300份玉米种质对两种灰斑病菌的抗性评价

2013～2016年,采用田间人工接种方法,评价300份玉米种质对两种灰斑病菌玉米尾孢(Cercospora zeina)和玉蜀黍尾孢(Cercospora zeae-maydis)的抗性。结果表明,对玉米尾孢表现高抗、抗和中抗的种质分别为10、100和121份,表现感和高感的种质分别为62份和7份;对玉蜀黍尾孢表现高抗、抗和中抗的种质分别为4、33和78份,表现感和高感的种质分别为137份和48份。76.99%的供试种质对玉米尾孢表现为高抗、抗或中抗,61.67%的供试种质对玉蜀黍尾孢表现为感或高感,玉米尾孢对大多数种质的致病力较玉蜀黍尾孢弱。     

不同品种甜菜褐斑病抗性分析及早期鉴定方法

采用人工病圃和自然病田同步进行抗褐斑病性鉴定筛选,初步试验结果表明,甜菜品种的含糖率随着抗病性的增强而明显提高,凡抗褐斑病品系材料,综合性状表现也较好。通过3期播种试验,植株生长至2～4对真叶期接种鉴定抗褐斑病性与田间成株鉴定结果相同,可以作为田间鉴定育种新材料的一种简便易行的方法。玛纳斯人工接种的最佳时间7月中下旬接种效果较理想,这为解决干旱地区抗病品种筛选鉴定提供了一条途径。利用甜菜褐斑病尾孢毒素粗提液对甜菜种子胚根生长的抑制作用,鉴定不同品种的抗病性,试验结果显示,各品种抗性结果与人工接种及自然病田抗性鉴定结果有一致性。试验表明采用早期鉴定方法,方法准确,可行性高,可以提高育种效率,有效缩短抗褐斑病育种进程。     

Genetic mapping for resistance to gray leaf spot in maize

The molecular marker technology has been used on mapping of quantitative trait loci (QTLs) associated with plant resistance. The objectives of this research were to estimate genetic parameters and to map genomic regions involved in the resistance to gray leaf spot in maize. Ninety F₃ families from the BS03 (susceptible) and BS04 (resistant) cross were used. Field trials were performed using a 10 × 10 square lattice design with three replications. Data from 62 SSR markers were used for linkage analysis. The locations of the QTLs on the linkage groups were determined by composite interval mapping method and the phenotypic variance explained by each marker was determined by regression analysis. Several QTLs associated to disease resistance were identified in the population BS03 × BS04. Some QTLs showed significant effects over the different environments studied. The existence of significant QTLs in common among different environments indicates these genomic regions as possible new tools for marker-assisted selection in maize breeding programs.     

大豆感染灰斑病菌后叶片中多酚氧化酶活性的变化

分析了大豆感染灰斑病菌后叶片中多酚氧化酶酶活性的动态变化,探讨了多酚氧化酶在大豆抗灰斑病中的作用。研究的结果表明,抗病品种感染灰斑病菌后,叶片中多酚氧化酶活性均比对照增加;而感病品种接种后叶片中多酚氧化酶活性比对照下降。这表明多酚氧化酶在大豆抗灰斑病中起着重要的作用,其活性的大小与大豆抗病性成正相关,可以作为大豆品种抗性鉴定的一个重要生理生化指标。     

应用关联分析挖掘大豆对灰斑病12号生理小种的抗性位点

利用126份SSR标记对320份对大豆灰斑病12号生理小种具有不同抗性的大豆材料进行基因组扫描、群体结构和连锁不平衡分析,并用STRUCTURE软件、TASSEL软件中的GLM分析方法对大豆抗性进行关联分析。结果表明:320份大豆品种中有23个表现高抗,53个表现抗病,178个表现中抗,56个感病,10个高感。找到与大豆抗灰斑病12号生理小种的相关位点共7个:H连锁群上的Satt052、F连锁群上的Satt335、C2连锁群上的Satt557、A1连锁群上的Sat_368、D1a连锁群上的Sat_346、O连锁群上的Satt243、J连锁群上的Sat_151。     

水稻窄条斑病及其种子传病与药剂防治

水稻窄条斑病是浙江杭州地区的新病害,本研究从症状识别、种子传病及防治药剂测试三方面入手对该病害进行研究。结果表明,通过对光观察病斑透明度,观察有无菌脓及喷菌现象可有效地将水稻窄条斑病与水稻细菌性条斑病区分开;水稻窄条斑病种子可带菌传病,传病率因品种和种子来源不同而异;25%丙环唑EC和50%多菌灵WP对水稻窄条斑病均有较好防效,其中以25%丙环唑EC有效成分用量150g/hm2为最佳,防效达68.73%。     

番茄煤霉病菌致病毒素提取及其活性测定

采用3种方法提取毒素,结果表明:活性碳法、有机溶剂法、硫酸铵分级沉淀法均提取到毒素,硫酸铵分级沉淀法是比较简便而有效的方法。生物测定结果表明:该毒素对番茄幼苗及叶片具有致萎作用。针刺叶片可产生褪绿斑。滤液透析及热稳定性测试结果表明:该毒素为大分子化合物,这与用有机溶剂提取毒素所得结果一致,同时测得它具有很强的热稳定性。     

Effect of planting date on severity of frogeye leaf spot and grain yield of soybeans

The influence of soybean (Glycine max) planting date on seasonal epidemics of frogeye leaf spot caused by Cercospora sojina and on grain yield, was evaluated during the 1991 and 1992 cropping seasons. Two susceptible (Samsoy 1 and TGx 849-313D) and one resistant (TGx 996-26E) soybean cultivars were used in field trials at Zonkwa, in the southern Kaduna state of Nigeria. Four field plantings were made at 14-day intervals from late May to mid0July. For each planting date, half the plots received foliar applications of benomyl at R₁ and R₃ growth stages, and the other half was untreated. Frogeye disease severity ratings were taken for all plots at R₄ to R₅ growth stages, and grain yield for each plot was measured at harvest. There was a significant (p < 0.05) increase in disease severity between the first and third plantings on the two susceptible cultivars in 1991, and on TGx 849-313D only in 1992. Corresponding yield reductions for the two susceptible cultivars averaged 13 and 31% for the treated and untreated plots, respectively, with each 2-week delay beyond the first planting date in 1991, and 5 and 6%, respectively, in 1992. There was no significant difference in disease among all treatments on the resistant cultivar, TGx 996-26E. Under Nigerian conditions, an increase in frogeye leaf spot severity can be expected with delayed planting of soybean after 1 June, and this can result in a corresponding loss of crop yield.     

水葫芦生防菌Cercospora piaropi菌株WH9BR的生物学性状

尾孢菌属的Cercospora piaropi是一种有潜力开发成为防治水葫芦的生物除草剂的真菌。文中研究了光照、温度、pH、碳源、氮源、湿度和介质对该真菌WH9BR菌株的生长、产孢和分生孢子萌发的影响。结果表明:全黑暗条件有利于WH9BR的菌丝生长和产孢,而全光照有利于其孢子萌发。WH9BR菌丝生长最适温度为25℃,产孢最适温度为25～30℃,孢子萌发最适温度为30℃。其生长、产孢和孢子萌发的最适pH分别为8.6、8.0～9.0和7.0。碳源中,甘露醇最适于WH9BR生长,葡萄糖和蔗糖有利于WH9BR产孢。以尿素作氮源时,WH9BR菌丝生长最快,而硝酸钠作氮源时,WH9BR产孢量最高。WH9BR的孢子在水滴中萌发率达到最高。玉米粉、蛋白胨、葡萄糖和蔗糖对WH9BR的孢子萌发有促进作用。     

玉米抵御玉蜀黍尾孢菌侵入的生理机制

为深入探讨玉米抗灰斑病的机制,以抗/感玉米灰斑病自交系78599-1、OH43Ht N和掖478、K12为材料,采用比色皿法和RT-PCR法相结合研究了接种玉蜀黍尾孢菌毒素后玉米叶片中防御酶活性、丙二醛(MDA)含量及防御酶合成相关基因SOD、CAT、APX和GR的表达量。结果显示,接种该病菌毒素后,抗、感材料叶片中防御酶活性均升高,多数在接种7 d时达到峰值,且抗病材料防御酶活性峰值高于感病材料;供试材料叶片中MDA含量均降低,且抗病材料低于感病材料;供试材料叶片中SOD、CAT和GR的表达量均上升,其中CAT的表达量在78599-1、掖478和K12接种5d时达到峰值,灰度值分别为228.67、161.33和178.00,与其酶活性变化趋势一致;SOD和GR的变化规律与其酶活性变化不一致;APX的表达量仅在OH43Ht N中上升,接种7 d后达到峰值。表明抗病材料调控防御酶活性的能力强,防御酶基因的表达与其酶活性变化存在关联性。