Comprehensive analysis of the full-length transcripts and alternative splicing involved in clubroot resistance in Chinese cabbage

Chinese cabbage is an economically important Brassica vegetable worldwide, and clubroot, which is caused by the soilborne protist plant pathogen Plasmodiophora brassicae is regarded as a destructive disease to Brassica crops. Previous studies on the gene transcripts related to Chinese cabbage resistance to clubroot mainly employed RNA-seq technology,although it cannot provide accurate transcript assembly and structural information. In this study, PacBio RS II SMRT sequencing was used to generate full-length transcriptomes of mixed roots at 0, 2, 5, 8, 13, and 22 days after P. brassicae infection in the clubroot-resistant line DH40R. Overall, 39 376 high-quality isoforms and 26 270 open reading frames(ORFs) were identified from the SMRT sequencing data. Additionally, 426 annotated long noncoding RNAs(lncRNAs),56 transcription factor(TF) families, 1 883 genes with poly(A) sites and 1 691 alternative splicing(AS) events were identified. Furthermore, 1 201 of the genes had at least one AS event in DH40R. A comparison with RNA-seq data revealed six differentially expressed AS genes(one for disease resistance and five for defensive response) that are potentially involved in P. brassicae resistance. The results of this study provide valuable resources for basic research on clubroot resistance in Chinese cabbage.

连州菜心小孢子培养体系的建立

游离小孢子培养技术是快速创制连州菜心双单倍体纯系的一条有效途径,为建立高效的连州菜心小孢子培养体系,应用于优势杂交育种实践,以引进的3个广东省连州市地方菜心品种迟熟连州菜心(17AY007)、连州尺寸心(17AY008)和连州尖叶迟菜心(17AY009)为试材进行小孢子培养,研究不同基因型和植物生长调节剂(芸薹素内酯,BR及噻苯隆,TDZ)对小孢子胚胎发生及植株再生的影响,并对获得的连州菜心小孢子再生植株进行倍性鉴定。结果表明:3个不同基因型连州菜心的小孢子胚胎发生率无显著差异;在NLN-13培养基中添加适宜浓度的BR或TDZ可显著提高连州菜心小孢子胚胎发生率和直接成苗率,其中,当BR浓度为0.04mg·L-1时,17AY007和17AY009的胚诱导率和直接成苗率均达到最高(2.38胚·蕾-1,72.82%;2.83胚·蕾-1,54.62%);当TDZ浓度为0.1mg·L-1和0.2mg·L-1时,17AY007的胚诱导率和直接成苗率分别达到最高(2.67胚·蕾-1,57.76%);TDZ浓度为0.3mg·L-1时,17AY009的胚诱导率和直接成苗率均达到最高(2.42胚·蕾-1,57.36%);3种连州菜心再生植株的双单倍体率均在56%以上,其中,17AY007双单倍体率最高,为64.29%。综上,创制了双单倍体植株42株,为连州菜心优势杂交育种奠定了材料基础。

生物菌肥和土壤调理剂处理对大棚春番茄生长、坐果和病害的影响

通过大田试验,探讨生物菌肥、土壤调理剂及其配施处理对大棚春番茄生长、坐果及病害的影响。结果表明,生物菌肥和土壤调节剂及其配施处理对番茄生长有一定的促进作用,提高了番茄坐果率和降低了畸形果率,调理剂+激抗菌968微生物菌肥+生物菌配施处理明显提高了第三、四层花穗的坐果率,明显降低了第二、三、四层花穗的畸形果率。生物菌肥和土壤调节剂及其配施处理对番茄晚疫病和叶霉病的发病率无显著影响,但均降低了番茄晚疫病和叶霉病的病情指数,提高了防治效果。调理剂+激抗菌968微生物菌肥+生物菌配施处理可使病情指数明显降低,防治效果分别达28.84%和29.95%。生物菌肥和土壤调节剂配施可应用于大棚番茄生产。