关键词: 农用抗生素, 农用抗生素, 正交试验, 浸提, 柱层析

Abstract: The pear chitinase gene Lchi1 was cloned and the gene related information of the bioinformatics was analyzed. Thus it could provide a theoretical basis for the identification of gene function, and provide a source of gene for pear resistance breeding. According to the conserved sequence of the plant chitinase gene in Genbank, blast was carried out in the pear genome database, and retrieved the DNA sequence. Primers were designed according to the DNA sequence. cDNA fragments of chitinase gene was amplified from ‘Xiao Xiang Shui’(Pyrus ussuriensis cv. Xiaoxiangshui). Bioinformatics analysis was also done. The DNA sequence was 2535bp including three exon regions and two intron regions. Bioinformatics analysis showed that the full length of Lchi1 gene was 1300 bp and it contained a complete ORF which encoded 322 amino acids. The predicted protein’s molecular formula was C1607H2407N415O468S17, whose relative molecular mass was 35573.3 Da and isoelectric point was 7.10. The secondary structure of the protein mainly included random coil and α-helix. Tertiary structure was highly conservative. It was predicted that the protein was soluble and extracellular protein, and there were a small amount of potential phosphorylation sites. The protein belonged to glycoside hydrolase 19 family, and there was a signal peptide and no chitin binding domain. Lchi1 gene belonged to CLASSⅡ chitinase gene, which was highly conservative among chitinases from other different plant species.