生物型种衣剂对玉米抗纹枯病防御酶系的诱导

以玉米抗、感纹枯病的4个品种为材料，研究了生物型种衣剂ZSB对玉米纹枯病的防效，经种衣剂处理后再接种玉米纹枯病病原菌R. solani主要寄主防御反应酶系POD、PPO和PAL活性的动态变化。结果表明生物性种衣剂ZSB处理后能在一定程度上控制纹枯病的危害，对抗病品种瓦试13和沈试28防效为39%和49.7%，高于对感病品种沈试29和掖单13的防效。4个玉米品种经种衣剂处理后再接种玉米纹枯病病原菌R. solani主要寄主防御反应酶系POD和PPO活性高峰出现的早，且高于单独接种的。但是种衣剂处理后寄主PAL活性没有明显差异。     

硫酰氟熏蒸剂对基质栽培番茄、茄子经济性状及病害的影响

硫酰氟熏蒸剂用于基质消毒在国内尚未见报道。为明确硫酰氟熏蒸剂对基质栽培番茄、茄子经济性状、产量及番茄晚疫病、茄子青枯病等土传病害的影响,2013—2014年,进行了硫酰氟熏蒸剂基质消毒对番茄晚疫病、茄子青枯病的防效及对产量影响的试验研究。结果表明,硫酰氟熏蒸剂10、20、40 g/m33个供试剂量和3、5、7天3个熏蒸时间处理,其对番茄晚疫病、茄子青枯病的防治效果显著优于常规甲醛消毒处理,番茄、茄子作物的经济性状指标株高、茎粗明显增加,产量提高。处理效果随着硫酰氟用量的增加显著提高,硫酰氟不同熏蒸时间处理间差异不显著。生产上推荐硫酰氟熏蒸剂基质消毒40 g/m3熏蒸5天为宜。     

植物激素配比对大蒜茎盘愈伤组织再生体系的影响

植物激素对大蒜茎盘愈伤组织再生的各个环节都发挥着重要的作用。试验结果表明：2,4．D对茎盘愈伤组织的诱导具有主要作用，高浓度的2，4-D有利于大蒜愈伤组织的诱导，但并不利于其增殖分化。MS＋NAA 2mg／L＋BA 1mg／L培养基适宜于愈伤组织的继代增殖，MS＋NAA 1mg／L＋BA 5mg／L培养基适宜不定芽的分化，只添加NAA或无激素的MS培养基有利于不定芽生根。     

一份新的水稻斑点叶突变体spl32的鉴定和基因定位

从F2(粤晶丝苗2号/H4)群体中,鉴定出一份显性斑点叶突变体spl32(spotted leaf 32)。其叶片褐色斑点受自然光诱导,在幼穗分化期从叶尖逐渐扩散至叶鞘,台盼蓝染色表明斑点并非由细胞死亡引起。以从F5杂合个体分离出的正常叶色植株为对照,斑点叶植株的穗粒数、结实率显著降低。斑点出现后,spl32的POD活性和MDA含量均显著高于对照;同时,spl32叶片光合色素含量降低,但荧光动力学参数并无显著变化。抽穗期人工接菌表明,spl32对水稻白叶枯病菌抗性较对照显著提高。遗传分析表明spl32斑点性状由一个显性基因Spl32(t)控制,利用F2(02428/spl32)群体将其定位在第11染色体Ind-c和RM206之间,推测该基因为一个新的水稻斑点叶基因。     

雪松叶枯病病原菌及其生物学特性

１９８７－１９８９年连续３年观察了雪松叶枯病的症状特点，分离培养出致病的病原菌，根据其分生孢子形态，鉴定为柳杉拟盘多毛孢菌该菌分生明发适温为２５－３０℃，相对湿度为９８％－１００％，ｐＨ值为４－６。在１０％雪松汁液中萌发率最高。在ＰＤＡ培养基上生长最好，在查彼氏，麦芽糖上生长较好，在甘露糖，黄豆培养基上生长一般，在乳糖上生长差。     

Effect of microwave radiation on dry bean seed infected with Xanthomonas axonopodis pv. phaseoli with and without the use of chemical seed treatment

Common bacterial blight (Xanthomonas axonopodis pv. phaseoli) is a seed-borne disease that is difficult to control in dry bean (Phaseolus vulgaris L.). Laboratory and field studies were conducted over a two-year period to determine the effect of microwave radiation on navy (cv. Navigator and Envoy) and pinto (cv. AC Ole) bean. Laboratory tests resulted in a 12 to 25% decrease in germination following 50–60 s of radiation, while less than a 10% loss was observed between 0 and 40 s. Pathogen viability was also tested, however the incidence of pathogen infection was low and no correlation was observed between exposure time and the incidence of colonization. In field studies conducted at Morden, MB (2012) and Ridgetown and Exeter, ON (2012–2013) microwave radiation and two chemical seed treatments (copper hydroxide 53.8% and pyraclostrobin + fluxapyroxad + metalaxyl) were evaluated for their effect on emergence, disease infection, seed pick, yield and return on investment. The application of microwave treatment decreased emergence by up to 7%, but did not impact the other parameters measured. Chemical treatment alone or in combination with microwave treatment also did not affect emergence, disease incidence, yield, seed pick, or return on investment.     

Are field populations of arbuscular mycorrhizal fungi able to suppress the transmission of seed-borne <Emphasis Type="Italic">Bipolaris sorokiniana</Emphasis> to aerial plant parts?

The development of seed-borne Bipolaris sorokiniana in barley in the presence of arbuscular mycorrhizal fungi was studied. To exploit natural variation in their ability to control disease development, arbuscular mycorrhizal fungi from various Swedish arable soils were multiplied in trap cultures using a mixture of plant species. Six out of eight trap culture soil inocula were able to reduce transmission of B. sorokiniana from seeds to stem bases when grown together with infected barley seed. Based on this result two soil inocula, of different origin, from semi-natural grassland and barley respectively, were chosen for further greenhouse studies. Both soil inocula gave significant reductions in pathogen transmission from seeds to seedlings compared to the untreated control. In addition, treatment with spore inocula, collected from the different trap culture soils, showed disease suppression. Treatment with spores from the pure culture Glomus intraradices gave significant reduction in leaf lesion development. A treatment with the commercial inoculum Vaminoc^® was included and gave some suppression of the pathogen. In conclusion this study has shown that AM soil inocula from trap cultures suppressed the transmission of seed-borne B. sorokiniana in the aerial parts of barley plants.     

不同时期毛苔草对不同水文情势的生长响应研究

 通过幼苗移植、水位控制试验,研究毛苔草对不同水文情势的生长响应,以及不同水文经历下的响应差别。结果表明,毛苔草对不同水文情势及水文经历存在显著生长响应。毛苔草地上、地下以及根茎生物量均在干湿交替条件下最大;鲜重根／茎随水分的增加而降低,干重根／茎则总体上随水分的增加而升高;根茎生物量比重在干旱处理下最大。不同水文经历的毛苔草,其生物量以有干湿交替经历的较大,根／茎及根茎占总生物量的比重则以经历干旱处理的较大;淹没水文情势下,毛苔草生长缓慢,但淹没抑制消除后,其生长过程可以通过根茎萌发得以延续。各生长指标极值的出现,要求在不同的生长阶段提供其所需的水文条件。在湿地恢复与管理过程中,针对生长季内优势植物水文需求的变化,采取不同的水文措施,有助于达到最佳的恢复及管理目标     

花椒春夏高接换优技术试验

针对花椒春季硬枝嫁接时间较短的现状,在花椒春季硬枝嫁接的基础上开展了嫩枝高接换优试验,有效地解决了硬枝嫁接接穗不能长时间贮藏的问题.通过春夏2个季节嫁接改进了花椒嫁接技术,延长了嫁接时间,花椒嫁接后减少了花椒皮刺,减少了采摘成本.     

Virulence and mycotoxic effects of Metarhizium anisopliae on Mahogany shoot borer, Hypsipyla robusta (Lepidoptera: Pyralidae)

Developing appropriate control measures for the Mahogany shoot borer,Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swietenia mahagoni Jacq(Sapindales:Meliaceae).Existing management methods are largely limited to silvicultural practices and spraying of chemical insecticides.To identify a potential fungal biocontrol agent,we compared the virulence of six native and two standard ARSEF isolates of Metarhizium anisopliae Metsch.against this pest.The average survival time and conidial yield of IWST-Ma7 was higher(6.2 to 7.3 days and 4.9 to 4.7 × 10 5 conidia/ml) than the standards.Significant difference in sporulation on the cadavers between isolates,doses and incubation periods were substantiated for the selection of potential strain.The mycotoxic effects of crude soluble protein extract when incorporated in the artificial diet,the ARSEF 2596 and ARSEF 3603 showed LD 50 value of 3.7% and 5.6%.However,IWST-Ma7 was highly lethal with significant lowest LD 50 value of 2.6%.The enzyme activity of IWST-Ma7 was highest for chitinase,CDA,protease and lipase viz.,1.90 U/mg,1.80 U/mg,0.98 U/mg and 0.80 U/mg respectively.However the enzyme activity of chitinase and Chitin deacetylase assay for all the isolates was significantly higher than protease and lipase activity.The ITS regions(5.8S rDNA and 28S rDNA) of seven isolates of M.anisopliae were amplified using the ITS1 and ITS4 primers which was a unique fragment of approximately 550 bp.Based on ITS regions,phylogenetic tree have been constructed and the isolates have been grouped in to 5 clades.The virulence and mycotoxic effects of different isolates could rationally be used to employ them for the management of the mahogany borer.