Data from: Closely related parasitic plants have similar host requirements and related effects on hosts

The performance of root hemiparasites depends strongly on host species
identity, but it remains unknown whether there exist general patterns in
the quality of species as hosts for hemiparasites and in their sensitivity
to parasitism. In a comparative approach, the model root-hemiparasites
Rhinanthus minor and R. alectorolophus were grown with 25 host species
(grasses, forbs and legumes) at two nutrient levels. Hosts grown without
parasites served as a control. Host species identity strongly influenced
parasite biomass and other traits and both parasites grew better with
legumes and grasses than with forbs. The biomass of R. alectorolophus was
much higher than that of R. minor with all host plants and R.
alectorolophus responded much more strongly to higher nutrient
availability than R. minor. The performance of the two species of
Rhinanthus with individual hosts was strongly correlated, and it was also
correlated with that of R. alectorolophus and the related Odontites
vulgaris in previous experiments with many of the same hosts, but only
weakly with that of the less closely related Melampyrum arvense. The
negative effect of R. minor on host biomass was less strong than that of
R. alectorolophus, but stronger relative to its own biomass, suggesting
that it is more parasitic. The impact of the two parasites on individual
hosts did not depend on nutrient level and was correlated. Several legumes
and grasses were tolerant of parasitism. While R. minor slightly reduced
mean overall productivity, R. alectorolophus increased it with several
species, indicating that the loss of host biomass was more than
compensated by that of the parasite. The results show that closely related
parasites have similar host requirements and correlated negative effects
on individuals hosts, but that there are also specific interactions
between pairs of parasitic plants and their hosts.

根半寄生植物（root hemiparasites）的生长表现强烈依赖于宿主物种身份（host species identity），但目前尚不清楚物种作为半寄生植物宿主的质量及其对寄生作用（parasitism）的敏感性是否存在普遍模式。本研究采用比较方法，将模式根半寄生植物（model root-hemiparasites）Rhinanthus minor和R. alectorolophus与25种宿主物种（禾本科植物、杂类草和豆科植物）在两种营养水平下共同培养。未与寄生植物共同培养的宿主作为对照。宿主物种身份显著影响寄生植物的生物量（biomass）及其他性状（traits），且两种寄生植物在豆科和禾本科宿主上的生长状况均优于杂类草宿主。在所有宿主植物上，R. alectorolophus的生物量均远高于R. minor，且R. alectorolophus对较高营养可利用性的响应显著强于R. minor。两种 Rhinanthus 物种在单一宿主上的生长表现呈强相关性，且与先前实验中R. alectorolophus及近缘种Odontites vulgaris在多数相同宿主上的表现也存在相关性，但与亲缘关系较远的Melampyrum arvense的表现相关性较弱。R. minor对宿主生物量的负面影响弱于R. alectorolophus，但其相对于自身生物量的影响更强，表明R. minor的寄生性更高。两种寄生植物对单一宿主的影响不依赖于营养水平，且二者的影响存在相关性。部分豆科和禾本科植物对寄生作用具有耐受性。尽管R. minor略微降低了平均总生产力，R. alectorolophus在部分物种上提高了总生产力，表明宿主生物量的损失被寄生植物的生物量增长所超额补偿。研究结果表明，亲缘关系较近的寄生植物具有相似的宿主需求，且对单一宿主的负面影响存在相关性，但寄生植物与宿主之间也存在特定的两两互作。