Yu Xin, Wu Tong, Wang Wei-Bin, Ma Tian-Yu, Ma Qiu-Yu, Zhang Jia-Ying, Zhang Jia-Liang
Key Laboratory of Major Agricultural Invasion Biological Monitoring and Control of Shenyang, College of Plant Protection, Shenyang Agricultural University, No.120 Dongling Road, Shenhe District, Shenyang, Liaoning, 110866, China.
Liaoning Key Laboratory for Biological Invasions and Global Changes, College of Bioscience and Biotechnology, Shenyang Agricultural University, No.120 Dongling Road, Shenhe District, Shenyang, Liaoning, 110866, China.
J Plant Res. 2025 Apr 25. doi: 10.1007/s10265-025-01639-3.
Compensatory growth of crops is argued to alleviate detrimental parasitic effects. Cuscuta campestris causes severe crop losses worldwide, and is the most important parasitic weed. In a two-year consecutive field investigation, C. campestris was found on Artemisia argyi var. argyi cv. Qiai, one traditional medicinal herb with a long cultivation history in Qizhou, China. In 2020, anatomical validation was conducted on haustorial connection, and competition between carbon (C) and nitrogen (N) in this parasitic system was quantified with isotope signature (δC, δN) at five sites in 2021. Across sites, leaf senescence of low canopy of infected Qiai was greatly accelerated. Enhancement of resource remobilization from aging leaves (emerging source) mainly supported growth of the parasite (additional sink) also host stem, Qiai successfully abstained intense resource competition with C. campetris, and both species had similar δC and δN. A new source-sink balance re-established between the parasite and host. Infected Qiai held relatively steady canopy C fixation (constant photosynthetic N use efficiency, biomass and N concentration of green leaves), and branched in top canopy markedly, increasing light access. Together, Qiai appeared to enhance canopy C gain in response to infection. Increase in δC in this parasite-host association was mild. Finally, this parasite evidently over-stimulated the aboveground biomass of its host, irrespective of infection density and load, and was left behind. This study first reported C. campestris on Qiai, and the latter species execute over-compensation in the field.
作物的补偿性生长被认为可以减轻有害的寄生影响。田野菟丝子在全球范围内造成严重的作物损失，是最重要的寄生杂草。在一项为期两年的连续田间调查中，在中国蕲州有着悠久种植历史的传统草药蕲艾变种蕲艾上发现了田野菟丝子。2020年，对吸器连接进行了解剖验证，并于2021年在五个地点用同位素标记（δC、δN）对该寄生系统中碳（C）和氮（N）之间的竞争进行了量化。在各个地点，受感染蕲艾低冠层的叶片衰老大大加速。衰老叶片（新兴源）资源再分配的增强主要支持了寄生植物（额外的库）以及寄主茎的生长，蕲艾成功避免了与田野菟丝子的激烈资源竞争，且两个物种具有相似的δC和δN。寄生植物与寄主之间重新建立了新的源 - 库平衡。受感染的蕲艾保持相对稳定的冠层碳固定（恒定的光合氮利用效率、生物量以及绿叶的氮浓度），并在顶部冠层显著分枝，增加了光照获取。总体而言，蕲艾似乎因感染而增强了冠层碳获取。在这种寄生 - 寄主关联中，δC的增加较为轻微。最后，这种寄生植物明显过度刺激了其寄主的地上生物量，无论感染密度和负荷如何，且被落在后面。本研究首次报道了蕲艾上的田野菟丝子，且后者在田间表现出超补偿现象。
