Influence of water logging time on the growth of Kandelia candel seedlings

Influence of waterlogging time on the growth of Kandelia candel(L.) Druce seedlings grown for 70 d in the artificialtidal tanks‘ simulated semidiurnal tide under greenhouse is studied. Sand and soil act as the substrate and artificial seawater with salinity of 15 is used in cultivation. Shorter waterlogging time (inundated for about 2 ～ 4 h) promotes the growth of K candel seedlings, while longer time (inundated more than 8 h) or no waterlogging (0 h) inhibits their growth. The number and length of aerating roots increase with the increase of waterlogging time. Under existing conditions, the optimal waterlogging time for the growth of K. candel seedlings is about 2 ～ 4 h in every tide cycle. Compared with other treatments, the 2 h sanded treatments obtain the highest biomass of seedlings, have the lowest mass loss ofhypocotyl and broaden the photosynthetic area by increasing the area per leaf after 70-d cultivation. And the soil treatments have the similar tendency. However, waterlogging for 8h in every tide cycle is critical for normal development of seedlings.K. candel seedlings are highly tolerant to waterlogging and a proper waterlogging is beneficial to the growth of K. candel seedlings.     

旱育稀植育秧田间小气候研究

研究旱育稀植育秧的田间小气候效应及对秧苗生长发育的影响，并以水播育秧为对照。结果表明，两种育秧方式的田间小气候变化差异明显，特别是在阴冷天气旱育秧增温保温效应更显著，旱育秧的生理性状明显优于水育秧，其抗寒性、抗旱性、抗逆性均比水育秧强，插后有很强的暴发力。同时根据本试验所得的资料，对旱育秧苗生长与积温的关系建立了其动态生长模拟模式，经检验，其模拟效果精确度很高。     

旱育稀植育秧田间小气候研究

研究旱育稀植育秧的田间小气候效应及对秧苗生长发育的影响，并以水稻衣秧为对照。结果表明：两种育秧方式的田间小气候变化差异明显，特别是在阴冷天气旱育秧增温保温效应更显著，旱育秧的生理性状明显优于水育秧，其抗寒性，抗旱性，抗逆性均比水育秧强，插后有很强的暴发力，同时根据本试验所得的资料，对旱育秧苗生长与积温的关系建立了其动态生长模拟模式，经检验，其模拟效果精确度很高。