ABSTRACT
Fungal disease is an important factor restricting the healthy development of Gastrodia elata industry. The control of fungal disease in G. elata is an important issue in production. This paper makes a detailed investigation on the current situation of G. elata disease in China through statistics on the failure rate, rotten pit rate and occurrence rate of G. elata disease in the main producing areas of China. It was found that G. elata disease was mainly infected from the top bud and junction, causing the occurrence rate of disease was 6%-17%, and the yield decreased by 10%-30%. The 23 dominant fungi were isolated from 18 typical G. elata disease samples. Through identification of colony morphology, mycelium morphology, spore morphology and genetic characteristics, they were finally identified as 13 species, belonging to 7 families and 7 genera. Trichoderma harzianum, Ilyonectria sp. and Ilyonectria destructans are the most frequently separated. Their isolation frequency were 22.22%,16.67%,16.67% respectively. Ilyonectria sp. and I. destructans were the first time isolated from G. elata disease samples. They may be the main pathogens causing soil-borne diseases of G. elata. T. harzianum has certain potential as Gastrodia biocontrol bacteria. This study can provide a theoretical basis for the research and development of control technology of Gastrodia fungi disease.
Subject(s)
China , Fungi/pathogenicity , Gastrodia/microbiology , Plant Diseases/microbiologyABSTRACT
This paper studied the influence ofsurface preponderantfungi on main effective substances of CitriReticulatae Pericarpium (CRP).Spreading plate method was used to isolatepredominant strains from the surface of CRP.Besides,the method combining microscopic and molecular identification was also adopted.HPLC and UVspectrophotometric methods were used to determine the main effective substances in CRP.From thesurface of CRP,the advantage strain fungi were Aspergillusniger and A.Flavus.After the inoculation of A.Niger and A.flavus against CRP,the effective compositionwas changed.And different A.niger strains had differenceeffectiveness oneffective chemical components,especially one strain of A.niger.Compared withthe control group,contents of total flavonoids and hesperidin were significantly increased (P<0.01);and five types of obvious new chemical compositions were produced.It was concluded that the metabolic transformation of fungi was related tochanges ofeffective substances of CRP,which played a significant role in the aging process of CRP.The growth and metabolism of fungi consumeeffeetive substances and producechanges of composition.From the perspective of microorganisms,"the older,the better" of CRP hasa better explanation.
ABSTRACT
A crystal with colourless and stick-form,C_(15)H_(26)N_2(M. W. 234, m. p.106), has been separated from the alcohol extract of leaves of Ammopiptanthus Mongolicus Maxim. It has been ascertained to be biguinalizidine alkaloid on the basis of its spectrum data and its structure was elucidated as L-?-isosparteine.