To ascertain the direct effects of water stress upon wheat plants (Triticum aestivum L.) and how these effects, in turn, influence the population growth of the bird cherry-oat aphid (Rhopalosiphum padi L.), we conducted a physiological analysis of wheat seedlings grown under three different watering regimes and subsequently determined the population parameters of the aphid using the age-stage, two-sex life table. A significantly higher content of free amino acids and soluble sugars were observed in wheat seedlings exposed to drought stress compared to seedlings that were well-watered and those that were grown under waterlogged conditions. Extended phloem salivation and stylet penetration with shorter duration of sustained ingestion from phloem was observed in an electrical penetration graph (EPG) of R. padi on drought-stressed wheat seedlings. This suggested that the aphid’s feeding activity, as well as nutrient intake, were impeded. The significantly higher percentage of essential amino acids found in wheat seedlings grown under waterlogged conditions promoted significantly higher fecundity and intrinsic rate of increase in R. padi populations compared to aphids fed on drought-treated or well-watered wheat seedlings. Our findings suggest that wheat seedling responses to water stress involve changes in sap composition that are responsible for altering the aphids’ nutrient intake and consequently affect their population growth. From a grower’s perspective, extending wheat cultivation in a rice–wheat rotation paddy field during the winter season may not be economically profitable if the fields are chronically waterlogged, since this may potentially lead to a higher infestation of cereal aphids.

中文翻译：

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水分胁迫对普通小麦（Poales：禾本科）营养成分和Rhopalosiphum padi（半翅目：蚜科）种群生长的直接和连锁效应

为了确定水分胁迫对小麦植物 (Triticum aestivum L.) 的直接影响以及这些影响又如何影响樱桃燕麦蚜 (Rhopalosiphum padi L.) 的种群增长，我们对小麦进行了生理分析在三种不同的浇水方式下生长的幼苗，随后使用年龄阶段的两性生命表确定了蚜虫的种群参数。与水分充足的幼苗和淹水条件下生长的幼苗相比，暴露于干旱胁迫的小麦幼苗中游离氨基酸和可溶性糖的含量明显更高。在干旱胁迫小麦幼苗上的水稻电渗透图 (EPG) 中观察到延长的韧皮部唾液分泌和管心针渗透，同时从韧皮部持续摄取的持续时间较短。这表明蚜虫的摄食活动以及营养摄入受到阻碍。与以干旱处理或水分充足的小麦幼苗为食的蚜虫相比，在淹水条件下生长的小麦幼苗中发现的必需氨基酸百分比显着提高，从而显着提高了 R. padi 种群的繁殖力和内在增长率。我们的研究结果表明，小麦幼苗对水分胁迫的反应涉及汁液成分的变化，这些变化负责改变蚜虫的养分摄入，从而影响它们的种群增长。从种植者的角度来看，如果田间长期淹水，在冬季稻麦轮作稻田中扩大小麦种植可能不会带来经济效益，