Table-top production of strawberries: Performance of six strawberry cultivars

Abstract

The potential for table-top production in Scandinavia is currently unknown, but may be considered more limited than in central Europe. In this study, the performance of six strawberry cultivars was studied in a table-top system using peat bags as substrate inside or outside an open polythene tunnel. The table-top system resulted in high-quality fruit production, with easy-to-pick fruit and a high percentage of marketable produce. The tunnel reduced average solar radiation and increased temperature slightly and simultaneously protected the plants from rain, this did reduce yield or fruit quality parameters compared with uncovered plots. Partly because of an increased incidence of powdery mildew (Sphaerotheca macularis) inside the tunnel, fruit brightness was reduced in the second harvest year. Of the cultivars included, ‘Elsanta’, ‘Sonata’ and ‘Alice’ may be considered well adapted to the system, whereas ‘Honeoye’, ‘Florence’ and ‘Babette’ are inferior.     

水杨酸诱导重瓣玫瑰对白粉病的抗性1）

喷施不同浓度的水杨酸（ SA）,研究其引发重瓣玫瑰对白粉病的诱导抗性,实验结果表明,不同浓度SA诱导处理均对重瓣玫瑰白粉病有抑制效果,SA处理显著减低了重瓣玫瑰叶片白粉病病情指数,0．5 mmol/L SA诱导效果最好。不同浓度SA诱导（接菌）后,对重瓣玫瑰叶片苯丙氨酸解氨酶（PAL）、多酚氧化酶（PPO）、过氧化物酶（ POD）活性有显著影响,且对总酚质量分数、木质素相对值的影响明显。经0．5 mmol/L SA诱导后,叶片PPO活性、总酚质量分数均在诱导（接菌）后第7（5）天时达到最大值,分别是CK1（喷施清水）的1．55、1．71倍,是CK2（喷施清水＋接种白粉菌）的1．33、1．50倍,且与CK1、CK2相比差异极显著（ P＜0．01）。1．0 mmol/L SA诱导（接菌）后PAL、POD活性在第7（5）天时达到最大值,分别是CK1的1．68、2．06倍,是CK2的1．35、1．56倍,且与CK1、CK2相比差异极显著（ P＜0．01）。0．5 mmol/L SA处理在整个试验期间诱导的木质素相对值均显著高于CK1、CK2。     

不同抗性黄瓜自交系接种白粉病原菌后生理特性的变化

对不同抗性黄瓜自交系接种白粉病原菌后,测定叶片中与抗性有关的叶绿素、可溶性糖、可溶性蛋白和4种防御酶活性.结果表明,叶绿素含量在接种后均呈先增加后减少的趋势,抗病自交系增加幅度较大,叶绿素含量高于感病自交系,黄瓜抗白粉病能力与叶绿素含量存在一定程度的正相关;可溶性糖含量在接种后先降低-后升高-再降低-再升高,抗病自交系可溶性糖含量高于感病自交系;可溶性蛋白含量在接菌后均逐渐升高,感病自交系的峰值出现早于抗病自交系,感病自交系对病原菌较敏感,抗病自交系对病菌的侵染反应呈一定程度的负相关;4种酶的活性在接菌后都有不同程度的提高,抗病自交系酶活性增加幅度高于感病自交系,说明这4种酶在黄瓜对白粉病的抗性机制中起了重要作用.     

黑龙江省黄瓜白粉病病原鉴定

对黑龙江省哈尔滨、齐齐哈尔、牡丹江、佳木斯和大庆等5个城市的11份黄瓜白粉病病样从分生孢子形状、大小、纤维体的有无、芽管着生位置、闭囊壳的特征以及鉴别寄主反应等方面进行了病原鉴定。结果表明,所有菌株分生孢子内均可见明显的纤维体,萌发管叉状,从分生孢子的侧面长出;闭囊壳内含1个子囊,每个子囊内有8个子囊孢子;均可侵染鉴别寄主Lagenaria leucantha。由此可知,引起黑龙江省黄瓜白粉病的病原为Sphaerotheca fuliginea。     

蛇床子素对南瓜白粉病菌侵染的影响

采用室内离体叶片法,发现蛇床子素(osthol)处理能显著降低南瓜白粉病菌侵染的病情指数,接菌6 d后对照的病情指数为68.89,经100 μg/mL蛇床子素处理组的病情指数仅为15.56。显微观察发现蛇床子素可有效降低南瓜白粉病菌对寄主的入侵,并可有效抑制菌丝的生长。接菌后48 h,对照菌丝的平均长度接近400 μm,蛇床子素处理组菌丝平均长度仅有122 μm。苯胺蓝染色后显微观察发现蛇床子素还可降低白粉病菌的产孢量。     

植物提取液对黄瓜白粉病的抑菌活性筛选研究

首先通过叶圆盘法用29种植物提取液对黄瓜白粉病菌的抑菌效果进行了生物活性测定,初步筛选出槐、黄檀、南瓜和石楠等4种植物的提取液对黄瓜白粉病有较好的预防效果。然后对这4种植物提取液进行预防性和治疗性的室内盆栽药效试验,结果表明黄檀提取液对黄瓜白粉病的预防效果达到72.97%,治疗效果达到91.28%,并且在处理12 d后仍保持42.60%以上的防效。而槐提取液的预防效果和治疗效果分别为79.73%和79.19%,处理12 d后也保持在50%以上的防效。这两种植物提取液均极显著优于对照药剂三唑酮。     

Biological control of cucumber powdery mildew by Tilletiopsis minor

Samenvatting Onder optimale omstandigheden konT. minor de ontwikkeling van komkommermeeldauw (Sphaerotheca fuliginea) tegengaan.Spuiten met 2×10⁷ sporen ml^–17 dagen na inoculatie met komkommermeeldauw gaf een reductie van meeldauwontwikkeling van ongeveer 90%. Wanneer een tweede bespuiting met dezelfde concentratie sporen 3 dagen na de eerste werd toegepast bleven de planten vrij van meeldauw tot ze werden opgeruimd 3 weken later.Bij een R.L. lager dan 70% en een temperatuur boven 30 °C had geen van de behandelingen succes. T. minor bleek ongevoelig voor dimethirimol (Milcurb) bij een concentratie van 125 g ml^–1, terwijl er gemakkelijk een mutant kon worden verkregen, die resistent was tegen 100 g fenarimol ml^–1, bij gelijk blijvende groeikracht en pathogeniteit ten opzichte van komkommermeeldauw, waardoorT. minor ingepast kan worden in een schema voor geïntegreerde bestrijding.     

Ts-86提取物防治黄瓜白粉病的研究

本文测试了中草药Ts-86提取物对黄瓜白粉病菌的保护活性,并对其稳定性、持效期及抑菌谱等作了进一步研究。结果表明,Ts-86提取物的50倍液防效达93.04%,与粉锈宁(15% WP)1000倍液防效相当;其酸碱稳定性与热稳定性较差,只在中性或微酸微碱条件下活性较高,且经100℃处理的活性最高,而且其光稳定性很好;保护作用的持效期可达3天;抑菌谱相对广泛。     

Impact of resistant melon cultivars on Sphaerotheca fuliginea

Effects of the resistant cultivars of melon on the powdery mildew fungus, Sphaerotheca fuliginea, were investigated in a melon‐growing area of Japan. Powdery mildew fungi were isolated from four melon cultivars (‘HN21’, ‘Quincy’, ‘Earl's Knight Natsu 2’ and ‘Earl's Miyabi Natsu 2′) which are resistant to different races of S. fuliginea.‘HN21’is resistant to races 1 and N1,‘Quincy’ and ‘Earl's Knight Natsu 2’are resistant to races 1 and N2, and ‘Earl's Miyabi Natsu 2’is resistant to races 1, N1 and N2. All 155 strains isolated from ‘HN21’were identified as race N2. Seventy out of 81 strains isolated from ‘Quincy’ and ‘Earl's Knight Natsu 2’were identified as race N1, while other strains were identified as races 1, 2US, N2 and N3. Nineteen out of 29 strains isolated from ‘Earl's Miyabi Natsu 2’were identified as race N3, while other strains were identified as races 10, 2US, N1 and N4. These results suggest that, although the resistant cultivars are extremely effective for protecting the plants from their respective races, a race succession rapidly takes place, even in a small area, and other minor races become predominant.     

生物型种衣剂诱导后黄瓜叶片蛋白质组学初步研究

以木霉菌(Trichoderma atroviride)T23的REMI突变株发酵液为主要原料配制生物型种衣剂处理黄瓜种子,然后播种,2~3叶期挑战接种白粉菌,调查病情指数并取样。结果表明:该生物型种衣剂能够明显提高黄瓜幼苗对白粉病的系统抗性,对白粉病相对防治效果达70%~75%。该研究建立了黄瓜叶片蛋白质提取和双向电泳分离技术。通过双向电泳及相应的分析软件(PDQuestTM2-D software)可将不同处理的幼苗叶片蛋白进行分离。结果发现种衣剂处理的叶片产生22种上游调控蛋白和7种下游调控蛋白,与对照的蛋白质组图谱相似系数为0.813。利用质谱分析发现黄瓜叶光合作用相关蛋白与抗白粉病有一定关系。