Jaganathan Ganesh K, Sánchez Jorge A, Pernús Mayté, Liu Baolin
Germplasm Conservation Laboratory, Department of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Institute of Ecology and Systematics, Ministry of Science, Technology and Environment, La Habana 200093, Cuba.
Plants (Basel). 2024 Nov 21;13(23):3269. doi: 10.3390/plants13233269.
Unconventional germination, wherein shoots emerge and establish true leaves before the root emerges, is only found in Zosteraceae. In , germination proceeds with the primary root emerging, followed by shoot emergence on the opposite side, but before leaf differentiation, adventitious roots emerge at the base of the shoots. However, germination and survival mechanisms in several species are still unclear. We subjected freshly collected seeds to an imbibition test, and germination was evaluated at various temperatures and light conditions. Desiccation sensitivity assessments were made at different stages of drying. The effect of natural drying (ambient storage) on germination was assessed by leaving the seeds outside in natural conditions. Seeds of with a moisture content (MC) of 67% had more than 95% germination only at 25 and 25/30 °C both in light/dark and darkness, but at 25/40 °C only 10% germinated. In 4% of the seeds, germination incepted with primary shoot emergence, and a secondary (adventitious) root emerged just before leaf differentiation. More than 95% of the seeds germinated with only a secondary root and shoot emerging concurrently. Drying fresh seeds above silica gel to 30% MC resulted in complete viability loss. Seeds stored at ambient conditions germinated without external water, and had no primary or secondary root, and the emerging shoot continued to grow into seedlings. A root develops in these seeds only when water becomes available. seeds are desiccation-sensitive and non-dormant. When no external water is available, seeds can germinate with shoots and establish seedlings. This is the first report on germination and successful seedling establishment without roots in .
非常规萌发，即地上部分在地下部分出现之前就萌出并长出真叶，仅在大叶藻科中被发现。在[具体植物名称未提及]中，萌发过程是主根先出现，随后在相对的一侧地上部分萌出，但在叶片分化之前，不定根在地上部分基部出现。然而，几种[植物名称未提及]物种的萌发和存活机制仍不清楚。我们对新鲜采集的[种子名称未提及]种子进行了吸胀试验，并在不同温度和光照条件下评估萌发情况。在干燥的不同阶段进行了脱水敏感性评估。通过将种子置于自然条件下室外放置来评估自然干燥（环境储存）对萌发的影响。含水量（MC）为67%的[种子名称未提及]种子仅在25℃以及25/30℃的光照/黑暗和黑暗条件下萌发率超过95%，但在25/40℃时只有10%萌发。在4%的种子中，萌发始于地上部分的主芽出现，并且在叶片分化之前一条次生（不定）根出现。超过95%的种子萌发时次生根和地上部分同时出现。将新鲜种子在硅胶上干燥至含水量30%导致完全丧失活力。在环境条件下储存的种子在没有外部水分时萌发，没有主根或次生根，并且长出的地上部分继续生长成幼苗。只有当有水时这些种子才会长出根。[种子名称未提及]种子对脱水敏感且无休眠特性。当没有外部水分时，[种子名称未提及]种子可以萌发出地上部分并长成幼苗。这是关于[种子名称未提及]无根萌发和成功建立幼苗的首次报道。
