Ozoliņa Katrīna Anna, Jēkabsone Astra, Andersone-Ozola Una, Ievinsh Gederts
Department of Plant Physiology, Faculty of Biology, University of Latvia, 1 Jelgavas Str., LV-1004 Riga, Latvia.
Plants (Basel). 2024 Feb 25;13(5):633. doi: 10.3390/plants13050633.
The aim of the present study was to evaluate the morphological and physiological responses of plants from five geographically isolated sites growing in habitats with different conditions to different substrate moisture levels in controlled conditions. Plants were produced from seed and cultivated in a greenhouse at four relatively constant soil moisture regimes: at 25, 50, and 75% soil water content and in soil flooded 3 cm above the surface (80% F). The two morphological traits that varied most strikingly among accessions were the number of flower stalks and the number of leaves. Only plants from two accessions uniformly produced generative structures, and allocation to flowering was suppressed by both low moisture and flooding. Optimum shoot biomass accumulation for all accessions was at 50 and 75% soil moisture. The Performance Index Total was the most sensitive among the measured photosynthesis-related parameters, and it tended to decrease with an increase in soil water content for all accessions. The initial hypothesis-that plants from relatively dry habitats will have a higher tolerance against low soil water levels, but plants from relatively wet habitats will have a higher tolerance against waterlogged or flooded soil-was not proven. The existence of three ecotypes of within the five accessions from geographically isolated subpopulations on the eastern coast of the Baltic Sea at the level of morphological responses to soil water content can be proposed. plants can be characterized as extremely tolerant to soil waterlogging and highly tolerant to soil flooding and low soil water content.
本研究的目的是评估来自五个地理隔离地点、生长在不同条件栖息地的植物在可控条件下对不同基质水分水平的形态和生理反应。植物由种子培育而成，并在温室中于四种相对恒定的土壤水分条件下种植：土壤含水量分别为25%、50%和75%，以及土壤表面以上3厘米被水淹没（80%田间持水量）。在不同种质间变化最为显著的两个形态特征是花茎数量和叶片数量。只有两个种质的植物一致地产生生殖结构，低水分和水淹均抑制了开花分配。所有种质的地上部生物量积累最佳状态是在土壤含水量为50%和75%时。在所测量的与光合作用相关的参数中，性能指数总和最为敏感，并且对于所有种质而言，它都倾向于随着土壤含水量的增加而降低。最初的假设——来自相对干旱栖息地的植物对低土壤水分水平具有更高的耐受性，但来自相对湿润栖息地的植物对涝渍或水淹土壤具有更高的耐受性——未得到证实。在波罗的海东海岸地理隔离亚种群的五个种质中，可提出存在三种在对土壤含水量的形态反应水平上的生态型。这些植物的特点是对土壤涝渍具有极强耐受性，对土壤水淹和低土壤含水量具有高度耐受性。
