Prevention And Treatment Of Marigold Leaf Spot Disease And Cloning Of Thaumatin-like Protein Gene

Marigold flowers (Tagetes erecta) can be extracted "lutein" which is widely used in medicine, health care, food and other industries. So it has a higher economic value. And marigold flowers is a long flowering,large-scale cultivation can be formed the landscape, driving the development of eco-tourism industry. Based on the above two points pigment marigold flower industry has become one of the pillars in Sihai. However, when the rainy season comes, the valley air is humidity lead to frequent marigold disease, seriously affecting the production and landscape effects. The study took Disease field investigation,pathogen isolation and identification,antifungal experiments,field trials of chemical control, ecological interplanting test, disease gene cloning,to develop the appropriate pesticides and interplanting for reduced the incidence of marigold leaf spot, TLP resistance gene has been cloned laying the foundation for future pigment marigold improve disease resistance by means of genetic modification.Disease field survey:the pre-disease of marigold is virus, root rot, blight; late-disease is leaf spot disease. In the production process, leaf spot has a significant impact for yield and landscape effectsThe collection of diseased leaves were isolated and purified strains of pathogens, morphological identification results is Alternaria.sp. By using result of ITS technologies is Alternaria tenuissima. Phylogenetic analysis showed that marigold leaf spot pathogen Alternaria tenuissima which is significantly different for other Alternaria.Experiment for Bacteriostasis found:mancozeb, difenoconazole, iprodione propiconazole,fuxing have good inhibitory effect.Chemical Control field found:The best method of prevention and treatment were mixture of difenoconazole and azoxystrobin, difenoconazole and bai tai. However, the pesticides of two programs are more expensive.Propiconazole and mancozeb are better control effect. Bacillus subtilis also has good control effect. Research has shown B. subtilis to Alternaria fungi have antagonistic effects, it also provides a new way for the ecological safety in Marigold productionIntercropping model:In four different modes interplanting, Pattern of Marigold-Dutch potato was highest yield and best prevention of diseases. Due to the height gap between Two Kind of Crops, growing staggered, different colors, this model has increased the overall ornamental effect.It is best model in Marigold productionUsing PCR and RACE cloning technology, TLP is separated from the marigold. Bioinformatics analysis showed that Marigold Sweet protein amino acid sequences of nature, hydrophobic transmembrane domains, signal peptides and homology phylogenetic tree. The results showed the gene of Thaumatin-like protein full-length cDNA is 880bp and the open reading frame encodes 223 amino acids from marigold. The molecular weight of TLP of the amino acid sequence is 23933.8 Da; theoretical isoelectrie point is 6.51; Molecular formula is C1051H1587N295O327S18; total atomic weight is 3278; extinction coefficient (280mm) is 26440; fat coefficient is 54.22; genus stable protein. There are 22 amino acids hydrophobic signal peptide and the transmembrane domain at the N-terminus. Thaumatin-like protein of marigold and PR5 protein of sunflowerhomology is 99%, and other plants have high homology TLP.By semi-quantitative techniques, it was found healthy plant stems, leaves, flowers tissues, TLP gene was not expression. After the diseased plants of roots, stems, leaves, flowers were found TLP genes upregulated,Among them, the the expression of TLP gene in flowers was least and roots, stems, leaves was similar to flowers.