灰斑病菌对大豆叶片总多酚和总黄酮的诱导研究

利用大豆灰斑病菌不同致病力的生理小种接种抗感不同的大豆品种,结果表明:大豆叶片内总黄酮类物质的含量与品种的抗病性呈明显正相关;感病品种叶片内总多酚含量变化显著降低,抗病品种总体变化不大.接种致病力强的生理小种能够大幅度提高抗病品种体内总黄酮含量,这一结果可以作为筛选和鉴定抗病品种的一种生化指标;大豆灰斑病菌弱毒菌株能够诱导感病品种体内总黄酮含量提高,进而提高大豆的抗病性,这一结果为大豆灰斑病的生物防治提供了依据.     

番茄尾孢叶霉病病原鉴定及生物学特性研究

对河南省新乡市郊保护地发生的番茄尾孢叶霉病的病原、症状、生物学特性等进行了初步研究。结果表明 ,该病的病原菌为番茄煤污尾孢 (CercosporafuligenaRoldan) ,主要危害叶片 ,形成近圆形、多角形或不规则形的灰黑色病斑。病菌分生孢子萌发的适宜温度为 2 5～2 7℃ ,最适 pH值为 6～ 7,致死温度为 5 3℃ 1 0min ,水滴是孢子萌发的必要条件 ,紫外光对分生孢子有很强的杀伤作用。     

玉米灰斑病菌菌丝生长的最适温度和pH值

应用SAS软件对玉米灰斑病菌菌落直径数据进行模拟.结果表明,模型y=xa2(c-x2)bEXP(dEXP(-ex1))能反映该病菌菌丝随时间和温度的变化情况,最佳模型为y=x1.29262(28.15-x2)a1743XP(-2.494 7EXP(-0.050 7x1));模型y=EXP(-(ax23 bx3 c))(dx1 e)能反映该病菌菌丝随时间和pH值的变化情况,最优模型为y=EXP(-0.0123x23 0.143 3x3)(0.0582x1 1.464 8);该病菌菌丝生长最适温度为24.81℃,最适pH值为5.82.pH值对菌丝生长的影响几乎是正态分布形式,而温度对菌丝生长的影响是偏态形式.     

The use of digital image analysis and real‐time PCR fine‐tunes bioassays for quantification of Cercospora leaf spot disease in sugar beet breeding

Cercospora leaf spot, caused by the fungus Cercospora beticola, is a major fungal sugar beet disease worldwide and the cause of significant yield losses. The disease is most successfully countered by the introduction of genetic tolerance into elite sugar beet hybrids. To this end, breeding programmes require high quality biological assays allowing discrimination of minor differences between plants within a segregating population. This study describes the successful implementation of image analysis software in the bioassays for quantification of necrotic lesions at different stages of C. beticola infection, allowing selection on minor phenotypic differences during the sugar beet breeding process for C. beticola resistance. In addition, a real‐time PCR assay was developed for the quantification of C. beticola pathogen biomass in infected beet canopy. The use of both techniques, even in an early stage of infection, fine‐tunes current bioassays, allowing more accurate and efficient selection of resistant breeding material.     

大豆灰斑病菌生物学特性与病害发生规律的研究

大豆灰斑病菌(Cercospora Sojina)生长最佳碳源为蔗糖,最佳氮源为天冬酰氨,硫胺素可显著地促进菌体生长和产孢,在常温干燥环境中,孢子可存活6天,维持其侵染力3—4夭,已萌发的孢子对干燥环境的耐力降低,孢子侵入大豆叶片所需的保湿时间与品种抗性和保湿期温度有关。病斑产孢的最适温度为24℃,保湿期少于4小时产孢量较少。     

辣椒褐斑病菌粗毒素的提取方法研究

对辣椒褐斑病病原菌(Cecospora capsici Heald.et Wolf)毒素提取方法进行了研究。结果表明,采用极性大的有机溶剂萃取效果最好,萃取产生沉淀,分别对上清液和沉淀进行生物测定,具有致病作用的物质基本都在上清液中,说明辣椒褐斑病菌在液体培养基中所产生的具有致病作用的物质属于小分子化合物。     

过氧化物酶同工酶及其活性与大豆灰斑病抗性的关系

不同抗病性大豆品种接种大豆灰斑病菌前后过氧化物酶同工酶及其活性的研究结果表明,抗病品种在接种前均缺少同工酶Ｃ３带,接种后出现同工酶Ｃ３带;感病品种在接种前后,只是同工酶活性发生变化,没有出现同工酶缺失或增加。接种前,抗病品种的过氧化物酶活性高于感病品种;接种后,抗感病品种过氧化物酶活性均增加,但抗病品种的活性仍高于感病品种。     

Monosomic addition lines of Beta corolliflora in sugar beet: plant morphology and leaf spot resistance

Monosomic addition lines in Beta vulgaris from Beta corolliflora were described morphologically and characterized for disease resistance. Monosomic addition plants (2n= 19) were selected among segregating offspring by a squash dot technique in combination with B. corolliflora‐specific probes. Plants carrying an added chromosome were characterized by leaf shape, plant size and plant vigour. In this way, most addition lines could be distinguished from diploid beets, however, to identify those plants unequivocally, molecular marker analysis was also necessary. Transmission frequencies of each addition line were determined to be in the range 13.9% (Cor‐4) to 60% (Cor‐9). High transmission rate of addition line Cor‐9 was assumed to be due to apomictic propagation because transmission rate after selfing cannot exceed 50%. Cercospora leaf spot resistance tests were performed on 167 monosomic plants from seven different addition lines, two fragment addition lines and 89 diploid controls. No line exhibited complete resistance, but the monosomic additions Cor‐3 and Cor‐4 showed significantly lower infection rates than their diploid sibling plants. The identification of monosomic addition lines with apomictic and disease resistance characters offers the possibility of transferring those genes to sugar beet.     

杜松赤枯病防治技术的研究

由Cercospora sequoiae var.juniperi引起的杜松赤枯病在黑龙江省分布比较普遍。两季发病严重,能导致被害株死亡。6月中旬至7月上旬喷药。在双效灵、甲基托布津可湿性粉剂和多菌灵三种农药中,以50％多菌灵,用量为70ml/a时,防治效果最好。     

人工接种与疫区诱发条件下大豆对灰斑病的抗性及后代选择研究

大豆灰斑病菌具有较强的生理分化的特点, 不同地区及气候条件都会影响大豆灰斑病的发病程度. 本试验将两份相同的大豆杂交材料分别种植在哈尔滨人工接种条件下及阿城疫区自然诱发条件下, 比较不同鉴定条件下杂交后代及亲本的抗性表现、抗性遗传与选择效果. 结果表明, 气候因素对大豆灰斑病抗性表现的影响很大. 在任何条件下,