安徽省草莓空心病病原菌的分离与鉴定

对来源于安徽、辽宁和河北地区的草莓空心病株的病原菌进行了分离、纯化、形态观察以及分子生物学鉴定。结果显示,该病原菌在PDA平板上均呈放射状,菌丝的颜色一般为白色,菌丝上具有分枝且分生孢子呈椭圆形和镰刀形。使用PCR法扩增该病原菌的ITS和18S rDNA的序列并进行DNA克隆和测序。根据测序结果,对病原菌的ITS和18S rDNA序列的BLAST同源性对比和系统进化树分析。最终根据病原菌的外部特征和分子鉴定的结果证明引起草莓空心病的病原菌为Fusarium solani。该研究为草莓空心病的防控提供科学依据。

甜查理草莓红叶病防治药剂筛选的研究

[目的]筛选出对草莓红叶病防治具有较为明显效果的药剂。[方法]在离体条件下,测定9种不同类型的杀菌剂对草莓红叶病原菌丝体的抑制作用,并筛选出抑制作用效果明显的药剂在草莓育苗期和生长期进行田间试验。[结果]在室内筛选出2种抑菌效果较好的药剂,分别为苯醚甲环唑和戊唑醇。上述药剂对病菌的抑制作用较强,其抑制率分别为95.8%和82.5%。在育苗期和生长期的田间药效测定均表明,施药后叶片上的病斑不扩展并保持原有的状态,同时草莓开始长出新叶并逐渐恢复正常的生长状态。其中在育苗期苯醚甲环唑和戊唑醇防效分别达90.16%和82.0%,而在生长期间苯醚甲环唑和戊唑醇死棵率的防效分别为61.89%和60.18%。[结论]苯醚甲环唑和戊唑醇对草莓红叶病的防治效果较好,可以在生产中推广应用。

Identification and expression patterns of alcohol dehydrogenase genes involving in ester volatile biosynthesis in pear fruit

Alcohol dehydrogenase （ADH） catalyzes the interconversion of aldehydes and their corresponding alcohols, and is a key enzyme in volatile ester biosynthesis. However, little is known regarding ADH and ADH encoding genes （ADHs） in pear. We identified 8 ADHs in the pear＇s genome （PbrADHs） by multiple sequences alignment. The PbrADHs were highly ho- mologous in their coding regions, while were diversiform in structure. 9 introns were predicted in PbrADH3-PbrADH8, while 8 introns, generated through exon fusion and intron loss, were predicted in PbrADH1 and PbrADH2. To study the genetic regulation underlying aroma biogenesis in pear fruit, we determined the PbrADH transcripts, ADH activities and volatile contents of fruits during ripening stage for Nanguoli and Dangshansuli, two cultivars having different aroma characteristics. ADH activity was strongly associated with the transcription of ADH~ in the two cultivars during fruit ripening stage. The higher ester content paralleling to a higher ADH activity was detected in Nanguoli than in Dangshansuli, so it is induced that the lower ester content in Dangshansuli fruit may be the result of weak ADH activity. The present study revealed that total ADH activity and volatile ester production correlated with increased PbrADHstranscript levels. PbrADH6 may contribute to ADH activity catalyzing aldehyde reduction and ester formation in pear fruit.