EFFECTS OF PHOSPHORUS LIMITATION ON THE EPIDEMIOLOGY OF A CHYTRID PHYTOPLANKTON PARASITE
EFFECTS OF PHOSPHORUS LIMITATION ON THE EPIDEMIOLOGY OF A CHYTRID PHYTOPLANKTON PARASITE
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DOI：
10.1111/j.1365-2427.1991.tb01385.x
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发表时间：
1991-06-01
影响因子：
2.7
通讯作者：
BRUNING, K
中科院分区：
文献类型：
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作者：
BRUNING, K
1. 台湾硅藻的限磷效果。其真菌寄生虫浮游根藻的生长、存活和流行发展。通过测量在不同磷限生长速率的寄主培养物上生长的壶菌游动孢子的产量和传染性来估计。磷限制寄主细胞对寄生虫游动孢子的易感程度低于非磷限制寄主细胞。限磷藻孢子囊产生的游动孢子数量明显减少，但孢子囊发育时间仅略有缩短。由于这些影响，在给定的寄主密度下，根藻的生长速度会降低，而当Asterionella受磷限制时，寄生虫的生存将需要更高的寄主密度。在限制和非限制磷水平下，游动孢子的产量仍然足够高，使寄生虫在足够高的寄主密度下比藻类生长得更快。尽管该寄生虫的生长速度降低，但发现Asterionella的磷限制促进了根癣菌流行的发展。这是在磷限制下藻类生长速度降低的结果，这使得寄主种群更容易被寄生虫超越。寄主限磷可使发生流行病所需的阈值寄主密度降低2.5倍。
1. The effect of phosphorus limitation of the diatom Asterionella formosa Hass. on growth, survival and epidemic development of its fungal parasite Rhizophydium planktonicum Canter emend. was estimated, using measurements of production and infectivity of the zoospores of the chytrid grown on host cultures with different phosphorus-limited growth rates.2. Phosphorus-limited host cells were less susceptible to infection with zoospores of the parasite than non-limited host cells.3. The sporangia on phosphorus-limited algae produced substantially less zoospores, but the development time of these sporangia was only slightly reduced.4. As a result of these effects, Rhizophydium will reach lower growth rates at a given host density, and survival of the parasite will require higher host densities when Asterionella is phosphorus-limited.5. The zoospore production remained high enough to enable the parasite to grow faster than the alga at sufficiently high host densities, both at limiting and non-limiting phosphorus levels.6. In spite of the reduced growth rate of the parasite, phosphorus limitation of Asterionella was found to facilitate the development of a Rhizophydium epidemic. This was a consequence of the reduced algal growth rate at phosphorus limitation, which makes the host population more easily outgrown by the parasite.7. Phosphorus limitation of the host could reduce the threshold host density required for the development of an epidemic by a factor of 2.5.