‘苏薹1号’菜心田间光合特性的研究

Photosynthetic Characteristics of Flowering Chinese Cabbage 'Sutai 1' in Field

通过研究菜心杂交一代新品种‘苏薹1号’在田间的光合特性,探索其高产的光合生理依据,并为生产上环境调控提供数据支撑,同时也为完善菜心光合特性和光合性状杂种优势的研究提供1个研究案例。以常规品种‘油绿501’为对照,其自交系是‘苏薹1号’的父本,分别在苗期、现蕾抽薹期、齐口采收期、开花期和结荚期测定2个品种的光合性状指标,并且在现蕾抽薹期测定光合性状指标的日变化。试验结果表明:(1)‘苏薹1号’在全生育期低光强下净光合速率与对照均无差异,中高光强下净光合速率明显高于对照,仅在结荚期出现光抑制现象,并迟于对照出现,而对照仅在齐口采收期没有出现光抑制现象,其他时期均出现光抑制现象。‘苏薹1号’和对照叶片光合能力均存在现蕾抽薹期>齐口采收期>开花期>苗期>结荚期的趋势,并且生育进程越往后‘苏薹1号’叶片光合能力强于对照越明显。(2)‘苏薹1号’全生育期的光合模拟参数:光补偿点14.31~40.57μmol/(m^2·s),平均值24.18μmol/(m^2·s),较对照低7.38%;光下呼吸速率0.39~1.03μmol/(m^2·s),平均值0.68μmol/(m^2·s),较对照低6.56%;表观量子效率0.0263~0.0323μmol CO_2/(μmol·photons),平均值0.0294μmol CO_2/(μmol·photons),比对照高3.66%;光饱和点1521.79~2008.53μmol/(m^2·s),平均值1776.61μmol/(m^2·s),比对照高8.36%;最大净光合速率17.33~25.72μmol CO_2/(m^2·s),平均值21.51μmol CO_2/(m^2·s),比对照高17.49%。(3)‘苏薹1号’在现蕾抽薹期的净光合速率日变化规律呈单峰型,10:00净光合速率达到最大值27.30μmol CO_2/(m^2·s),较对照最大值高7.79%,8:00—15:00光照强度大于800μmol/(m^2·s),净光合速率较对照高,16:00—17:00光照强度小于500μmol/(m^2·s)时,净光合速率与对照无差异;12:00—14:00气温达到35℃以上时,‘苏薹1号’净光合速率比最大值下降了13.37%,但依然能保持在23.65μmol CO_2/(m^2·s)的高位,而对照净光合速率比最大值下降了17.43%。上述试验结果说明‘苏薹1号’全生育期光合能力均较强,尤其在商品形成的关键时期(现蕾抽薹期),在高温强光下依然能够保持较高的净光合速率,具备高产的光合生理基础。

By studying the photosynthetic characteristics of hybrid variety flowering Chinese cabbage ’Sutai 1’ in field,the authors aim to understand the physiological basis for high yield,provide data support for environmental regulation on production,as well as improve the photosynthetic characteristics and photosynthetic traits heterosis of flowering Chinese cabbage.’Youlv 501’ ,whose inbred lines is the male parent of ’Sutai 1’ ,was used as the control to determine the photosynthetic indicators of two varieties in different growth periods,and daily changes in bud bolting stage.The experimental results showed that：（1）compared with control, ’Sutai 1’ displayed no difference on net photosynthetic rate under low light intensity in the whole growth period,and displayed obviously higher net photosynthetic rate than control under high light intensity,moreover, ’Sutai 1’ appeared the photoinhibition phenomenon only in fruiting period,which was later than control;the control group appeared the photoinhibition phenomenon in all the stages except for collection period;the trend of the photosynthetic capacity of ’Sutai 1’ and control leaves exhibited a sequence from high to low as：squaring and bolting stage,picking stage,flowering stage,seedling stage and fruiting stage;the photosynthetic capacity of ’Sutai1’ leaves was obviously stronger than control with later development progress;（2）the photosynthetic simulation parameters of ’Sutai 1’ in the whole growth period were：the range of light compensation point with ’Sutai 1’ was 14.31-40.57 and the average was 24.18 which led to 7.38% reduction in value compared with control;the range of respiratory rate was 0.39-1.03 μmol/and the average was 0.68 which led to 6.56% reduction in value compared with control;the range of apparent quantum yield was 0.0263-0.0323 μmol·photons）,and the average was 0.0294 μmolwhich led to 3.66% increment in value compared with control;the range of light saturation point was 1521.79-2008.53 and the average was 1776.61 which lead to 8.36% increment in value compared with control;the range of maximum net photosynthetic rate was 17.33-25.72 μmoland the average was 21.51 μmolwhich led to 17.49% increment in value compared with control;（3）in the bud bolting stage,the daily variation of net photosynthetic rate of ’Sutai1’ displayed unimodal curve,and the maximum net photosynthetic rate was 27.30 μmol at 10：00,and led to 7.79% increment in value compared with control;light intensity was more than 800 during 8：00-15：00 period,and the net photosynthetic rate was higher than control;the net photosynthetic rate displayed no difference with control when light intensity was less than 500 during 16：00-17：00 period;the maximum net photosynthetic rate of ’Sutai 1’ decreased 13.37% when the temperature was above 35℃ during 12：00-14：00 period,but remained 23.65 μmol·s）high,and the maximum net photosynthetic rate of control decrease 17.43% at the same time.The experimental results showed that the photosynthetic capacity of ’Sutai 1’ was stronger in the whole growth period,especially in key period of forming commodity（squaring and bolting stage）,and the net photosynthetic rate under high temperature and intensive light could still remain strong,possessing a photosynthetic physiological basis of high yield.