林木抗旱生理研究进展

从林木的表型特征、生理生化特性、抗旱分子生物学与抗旱基因表达3方面对国内外林木抗旱性研究进行综述。当前国内外学者对植物叶茎根的表形特征、渗透调节、光合生理、叶绿素荧光变化、活性氧代谢、植物激素的研究较多, 而对受干旱胁迫下林木的分子生物学与基因表达研究相对较少。最后提出了林木抗旱生理研究的主要评价方法、研究指标、研究方法与内容。随着技术的发展及相关研究的深入, 抗旱分子生物学与抗旱基因等方面的研究将成为林木抗旱生理方面的热点。

Research Progress on Physiological Response of Drought-resistance of Tree Species

The soil seed bank was composed of all dormant seeds present in the soil or litter,which still keep their viability without germination.Several conclusions on the characteristics of soil seed bank had been summed up: 1.Most species showed a decrease in the number of seeds with soil depth.2.Mostly the soil seed banks were dominated by the seeds of annual plants and short-lived species.3.There were also seasonal and yearly changes in the density and composition of the soil seed bank.4.Little relevancy had been founded between the composition of soil seed bank and vegetation above ground.5.The germination,seed rain,dispersal of the seeds and others effecting on the soil seed bank were confined to the climatic factors,such as temperature,humidity and so on.6.There was a small soil seed bank in alien-invaded vegetation because of the poor competence of the local species compared with the alien species.Appropriate measures should be taken to break the dormancy of seeds in soil in order to carry out the restoration.At present,the attention of the researchers is focused on the yearly change,persistence of the soil seed bank,influence caused by global climate change and the gene protection of the rare species.