School of Life Science, Guizhou Normal University, Guiyang, China.
Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou Province, Guizhou Normal University, Guiyang, China.
Plant Biol (Stuttg). 2021 Nov;23(6):1018-1026. doi: 10.1111/plb.13285. Epub 2021 Aug 15.
The effect of humidity change on spore release of the Nematodontae Polytrichaceae has never been tested experimentally. Similarly, the impact of humidity alterations on structure of the peristome have never been studied. Polytrichum commune Hedw. var. commune from Guizhou Province, China, was selected as the research object to examine effects of simulated wind in the laboratory. By controlling humidity and wind, the mechanism of spore dispersal was revealed. When humidity increased, the size of the peristome and epiphragm enlarged significantly (the peristome has no obvious spatial displacement, unlike the hygroscopic movement of Arthrodontae mosses. Thus, we named it 'sub-hygroscopic movement'), then recovered to normal size when humidity decreased. When humidity was controlled and wind applied, the scattering of spores gradually decreased as the capsule dried out and finally reached a very low level; when the capsule was wetted or rewetted, the amount of spores released rose and returned to the initial state. Through comparison of moist and dry capsules, only enhanced humidity of the sporophytes led to increases in spore release. The results show that the dispersal of spores was significantly improved in windy conditions and the sub-hygroscopic movement of the capsule peristome, which ensure the continuity and effectiveness of P. commune reproduction.
湿度变化对弹丝藻科的孢子释放的影响从未经过实验测试。同样，湿度变化对口盖结构的影响也从未被研究过。本研究以中国贵州省的普通扭叶泥炭藓为研究对象，在实验室中模拟风的影响，来检验湿度和风力对孢子扩散的影响。通过控制湿度和风力，揭示了孢子传播的机制。当湿度增加时，口盖和副盖的大小显著增大（口盖没有明显的空间位移，与弹丝藻的吸湿运动不同。因此，我们将其命名为“亚吸湿运动”），然后当湿度降低时恢复到正常大小。当控制湿度并施加风力时，随着蒴果变干，孢子的散射逐渐减少，最终达到非常低的水平；当蒴果被润湿或重新润湿时，释放的孢子数量增加并恢复到初始状态。通过比较湿润和干燥的蒴果，只有增加配子体的湿度才能导致孢子释放增加。结果表明，在有风的条件下，孢子的扩散明显增强，而蒴果口盖的亚吸湿运动，保证了普通扭叶泥炭藓繁殖的连续性和有效性。
