Plant height is a key plant architectural trait that affects the seed yield, harvest index and lodging resistance in Brassica napus L., although the genetic mechanisms affecting plant height remain unclear.  Here, a semi-dwarf mutant, df34, was obtained by ethyl methanesulphonate-induced mutagenesis.  Genetic analysis showed that the semi-dwarf phenotype is controlled by one semi-dominant gene, which was located on chromosome C03 using a bulked segregant analysis coupled with whole-genome sequencing, and this gene was named BnaSD.C3.  Then BnaSD.C3 was fine-mapped to a 297.35-kb segment of the “Darmor-bzh” genome, but there was no potential candidate gene for the semi-dwarf trait underlying this interval.  Furthermore, the interval was aligned to the Zhongshuang 11 reference genome.  Finally, combining structural variation analysis, transcriptome sequencing, phytohormone analyses and gene annotation information, BnaC03G0466900ZS and BnaC03G0478900ZS were determined to be the most likely candidate genes affecting the plant height of df34.  This study provides a novel major locus for breeding and new insights into the genetic architecture of plant height in B. napus

    Flixweed (Descurainia sophia L.) is a problematic and widespread weed in winter wheat fields and has been controlled by tribenuron-methyl for more than twenty years in China. In this study, a flixweed accession (Hebei 25, HB25) with an Asp-376-Glu mutation in acetohydroxy acid synthase (AHAS) was identified and purified. The purified HB25 accession (pHB25) developed 758.1-fold resistance to tribenuron-methyl and exhibited obvious cross-resistance to four AHAS-inhibiting herbicides. The resistant/susceptible (R/S) ratios of 50% plant growth reduction (GR₅₀) to herbicides of halosulfuron-methyl, flumetsulam, imazethapyr and pyribenzoxim were 346.1, 15.7, 8.1 and 7.1, respectively. The reduced AHAS sensitivities to four different AHAS-inhibiting herbicides, which were caused by the Asp-376-Glu mutation, were responsible for the resistance and cross-resistance to AHAS-inhibiting herbicides. The R/S ratios of 50% inhibition of AHAS activity (I₅₀) to tribenuron-methyl, halosulfuron-methyl, flumetsulam, imazethapyr and pyribenzoxim were 844.5, 532.9, 74.5, 13.3 and 5.5, respectively. The results of AHAS activity in vitro were highly correlated with that of whole-plant response experiments.

Hybridization, which allows for gene flow between crops, is difficult between maize and Zea perennis. In this study, we aim to initiate and study gene flow between maize and Z. perennis via a special aneuploid plant (MDT) derived from an interspecific hybrid of the two species. The chromosome constitution and morphological characters of MDT as well as certain backcross progenies were examined. Results from genomic in situ hybridization (GISH) indicate that aneuploid MDT consisted of nine maize chromosomes and 30 Z. perennis chromosomes. The backcross progenies of MDT×maize displayed significant diversity of vegetative and ear morphology; several unusual plants with specific chromosome constitution were founded in its progenies. Some special perennial progeny with several maize chromosomes were obtained by backcrossing MDT with Z. perennis, and the first whole chromosome introgression from maize to Z. perennis was detected in this study. With this novel material and method, a number of maize-tetraploid teosinte addition or substitution lines can be generated for further study, which has great significance to maize and Z. perennis genetic research, especially for promoting introgression and transferring desirable traits.

To identify and analyze the Orf virus in Shanxi Province, China, an Orf virus strain was successfully isolated from crust materials of boer goat with clinical sore mouth symptom from a goat farm of Shanxi Province by passaging in lamb testis (LT). The Orf virus was identified by enzyme linked immunosorbent assay (ELISA) test, recurrent infection test, transmission electron microscopy, and PCR. The nucleotide and amino acid sequences of two genes of the Orf virus were analyzed.The results showed that under the electron microscopy the virus had a presence of typical parapoxvirus virions and there were many eosinophilic intracytoplasmic inclusions observed by hematoxylin-eosin (H&E) stain. In ELISA test, optical density (OD) readings of the sample showed a positive result, and the rabbits infected with the virus showed a typically Orf virus-infected appearance. All these findings proved that the sample was an Orf virus. The phylogenetic studies of Orf B2L and Orf F1L genes showed that the virus clustered in different branches and were closer to the Orf virus Nantou (DQ904351) and the OV-SA00 isolates (AY386264). Furthermore, the above results may provide some insight into the genotype of the etiological agent responsible for the Orf outbreak in Shanxi Province, and could also provide a comparative view of the B2L and F1L genes of parapoxvirus.