Biological Characteristics Of Santalum Album Linn. Anthracnose And Pollution-free Control Technology

Santalum album Linn is a semi parasitic small trees in Santalum album genus,Santalaceae,as the national key protected plants.Santalum album is widely used,has been applied in industry,medicine,spices,sculpture and other skin care products.But the Santalum album grows extremely slowly,usually for several decades to become useful,is one of the most slow tree growth.Therefore,prevention and treatment of disease of Santalum album is crucial.This topic through the investigation on the main diseases and insect pests group in Hainan Province,we found that anthracnose is the main disease of Santalum album.There is no system for Santalum album anthrax reports.This article studied the morphological and molecularlevel of Santalum album anthracnose pathogen iden-tification,occurrence regularity and its biological characteristics,the determination of 3 different fungicides against Santalum album anthracnose in different Santalum alb-um mixed forest to obtain an effective technology pollution prevention and control on Santalum album anthrax.The main results as follows:(1)Identification of the pathogens.The pathogens colony on PDA culture medi-um were round,neat edge,thick,fluffy.The mycelium is white at first,with growth,the mycelium became gray,but the edge is still white.The back of colonies was dark green.After 5d in culture,the pathogen produce orange conidia mass.Microscopic examination found that the mycelium was septate hyphae,and the branches are mostly in the basal.The spore morphology is basically the same,unicellular,terete,colorless,rounded at both ends,the size of(10-20)×(3.5-6.0)?m,conidia appressorium is brown.The rDNA-ITS sequences can be acquired by sequencing and MEGA5.0 is used here to build the phylogenetic tree which finds that the homology between the pathogens and Colletotrichum fructicola is 99%.Combination the indentifications of morphology and molecular,it can be known that this nosophyte is Colletotric-hum fructicola.(2)The biological characteristics and occurrence regularity of Santalum album anthracnose pathogen.Colletotrichum fructicola mycelia could grow at 10 to 35?,30? had the best growth,after 5d culture colony diameter up to 6.85cm;the coni-dia germination at 10 to 3 5 ?,optimal germination temperature is 30?.After 15h,the germination rate was 84.5%.When the pH was 3-11,the mycelium could grow,The pH of the most conductive to the growth of pathogens is 6.0,the colony diameter was 6.92cm;the pH was 3-11 range conidia can germinate,when the pH value was 5,the spore germination rate up to 94.7%.Continuous illumination was beneficial for mycelial growth,continuous darkness for spore germination.The experiment selected 8 kinds of carbon sources,the pathogens of sucrose was the highest,after 5d cultu-re colony diameter was 7.91cm,cultured 15h conidia germination rate as high as 88%;the pathogenic bacteria in the experiment selected 7 kinds of nitrogen source in the culture medium were made to growth,but in the protein peptone as nitrogen sour-ce for hypha growth was the most exuberant,up to 1.06g after 5d cultured mycelium dry;but the most conducive to sporulation of nitrogen source was urea.This year in November to next April Santalum album anthracnose was less,with the increase of temperature and humidity,5-7 months had a slowly increase,8-10 monthwas the peak incidence.(3)Research of Colletotrichum fructicola fungicides.The different incidence of anthracnose Colletotrichum fructicola cultivation mode is different,but the incide-nce and severity of the difference is not large.One of the most serious disease of Santalum album nurseries,the incidence rate is 84.61%,mixed forest Santalum album and Homalium hainanense,the incidence rate is 81.24%,mixed forest Santalum album and Dalbergia odorifera‘s incidence rate was only 79.37%.The indoor toxicity test showed that the EC50 of kresoxim methyl 80%,70%thiophanate methyl and 3%Zhongshengmycin was 6.6751mg/L,4.5017mg/L and 5.3600mg/L respectively.The different planting patterns of Santalum album plantations were sprayed with 80%kresoxim methyl 3%,70%thiophanate methyl,Zhongs hengmycin,results showed that:80%kresoxim methyl 4000 times liquid,70%thiophanate methyl and 1500 times liquid,3%tebuconazole 900 times liquid of these three agents had certain control effect anthracnose of Santalum album.Investigation of 7d after the second application,the application of 70%thiophanate methyl 1500 times liquid of Santalum album anthracnose control effect is the best,Santalum album artificial planting mode control effect were 61.13%,62.37%,62.35%;80%kresoxim control effect of Santalum album anthracnose was the worst.