提高小麦产量是全球小麦育种者的长期目标。发掘优良遗传资源，解析小麦重要农艺性状的遗传基础，是小麦高产育种的必经之路。本研究评价了两年七个环境中由156个育成品种和77个地方品种组成的四川小麦自然群体的9个重要农艺性状表现。农艺性状调查结果表明，地方品种分蘖较多，穗粒数（KNS）较高，育成品种千粒重（TKW）和穗粒重（KWS）较高。9个农艺性状的广义遗传力（H ²）在0.74到0.95之间。利用来自小麦55K SNP芯片的43198个单核苷酸多态性（SNP）标记进行群体结构分析可以将自然群体分为三组。基于混合线性模型Q+K方法的全基因组关联分析（GWAS）共鉴定出67个数量性状位点（QTL）。本研究主要对三个重要性状的QTL进行了分析，即分别检测到的可育分蘖数（FTN）位点QFTN.sicau-7BL.1的四种单倍型、KNS位点QKNS.sicau-1AL.2的三种单倍型和TKW位点QTKW.sicau-3BS.1的四种单倍型。从2002—2013年区域试验的42个品种的产量表现来看，FTN-Hap2、KNS-Hap1和TKW-Hap2分别是每个QTL中的优良单倍型。具有三个优良单倍型的品种相比具有两个或一个优良单倍型的品种产量更高。此外，基于每穗粒数的QTL位点 QKNS.sicau-1AL.2开发了连锁的KASP-AX-108866053标记能在2018年至2021年区域试验中鉴定63个品种的三种单倍型（或等位基因）。这些遗传位点和连锁标记可用于标记辅助选择或基于图谱的基因克隆，用于小麦产量的遗传改良。

The reverse genetics for classical swine fever virus (CSFV) is currently based on the transfection of in vitro transcribed RNA from a viral genomic cDNA clone, which is inefficient and time-consuming. This study was aimed to develop an improved method for rapid recovery of CSFV directly from cloned cDNA. Full-length genomic cDNA from the CSFV Shimen strain, which was flanked by a T7 promoter, the hepatitis delta virus ribozyme and T7 terminator sequences, was cloned into the lowcopy vector pOK12, producing pOKShimen-RzT . Direct transfection of pOKShimen-RzT into PK/T7 cells, a PK-15- derived cell line stably expressing bacteriophage T7 RNA polymerase, allowed CSFV to be rescued rapidly and efficiently, i.e., at least 12 h faster and 31.6-fold greater viral titer when compared with the in vitro transcription-based rescue system. Furthermore, the progeny virus rescued from PK/T7 cells was indistinguishable, both in vitro and in vivo, from its parent virus and the virus rescued from classical reverse genetics. The reverse genetics based on intracellular transcription is efficient, convenient and cost-effective. The PK/T7 cell line can be used to rescue CSFV directly from cloned cDNA and it can also be used as an intracellular transcription and expression system for studying the structure and function of viral genes.

Classical swine fever (CSF) and porcine reproduction and respiratory syndrome (PRRS) are both economically important, highly contagious diseases of swine worldwide. To develop an effective vaccine to control these two diseases, we constructed a recombinant adenovirus rAdV-GP52AE2, using a replication-defective human adenovirus serotype 5 as a delivery vector, to co-express the GP5 protein of highly pathogenic porcine reproduction and respiratory syndrome virus (PRRSV) and the E2 protein of classical swine fever virus (CSFV). Foot-and-mouth disease virus (FMDV) 2A peptide was used as a linker between the GP5 and E2 proteins to allow automatic self-cleavage of the polyprotein. The GP5 and E2 genes were expressed as demonstrated by immunofluorescence assay and Western blotting. Immunization of mice resulted in a CSFV-neutralizing antibody titer of 1:128 and a PRRSV-neutralizing antibody titer of 1:16. The lymphoproliferative responses were detected by Cell Counting Kit-8 assay and the stimulation index of CFSV-specific and PRRSV-specific lymphocytes in the rAdV-GP52AE2 group was significantly higher than that in the negative control group. The results show that rAdV-GP52AE2 can induce both effective humoral and cell-mediated immune responses in mice. The protective efficacy of the recombinant virus against CSF was evaluated in immunized rabbits, which were protected from fever induced by challenge with C-strain. Our study provides supporting evidence for the use of FMDV 2A to develop a bivalent genetically-engineered vaccine.