Selection and Molecular Biological Identification of a Strain of Bacillus sp. Inhibiting the Growth of Saprolegnia ferax

Based on the theory of biological control of Saprolegnia ferax,antagonism test of nine strains of Bacillus sp. to S. ferax JL was carried out. Bacillus sp.BA1 was screened to have significantly inhibitory effects on the growth of S. ferax JL( P 【 0. 05). Then,the effects of Bacillus sp. BA1 on different sources of S. ferax were carried out. Results showed that BA1 also had significantly inhibitory effects on S. ferax 6#,10# and S2( P 【 0. 05). Sequence of 16 S r DNA of BA1 was analyzed; and homologous alignment analysis showed that BA1 had more than 99% similarity with Bacillus cereus. Therefore,it could be concluded that strain BA1 was B. cereus,which significantly inhibited the growth of S. ferax and could be used as the biological control agent for S. ferax diseases in aquaculture.

Isolation and Identification of a High-pathogenicity Strepto- coccus suis Serotype 7 Strain

In order to diagnose the diseased pigs in a certain large pig farm in Binzhou City, Shandong Province, the dead piglets with joint swelling were subjected to necroscopy, and the pathogenic bacterium was isolated and identified. One Gram-positive Streptococcus was isolated. The strain was subjected to characteristic culture, microscopic examination and molecular biological identification, and resistance detection, animal regression experiment and mouse pathogenicity test were carried out. The results showed that the isolate was identified to be Streptococcus suis serotype 7, which was resistant to multiple drugs; and the pathogenicity test showed that the strain had high pathogenicity to pigs, resulting in neurosis on partial pigs, and the strain had no pathogenicity to Kunming and BALB/c mice but certain pathogenicity to CD1 mice.

Identification of Mulberry Endophytic Fungus Macrophomina phaseolina Strain

An endophytic fungus MOD-1 was isolated from the roots of mulberry trees,and was identified as Macrophomina phaseolina by morphology and molecular biology.The 5.8 S rDNA/ITS region sequence of the strain has been registered in GeneBank with the accession number of EU250575.

Identification of Biocontrol Strain HJX1 and Determination of Its Antifungal Spectrum

A biocontrol strain HJX1,which had good inhibitory effect against Fusarium oxysporum f. sp. cubense,was identified as Bacillus subtilis based on traditional morphology,16 S rRNA gene sequence and fatty acid profiles. The sequence of 16 S rRNA gene had 99% homology to B. subtilis according to the DNA fragment of 1 521 bp amplified with a pair of universal primers,P0 and P6,of bacteria. Confront culture with pathogenic fungi showed that this strain had good inhibitory effect against 10 pathogenic fungi.

A review of the application of computer vision technology in aquaculture

In recent years, aquaculture industry in China is developing rapidly, and especially, China has the largest aquaculture area and the most output in the world. In the past, traditional aquaculture mainly depended on manual labour to breed and gain aquatic organisms. However, with the increasing scale of production and the continuous improvement of science and technology, the traditional aquaculture approach has become more and more unsuitable for the development of the times. With the rapid development of computer technology, computer vision technology infiltrates through the traditional aquaculture industry quickly and improves the aquaculture production efficiency .This paper mainly introduces the basic situation of computer vision technology and summarizes the application of computer vision technology in aquaculture industry at home and abroad. The paper concludes with the expectation of application of computer vision in the aquaculture.