A total of 82 isolates of Colletotrichum species were obtained from anthracnose symptoms of highbush blueberry trees grown in the Gochang area of Korea during a disease survey in 2008. Out of the isolates, 75 were identified as Colletotrichum gloeosporioides and the others as C. acutatum based on their morphological and cultural characteristics. Twenty six of C. gloeosporioides isolates produced their teleomorph Glomerella cingulata in PDA culture. Three isolates of each C. gloeosporioides and C. acutatum caused anthracnose symptoms on the leaves by artificial inoculation, which were similar to what was observed in the orchards. Previously in Korea, only C. gloeosporioides has been reported as causing anthracnose in blueberries. This is the first report that C. acutatum causes anthracnose in the highbush blueberry in Korea.
Blueberry Plant ; Colletotrichum ; Cultural Characteristics ; Korea ; Phyllachorales ; Trees

The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus of Glomus intraradices and/or infection with pathogenic strain of Phytophthora capsici, and the biological control effect of G. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated with G. intraradices (Gi), (2) plants pre-inoculated with G. intraradices and then infected with P. capsici (Gi+Pc), (3) plants infected with P. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal colonization rate was reduced by about 10% in pathogen challenged plants. Root mortality caused by infection of P. capsici was completely eliminated by pre-inoculation with antagonistic G. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only 21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase (PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9% in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major POD isozymes (45,000, 53,000 and 114,000) were present in Pc-treated roots, while two major bands (53,000 and 114,000) and one minor band (45,000) were present in spectra of Gi+Pc-treated roots, the 45,000 POD isozyme was significantly suppressed by G. intraradices, suggesting that the 45,000 POD isozyme was induced by the pathogen infection but not induced by the antagonistic G. intraradices. A 60,000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the inoculation of antagonistic G. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper plants infected by P. capsici. The results suggested that G. intraradices is a potentially effective protection agent against P. capsici.
Capsicum ; cytology ; enzymology ; microbiology ; Lignin ; metabolism ; Pest Control, Biological ; methods ; Phyllachorales ; cytology ; physiology ; Phytophthora ; cytology ; physiology ; Plant Proteins ; metabolism

To study the effects of the extract of fungal elicitor, AgNO3, MeJA and yeast on the growth and content of secondary metabolites of adventitious roots in Tripterygium wilfordii. The above elicitors were supplemented to the medium, the growth and the content of secondary metabolites were measured. When the medium was supplemented with the elicitor Glomerella cingulata or Collectotrichum gloeosporioides, the content of triptolide was increased by 2.24 and 1.93-fold, the alkaloids content was increased by 2.02 and 2.07-fold, respectively. The optimal concentration of G. cingulata was 50 μg/mL for accumulation of triptolide, alkaloids and for the growth of adventitious roots. AgNO3 inhibited the growth of adventitious roots and the accumulation of the alkaloids, whereas it (at 25 μmol/L) increased the accumulation of triptolide by 1.71-fold compared to the control. The growth of adventitious roots, the contents of triptolide and alkaloids were increased 1.04, 1.64 and 2.12-folds, respectively when MeJA was at 50 μmol/L. When the concentration of yeast reached 2 g/L, the content of triptolide increased 1.48-folds. This research demonstrated that supplementation of AgNO3 and yeast enhanced the biosynthesis of triptolide in adventitious roots and the synergism of G. cingulata and MeJA could promote the biosynthesis of both triptolide and alkaloids.
Acetates ; pharmacology ; Alkaloids ; biosynthesis ; Colletotrichum ; Cyclopentanes ; pharmacology ; Diterpenes ; metabolism ; Drugs, Chinese Herbal ; Epoxy Compounds ; metabolism ; Oxylipins ; pharmacology ; Phenanthrenes ; metabolism ; Phyllachorales ; Plant Roots ; drug effects ; growth & development ; Secondary Metabolism ; Tripterygium ; drug effects ; growth & development ; metabolism