Root-knot nematodes (RKNs) cause huge yield losses to agricultural crops worldwide.  Meanwhile, livestock manure is often improperly managed by farmers, which leads to serious environmental pollution.  To resolve these two problems, this study developed a procedure for the conversion of chicken manure to organic fertilizer by larvae of Hermetia illucens L. and Bacillus subtilis BSF-CL.  Chicken manure organic fertilizer was then mixed thoroughly with Paenibacillus polymyxa KM2501-1 to a final concentration of 1.5×10⁸ CFU g^–1.  The efficacy of KM2501-1 microbial organic fertilizer in controlling root-knot nematodes was evaluated in pot and field experiments.  In pot experiments, applying KM2501-1 microbial organic fertilizer either as a base fertilizer or as a fumigant at the dose of 40 g/pot suppressed root-knot disease by 61.76 and 69.05% compared to the corresponding control treatments, respectively.  When applied as a fumigant at the dose of 1 kg m^–2 in field experiments, KM2501-1 microbial organic fertilizer enhanced the growth of tomato plants, suppressed root-knot disease by 49.97%, and reduced second stage juveniles of RKN in soil by 88.68%.  KM2501-1 microbial organic fertilizer controlled RKNs better than commercial bio-organic fertilizer in both pot and field experiments.  These results demonstrate that this co-conversion process efficiently transforms chicken manure into high value-added larvae biomass and KM2501-1 microbial organic fertilizer with potential application as a novel nematode control agent.

Melatonin is a naturally occurring compound in plants.  Here, we tested the effect of exogenous melatonin on rapeseed (Brassica napus L.) grown under salt stress.  Application of 30 μmol L^–1 melatonin alleviated salt-induced growth inhibition, and the shoot fresh weight, the shoot dry weight, the root fresh weight, and the root dry weight of seedlings treated with exogenous melatonin increased by 128.2, 142.9, 122.2, and 124.2%, respectively, compared to those under salt stress.  In addition, several physiological parameters were evaluated.  The activities of antioxidant enzymes including peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were enhanced by 16.5, 19.3, and 14.2% compared to their activities in plants without exogenous melatonin application under salt stress, while the H₂O₂ content was decreased by 11.2% by exogenous melatonin.  Furthermore, melatonin treatment promoted solute accumulation by increasing the contents of proline (26.8%), soluble sugars (15.1%) and proteins (58.8%).  The results also suggested that higher concentrations (>50 μmol L^–1) of melatonin could attenuate or even prevent the beneficial effects on seedling development.  In conclusion, application of a low concentration of exogenous melatonin to rapeseed plants under salt stress can improve the H₂O₂-scavenging capacity by enhancing the activities of antioxidant enzymes such as POD, CAT and APX, and can also alleviate osmotic stress by promoting the accumulation of osmoregulatory substances such as soluble proteins, proline, and water soluble glucan.  Ultimately, exogenous melatonin facilitates root development and improves the biomass of rapeseed seedlings grown under salt stress, thereby effectively alleviating the damage of salt stress in rapeseed seedlings.

Somatic embryogenesis (SE) is one of the most important steps during regeneration of cotton, but the molecular mechanism of SE remains unclear.  SOMATIC EMBRYOGENSIS RECEPTOR KINASE (SERK) gene is known to function in SE.  A homolog GhSERK2 (accession number: JF430801) was cloned from Upland cotton and characterized for its functions in SE.  GhSERK2 expressed in different tissues and showed higher expression level in floral organs than vegetative ones with the highest levels in ovule and anther.  GhSERK2 expressed during SE with a high level at globular embryos stage.  Upon treatment with indole-3-butytic acid (IBA), the transcription level of GhSERK2 was induced and promoted SE subsequently.  A 2-day treatment of 2,4-dichlorophenoxyacetic acid (2,4-D) induced the expression of GhSERK2, but treatments of 2,4-D for longer periods sharply inhibited the GhSERK2 transcription level of embryogenic callus (EC).  The levels of hormones, including 3-indoleacetic acid (IAA), abscisic acid (ABA), and brassinosteroid (BR), were increased in the initial calli induced from the over-expression of GhSERK2 cotton.  Our results indicated that GhSERK2 expression was associated with induction of SE and closely related to hormone levels during tissue culture in Upland cotton, and the gene might play an important role in regeneration of cotton.

   Grain appearance quality traits, measured as grain length (GL), grain width (GW), length to width ratio (LWR), grain thickness (GT) and the percentage of grain with chalkiness (PGWC), as well as 1 000-grain weight (TGW), are very important factors that contribute to rice grain quality and yield. To detect quantitative trait loci (QTLs) affecting these traits, we developed a set of recombinant inbred lines (RILs) derived from Gang46B (G46B) and K1075, a G46B introgression line with lower PGWC. Based on a linkage map containing 33 simple sequence repeat (SSR) markers, a total of 15 additive QTLs governing six measured traits were identified on 4 chromosomes across two environments. Of these, the five major QTLs which controlled GW, LWR, GT, PGWC, and TGW, each explaining up to 44.30, 55.29, 62.30, 30.94, and 28.78% of the variation, respectively, were found in the same interval of RM18004–RM18068 on chromosome 5. The G46B alleles contributed to the increase in GW, GT and PGWC at all loci, as well as the increase in TGW at its major QTL locus. Significant interactions between additive QTL and the environment were found at most loci, in which the largest, accounting for 15.06% of variation, was observed between qPGWC-5 and the environment. A total of 15 epistasis QTLs were detected for all the traits, and GL, GW and PGWC had significant epistasis QTLs based on environment interactions with minor effects. These results are valuable for future map-based cloning of the QTLs and the collaborative improvement of G46B in grain appearance quality and yield.

RNA sequencing of the sensitive GH01 variety of Brassica napus L. seedling roots under 12 h of waterlogging was compared with previously published data of the ZS9 tolerant variety to unravel genetic mechanisms of waterlogging tolerance beyond natural variation. A total of 2 977 genes with similar expression patterns and 17 genes with opposite expression patterns were identified in the transcription profiles of ZS9 and GH01. An additional 1 438 genes in ZS9 and 1 861 genes in GH01 showed strain specific regulation. Analysis of the overlapped genes between ZS9 and GH01 revealed that waterlogging tolerance is determined by ability to regulate genes with similar expression patterns. Moreover, differences in both gene expression profiles and abscisic acid (ABA) contents between the two varieties suggest that ABA may play some role in waterlogging tolerance. This study identifies a subset of candidate genes for further functional analysis.