Differences in the microflora of scarified and unscarified seeds ofKarwinskia humboldtiana (Rhamnaceae)

摘要

Seeds ofKarwinskia humboldtiana obtained from a 1997 collection in the locality of Villa de García Nuevo (León, Mexico) were contaminated with spores of filamentous fungi, bacteria and yeasts. The concentration of microorganisms in unscarified seeds ranged from 3.0×103 to 7.5×103 CFU/g. Predominant were bacterial isolates of the generaAeromonas sp.,Bacillus, andPseudomonas; from filamentous fungi were identifiedAlternaria, Aspergillus niger, Cladosporium sp.,Fusarium sp.,Mucor sp.,Penicillium commune, Trichothecium sp.; from yeastsRhodotorula sp. andSaccharomyces cerevisiae. Seed scarification significantly reduced the microbial contamination. Of the original fungal isolates, only two were identified on scarified seeds,viz. Cladosporium sp. andSaccharomyces cerevisiae; although a relatively high incidence of a unidentifiable ofPenicillium sp. was found, the bacterial spectrum was not altered. Treatment of scarified seeds with Vitavax 200 WP and Pomarsol Forte 80 WP (3 mg/g seeds) augmented germination by 10–19% compared to treated unscarified seeds, and by 16–31% compared to untreated unscarified seeds.