Effects of Drought Stress on Linear Changes of Seedling Growth and Leaf Photosynthesis of Taxus Yunnanensis
The effects of drought stress on the linear changes of seedling growth and leaf photosynthesis of Taxus yunnanensis were ana-lyzedBRRR.This study was conducted in a taxus seedling research base in Longyang District,Baoshan City,Yunnan Province.Taxus seedlings cultivated in greenhouses for 3 years were selected as test subjects.Under manual intervention,control group(normal water supply),mild drought group,moderate drought group and severe drought group were set up.To compare the effects of different drought stress levels on the growth characteristics of Taxus chinensis seedlings and the linear changes of leaf photosynthesis.The results showed that under different drought stress,the new shoot length,new shoot diameter and root-shoot ratio of Taxus chinensis were affected.The growth of taxus chinensis seedlings in control group was good,and the difference between groups was significant(P<0.05),and the decline trend of severe drought stress was the most obvious.With the aggravation of drought stress,net photosynthetic rate,transpira-tion rate and stomatal conductance showed a downward trend,and the three photosynthetic parameters in control group were the high-est,followed by mild drought,moderate drought and severe drought,with significant differences among groups(P<0.05).With the in-crease of drought stress gradient,the content of osmoregulatory substances of soluble sugar and soluble protein increased significantly.The higher the drought stress gradient,the higher the osmoregulatory substances content,the overall trend was severe drought>moder-ate drought>mild drought>control group.The leaf water content,leaf biomass,stem biomass and root biomass of the control group were the highest,and the differences were significant compared with other groups(P<0.05),and there was a decreasing trend in mild drought,moderate drought and severe drought.It was concluded that drought stress had a certain effect on the growth of Taxus yunnanensis.The gradient of drought stress increased,the contents of soluble sugar and soluble protein increased,and the three photo-synthetic parameters of net photosynthetic rate,transpiration rate and stomatal conductance showed a downward trend.The drought re-sistance of Taxus chinensis could be enhanced by increasing the content of soluble sugar and soluble protein,and the effect of drought stress on taxus chinensis could be reduced.
万方数据
维普
