The white rust,caused by Puccinia horiana was one of the most important epidemic diseases on Chrysanthemum,and also was a quarantine action pest in the world.Trials determined the teliospores germinating biology of P....The white rust,caused by Puccinia horiana was one of the most important epidemic diseases on Chrysanthemum,and also was a quarantine action pest in the world.Trials determined the teliospores germinating biology of P.horiana : the teliospores were germinated between 4 ℃ and 32 ℃,while the optimum temperature range was 15 ℃ to 24 ℃,especially between 18 ℃ and 21 ℃.Water was necessary for the teliospores germination.Without free water,it couldn’t germinate in 24 h,even with 100 % R.H.The propriety of pH for germination was pH 4 to 6.5, while pH 6 was the most favorite.2 % glucose solution promoted the germination of the teliospores evidently,whereas the fresh juice of chrysanthemum foliages restrained it prominently.Light didn’t influence on the germination.展开更多
Ustilago coicis causes serious smut on Coix lacryma-jobi in Dayang Town,Jinyun County,Zhejiang Province of China.In this paper,ultrastructural assessments on fungus-host interactions and teliospore development are pre...Ustilago coicis causes serious smut on Coix lacryma-jobi in Dayang Town,Jinyun County,Zhejiang Province of China.In this paper,ultrastructural assessments on fungus-host interactions and teliospore development are presented,and molecular phylogenetic analyses have been done to elucidate the phylogenetic placement of the taxon.Hyphal growth within infected tissues was both intracellular and intercellular and on the surface of fungus-host interaction,and the fungal cell wall and the invaginated host plasma membrane were separated by a sheath comprising two distinct layers between the fungal cell wall and the invaginated host plasma membrane.Ornamentation development of teliospore walls was unique as they appeared to be originated from the exosporium.In addition,internal transcribed spacer(ITS) and large subunit(LSU) sequence data showed that U.coicis is closely related to Ustilago trichophora which infects grass species of the genus Echinochloa(Poaceae).展开更多
Following a 2004-outbreak of Karnal bunt in an Arizona wheat field where infection had not been detected in recent years, the population and viability of Tilletia indica teliospores in surface and subsurface layers of...Following a 2004-outbreak of Karnal bunt in an Arizona wheat field where infection had not been detected in recent years, the population and viability of Tilletia indica teliospores in surface and subsurface layers of soil were monitored over a four-year period. The field was seeded with two parallel 1.8 m × 190 m strips of wheat, 11 m apart and the remainder planted in non-host barley. Thirty-eight 1.22 m2 wheat plots were harvested and seed examined for infection. Several times throughout each season soil samples were taken from each of 25 points throughout the field. Teliospores extracted from subsamples of each soil sample were examined to estimate the number of teliospores per gram soil and germination percentage. The average (SD) infection observed for each of the four consecutive seasons was 7.05 (4.6), 2.89 (5.5), 0, and 0.004% (0). The average number of teliospores recovered per gram of soil during the first sampling was 36 and 39 for the 0.5 cm deep (surface) and 5.5 cm deep (subsurface), respectively, with an average teliospore germination of 29%. By the last season, the average numbers of teliospores recovered were 5 and 2.5 per gram of soil, respectively, with an average germination of 1.0%.展开更多
文摘The white rust,caused by Puccinia horiana was one of the most important epidemic diseases on Chrysanthemum,and also was a quarantine action pest in the world.Trials determined the teliospores germinating biology of P.horiana : the teliospores were germinated between 4 ℃ and 32 ℃,while the optimum temperature range was 15 ℃ to 24 ℃,especially between 18 ℃ and 21 ℃.Water was necessary for the teliospores germination.Without free water,it couldn’t germinate in 24 h,even with 100 % R.H.The propriety of pH for germination was pH 4 to 6.5, while pH 6 was the most favorite.2 % glucose solution promoted the germination of the teliospores evidently,whereas the fresh juice of chrysanthemum foliages restrained it prominently.Light didn’t influence on the germination.
基金Project supported by the National Natural Science Foundation of China(No.31070123)the Special Fund for Agro-scientific Research in the Public Interest of China(No.201003004)
文摘Ustilago coicis causes serious smut on Coix lacryma-jobi in Dayang Town,Jinyun County,Zhejiang Province of China.In this paper,ultrastructural assessments on fungus-host interactions and teliospore development are presented,and molecular phylogenetic analyses have been done to elucidate the phylogenetic placement of the taxon.Hyphal growth within infected tissues was both intracellular and intercellular and on the surface of fungus-host interaction,and the fungal cell wall and the invaginated host plasma membrane were separated by a sheath comprising two distinct layers between the fungal cell wall and the invaginated host plasma membrane.Ornamentation development of teliospore walls was unique as they appeared to be originated from the exosporium.In addition,internal transcribed spacer(ITS) and large subunit(LSU) sequence data showed that U.coicis is closely related to Ustilago trichophora which infects grass species of the genus Echinochloa(Poaceae).
文摘Following a 2004-outbreak of Karnal bunt in an Arizona wheat field where infection had not been detected in recent years, the population and viability of Tilletia indica teliospores in surface and subsurface layers of soil were monitored over a four-year period. The field was seeded with two parallel 1.8 m × 190 m strips of wheat, 11 m apart and the remainder planted in non-host barley. Thirty-eight 1.22 m2 wheat plots were harvested and seed examined for infection. Several times throughout each season soil samples were taken from each of 25 points throughout the field. Teliospores extracted from subsamples of each soil sample were examined to estimate the number of teliospores per gram soil and germination percentage. The average (SD) infection observed for each of the four consecutive seasons was 7.05 (4.6), 2.89 (5.5), 0, and 0.004% (0). The average number of teliospores recovered per gram of soil during the first sampling was 36 and 39 for the 0.5 cm deep (surface) and 5.5 cm deep (subsurface), respectively, with an average teliospore germination of 29%. By the last season, the average numbers of teliospores recovered were 5 and 2.5 per gram of soil, respectively, with an average germination of 1.0%.
