Macedo T B, Higley L G, Ni X, Quisenberry S S
Department of Entomology, University of Nebraska, Lincoln, NE 68583-0816, USA.
J Econ Entomol. 2003 Feb;96(1):194-201. doi: 10.1093/jee/96.1.194.
The impact of light and its role in Russian wheat aphid, Diuraphis noxia (Mordvilko), damage symptom formation, and photosynthetic capacity in 'Arapahoe' wheat (Triticum aestivum L.) were examined. After 72 h under continuous dark or continuous light regimes, the number of aphids (nymphs), leaf rolling and chlorosis ratings, fresh leaf weight, and chlorophyll contents were recorded. Photosynthetic rates, chlorophyll a, kinetics and chlorophyll extractions also were determined. Aphid infestation caused significant reductions in plant height, fresh weight, gas exchange, and chlorophyll fluorescence only under continuous light. Under the 72 h continuous dark regime, aphid infestation did not cause either damage symptom formation or reduction in plant growth or metabolism (photosynthesis). Furthermore, significantly more D. noxia nymphs were produced under continuous light condition than continuous dark. Our results demonstrate that the development of D. noxia feeding damage symptoms (i.e., leaf rolling and chlorotic streaks) on susceptible wheat seedlings is a light-activated process, even though the elicitor of the plant damage symptoms is aphid feeding.
研究了光照对俄罗斯小麦蚜虫（Diuraphis noxia (Mordvilko)）的影响及其在‘阿拉帕霍’小麦（Triticum aestivum L.）损伤症状形成和光合能力方面的作用。在连续黑暗或连续光照条件下处理72小时后，记录蚜虫（若虫）数量、叶片卷曲和褪绿等级、鲜叶重量以及叶绿素含量。还测定了光合速率、叶绿素a、动力学和叶绿素提取量。仅在连续光照条件下，蚜虫侵染才会导致株高、鲜重、气体交换和叶绿素荧光显著降低。在72小时连续黑暗条件下，蚜虫侵染既未导致损伤症状形成，也未使植株生长或代谢（光合作用）降低。此外，连续光照条件下产生的俄罗斯小麦蚜虫若虫显著多于连续黑暗条件下。我们的结果表明，在易感小麦幼苗上，俄罗斯小麦蚜虫取食损伤症状（即叶片卷曲和褪绿条纹）的发展是一个光激活过程，尽管植物损伤症状的引发因素是蚜虫取食。
