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Rapeseed, an allotetraploid oil crop, provides vegetable oil for human consumption. The growing demand for oilseeds has necessitated the development of rapeseed varieties with improved quality. Therefore, a clear understanding of the genetic basis underlying the seed oil content (SOC) is required. In this study, a natural population comprising 204 diverse accessions and recombinant inbred lines (RILs) derived from Brassica napus and Sinapis alba via distant hybridization were collected for genome-wide association analysis (GWAS) and quantitative trait loci (QTL) mapping of the SOC trait, respectively. The variable coefficient of the RIL and natural populations ranged from 7.43 to 10.43% and 8.40 to 10.91%. Then, a high-density linkage map was constructed based on whole genome re-sequencing (WGS); the map harbored 2,799 bin markers and covered a total distance of 1,835.21 cM, with an average marker interval of 0.66 cM. The QTLs for SOC on chromosome A07 were stably detected in both single and multiple environments. Finally, a novel locus qA07.SOC was identified as the major QTL for SOC based on the GWAS and RIL populations. In addition, the RNA-seq results showed that photosynthesis, lipid biosynthesis proteins, fatty acid metabolism, and unsaturated fatty acid biosynthesis were significantly different between the developed seeds of the two parents of the RIL population. By comparing the variation information and expression levels of the syntenic genes within qA07.SOC and its syntenic genomic regions, as well as through haplotype analysis via GWAS, BnaA07.STR18, BnaA07.NRT1, and BnaA07g12880D were predicted as candidate genes in the qA07.SOC interval. These stable QTLs containing candidate genes and haplotypes can potentially provide a reliable basis for marker-assisted selection in B. napus breeding for SOC.

Perilla frutescens L. is a traditional medicinal plant in china. In recent years, with more and more attention is paid to the nutritional and health values of Perilla frutescens L., it has become a potential medicinal and edible crop. Two Perilla frutescens cultivars, Qisu No.1 (oil type) and Qisu No.3 (leaf and seed-using type), bred by Rapeseed Research Institute of Guizhou Academy of Agricultural Sciences, were used as test material for studying the effects of different planting density on the economic yield and agronomic characters of Perilla frutescens L. under moderate fertility level. The results showed the variation tendency of agronomic characters with the change of planting density was similar for the two Perilla frutescens cultivars. Among them, the plant height, main-stem nods, first effective branch length, first effective branch height, spikes per plant, and yield per plant were negatively related to the planting density; and main spike length and mainspike grains were positively related to the planting density. The effects of planting density on kilo-grain weight were not significant. The yield of the two cultivars all increased first and then decreased with the increase of planting density. The regression analysis of planting density versus yield of Perilla frutescens L. was performed for obtaining the regression equations (Qisu No.1: y=54.046 5+96.777 1x45.719 8x2, r=0.999 4; Qisu No.3: y=38.717 6+42.111 3x-16.757 7x2, r=0.999 8). Based on the regression equations, the optimal planting density for Qisu No.1 was 158 745 plants/hm2 with peak yield of 1 578.90 kg/hm2, and for Qisu No.3 was 188 745 plants/hm2 with peak yield of 977.55 kg/hm2. Under the optimal planting density, Qisu No.3 could also harvest 3 000 kg/hm2 of Perilla frutescens dry leaves and 2 400 kg/hm2 of Perilla frutescens stems. This research would provide an important reference for the promotion, high-yield cultivation and comprehensive utilization of Perilla frutescens L. [ABSTRACT FROM AUTHOR]

In plants, powdery-mildew-resistance locus o (Mlo) genes encode proteins that are calmodulin-binding proteins involved in a variety of cellular processes. However, systematic characterization of this gene family in soybean (Glycine max L. Merr.) has not been yet reported. In this study, we identified MLO domain-contained members in soybean and examined their expression under phytohor-mone treatment and abiotic stress conditions. A total of 20 soybean Mlo genes were identified (GmMlo1-20), which are distributed on 13 chromosomes, and display diverse exon-intron structures. Phylogenetic analysis indicated that the Mlo family can be classified into four subfamilies. Sequence comparison was used to reveal the conserved calmodulin-binding domain (CaMBD) in GmMLO proteins. The expression of GmMlo genes was influenced by various phytohormone treatments and abiotic stresses, suggesting that these Mlo genes have various roles in the response of soybean to environmental stimuli. Promoter sequence analysis revealed an overabundance of stress and/or phytohormone-related cis-elements in GmMlo genes. These data provide important clues for elucidating the functions of genes of the Mlo gene family. [ABSTRACT FROM AUTHOR]