Liu Mingyang, Hulting Andrew, Mallory-Smith Carol
Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon, United States of America.
PLoS One. 2017 Jul 27;12(7):e0182035. doi: 10.1371/journal.pone.0182035. eCollection 2017.
Roughstalk bluegrass (Poa trivialis) is a weed in cool season grass seed production fields in Oregon. Populations of this weed are often greater in fields prone to waterlogging. A greenhouse study was conducted to investigate the morphological and physiological differences between recently established roughstalk bluegrass and tall fescue (Lolium arundinaceum) plants in response to simulated waterlogging. Differences in root morphological development and root respiration were found between waterlogged tall fescue and roughstalk bluegrass. Plants after 4 weeks of waterlogging, leaf number, plant height, and root biomass were reduced more in tall fescue than in roughstalk bluegrass plants. The root length increased 6% in waterlogged tall fescue plants, and decreased 42% in waterlogged roughstalk bluegrass plants, which lead to a shallower root system in roughstalk bluegrass. Root aerenchyma area increased more in waterlogged roughstalk bluegrass than in tall fescue. Alcohol dehydrogenase and lactate dehydrogenase activities increased in the roots of both species, but not in the leaves. The increases were greater in tall fescue than in roughstalk bluegrass. Turf quality, aboveground biomass, photosynthetic capacity, and water-soluble carbohydrate concentrations were reduced by waterlogging, but there were no differences over time or species. Thus, the shallower root system, larger aerenchyma, and reduced fermentation rates were the characteristics most likely to contribute to better waterlogging tolerance in roughstalk bluegrass compared to tall fescue and invasion of roughstalk bluegrass in waterlogged cool season grass seed fields.
粗茎早熟禾（Poa trivialis）是俄勒冈州冷季型草种生产田中的一种杂草。在容易发生涝渍的田块中，这种杂草的种群数量通常更多。进行了一项温室研究，以调查新建立的粗茎早熟禾和高羊茅（Lolium arundinaceum）植株在模拟涝渍条件下的形态和生理差异。发现涝渍处理的高羊茅和粗茎早熟禾在根系形态发育和根系呼吸方面存在差异。涝渍4周后，高羊茅植株的叶片数量、株高和根生物量比粗茎早熟禾植株减少得更多。涝渍处理的高羊茅植株根长增加了6%，而涝渍处理的粗茎早熟禾植株根长减少了42%，这导致粗茎早熟禾的根系更浅。涝渍处理的粗茎早熟禾根通气组织面积比高羊茅增加得更多。两种植物根系中的乙醇脱氢酶和乳酸脱氢酶活性均增加，但叶片中未增加。高羊茅的增加幅度大于粗茎早熟禾。涝渍会降低草坪质量、地上生物量、光合能力和水溶性碳水化合物浓度，但随时间和物种没有差异。因此，与高羊茅相比，根系更浅、通气组织更大以及发酵速率降低是粗茎早熟禾在涝渍条件下更耐涝并能侵入涝渍冷季型草种田的最可能原因。
