Microvitellogenin (mVg) belongs to the lepidopteran-specific lipoprotein_11 super family and is thought to be involved in insect reproduction.  However, the function of mVg in reproduction has not been established.  In this study, we identified and characterized MsmVg in Mythimna separata, a destructive insect pest of grain crops.  MsmVg is comprised of a 1,310 bp open reading frame (ORF) encoding 437 amino acids.  Structural analysis showed that MsmVg contains three conserved domains in the lipoprotein_11 super family, including the all-α-N-terminal domain (NTD), a Pseudomonas putida homologous domain (PPD), and an all-β-C-terminal domain (CTD).  MsmVg was highly expressed in mature female adults and enriched in the ovaries of 3-day-old female adults.  Disruption of MsmVg by RNA interference did not change the expression of MsmVg, vitellogenin (MsVg) or the vitellogenin receptor (MsVgR) in fat bodies, but it inhibited their transcription in ovaries.  Phenotype analysis showed that knockdown of MsmVg did not affect yolk deposition in ovaries, but impaired eggshell formation and led to a reduction in the reproductive capacity.  Furthermore, knockdown of MsmVg significantly inhibited the expression of genes associated with eggshell formation (MsChP1-3 and MsFcP3C).  Taken together, these data suggest that MsmVg plays an important role in female reproduction by affecting eggshell formation in M. separata, which provides a potential target for managing this insect pest.

Identifying stable quantitative trait loci (QTLs) for yield-related traits across populations and environments is crucial for wheat breeding and genetic studies.  Consensus maps also play important roles in wheat genetic and genomic research.  In the present study, a wheat consensus map was constructed using a doubled haploid (DH) population derived from Jinghua 1×Xiaobaidongmai (JX), an F₂ population derived from L43×Shanxibaimai (LS) and the BAAFS Wheat 90K SNP array single nucleotide polymorphism (SNP) array.  A total of 44,503 SNP markers were mapped on the constructed consensus map, and they covered 5,437.92 cM across 21 chromosomes.  The consensus map showed high collinearity with the individual maps and the wheat reference genome IWGSC RefSeq v2.1.  Phenotypic data on eight yield-related traits were collected in the JX population, as well as the F_2:3 and F_2:4 populations of LS, in six, two and two environments, respectively, and those data were used for QTL analysis.  Inclusive composite interval mapping (ICIM) identified 32 environmentally stable QTLs for the eight yield-related traits.  Among them, four QTLs (QPH.baafs-4B, QKNS.baafs-4B, QTGW.baafs-4B, and QSL.baafs-5A.3) were detected across mapping populations and environments, and nine stable QTLs (qKL.baafs-1D, QPH.baafs-2B, QKNS.baafs-3D, QSL.baafs-3D, QKW.baafs-4B, QPH.baafs-5D, QPH.baafs-6A.1, QSL.baafs-6A, and QSL.baafs-6D) are likely to be new.  The physical region of 17.25–44.91 Mb on chromosome 4B was associated with six yield-related traits, so it is an important region for wheat yield.  The physical region around the dwarfing gene Rht24 contained QTLs for kernel length (KL), kernel width (KW), spike length (SL), and thousand-grain weight (TGW), which are either from a pleiotropic effect of Rht24 or closely linked loci.  For the stable QTLs, 254 promising candidate genes were identified.  Among them, TraesCS5A03G1264300, TraesCS1B03G0624000 and TraesCS6A03G0697000 are particularly noteworthy since their homologous genes have similar functions for the corresponding traits.  The constructed consensus map and the identified QTLs along with their candidate genes will facilitate the genetic dissection of wheat yield-related traits and accelerate the development of wheat cultivars with desirable plant morphology and high yield.