Localized hemibiotrophy in Colletotrichum : cytological and molecular taxonomic similarities among C. destructivum, C. linicola and C. truncatum

摘要: The infection process of hemibiotrophic isolates Colletotrichum linicola (from flax, Linum usitatissimum) and C. truncatum broad bean, Vicia faba lentil, Lens culinaris) was studied by light microscopy. Host surfaces were penetrated directly leading to a symptomless, biotrophic phase characterized the elaboration large multilobed, multiseptate, vesicular primary hyphae that restricted initially infected epidermal cells. Biotrophy lasted for first 48 h host-pathogen interaction rapidly succeeded necrotrophic during which narrow, secondary invaded surrounding leaf tissues water-soaked spreading lesions with sporulating, monosetate acervuli produced on host surfaces. Molecular taxonomic analysis nucleotide sequences amplified D2 ITS-2 regions rDNA revealed very close similarities (97-99%) between these those destructivum obtained from cowpea (Vigna unguiculata) lucerne (Medicago sativa), also pea (Pisum sativum). This association consistent results comparative assessment some in-planta in-vitro morphological growth characteristics fungi. It concluded localized hemibiotrophy is an strategy utilized predominantly closely-related group pathogens comprising destructivum, truncatum, formation multilobed cell might therefore be key character correlates consistently ITS sequence data.