Juliana Echeverry Holguín, María Crepy, Gustavo G Striker, Federico P O Mollard
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引用次数: 0
Abstract
Underwater germination could risk seedling survival, suggesting the need for control through seed perception of environmental cues. These cues include diurnally alternating temperatures tied to drained soils or shallow water tables. We examined high-amplitude alternating temperatures impact on underwater germination. Besides, the conditions experimented by seeds in the soil (e.g. hydration/dehydration phases) change their germinability so we tested if osmopriming could affect underwater germination. We worked with Echinochloa colona seedlots from extensive crop fields, exposing seeds to sequential submergence and drained treatments in combination with cues that promote germination. While a 10°C difference between maximum and minimum daily temperatures maximised germination in drained conditions, higher amplitudes (>15°C) alternating temperatures promoted E. colona underwater germination under hypoxic water (pO2 <4.1kPa). KNO3 osmopriming in drained conditions promoted later underwater germination even under hypoxic water; however, PEG 6000 osmopriming induced seeds to enter secondary dormancy inhibiting underwater germination. KNO3 improved E. colona underwater germination under air-equilibrated floodwater (pO2 : 16.5-17.4kPa) yet not under hypoxic conditions. This suggests that germination can proceed in flooded nitrate-fertile soils as long as it remains aerobic. Hypoxic submergence did not inhibit the induction of hypersensitivity to light in E. colona seeds. This research expands our understanding of wetland seed germination ecophysiology, shedding light on the inducible nature of underwater germination in hydrophyte weeds.
期刊介绍:
Functional Plant Biology (formerly known as Australian Journal of Plant Physiology) publishes papers of a broad interest that advance our knowledge on mechanisms by which plants operate and interact with environment. Of specific interest are mechanisms and signal transduction pathways by which plants adapt to extreme environmental conditions such as high and low temperatures, drought, flooding, salinity, pathogens, and other major abiotic and biotic stress factors. FPB also encourages papers on emerging concepts and new tools in plant biology, and studies on the following functional areas encompassing work from the molecular through whole plant to community scale. FPB does not publish merely phenomenological observations or findings of merely applied significance.
Functional Plant Biology is published with the endorsement of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Academy of Science.
Functional Plant Biology is published in affiliation with the Federation of European Societies of Plant Biology and in Australia, is associated with the Australian Society of Plant Scientists and the New Zealand Society of Plant Biologists.