The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‐associated 9 (Cas9) system is a versatile, efficient and heritable gene editing tool that can be useful for genome engineering. Bactrocera dorsalis (Hendel) is a major pest of agriculture that causes great economic losses. We used the B. dorsalis multiple edematous wings (Bdmew) gene as the target gene to explore the effectiveness of CRISPR/Cas9 for B. dorsalis genome manipulation. We studied the physiological functions of the Bdmew gene, particularly those related to muscle development. Site‐specific genome editing was feasible using direct microinjection of specific guide RNA and the Cas9‐plasmid into B. dorsalis embryos. Mutation frequencies ranged from 12.1 to 30.2% in the injected generation. Mosaic G0, with the mew mutation, was heritable to the next generation. The G1 displayed a series of defective phenotypes including muscle weakness, flightlessness, failure to eclose, wing folds and unbalanced movement. These results demonstrated that CRISPR/Cas9 can act as a highly specific, efficient, heritable tool for genome manipulation in B. dorsalis and this has significance for gene function research and genetic control of pests. The Bdmew gene possesses key functions in muscle development of B. dorsalis. Bdmew mutations cause a series of serious defects by interfering with muscle development and may provide a means for controlling B. dorsalis via a gene‐based method such as gene drive.

The pharmacokinetics of florfenicol (FF) and its metabolite, florfenicol amine (FFA), were studied in rice field eel (Monopterus albus) after a single dose (20 mg/kg) by intramuscular (i.m.) or oral gavage (p.o.) dose at 25 °C. The elimination half-lives (t1/2β ), peak concentration of FF (Cmax ), and time to reach FF peak concentration (Tmax ) in plasma were estimated as 18.39 h, 10.83 μg/mL, and 7.00 h, respectively, after i.m. injection and 13.46 h, 8.37 μg/mL, and 5 h, respectively, after p.o. administration. The Tmax values of FF in tissues (i.e., kidney, muscle, and liver) were larger for i.m. injection compared with those for p.o. administration. The t1/2β had the following order kidney>muscle>liver for i.m. administrated and kidney>liver>muscle for p.o. administrated. The largest area under the concentration-time curve (AUC) was calculated to be 384.29 mg·h/kg after i.m. dosing, and the mean residence time (MRT) was 42.46 h by oral administration in kidney. FFA was also found in all tissues with a lower concentration than FF for both i.m. and p.o. administrations throughout the study. The elimination of FFA was slow with a t1/2β between 18.19 and 47.80 h in plasma and tissues. The mean metabolic rate of FFA for i.m. and p.o. administrations was >23.30%.

Houttuynia cordata is a perennial herbaceous plant (family Saururaceae) that is native to southern China, Japan, Korea, and Southeast Asia where it grows well in moist to wet soils. It is commonly used as a Chinese herbal medicine and as a vegetable. In North America and Europe it is also used as an ornamental. From September 2007 to November 2009, symptoms of leaf spot were found on H. cordata leaves in Dangyang County, Hubei, China, with the crop area affected estimated to be over 600 ha per year. Rhizome yield was reduced by 20% on average, with up to 70% yield losses in some fields during the autumn growing season. Lesions were initially small, brown, and oval or circular that developed into dark spots and sometimes formed target spots with white centers. These spots enlarged and overlapped, extending until the leaves withered entirely usually within 2 months. A fungus was consistently recovered from symptomatic leaf samples collected in October 2008 or 2009 with an average 90% isolation rate from ~60 leaf pieces that were surface sterilized with 0.1% mercuric chloride solution. Three isolates, HCDY-2, HCDY-3, and HCDY-4, were used to further evaluate characteristics of the pathogen. On potato dextrose agar, all cultures initially developed white colonies and the centers turned gray or brown after 4 days of incubation. Conidiophores were single or fasciculate, straight or knee curved, gray-brown with regular septa, and 42 to 61 × 4 to 5 μm. Conidia were obclavate or ovate, brown, and 26 to 38 × 12 to 20 μm with three to five transverse and one to three longitudinal or oblique septa. The tops of some conidia developed into secondary conidiophores, which were cylindrical, beige, and 5 to 17 × 3 to 5 μm. The pathogen was identified as Alternaria alternata based on descriptions in Simmons (3). Genomic DNA of HCDY-2 was extracted, and the rDNA-internal transcribed spacer sequence showed 99.6% identity to A. alternata (GenBank No. AY513941). Pathogenicity tests were performed with the three isolates by spraying conidial suspensions (1 × 106 conidia/ml) containing 0.1% Tween 20 onto upper and lower surfaces of leaves of 40-day-old 15-cm high plants. There were 20 leaves from five replicate plants for each isolate. Control plants were treated with sterilized water containing 0.1% Tween 20 only. All plants were incubated with a 16-h photoperiod at 25°C and 90% relative humidity in an artificial climate chamber. Five days after inoculation, typical brown spots were observed on all inoculated leaves but no symptoms were seen on water-treated control plants. Koch's postulates were fulfilled by reisolation of A. alternata from diseased leaves. The pathogenicity tests were carried out twice. A survey of the literature revealed only a few fungal diseases associated with H. cordata (1,2,4), including Phyllosticta houttuyniae, Pseudocercospora houttuyniae, Rhizoctonia solani, and Sclerotium rolfsii. Although A. alternata is a cosmopolitan plant pathogen, it has not been reported on any species in the four genera in Saururaceae (Anemopsis, Gymnotheca, Houttuynia, and Saururus) (3). To our knowledge, this is the first report of A. alternata infecting H. cordata worldwide. References: (1) Y. L. Guo and W. X. Zhao. Acta Mycol. Sin. 8:118, 1989. (2) K. Sawada. Spec. Publ. Taiwan Univ. 8:138, 1959. (3) E. G. Simmons. Alternaria: An Identification Manual. The American Phytopathological Society, St. Paul, MN, 2007. (4) Y. Wu et al. J. Changjiang Vegetables (In Chinese) 2:19, 2007.