配方为对照配制培养基,设置竹笋加工废弃物不同添加比率15%(T1)、30%(T2)、45%(T3)、60%(T4)、75%(T5)共5个配方处理,测定大球盖菇菌丝生长速率、采收时间和产量。【结果】大球盖菇菌丝在不同培养基上均能生长,T1、T2处理菌丝生长速率均快于对照,T2处理的菌丝生长速率最快,达到2.36 mm/d,显著快于对照,随着竹笋加工废弃物添加比率的提高,菌丝生长速率逐渐减慢。在不同培养基上均能出菇,T1、T2的采收时间比对照短,竹笋加工废弃物添加比率大于45%时,采收时间变长,产量降低。各处理之间的产量差异均显著,T1、T2产量显著高于对照,T2产量最高为6.47 kg/m^(2),比对照提高10.79%,竹笋加工废弃物添加到45%以上时,产量逐渐降低。【结论】竹笋加工废弃物添加比率30%(T2)的培养基大球盖菇产量最高,采收时间短,适合大球盖菇栽培与推广。

干旱胁迫对‘济菊’生长及光合生理特性的影响

设置正常水平、轻度干旱、中度干旱、重度干旱4个不同的控水梯度,研究不同干旱胁迫条件下‘济菊’生长指标及光合生理特性参数的变化,为其规范化栽培提供参考。随着干旱胁迫程度的加剧和时间的持续,植株的生物量、叶片的相对含水量呈下降趋势,叶绿素含量先上升后下降;光合速率、蒸腾速率、气孔导度和胞间二氧化碳浓度总体均呈下降趋势,但胞间二氧化碳浓度在重度干旱条件下有一个先升后降的过程;超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性均呈先上升后下降趋势。重度干旱胁迫下‘济菊’可持续耐旱21 d以上,说明‘济菊’具有很强的抗旱性,同时也表明一定范围的干旱胁迫下,‘济菊’可以通过保护酶实现自我调节来维持生理代谢以适应干旱环境。

陕北野生羊肚菌菌核形成中氧化应激影响的初步探索

为了解氧化应激对陕北野生羊肚菌菌核形成的影响,采用平板培养法,初步探讨温度、pH、过氧化氢、抗坏血酸(强抗氧化剂)、苯甲酸钠(羟基自由基清除剂)和L-半胱氨酸(巯基化合物)等对羊肚菌菌丝生长和菌核形成的影响,并对菌丝和菌核中过氧化氢浓度和过氧化氢酶活力进行了检测。结果可知,实验菌株形成菌核的最适温度是20℃,最佳pH为6;过氧化氢在适当浓度下可促进菌核形成;活性氧自由基清除剂则可消除胞内的氧化应激而抑制菌核形成,抗坏血酸、苯甲酸钠和L-半胱氨酸对菌丝生长和菌核发生均有抑制作用,随浓度升高而增强,抗坏血酸抑制菌核形成的效果最强;菌核中过氧化氢浓度明显低于菌丝,但过氧化氢酶活力则明显高于菌丝。因此,外界条件的变化可导致菌丝细胞中活性氧浓度的改变,活性氧升高到一定浓度会促使胞内产生氧化应激,进而菌丝细胞分化形成菌核。

不同碳氮源对香菇液体菌种生长的影响

以香菇‘沪香F2’为试验材料,探究了9种碳源配方和10种氮源配方对菌丝在固体培养基上生长速度、在液体培养基中菌丝生物量和发酵固形物体积比以及发酵完成时接种后菌丝在木屑试管中生长速度的影响。结果表明:在固体培养基上,以糖蜜为碳源时,菌丝生长速度最快,达6.10 mm∕d,以木糖为碳源时,菌丝生长速度最慢,仅3.84 mm∕d;以麸皮为氮源时,菌丝生长速度为4.01 mm∕d,以尿素为氮源时,菌丝生长速度最慢,仅3.19 mm∕d。在液体培养基中,以糖蜜为主要碳源时,菌丝生物量达8.04 g∕L,发酵固形物体积比达98.69%;以麸皮为主要氮源时,菌丝生物量达7.90 g∕L,发酵固形物体积比达96.57%。相关性分析发现,在不同碳源的固体培养基上,菌丝生长速度与菌丝生物量呈显著正相关;在不同氮源的液体培养基中,菌丝生物量与发酵固形物体积比呈显著正相关;不同碳氮源的菌丝生物量与菌丝接种后在木屑试管中的生长速度呈显著正相关。综上,糖蜜和麸皮是香菇液体菌种最佳的碳氮源组合。该研究结果可为工厂化香菇液体菌种原材料的选择提供参考。

培养料容重对黑木耳菌丝特性及出耳的影响

采用机械压料装置,通过湿热塑形制备0.72、0.80(对照)、0.88、0.96、1.04 g·cm^(-3)黑木耳(Auricularia heimuer)菌包,比较蒙古栎(Quercus mongolica)屑为主料的不同培养料容重对菌丝生长速度、CO_(2)释放和水分挥发强度、干物质分解利用、pH、电导率、胞外酶活性、木质纤维素含量和第一潮产量和性状的影响。结果表明:在实验范围内,与对照相比,容重最小(0.72 g·cm^(-3))时,侧面和垂直菌丝生长速度较快,干物质分解利用较多,体积消耗较少,pH较高,电导率较高,木质素、纤维素含量较高,出耳时间(8.00±1.00) d较短、耳片较长(8.93±1.29) cm、耳片较厚(0.39±0.09) mm、硬度(1.62±0.08) N和泡发率7.31±0.59较低;研究结果可为黑木耳培养料容重的选择提供参考。

配比施肥对不同川黄柏种源幼苗生长及生理特性的影响

【目的】探究不同配比施肥对3个川黄柏种源幼苗生长及生理特性的影响,旨在为川黄柏的科学应用提供适宜的种源与施肥方案。【方法】以1年生3个川黄柏种源幼苗为试验材料,采用L27(313)正交试验设计,对3个种源进行配比施肥试验,测定其生长指标(苗高、地径)和生理特性指标(叶绿素、可溶性糖、可溶性蛋白、丙二醛(MDA)、超氧化物歧化酶(SOD)、硝酸还原酶(NR)、谷氨酰胺合成酶(GS)),并运用相关性分析及隶属函数模糊评价法进行综合评价。【结果】与CK相比,配比施肥能显著促进川黄柏苗高、地径生长及叶片叶绿素含量,增强可溶性糖、可溶性蛋白及酶活性(SOD、NR、GS),对抑制丙二醛含量降低膜脂过氧化效果明显。隶属函数综合评价结果表明,3个种源综合表现最差的均为CK,其中重庆江津种源在T6(N2P3K1)处理下综合表现最好;湖北恩施种源在T4(N2P1K2)处理下的综合表现最佳;湖南湘西种源在T8(N3P2K1)处理下的综合表现最优。【结论】合理的氮磷钾配比施肥可以改善川黄柏幼苗的生理代谢水平,促进苗木生长发育。研究表明3个川黄柏种源中湖北恩施种源综合表现最佳,为优选栽培种源,其次为湖南湘西及重庆江津种源。本试验条件下,生产上适宜重庆江津种源的最佳氮磷钾施入量为尿素6 g·株^(-1)、过磷酸钙5 g·株^(-1)、氯化钾2 g·株^(-1);湖北恩施种源为尿素6 g·株^(-1)、过磷酸钙1 g·株^(-1)、氯化钾3 g·株^(-1);湖南湘西种源为尿素8 g·株^(-1)、过磷酸钙3 g·株^(-1)、氯化钾2 g·株^(-1)。

氟啶胺对河南省小麦茎基腐病菌的抑制活性及田间防治效果

为了明确假禾谷镰刀菌对吡啶胺类药剂氟啶胺的敏感性,采用菌丝生长速率法测定了氟啶胺对2022年4—5月份从河南省各地市分离的86株假禾谷镰刀菌菌丝生长的毒力,建立了敏感性基线,并开展了氟啶胺对小麦茎基腐病的田间防治效果试验。结果表明:氟啶胺对假禾谷镰刀菌菌丝生长的最低抑制浓度(MIC)为20μg/mL,对86个菌株菌丝生长的有效抑制中浓度(EC_(50))为0.013~0.492μg/mL,平均EC_(50)值为0.194μg/mL;57株(占总数的66.3%)的敏感性呈近似正态分布,将其平均EC_(50)值(0.201±0.057)μg/mL作为假禾谷镰刀菌对氟啶胺的敏感性基线;同一地市内菌株间敏感性差异较大,EC_(50)最大值与最小值的比值在2.8~36.7之间,漯河差异最大,许昌差异最小;不同地市间菌株对氟啶胺的敏感性无显著性差异;河南省假禾谷镰刀菌对氟啶胺的敏感性差异与菌株的地理来源无明显关联性;菌株对氟啶胺的敏感性与其对多菌灵和戊唑醇的敏感性之间无明显相关性;采用500 g/L氟啶胺悬浮剂浸种,对小麦茎基腐病防治效果较好,伊川县、新安县两地在起身期的发病率分别降低了45.46%和56.88%,乳熟期的白穗率分别降低了8.73%和13.67%。表明500 g/L氟啶胺悬浮剂浸种对起身期小麦茎基腐病的防效较好,两地均达51%以上。本研究为氟啶胺对小麦茎基腐病的防治提供了参考。