关于青海省马铃薯晚疫病的发生和予测

马铃薯晚疫病(Phytophthora infestans)在青海的流行范围,基本限于东部农业区,海南藏族自治州虽能发病但不流行,柴达木地区则至今连典型中心病株亦未发现。这与各该地区的气候条件有极密切关系:海南州(如恰卜恰)7、8两月,旬平均气温皆在10℃以上,但降水仅约140毫米旬     

马铃薯抗晚疫病遗传工程研究获得重大突破

马铃薯抗晚疫病遗传工程研究获得重大突破马铃薯晚疫病是由卵菌Ｐｈｙｔｏｐｈｔｈｏｒａｉｎｆｅｓｔａｎｓ（Ｍｏｎｔ．）ｄｅＢａｒｙ引起的马铃薯毁灭性病害。由于该病危害马铃薯块茎全世界年损失达１７０亿美元。据不完全统计，９０年代以来我国马铃薯因晚疫病危害年...     

马铃薯块茎薄片抗晚疫病条件的研究

马铃薯抗晚疫病品种块茎切片的浸渍液并不能抑制病菌的生长繁殖。但薯片愈薄,抗性愈弱。厚度在1毫米以下、基本上失去抗性,但这种块茎切片,在组织培养液中却仍能保持抗性。因此认为马铃薯抗晚疫病的基础首先是寄主的生命活动强度。     

马铃薯晚疫病菌抗甲霜灵的SCAR标记

建立马铃薯晚疫病菌抗甲霜灵SCAR(sequenced characterized amplified region,序列特征扩增区域)标记,以马铃薯晚疫病菌对甲霜灵高抗菌株HD01-3和对甲霜灵高感菌株DK98-1为亲本,通过无性单游动孢子分离和有性杂交获得菌株HD01-3无性后代群体、菌株DK98-1无性后代群体以及F1代分离群体,以此为试验材料,利用BSA法(bulked segregant analysis,分离群体分组分析法)构建抗感基因池对后代菌系的甲霜灵抗性进行RAPD(random amplified polymorphic DNA,随机扩增多态性DNA)分析。从178条RAPD随机引物中找到一条特异性引物S2054,其可以扩增出一个与晚疫病菌对甲霜灵抗性相关的遗传标记,将该特异条带回收、克隆、测序,发现此标记大小为457bp,根据测序结果设计特异PCR引物,用于扩增抗感基因池,成功地将特异RAPD标记转化为SCAR标记。初步建立了马铃薯晚疫病菌抗甲霜灵SCAR标记,辅助监测晚疫病菌对甲霜灵的抗性。     

不同品种马铃薯晚疫病田间抗性监测研究

通过5个马铃薯参试品种晚疫病抗性监测的试验,摸清荔波县主栽品种对马铃薯晚疫病的田间抗性情况。结果表明,抗性最好的品种是青薯9号,其次是宣薯2号和中薯3号,再次是荷兰7号,费乌瑞它品种的抗性最差。从产量上看,青薯9号品种产量最高,其次是宣薯2号和中薯3号,最后是荷兰7号,最低的是费乌瑞它品种。     

马铃薯品种抗病力与晚疫病菌侵染力的关系

在黑龙江省栽培的马铃薯品种中,292—20和波友一号为抗病品种,男爵、白头翁和红纹白为感病品种。从抗病品种上分离到的菌株不仅能够侵染抗病品种的块茎,而且对于感病品种块茎的侵染能力也强于从感病品种上分离到的菌株。后者对于抗病品种的块茎只能引起褐斑反应。表1列出了两次试验中所获得的典型资料。在这两次试验中用了四个菌株。“红 AS”采自克山红     

部分马铃薯主栽品种对晚疫病的田间抗性研究

为摸清贵州省低海拔地区主栽马铃薯品种对晚疫病的抗性情况,2012年对贵州省13个主栽马铃薯品种进行晚疫病抗性鉴定试验。结果表明：Z-30、BP05-003（产量在25500kg／hm2以上）对晚疫病表现为中感,为早、中熟品种,适宜在低海拔发病不重的区域推广;滇黔芋2号、米拉（产量在13500kg／hm2以上）对晚疫病表现为感病,如在晚疫病常发区、重发区种植,生产上应加大防治力度;BPHFl01、20-4．5、威薯002为中感及感病品种,产量一般,为晚熟品种,适宜在高海拔地区种植,需要加强晚疫病防治并配套高产栽培技术。     

29个马铃薯品种(品系)抗晚疫病基因组成与抗病相关性分析

由致病疫霉引起的马铃薯晚疫病是马铃薯生产中最具危害性的病害,明确现有马铃薯品种(品系)中抗病基因组成情况对于指导抗病品种合理布局及抗病育种具有重要意义。本研究利用农杆菌介导的无毒基因瞬时表达技术分析了致病疫霉8个无毒基因在29个马铃薯品种(品系)中的分布情况。结果表明,品种间抗病基因组成各异,平均每个品种含有4个抗病基因。同时,不同抗病基因在品种中的分布频率也不同,抗病基因R1(76%)、Rpi-blb1(66%)和Rpi-blb2(66%)在品种中分布较普遍;而含抗病基因R3b(45%)、R4(38%)和Rpi-vnt1(34%)的品种较少。此外,品种中所含抗性基因的数量和品种室内抗性程度呈显著正相关(r=0.915 6,P=0.029 1)。     

日齐素在马铃薯抗晚疫病中作用的评价

 对5种含有和不含R-基因的马铃薯品种的块茎[阿奎拉(R₁),抗疫白(R₁),疫不加(R₃R₄).卡塔丁(r)及紫山药(r)]在不同块茎发育期和贮藏期(成熟前1个月不经贮藏,成熟期收获后在4-6℃下贮藏0,1,2,3,4,5个月)用3种晚疫病菌小种(小种0,1.4和3.4)接种,检查块茎的反应型和用气相色谱法测日齐素的积累量。结果是马铃薯各品种与其对应小种的反应型保持相当的稳定,不因未经贮藏或经不同时期贮藏而改变。然而日齐素的含量,在未经贮藏的块茎即使是不亲和反应也没有或很少有日齐素积累。只有在1个月的贮藏以后,含R₁基因的品种不亲和反应组合的日齐素含量比亲和反应组合为高。可是,在对所有小种都亲和的r基因品种也测到很高的日齐素浓度,如紫山药/小种0的日齐素高达134微克/克鲜重,而抗疫白/小种0也只达到107微克/克鲜重。所以未能得出日齐素的积累和不亲和性有密切的直接相关的结论。     

马铃薯品种各生育期对于晚疫病菌小种抵抗性的比较

 从试验的三个品种对于三个晚疫病菌小种的反应看来,马铃薯各生育期的小种抗性十分稳定。对于能侵染的小种,各时期都能感病,没有免疫或高度抵抗的生育期;对于不能侵染的小种,各时期都同样地抗病,也没有抗性特别低而可被低一级的小种越级侵染的时期。     

小麦品种(系)抗麦红吸浆虫鉴定及利用

2004-2006年利用一套较完整的田间抗性鉴定方法,对425份生产推广品种(审定品种)、区试品种及品种资源进行了抗麦红吸浆虫鉴定。结果表明,不同小麦品种(系)对麦红吸浆虫的抗性差异显著,高抗品种(系)有56份,占供鉴品种的13.18%、中抗品种54份,占12.71%、低抗品种99份,占23.29%。在近年已审定品种中,石7221、良星99、1457、衡71-3、中麦9、石新822、石家庄11号等7个小麦品种对麦红吸浆虫均表现出稳定的抗性。     

基于CARAH模型的重庆春马铃薯晚疫病侵染特征模拟分析

马铃薯晚疫病是影响马铃薯产量的首要病害, 研究其在山地立体气候条件下的发生流行特征具有重要意义。本文利用重庆地区260个地面气象观测站2019年－2023年小时级温湿度数据, 采用CARAH模型模拟分析了春马铃薯晚疫病侵染频度、严重程度、关键侵染周期等时空特征, 并采用巫溪县2022年马铃薯田间小气候监测数据对模拟精度进行了检验。结果表明, 采用小时级地面气象观测数据模拟的晚疫病侵染空报率、漏报率均在20%以内, 整体精度较佳。5年气象数据模拟结果显示, 重庆地区气候条件有利于春马铃薯晚疫病的发生发展, 早、晚熟品种栽培期普遍发生4～8代(11～20次)、8～12代(21～40次)侵染;严重程度呈现“两极化”特点, 轻度和极重度侵染次数具有明显优势。第3代第1次和第5代第1次2个关键侵染周期的开始期分别在3月上旬至4月下旬、3月下旬至5月中旬, 高峰期分别为3月下旬和4月中旬。春马铃薯晚疫病侵染的空间分异特征明显, 东北部主产区侵染代数、次数、极重度侵染次数均少于其他产区, 是晚疫病发生最轻的地区。关键侵染周期的开始时间随海拔升高而推迟, 中西部丘陵低山地区早, 东部武陵山与大巴山区晚。     

Measurement of healthy and diseased haulm area for assessing late blight epidemics in potatoes

The advantages of assessing disease severity by visual grading and by measuring healthy and diseased plant area were compared in four mild to moderate late blight epidemics during spring and in two severe epidemics during autumn in Israel. Disease progress curves obtained through visual grading showed a continuous increase, but the area of lesions tended to fluctuate during the cropping season and often reached a maximum in plots in which the total amount of foliage was also largest. The healthy haulm area differed with disease intensity and undefined seasonal and cultural influences. The decrease in healthy haulm area was not related to expansion of the blighted area only, but also to the breaking of plants at stem lesions. This phenomenon was especially evident in the warm spring season and was not determined by visual grading of disease severity. Each kind of assessment revealed different features of the epidemics and suited different applications. Visual grading enabled the easiest comparison of epidemic patterns. Lesion areas reflected patterns of inoculum potential, while healthy haulm areas reflected the integrated influences of factors affecting the crop and disease and thus provided useful data for simulating epidemics and for estimating yield losses.     

A review of biocontrol agents in controlling late blight of potatoes and tomatoes caused by Phytophthora infestans and the underlying mechanisms

Phytophthora infestans causes late blight on potatoes and tomatoes, which has a significant economic impact on agriculture. The management of late blight has been largely dependent on the application of synthetic fungicides, which is not an ultimate solution for sustainable agriculture and environmental safety. Biocontrol strategies are expected to be alternative methods to the conventional chemicals in controlling plant diseases in the integrated pest management (IPM) programs. Well-studied biocontrol agents against Phytophthora infestans include fungi, oomycetes, bacteria, and compounds produced by these antagonists, in addition to certain bioactive metabolites produced by plants. Laboratory and glasshouse experiments suggest a potential for using biocontrol in practical late blight disease management. However, the transition of biocontrol to field applications is problematic for the moment, due to low and variable efficacies. In this review, we provide a comprehensive summary on these biocontrol strategies and the underlying corresponding mechanisms. To give a more intuitive understanding of the promising biocontrol agents against Phytophthora infestans in agricultural systems, we discuss the utilizations, modes of action and future potentials of these antagonists based on their taxonomic classifications. To achieve a goal of best possible results produced by biocontrol agents, it is suggested to work on field trials, strain modifications, formulations, regulations, and optimizations of application. Combined biocontrol agents having different modes of action or biological adaptation traits may be used to strengthen the biocontrol efficacy. More importantly, biological control agents should be applied in the coordination of other existing and forthcoming methods in the IPM programs. © 2023 Society of Chemical Industry.     

Toxicity of propamocarb to the late blight fungus on potato

Propamocarb (Previcur-N; propyl-[3-dimethylamino-propyl] carbamate-monohydrochloride) was testedin vivo against 32 field isolates ofPhytophthora infestans from six countries. Fungicide dosages required to achieve 90% control of the blight ranged between 676 and 1530 ppm a.i. in potted potato (cv. ‘Alpha’) plants and between 1135 and 2648 ppm in potato tuber slices. Isolates from Israel were less sensitive to the fungicide than isolates from Europe or North America. Toxicity of propamocarb was not related to resistance or sensitivity to phenylamide fungicides (e.g. metalaxyl). Nevertheless, most metalaxyl-resistant isolates from Israel were less sensitive to propamocarb than most metalaxyl-sensitive isolates from this country. Monocyclic epidemics conducted with the 20 Israeli isolates in the field showed that 1081–2012 ppm of the fungicide was required to achieve 90% control of the disease. Laboratory experiments revealed that the fungicide was poorly active against sporangial germination and had a limited curative efficacy. It exhibited a translaminar translocation in leaves but a poor acropetal or basipetal systemicity from foliage. Propamocarb + mancozeb mixtures (1:1, v/w) were synergistically effective in controlling the blight. Growers in Israel use tank mixtures of propamocarb (Dynone) and mancozeb to combat late blight in potato fields where phenylamide-resistant isolates ofP. infestans are prevalent.     

An epidemiological analysis of the dilemma of plant age and late blight (Phytophthora infestans) susceptibility in potatoes

European Journal of Plant Pathology - While the age-related susceptibility of potatoes to late blight is well-known, the universality of this relationship is unclear. This study aimed at resolving...     

不同水稻品种对条纹叶枯病抗(耐)病性比较

田间对比试验表明,供试7个水稻品种对条纹叶枯病的抗性可初步分为高抗、中抗、中感、高感4个类型。其中常优1号、常农粳3号抗病性较强,丰产性能也好。     

Effects of strip intercropping of potatoes with non‐hosts on late blight severity and tuber yield in organic production

The effects of strip cropping of potatoes with cereals or a grass‐clover mix in and perpendicular to the main wind direction on foliar late blight severity and tuber yield were studied in large‐scale field experiments in Germany. Disease progress was assessed in 12–18 sections per plot and yields determined from the same sections. In 2000, plot size was 3 × 10 m and there were no disease reductions apparently due to interplot interference. In 2001 and 2002, with plot sizes of 6 × 18 and 6 × 36 m in strip‐cropped potatoes, disease was significantly reduced by 9–20% and 4–12%, respectively, compared to pure stands of potato, with the greatest reductions in plots planted perpendicular to the wind and neighboured by grass‐clover. The most important factors contributing to disease reduction were loss of inoculum outside of the plots and barrier effects of neighbouring non‐potato hosts. Only 0–20% of the overall yield variation could be explained by the area under the disease progress curve, depending on cultivar and year. In one year disease effects on the yield of a moderately resistant cultivar were higher than on the yield of a susceptible cultivar. This was probably caused by differences in bulking behaviour. Nutrient limitation appeared to be more important than disease in reducing yields. Yields in the edge potato rows directly neighboured by cereals were significantly reduced in all 3 years, but competition by cereals did not change the disease–yield‐loss relationship. Strip intercropping might be a useful component in an overall management strategy to reduce incoming late blight inoculum.