彩色马蹄莲品种对果胶软腐杆菌Pcc抗性的评价方法及鉴定

为探索彩色马蹄莲（Zantedeschia spp.）接种胡萝卜软腐果胶杆菌（Pectobacterium carotovora subsp. Carotovora, Pcc）的适宜方法,鉴定彩色马蹄莲组内品种对软腐病菌Pcc的抗性情况,本研究先以10个彩色马蹄莲品种为试验材料,进行以完整叶片、叶片圆片（叶盘）为接种材料的室内离体接种,以及以主脉、侧脉为接种部位的温室活体植株接种,接种后分别于12、24、36 h 3个时间点,以发病率、病情指数为指标,统计马蹄莲软腐病发病情况;在明确适宜的接种方法和发病时间后,选取包括第1步试验品种在内的34个彩色马蹄莲品种进行Pcc抗性鉴定。结果表明：离体接种的最佳材料为完整叶片,最佳发病观察时间是24 h;活体接种的最佳接种部位为叶片主脉,最佳发病观察时间是36 h;离体鉴定的中抗品种为5个,感病品种为11个,高感品种为18个;而活体鉴定的中抗、感病和高感品种分别为2、17、15个。离体方法鉴定的中抗品种多于活体鉴定,离体方法鉴定的抗性情况更接近田间大规模生产,其原因可能是离体方法鉴定时接种材料的均一性、环境条件的一致性好,更能反应品种本身的抗性情况。     

烟草品种（系）的烟草黑胫病抗性鉴定

采用离体叶片法测定了分离自湖南主产烟区的3个烟草黑胫病菌菌株的致病性,结果表明以Phy2菌株致病性最强。以Phy2为接种菌株,采用田间人工接种方法对13个烟草品种（系）进行了烟草黑胫病抗性鉴定。试验结果表明,对烟草黑胫病表现抗、中抗、中感和感病的分别为10份、1份、1份、1份,占鉴定品种（系）总数的76.9%、7.7%、7.7%、7.7%。其中湘烟3号和4-10-1抗性优于抗病对照品种K326和革新3号,而津巴布韦新引进品种KRK26对烟草黑胫病抗性较差。     

玉米瘤黑粉病抗性鉴定技术的评价

选用西北灌区生产上具有代表性的10个玉米品种,采用不同接种方法及接种浓度在玉米不同生育时期人工接种玉蜀黍黑粉菌,研究抗性鉴定技术,筛选出一整套重复性好、发病完全、受外界因素干扰小的接种技术体系。结果表明,供试玉米品种接种玉蜀黍黑粉菌的最佳方法是注射法,最佳接种时期为6叶1心期,最佳接种浓度为9×10³～10×10³个孢子/mL。     

内蒙古9种马铃薯主栽品种对黑胫病抗性评价

为明确内蒙古自治区主栽马铃薯品种对黑胫病的抗性,试验采用离体块茎接种和温室盆栽注射接种2种方法,对内蒙古自治区各地方9个主栽马铃薯品种('V7'英尼维特'费乌瑞它'大西洋'冀张薯12号'夏坡蒂'布尔斑克'中加7号'和'中加2号')的黑胫病抗性进行了评价.离体块茎接种法结果表明'英尼维特'与'V7'为抗性品种,'大西洋'...     

花生的抗锈性成分研究

本项研究用温室整株接种和实验室离体生根叶片接种的方法对一些新鉴定出的花生抗锈种质材料的8个抗锈性成分进行观察。结果表明这些花生种质材料在抗锈性成分上存在较大的变异。多数抗性成分在高抗材料或低抗(感病)材料之间是整齐一致的,而且与田间锈病级数高度吻合,但抗性成分在中抗材料之间有较大的变异。本文对栽培花生与种间杂种衍生材料在抗锈性成分上的差异也作了分析。所有抗性成分的广义遗传力均较高,具有遗传改良的潜力。     

229份杧果种质对炭疽病抗性初步评价

炭疽病是杧果的重要病害,严重影响杧果的生长势以及杧果的产量和质量,选种抗病品种是有效的防治方法之一。采用室内离体叶片抗病性鉴定法,初步鉴定了在农业部儋州杧果种质资源圃中的229份杧果种质对炭疽病的抗病性。结果表明,在参试的种质中未发现免疫和高感种质,其中高抗种质13份、中抗种质36份、中感种质116份、感病种质64份,这些种质的初步评价,为进一步展开杧果抗病遗传规律及分子育种研究打下了基础。     

不同浓度锈菌对大豆叶片的致病反应

采用离体叶片接种法,观察不同浓度夏孢子悬浮液对大豆叶片的致病反应。结果表明：各个接种浓度均可引起叶片发病,发病率随接种浓度的升高而增加,夏孢子堆密度随接种浓度升高而增加,夏孢子堆破裂时间随接种浓度的增加而缩短,不同品种的致病反应差异主要表现在病斑出现时间、夏孢子堆密度、夏孢子堆破裂时间和发病率等方面。锈菌浓度对孢子堆大小没有显著影响,采用105个夏孢子/mL的接种浓度可以有效地区分不同品种的抗病性。     

美国引进甘蔗材料对梢腐病菌（Fusarium sacchari）的室内抗性评价

为了筛选抗甘蔗梢腐病的优异种质材料,采用室内离体接种方法对70份甘蔗种质材料进行梢腐病抗性鉴定。根据发病程度划分的抗性等级和聚类分析的方法综合评价种质材料的抗性。结果表明,甘蔗分蘖期对梢腐病菌的免疫力较伸长期差。参试的70个种质材料中,高抗材料6个,占8.57%;抗病材料15个,占21.43%;中抗材料13个,占18.57%;中感材料12个,占17.14%;感病材料13个,占18.57%;高感材料11个,占15.71%。在2次不同生育期接种过程中‘HoCP02-263’均未发病,很可能是对Fusarium sacchari免疫的材料。系统聚类分析的结果与材料的抗性表现基本一致。甘蔗梢腐病的抗性评价较佳时期为分蘖期。     

茶树品种对茶饼病的抗性研究

通过对云南省选育和推广的4个茶树品种进行室内离体接种抗病性鉴定和田间品种抗病性调查。结果表明，4个品种均不同程度地感染茶饼病，其发病率和病情指数存在着一定差异（云抗10号〈佛香3号〈佛香2号〈佛香1号），但按照抗性分级标准分别属于高抗和中抗品种；室内离体接种不同浓度孢子发病情况试验表明，最适的接种孢子浓度为显微镜10×10倍数下每视野50-60个孢子。     

水稻抗二化螟特性鉴定技术的评价研究

采用离体叶片、离体茎秆、离体剥开茎秆及活体成株4种室内抗虫性鉴定方法,对相同水稻材料进行抗二化螟特性鉴定,同时对这些水稻室内抗二化螟鉴定技术进行了综合评价。结果表明,这些方法的抗性鉴定结果高度吻合,离体叶片鉴定方法是目前最快速、有效的抗二化螟鉴定方法。并通过离体叶片和活体成株鉴定方法对转Vip3A基因水稻材料进行鉴定,再次验证了离体叶片鉴定方法的有效性。此外,初步发现对于同为鳞翅目水稻害虫稻纵卷叶螟,用离体叶片鉴定方法也可进行有效鉴定。     

Leaf inoculation as an early screening test for cocoa (Theobroma cacao L.) resistance to Phytophthora black pod disease

In this study a leaf inoculation method was used to standardize a bioassay for testing the genetic susceptibility (or resistance) of cocoa cultivars to black pod disease caused by Phytophthora palmivora and Phytophthora megakarya. Both whole leaves and leaf discs from non-lignified twigs, were suitable for inoculation with suspensions of 3 × 10⁵ zoospores/ml. Cocoa clones tested for resistance to black pod with leaf bioassays responded in the same rank order as reported for fruit inoculation in the literature. Furthermore, the rank of a cultivar within the classification stabilizes between 5 and 7 days after inoculation. The leaf bioassay for susceptibility of hybrid families, demonstrated a highly significant plant effect within the family, so that comparison between families was of limited value. Leaf bioassays enabled early and rapid selection of cocoa cultivars resistant to black pod disease, provided the method was strictly standardized and that results are compared with those from fruit inoculations reported in the literature.     

Selection for resistance to Phytophthora pod rot of cocoa (Theobroma cacao L.) in Cameroon: Repeatability and reliability of screening tests and field observations

Phytophthora pod rot (Ppr) disease caused by Phytophthora megakarya is the major constraint to cocoa production in Cameroon. The development of resistant varieties requires the use of effective resistance testing methods. The repeatability and reliability of the leaf disc and detached pod tests, as applied in selection activities in Cameroon, were studied. Repeatability of the tests was estimated by calculating the correlation (r) between resistance scores of clones, progenies and individuals within progenies in different inoculations rounds of the leaf disc and detached pod tests. Such correlations were generally significant for both tests. For the leaf disc test, as expected, correlations were lower for individuals within seedling progenies than for the average of seedling progenies or of clones. This suggests that a higher number of replicate observations are required for correct evaluation of individual seedlings than for evaluation of the average level of resistance of progenies. Observations carried out 5 or 7 days after inoculation was highly correlated, suggesting that scoring in the leaf disc test may be done only once at 5, 6 or 7 days after inoculation. In one experiment the ranking of leaf disc and detached pod inoculation test results could be compared statistically, with data being significantly correlated (r 0.78). The reliability of the tests was evaluated by the correlations between results of the tests and the level of field infection. These were generally positive and significant, for the leaf disc and detached pod test. A variation between mean scores of 5 and 8 in the detached pod test appeared to be related to a 40% difference in field infection with P. megakarya in years with medium disease pressure. However, correlations with field resistance were not always significant, suggesting the influence of uncontrolled environmental factors affecting field observations or the results in the screening tests. It is concluded that the leaf disc and detached pod tests, if applied under standardized conditions, can be of great value to speed up selection for Ppr resistance.     

芒果种质对炭疽病的抗病性评价

采用离体叶片抗病性鉴定法对来自国内外的189份芒果种质进行了抗炭疽病抗性评价.结果表明:参试种质中未发现免疫种质,其中高抗种质9份、中抗种质55份、中感种质90份、感病种质34份和高感种质1份.对于这64份抗病种质,应在炭疽病流行年份继续开展田间抗病性评价工作,同时结合农艺性状评价,确定种质是否能在生产上推广或能否作为育种材料.试验结果为189份芒果种质抗炭疽病创新利用奠定了基础.     

影响芒果炭疽病病斑扩展的因素

采用离体叶片接种法,研究分生孢子浓度、芒果抗病性、温度、相对湿度、光照条件等因素对芒果炭疽病病斑扩展的影响.结果表明:分生孢子悬浮液浓度对病斑扩展有显著影响,接种4个分生孢子就能引起侵染;不同的芒果品种抗性级别和病斑大小之间显著相关;适合病斑扩展的温度是24～33℃,最适宜温度28℃;高湿和全黑暗条件有利于病斑的扩展.     

可可种质资源抗寒性初步评价及低温胁迫下生理响应

本研究以收集保存的38份可可种质资源为对象,在2016年1月极端低温期间,进行抗寒性初步评价,依据低温危害后可可果实和叶片损害程度,可可资源抗寒性可分成5级。以具有抗寒性差异的INA-t5（Ⅰ级）、COM-e8（Ⅱ级）、ECU-ev6（Ⅳ级）、THA-o6（V级）种质为材料,研究抗寒性差异种质在4 ℃胁迫条件下植株的伤害情况、叶片解剖结构和生理生化指标变化。结果表明：低温胁迫条件下,INA-t5、COM-e8种质比THA-o6、ECU-ev6种质具有明显的耐寒表型,可可叶片受害程度差异显著;可可的丙二醛和脯氨酸含量的变化幅度与其抗寒性呈现负相关;胁迫48 h 后,THA-o6、ECU-ev6种质保护酶系统逐渐被破坏,INA-t5、COM-e8种质则仍然表现活跃。综合以上结果,INA-t5、COM-e8为抗寒性种质,其抗寒性比THA-o6、ECU-ev6强,抗氧化酶活性和渗透物质含量变化规律以及差异种质,可为可可开展抗寒育种和抗寒分子机理研究提供理论和材料基础。     

大豆不同株龄及不同的叶龄、荚龄对灰斑病的反应

本研究用人工接种方法探讨了大豆不同株龄及不同的叶龄和荚龄对灰斑病的反应。结果表明,株龄越大的大豆其灰斑病愈轻,反之则重。完全展开叶和正在扩展叶易感灰斑病,嫩叶（叶缘未分离）和老化叶不易感病。荚龄大于１ｃｍ的最易感病、病粒率高,０．５ｃｍ以下的荚不易感病。     

大豆菌核病鉴定方法研究进展

大豆菌核病在全球范围内均有发生,由于病原菌寄主范围较广,难于防治,对大豆产量和品质产生严重影响。对于大豆菌核病抗性种质资源的鉴定是抗性机理研究、基因定位及抗病育种工作的重要基础,文章对大豆菌核病资源鉴定中涉及的接种体(菌丝、孢子和菌核)的培养、植株不同部位的接种鉴定、草酸鉴定、茎中可溶性色素水平测定及田间鉴定方法进行了系统的总结和分析,并针对接种体的选择、环境条件对发病的影响及田间与温室鉴定结果不一致等问题展开讨论,为大豆菌核病抗性资源的筛选,菌核病发病机理及抗性基因的定位研究奠定基础。     

产量和株型性状良好的抗晚斑病花生新种质创制

花生晚斑病抗性常与不良的产量和株型性状相连锁,为发现更多综合性状优良的抗晚斑病品种,以感病亲本中花5号和抗病亲本ICGV 86699及其杂交构建的重组自交系群体（recombined inbreed lines, RIL）为材料,进行晚斑病抗性、产量和株型相关性状的调查,以筛选综合性状优良的抗病新种质。结果表明,4个环境下共发现18个稳定高抗和26个稳定中抗晚斑病的家系;在两个环境中对百果重和单株结果数进行考察,筛选出38个百果重（≥180.0 g）和单株果数（≥20.0个）都比较大的家系;同样,在两个环境中筛选出主茎高（30～60 cm）和总分枝数（≤20.0个）适中的家系54个。综合分析晚斑病病害等级、产量和株型相关性状,共鉴定出4份产量和株型相关性状优良的抗晚斑病新种质,其中1份高抗晚斑病,3份为中抗晚斑病。该研究结果为培育综合性状优良的抗晚斑病花生品种奠定了理论和材料基础。     

A detached-leaf method to evaluate late blight resistance in potato and tomato

We developed a detached leaf method for evaluating potato (Solanum tuberosum L.) and tomato (Lycopersicon esculentum Mill.) germplasm for reactions toPhytophthora infestans, the causal organism of late blight. Primary leaves from the third to the sixth node of potato plants, and the fourth to sixth node of tomato plants were excised at the stem. Their petioles were inserted into 14 mm × 100 mm floral aqua tubes containing 9 ml of sterilized distilled water. The leaves in the aqua tubes were placed with abaxial sides down on galvanized metal hardware cloth (12.5 × 12.5 mm mesh). A 12.5 mm sensi-disc containing 50μl of 2 × 10⁴ zoospores was placed in the centers of the terminal leaflet and the second leaflet pair of the potato leaf. A single disc was placed on the center of the tomato leaf. The supporting hardware cloth was placed 2.5 cm above distilled water (2.5 cm deep) in 31 cm × 17 cm × 8 cm clear plastic boxes with tight fitting lids. Leaves on intact tomato and potato plants were inoculated in a similar manner and placed in a mist chamber. Lesion growth was determined 4, 5, and 6 days following inoculation. There were no significant differences in reactions to isolates ofP. infestans on detached and intact leaves of potato cultivars Green Mountain and Kennebec and the tomato cultivar Bonnie Best.