西瓜炭疽病(Anthracnose)是由瓜类炭疽病菌(Colletotrichumorbiculare)引起的真菌性病害。本研究以抗病自交系PI189225和感病自交系Black Diamond杂交并自交获得F1、F2、F3为材料,采用炭疽病菌生理小种1接种,对西瓜抗炭疽病生理小种1进行遗传规律分析和基因定位研究。研究结果表明,西瓜炭疽病抗性基因由显性单基因控制,抗病对感病为显性,将此基因命名为Rco-1。用分离群体分组分析法(BSA)和AFLP分子标记技术对PI189225中的抗炭疽病基因进行分子标记鉴定,并利用MAPMAKER/Exp version 3.0软件进行了标记与目的基因间的遗传距离计算,发现E4/M19、E1/M8、E29/M5与抗炭疽病基因Rco-1连锁,遗传距离分别为34.8、23.4、6.9cM。为采用分子标记辅助选育抗炭疽病西瓜新品种奠定了基础。
Cucumber green mottle mosaic virus(CGMMV) is a member of the genus Tobamovirus, and is a serious pathogen of Cucurbitaceae crops. Virusderived small interfering RNAs(vsi RNAs), which are processed by Dicer-like and Argonaute proteins as well as RNA-dependent RNA polymerase,mediate the silencing of viral genomic RNA and host transcripts. To identify the CGMMV derived vsi RNAs and reveal interactions between CGMMV and watermelon host plant, deep sequencing technology was used to identify and characterize the vsi RNAs derived from CGMMV in infected watermelon plants in present study. A total of 10 801 368 vsi RNA reads representing 71 583 unique s RNAs were predicted in CGMMVinoculated watermelon plants. The CGMMV vsi RNAs were mostly 21 or 22 nt long. The majority of the CGMMV vsi RNAs(i.e., 91.7%) originated from the viral sense strand. Additionally, uracil was the predominant 5′-terminal base of vsi RNAs. Furthermore, the putative targets and functions of some of the CGMMV vsi RNAs were predicted and investigated. The results enhance our understanding of the interaction between CGMMV and the host watermelon and provide molecular basis for CGMMV resistance improvement in watermelon and other Cucurbitaceae crops.
