Interaction between the effects of evaporation rate and amount of simulated rainfall on development of the free-living stages of Haemonchus contortus.
Interaction between the effects of evaporation rate and amount of simulated rainfall on development of the free-living stages of Haemonchus contortus.
复制标题
蒸发速率和模拟降雨量对捻转血矛线虫自由生活阶段发育的影响之间的相互作用。
DOI：
10.1016/j.vetpar.2008.05.010
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发表时间：
2008
影响因子：
2.6
通讯作者：
S. Walkden
中科院分区：
文献类型：
--
作者：
L. J. O'connor;L. Kahn;S. Walkden
采用3×4×2×3析因设计，研究了降雨量、降雨分布和蒸发速率对捻转血矛线虫L3发育的交互作用。含H.在澳大利亚新南威尔士州的北方高原，在夏季典型的可变温度下，将捻转螺卵在灭菌土壤上孵育。模拟降雨量为3个数量（12，24或32毫米）和4个分布（沉积后第二天的单一事件，或相同的总量分为2，3或4个相等的事件，分别在2，3或4天）中的一个。样品以低或高蒸发率（低：2.1- 3.4 mm/天，高：3.8- 6.1 mm/天）进行培养，并在沉积后4、7和14天对粪便和土壤进行破坏性取样。L3从土壤中的回收率（颗粒外L3）随着时间的推移（在第14天达到0.52%）和降雨量的增加而增加（12 mm：<0.01%; 24 mm：0.10%; 32 mm：0.45%），但与低蒸发率（0.31%）相比，在高蒸发率（0.01%）下降低。在低蒸发率条件下，不同降雨量对L3的回收率差异显著，而在高蒸发率条件下，12 mm和24 mm降雨量处理间L3的回收率差异不显著。模拟降雨的分布对感染性幼虫的恢复没有显著影响。粪便水分含量与L3恢复呈正相关，是累积降水和累积蒸发（P/E）的比率，特别是在沉积后的前4天测量。结果表明，蒸发速率对降雨量对L3传播成功的影响起着重要的调节作用。
A factorial experiment (3×4×2×3) was conducted in programmable incubators to investigate interaction between the effects of rainfall amount, rainfall distribution and evaporation rate on development of Haemonchus contortus to L3. Sheep faeces containing H. contortus eggs were incubated on sterilised soil under variable temperatures typical of summer in the Northern Tablelands of NSW, Australia. Simulated rainfall was applied in 1 of 3 amounts (12, 24 or 32mm) and 4 distributions (a single event on the day after deposition, or the same total amount split in 2, 3 or 4 equal events over 2, 3 or 4 days, respectively). Samples were incubated at either a Low or High rate of evaporation (Low: 2.1–3.4mm/day and High: 3.8–6.1mm/day), and faeces and soil were destructively sampled at 4, 7 and 14 days post-deposition. Recovery of L3 from the soil (extra-pellet L3) increased over time (up to 0.52% at day 14) and with each increment of rainfall (12mm: <0.01%; 24mm: 0.10%; 32mm: 0.45%) but was reduced under the High evaporation rate (0.01%) compared with the Low evaporation rate (0.31%). All rainfall amounts yielded significantly different recoveries of L3 under Low evaporation rates but there was no difference between the 12 and 24mm treatments under the High evaporation rate. The distribution of simulated rainfall did not significantly affect recovery of infective larvae. Faecal moisture content was positively associated with L3 recovery, as was the ratio of cumulative precipitation and cumulative evaporation (P/E), particularly when measured in the first 4 days post-deposition. The results show that evaporation rate plays a significant role in regulating the influence of rainfall amount on the success of L3 transmission.