Rare or remarkable microfungi from Oaxaca (south Mexico)--Part II.

Microfungi were collected in southern Mexico in the vicinity of Puerto Escondido, Oaxaca in 2007. In 2006, samples were gathered from Acacia myrmecophytes [(Remarkable microfungi from Oaxaca of Acacia species) Part I]. In the present investigation [Part II], we collected microfungi from different parts of a variety of wild and cultivated higher plants belonging to the families Anacardiaceae, Caricaceae, Fabaceae, Moraceae, and Nyctaginacae. The microfungi found here live as parasites or saprophytes. Interestingly, the species Colletotrichum lindemuthianum (Sacc. and Magn.) Briosi and Cavara has repeatedly been used to cause fungal infections of Phaseolus lunatus leaves in laboratory experiments. We could now find the same fungus as parasite on the same host plants under field conditions showing that results obtained in the laboratory are also relevant in nature. Most of the fungal species collected belong to the classes Ascomycotina, Basidiomycotina and Deuteromycotina. Until now, some of the microfungi identified in this study have been rarely observed before or have been reported for the first time in Mexico, for example: Pestalotia acaciae Thüm. on Acacia collinsii Safford; Corynespora cassiicola (Berk. and M.A. Curtis) C.T. Wei on Carica papaya L.; Botryosphaeria ribis Grossenb. and Duggar and Cercosporella leucaenae (Raghu Ram and Mallaiah) U. Braun (new for Mexico) and Camptomeris leucaenae (F. Stevens and Dalbey) Syd. (new for Mexico) on Leucaena leucocephala (Lam.) de Wit.; Oidium clitoriae Narayanas. and K. Ramakr. and Phakopsora cf. pachyrhizi Sydow and Sydow (new for Mexico) on Clitoria ternatea L.; Botryosphaeria obtusa (Schw.) Shoemaker on Prosopis juliflora (Sw.) DC.; Cylindrocladium scoparium Morg. on Ficus benjamina L.; Acremonium sp. on Bougainvillea sp. All specimens are located in the herbarium ESS. Mycotheca Parva collection G.B. Feige and N. Ale-Agha.

Approaches to assess the biodiversity of bacteria in natural habitats.

Any attempt to characterize a bacterial community and their functional genes coding for enzymes of the nitrogen cycle is faced with its extreme biodiversity. Novel techniques, based on PCR amplification of target genes in DNA from environmental samples, have been developed for characterizing both cultured and as yet uncultured bacteria in the last few years. Computer-based assignment tools have now been developed utilizing terminal restriction fragments obtained from digestions with multiple restriction enzymes. Such programs allow the gross characterization of bacterial life in any complex bacterial community with confidence.