橡胶树叶片不同发育时期SPAD值及叶色动态变化

以橡胶树12个无性系为试验材料,测定叶片从萌动至脱落整个生长周期的SPAD值及记录叶色的动态变化情况,绘制叶片SPAD值随生长时间的变化趋势图,比较分析无性系间叶片SPAD值及叶色动态变化过程的差异与联系,为橡胶树叶片物候期划分提供理论参考。结果表明,橡胶树叶片SPAD值随时间的变化趋势可以分成3个阶段:上升阶段、稳定阶段和下降阶段。叶片颜色在各阶段的表现差异明显,上升阶段包括古铜色、古铜-浅黄色过渡色、浅黄色、淡绿色及绿色,平稳阶段只含深绿色,下降阶段包括深绿-绿带紫过渡色、绿带紫色、黄带红色及黄色。不同物候期无性系间历时时长存在较大差异,且对应的SPAD值差异也较大。186、272、314、277及620等5个无性系萌动至浅色期持续时间较短,而深绿色期持续时间较长,且整个生长期SPAD值相对较高;而551、552及553等3个无性系萌动至浅色期持续时间较长,深绿色期持续时间较短,且整个生长期SPAD值相对较低。建议根据橡胶树叶片SPAD值与叶色相结合将橡胶树叶片生长物候划分成3个阶段11个时期,包括萌动期、古铜期、变色期、浅色期、淡绿期、绿色期;深绿色期;深绿-绿带紫过渡期、绿带紫色期、黄带红色期及脱落期。

Dynamic Changes of SPAD Value and Color of Hevea brasiliensis Leaves during Different Growth and Development Periods

This paper studied dynamic changes of SPAD values and leaf colors of 12 Hevea brasiliensis clones during the whole leaf growth period.The variation trend of SPAD values with the growth time was plotted.The difference and relationship of dynamic change process between SPAD value and leaf color were analyzed to provide theoretical reference for the phenological classification of H.brasiliensisleaves.The results showed that the change trend of SPAD values of H.brasiliensis leaves with the growth time could be divided into three stages,namely ascending,stable and descending stages.The difference of leaf color in each stage was obvious:the ascending stage included bronze,bronze-light yellow transition color,light yellow,light green and green;the stable stage contained only bottle green;and the descending stage included bottle green-green with purple transition color,green with purple,yellow with red and yellow.There were significant differences in duration of different phenological periods and corresponding SPAD values in H.brasiliensis clones.Five clones(clone 186,272,314,277 and 620)showed a shorter duration from germination to light color period,but longer duration in the bottle green period.SPAD values were relativelyhigh during the whole growth period.However,three clones(clone 551,552 and 553)showed the contrary results.It was suggested to divide the growth phenology of H.brasiliensis leaves into 3stages and 11 periods by the combination of SPAD value and leaf color,including germination,bronze,discoloration,light-colored,light green,green periods of the first stage;bottle green period of the second stage;bottle greengreen with purple transition,green with purple,yellow with red and shedding period of the third stage.