PEG模拟干旱胁迫对不同种源白及生理指标的影响

Effect of PEG Stimulated Drought Stress on Physiological Indexes of Bletilla striata from Different Growing Areas

【目的】探明不同种源白及在干旱胁迫下的光合生理特性,明确其光合系统对干旱胁迫的响应规律,以期为白及抗旱性机理研究、育种和白及种源选择提供参考。【方法】采用不同浓度PEG(0 g/L、5 g/L、20 g/L、50 g/L)进行处理,对不同处理下不同种源(铜仁、正安、安龙)白及的生理指标变化进行分析。【结果】不同浓度PEG胁迫影响白及叶绿素含量、净光合速率、气孔导度、胞间CO 2浓度、蒸腾速率等光合指标以及瞬时水分利用率。各个种源白及的叶绿素、净光合速率、气孔导度、胞间CO 2浓度、蒸腾速率等光合指标均随着PEG浓度的增大而呈下降趋势,其中安龙白及光合指标下降幅度最小;3个种源白及瞬时水分利用率均随PEG浓度的上升呈先降后升的变化趋势。【结论】安龙白及抗干旱胁迫较好,在大田栽培时可优先选择安龙白及并做好相关防护措施。

【Objective】The photosynthetic physiological characteristics of different growing areas of Bletilla striata under drought stress are explored,and the response rules of their photosynthetic system toward drought stress are clarified,which provide a reference for drought-resistance mechanism research,breeding and seed-source selection of B.striata.【Method】The variation of physiological indexes in different growing areas(Tongren,Zheng’an and Anlong)of B.striata treated with four different concentrations of PEG(0 g/L,5 g/L,20 g/L and 50 g/L)is analyzed.【Result】The photosynthetic indexes of chlorophyll content,net photosynthetic rate,stomatal conductance,intercelluar CO 2 concentration and transpiration rate and instantaneous water efficiency of B.striata are affected by different concentrations of PEG stress.The photosynthetic indexes of chlorophyll content,net photosynthetic rate,stomatal conductance,intercelluar CO 2 concentration and transpiration rate of B.striata from different growing areas show a decreasing trend with increase of PEG concentration.The decrease rate of photosynthetic indexes in Anlong B.striata is the least.The instantaneous water efficiency of three growing areas of B.striata shows a first decreasing and then rising trend with increase of PEG concentration.【Conclusion】The drought resistance of Anlong B.striata is better.Anlong B.striata can be selected preferably and the related protection measures should be taken in field cultivation.