摘要
引种于青藏高原的大田玉米 ,在拔节期其净光合速率 (Pn)日变化为一单峰曲线 ,最大值 3 9. 0 3 μmol CO2 ·m- 2· s- 1出现在 1 5:0 0 ;而文献中生长在干旱半干旱交错平原区的同品种玉米 , Pn日变化为双峰曲线 ,最大值 2 0 . 0 3μmol CO2 · m- 2· s- 1出现在 1 2 :0 0。表明玉米从低海拔平原引种到高海拔地区使叶片净光合速率变大。适宜的白天高温、充足的太阳光能和水分供应是出现这一变化的主要原因 ;而且引种玉米叶片的光饱和点与光补偿点均增大 ,认为这是对高原环境强烈光照的一种适应。另外 ,玉米叶片细胞间隙 CO2 浓度并非象某些文献所报道是保持不变 。
The diurnal pattern of net photosynthetic rate in field grown maize introduced into Tibetan Plateau was an one peak curve and the maximum value was 39.03 μmol CO 2·m -2 ·s -1 at 15:00 during the jointing stage, compared to a two peak curve, the maximum 20.03 μmol CO 2·m -2 ·s -1 at 12:00 in the same cultivar grown in interim of arid and semiarid plain reported by some researchers. These indicated an increase in leaf photosynthetic rate as maize was introduced from the low elevation region to the high. Optimal day temperature, plenty of solar radiation and sufficient water supply should be responsible for the differences. Furthermore, both light saturation and compensation point were higher in introduced maize, implying an adaptation to plateau environment of intense radiation. The intercellular CO 2 concentration of maize leaves fluctuated in the day course, not maintained constant as suggested by some researchers.
出处
《作物学报》
CAS
CSCD
北大核心
2002年第4期475-479,共5页
Acta Agronomica Sinica
基金
中国科学院 1996年度"西部之光"资助~~
