细菌对植物病害生物防治研究进展

细菌作为重要的生防因子在植物病害防治上具有重要作用,文章介绍了生防细菌研究进展,包括细菌作为生防因子的优势、细菌对植物病害的作用机制、生防细菌定殖、生防细菌鉴定、影响生防细菌效果的环境因素、重要的生防细菌假单胞菌和芽孢杆菌应用研究及生防细菌菌剂开发,并对未来生防细菌的遗传改造等生物工程进行了展望。     

In vitro compatibility of microbial agents for simultaneous application to control strawberry powdery mildew (Podosphaera aphanis)

Biological control of plant pathogens on strawberries may be improved by the simultaneous application of different biological control agents (BCAs). Therefore, the compatibility of various BCAs which had previously shown to be effective against powdery mildew (Podosphaera aphanis (Wallr.) U. Braun & S. Takam) under laboratory conditions was examined in vitro. Inhibitory effects between fungal and bacterial BCAs were demonstrated in dual culture tests on two solid nutrient media. Leaf disc assays with single and multiple strain treatments demonstrated either unaffected or significantly improved control of P. aphanis for many multiple strain treatments, even if antagonistic interactions previously occurred in dual culture tests. Highest inhibition of powdery mildew conidiation (80.7% reduction) was achieved with multiple strain treatments with Bacillus subtilis FZB24 and Metarhizium anisopliae (p < 0.001). In this combination, conidiation was 3.7 times lower than in single treatments with B. subtilis indicating synergistic interactions between these BCAs. Combinations of Trichoderma harzianum T58 and B. subtilis FZB24 showed antagonistic interactions in dual culture tests as well as in leaf disc assays. In this combination, powdery mildew conidiation on leaf discs was four times higher compared to single treatments with T. harzianum T58.     

虫霉防治大豆蚜虫效果及其评价

2002年和2003年应用虫霉防治大豆蚜虫,盆栽试验结果表明,喷施10ml/L虫霉的处理对大豆蚜虫校正 防效最高,两年分别为100%和99. 3% ,虫霉浓度为6. 7ml/L则校正防效分别为93. 5%和95. 6%。2003年采用虫 霉浓度为10ml/L和6. 7ml/L的处理其校正防效与化学农药氧化乐果的校正防效差异不显著。2004年田间小区试 验结果表明,虫霉浓度为10ml/L对大豆蚜虫校正防治效果达100% , 6. 7ml/L的校正防治效果为98. 6%;田间大区 试验的校正防效分别为62. 3%和50. 4% ,所以建议使用10ml/L的虫霉防治大豆蚜虫。     

Effect of antagonistic Fusarium spp. and of different commercial biofungicide formulations on Fusarium wilt of basil (Ocimum basilicum L.)

The ability of antagonistic Fusarium spp. to control Fusarium wilt of basil caused by F. oxysporum f. sp. basilici was tested under glasshouse conditions from 1994 to 1996. Fusarium oxysporum antagonistic strain 251/2, a protoplast fusion-derived hybrid coded FI-11 and F. moniliforme strains TF4 and TF4 RB were able to decrease (P = 0.05) the incidence of Fusarium wilt significantly. Biocontrol was consistent, especially when the antagonists were applied by mixing a talc preparation of propagules in the substrate (10⁵ CFU/ml of substrate) 1–2 weeks before sowing or at sowing. Seed coating with the biocontrol strains (10⁸ CFU/g of seed) did not generally provide sufficient disease containment, whereas the combination of substrate treatment and seed coating did not improve wilt control in comparison with substrate treatment alone. Two commercial formulations, based on antagonistic F. oxysporum strains and one containing the antagonistic strain K61 of Streptomyces griseoviridis, were generally not sufficiently effective at the tested dosages.     

Shoot development and flowering in potato (Solanum tuberosum L.)

Summary The shoot system of potato is a configuration of stems with terminal inflorescences. In this review, shoot development is quantified in terms of stem production, while stem development is quantified in terms of leaf and flower primordia production per stem, which are functions of the rates and the durations of primordia initiation. The effect of the position of the stem in the shoot system on number of leaves and flowers per stem is also evaluated. Flowering of individual stems is described by the ‘time to flower primordia initiation’ (expressed in number of leaves produced) and ‘flower production’ (a function of the number and the development of flower primordia). At warmer temperatures and longer daylengths the number of leaves and flower primordia per stem, and the number of stems per shoot increase by prolonging stem production and primordia development. Temperature and photoperiod also affect flower primordia survival by altering assimilate production and partitioning. The photothermal response of the number of leaves per stem is small compared to the response of stem production; at higher temperatures, flower primordia survival becomes the principal factor determining flower production. The similarity of the signals leading to flower primordia initiation and tuberization, and the relation between shoot and tuber growth are discussed.     

Local and systemic control of powdery mildew (Leveillula taurica) on pepper plants by foliar spray of mono-potassium phosphate

A foliar spray of 1% (w/v) solution of the fertilizer mono-potassium phosphate (MKP) (KH₂PO₄) on the upper surfaces of lower leaves of greenhouse-grown peppers induced local and systemic control against Leveillula taurica, as compared with control plants. This protection was expressed by a reduction in the leaf area covered with sporulating colonies and in conidial production on leaf tissue, 24 or 48 h post-treatment, when MKP was applied on lower leaves of plants that had been exposed to the source of inoculum. Foliar application of MKP, initiated before or after exposure to heavily diseased plants as the source of inoculum, was effective in controlling powdery mildew. Application of MKP efficiently suppressed powdery mildew as expressed by inhibition of the development of new sporulating colonies, as well as the conidial production of the fungus on infected tissue. Microscopic examination indicated destruction of both hyphae and conidial structures on MKP-treated leaves. The efficacy of MKP in controlling powdery mildew on greenhouse-grown plants was compared with a sterol-inhibiting systemic fungicide. Both treatments significantly inhibited powdery mildew as compared with non-treated control plants, although the fungicide-based treatment seemed to be slightly more effective (not significant) in controlling the disease. Phosphate solutions were not phytotoxic to plant tissue and did not affect the yield, as compared with the fungicide treatment. However, a lower yield was recorded for the non-treated control plots because of mildew infection on leaves. These data indicate that MKP spray may be applied as an alternative practice for the control of powdery mildew in peppers.     

Aircraft-applied sulfur for control of powdery mildew (erysiphe cichoracearum) on potato in washington state

Aircraft-applied dust and liquid sulfur sprays were evaluated for control of powdery mildew (Erysiphe cichmacearumDC), on rill irrigated potatoes (cv. Russet Burbank). Either form of sulfur applied weekly or biweekly usually controlledE. chichoracearum through September, but not in October. Significant yield increases were obtained in only two of five trials. The small differences in disease severity between weekly and biweekly applications of sulfur were not significant. Sulfur gave very little control if applied after infection was established. Applications of liquid sulfur, the formulation less likely to cause environmental problems, should be started at the first trace of stipples on stems and continued biweekly throughout the season.     

Screening of endophytic bacteria and evaluation of selected isolates for suppression of burrowing nematode (Radopholus similis Thorne) using three varieties of black pepper (Piper nigrum L.)

Radopholus similis is a serious threat to black pepper (Piper nigrum L.) cultivation being the main causal organism of slow decline disease. Because of its migratory nature most fungal and bacterial antagonists are ineffective in suppressing R. similis. The presence of a number of endophytic bacteria in black pepper tissues has been proved in earlier studies. This study was undertaken to evaluate the bacteria isolated from black pepper for suppressing R. similis. In vitro and in vivo screenings were used initially to identify the efficient strains of endophytic bacteria that suppress R. similis. Seventy four isolates of endophytic bacteria obtained from black pepper were screened against R. similis by various bioassays. Results of the in vitro experiments were inconclusive and did not match the rest of the studies. However, six isolates were short-listed based on the preliminary in vivo screening and further tested in an evaluation trial using three varieties of black pepper. Irrespective of the varieties, significantly higher nematode suppression was observed with one isolate (TC 10) followed by another (BP 17). These isolates were identified to the species level by sequence analysis of the 16S rRNA gene. The results showed that these isolates shared 99% identity with Bacillus megaterium and Curtobacterium luteum, respectively. More studies are required to understand their mode of action as well as the dose–response relationship with nematodes.     

15个澳洲坚果品种在云南的产量及品质

对云南4个澳洲坚果品比点的产量及品质数据分析结果表明:15个品种的产量及品质均低于澳大利亚和夏威夷等澳洲坚果主产区.在4个品比点中,15个品种6a的平均产量为2.24 kg/株,仅有H2、O.C、HAES900和广11的平均产量大于4 kg/株,接近澳大利亚良种标准.在品质指标的比较中,O.C、HAES900、H2、和广11好于其它品种.综合产量和品质分析.供试的15个澳洲坚果品种中,HAES900、O.C、H2、广11优于其它品种,但因广11果仁偏小,在云南热区可将HAES900、O.C和H2作为主导品种在生产上推广种植.     

油菜雌性不育突变体FS-M1的生物学特性研究

对甘蓝型油菜雌性不育突变体FS-M1的研究结果表明，FS-M1天然授粉、人工授粉自交、自交套袋隔离、兄妹互交、剥蕾自交结角率均为3％左右，平均每角粒数1．3-1．8粒，表明雌性不育性稳定。用FS-M1花粉授予正常油菜品种，杂交结实率正常，F1植株自然授粉结实正常，F1植株自交结角率为97％，平均每角2l粒，雌性不育花粉对F1育性无异常影响。电镜扫描发现：FS-M1柱头乳突细胞扁平干瘪，发育畸形，可能是形成FS-M1雌性不育的主要原因。     

几种番荔枝属果树的酯酶和多酚氧化酶同工酶分析

应用垂直板不连续聚丙烯酰胺凝胶电泳技术对番荔枝属的7种果树共14份材料进行酯酶和多酚氧化酶同工酶分析.结果表明,2种同工酶共表现出23条酶带,其中酯酶同工酶9条,多酚氧化酶同工酶14条,不同番荔枝种间酶谱差异较大.2种同工酶酶谱除不能区分2份红毛榴莲和2份毛叶番荔枝外,对其余的10份材料均可区分.实验用几个番荔枝种间的遗传距离在0.000～0.895之间.聚类结果将14份番荔枝材料分成了2类.     

High temperature and low solar radiation during ripening differentially affect the composition of milky-white grains in rice (Oryza sativa L.)

ABSTRACT

Temperatures and solar radiation during ripening critically affect grain appearance in rice (Oryza sativa L.). Climatic factors to induce chalky grains were analyzed under the experimental conditions of high-temperature and shading treatment and also under the ambient condition in a high-temperature-prone region of Japan. The frequency of white-back (WB) and basal-white (BW) grains correlated with temperature and solar radiation, whereas that of milky-white (MW) grains was not correlated, suggesting that complicated climatic factors are involved in the formation of MW grains. Further investigation was carried out to identify the parameters that distinguish perfect and MW grains grown in high-temperature versus those grown in low-solar-radiation conditions. As reported previously, the chalk phenotypes in the transverse section of the MW grains were quite different between environments: oval-shaped chalk for MW grains grown in low-solar-radiation condition and center chalk for MW grains grown in high-temperature condition. Grain hardness and amylopectin chain-length distribution did not explain the difference in MW grains between environments. MW grains subjected to high temperatures had a lower protein content without a consistent reduction in the single-grain weight, whereas those from the low-solar-radiation condition had a lower amylose content with a consistent reduction in the single-grain weight, when compared with perfect grains that developed in either environmental condition. Overall, our results suggest that MW grains are formed through different physiological mechanisms with altered starch and protein synthesis under high-temperature and low-solar-radiation conditions.

Abbreviations: BW: basal-white; DAH: days after heading; DP: degree of polymerization; MW; milky-white WB: white-back     

Chemical control of weeds in wheat (Triticum aestivum L.) in Iran

Experiments were conducted in 2006–2007 at six research stations of the Iranian Plant Protection Research Institute to study the efficacy of different herbicides to control weeds in wheat. Treatments included mesosulfuron-methyl plus iodosulfuron-methyl-sodium plus mefenpyr-diethyl (WG) at 45 + 45 + 135 g a.i./ha, respectively, sulfosulfuron at 21, 31.5, 42 and 51 g a.i./ha, chlorsulfuron at 15 g a.i./ha, bromoxynil plus MCPA at 600 g a.i./ha with clodinafop propargyl at 64 g a.i./ha, sulfosulfuron plus metsulfuron-methyl at 36 g a.i./ha, mesosulfuron-methyl plus iodosulfuron-methyl-sodium plus mefenpyr-diethyl (OD) at 15 + 3 + 45 g a.i./ha, respectively, and a full season weed-free control. Herbicides were applied at wheat tillering. Results showed that sulfosulfuron plus metsulfuron-methyl, and bromoxynil plus MCPA with clodinafop propargyl resulted in satisfactory weed control and wheat grain yield at most locations. Weed control efficacy of both formulations of mesosulfuron-methyl plus iodosulfuron-methyl-sodium was variable across locations. Efficacy of the OD formulation appears to depend upon location, so that application of this herbicide at Shiraz and Gorgan resulted in better weed control compared to use of the WG. Satisfactory performance of the OD formulation at Gorgan and Shiraz could be attributed in part to the even pattern of rainfall distribution during the growing season and wheat cultivar used, respectively. With respect to grain yield, however, the OD formulation was better than WG formulation at most of the locations.     

利用栽培措施控制油菜菌核病的研究

以2个甘蓝型油菜品种为材料，利用自然鉴定和人工接种方法研究不同播期和不同密度等栽培措施对控制油菜菌核病的作用。结果表明，品种 播期对油菜菌核病的影响均达显著水平，种植密度对油菜菌核病的影响不显著，选用抗（耐）病性品种和适当晚播可有效控制或避开油菜菌核病发生。合理密植可提高油菜产量。     

Impact of glyphosate-resistant volunteer corn (Zea mays L.) density,control timing,and late-season emergence on yield of glyphosate-resistant soybean (Glycine max L.)

Glyphosate-resistant (GR) volunteer corn is a troublesome weed in soybean fields in a corn-soybean rotation as well as in corn fields in a continuous corn production system. The objectives of this study were to evaluate the impact of (1) different densities of GR volunteer corn on soybean yields, present as individual plants or clumps, controlled at fourth trifoliate (V4), sixth trifoliate (V6), or full flowering (R2) soybean growth stages, and (2) late-season volunteer corn emergence on soybean yields, after being controlled at different soybean growth stages. Field experiments were conducted in 2013 and 2014 under irrigated conditions in Clay County, Nebraska, and under rain-fed conditions in Lancaster County, Nebraska, USA. To maintain the desired number of isolated volunteer corn plants (1250, 2500, 5000, and 10,000 plants ha⁻¹) and clumps (63, 125, 250, and 500 clumps ha⁻¹), individual seeds and/or corn ears were hand-planted in each plot based on their respective target densities. Volunteer corn was controlled with applications of clethodim at V4, V6, or R2 soybean growth stages. Late-season volunteer corn emergence had no effect on soybean yield with volunteer corn densities and control timings at both locations in 2013 and 2014. During the first year of study at Clay County, volunteer corn densities and control timings had no effect on soybean yield. When volunteer corn was left uncontrolled or controlled at the R2 soybean growth stage, yield was the lowest at highest isolated volunteer corn plants (10,000 plants ha⁻¹) plus clump density (500 clumps ha⁻¹) during the second year of study in Clay County (≤5068 kg ha⁻¹) and during both years of study in Lancaster County (≤1968 kg ha⁻¹).     

茶小绿叶蝉生物防治研究进展

本文综述了国内近十多年来对茶小绿叶蝉生物防治的研究进展,包括对茶小绿叶蝉天敌、植物源农药的研究,提出了今后茶小绿叶蝉生物防治的研究重点和发展方向。     

植物生长调节剂对槟榔各生育期座果率的影响

以海南槟榔为材料,采用不同浓度水平配比于槟榔花期、花果期、果期分别喷施的方法,研究IBA、GA、云大-120三种植物生长调节剂对槟榔座果率的影响。结果表明：IBA 250 mg/L、GA 30 mg/L、云大-120 1 000 mg/L这3种处理水平在提高槟榔座果率上都达到显著或极显著影响。其中,IBA 250 mg/L处理较对照相比,达到极显著水平,GA 30 mg/L、云大-120 1 000 mg/L较对照相比,达到显著水平。而其余6种处理水平,在提高槟榔座果率上效果不太明显。     

Effects of nitrogen fertilizer and weed control on nutritive quality of carrots (Daucus carota L.)

The nutritive quality of carrots, obtained from different herbicide-treated plots and under different levels of nitrogen application ranging from zero to 80kg nitrogen/ha, was compared. There were significant differences in carotene content, T.S.S. (total soluble solids) and organolptic characteristics under the influence of different treatments. The maximum carotene content, T.S.S. and organoleptic characteristics were observed with the application of 80 kg. nitrogen/ha and fluchloralin herbicide at 0.90 and 1.20 kg/ha.     

油菜开花期QTL定位和候选基因分析

为辅助选育早熟油菜品种、克隆油菜开花期基因及开发花期分子标记,以已测序的油菜品种中双11 (Z) 和重测序的油菜品系No.73290 (N)为亲本构建的含184个单株的BnaZNF2群体为材料,通过分析该群体的基因型数据和F2:3家系连续三年（2010-2012）在武汉的表型数据,对开花期QTL进行检测和整合,定位到分布在11个连锁群上的14个开花期QTL。其中只有5个QTL能在3年中重复检测到,分别是qDtF.A2-1、qDtF.A6-2、qDtF.C2-1、qDtF. C2-2 和qDtF.C3-1,贡献率在7.1%～21.1%之间。通过查阅文献和在拟南芥、水稻等作物网站上搜索,搜集到442 个与植物开花期有关的基因。基于油菜基因组物理图谱,通过生物信息学分析,在本研究定位的QTL区间上筛选到54个可能的候选基因,可以用于开花期基因的克隆。在5个主要QTL区间内分别定位到8、5、4、2和4个候选基因,其中有15个双亲中存在序列差异,可以开发开花期的功能标记用于分子标记辅助选择育种。     

不同施肥处理对枳及柠檬容器苗生长的影响

研究9个不同施肥处理对枳及柠檬容器苗生长的影响。结果表明:不同施肥处理对枳容器苗的苗高、地径、分枝高度及嫁接后柠檬苗的发芽率、株高、茎粗、分枝数及生物量都存在显著差异;不同施肥处理对枳及柠檬容器苗综合表现最好的为T4(撒施柠檬专用肥1.6 g)处理,其次是T2(撒施尿素0.6 g)、T3(撒施柠檬专用肥0.8 g)处理,表现最差的是T8(浇施5%柠檬专用肥)和T7(浇施3%柠檬专用肥)处理。在一定施肥浓度范围内,施肥对嫁接后柠檬容器苗的生物量积累有明显促进作用。柠檬容器苗培育时建议采用在基质中撒施柠檬专用肥1.6 g。