三个澳洲坚果品种在云南干热河谷区的光合特性分析

Characteristics of Photosynthesis of Three Macadamia Nut Varieties in Dry-Hot Valley Regions in Yunnan Province

以云南干热河谷区引种栽培的3个澳洲坚果品种为试验材料,测定比较净光合速率、蒸腾速率、胞间CO_(2)浓度、气孔导度、水分利用效率等光合参数的日变化。结果表明:(1)O.C、A4和816三个澳洲坚果品种在云南干热河谷种植环境下均存在光合“午休”现象,其中O.C的净光合速率变化趋势呈典型的双峰模式,A4和816的净光合速率变化因光合“午休”严重呈特殊的单峰模式。在光合有效辐射的日均值无显著差异的情况下,3个澳洲坚果品种的净光合速率日均值从大到小依次为O.C>A4>816,蒸腾速率日均值从大到小依次为816>A4>O.C,水分利用效率日均值从大到小依次为O.C>A4>816。(2)相关性分析表明,3个澳洲坚果品种的净光合速率与光合有效辐射呈极显著正相关(p<0.01),且与胞间CO_(2)浓度呈极显著负相关(p<0.01)。通过比较发现,O.C具有较高的净光合速率、较低的蒸腾速率和较高的水分利用效率,其光合性能表现更为出色,说明O.C对高温干旱环境的适应性较强,从光合性能表现可以初步判定O.C具有在云南干热河谷区种植的潜力。

Three macadamia nut varieties introduced in the dry-hot valley of Yunnan were used as experimental materials to measure and compare the diurnal changes of photosynthetic parameters such as net photosynthetic rate,transpiration rate,intercellular CO2 concentration,stomatal conductance,water use efficiency and so on.The results showed that:(1) The three macadamia nut varieties O.C,A4 and 816 had midday depression of photosynthesis in the dry-hot valley of Yunnan,the variation trend of net photosynthetic rate of O.C showed a typical double-peak pattern,while the changes of net photosynthetic rate of A4 and 816 showed a special single-peak pattern.Under the condition that there was no significant difference in the daily mean value of photosynthetic active radiation,the daily average value of net photosynthetic rate of the three macadamia varieties from high to low was O.C> A4 > 816,the daily mean of transpiration rate from high to low was 816>A4> O.C,the daily mean value of water use efficiency from high to low was O.C > A4 > 816.(2) The correlation analysis showed that the net photosynthetic rate of three macadamia nut varieties was significantly positively correlated with photosynthetic effective radiation(p < 0.01) and significantly negatively correlated with intercellular CO2 concentration(p < 0.01).By comparison,O.C had higher net photosynthetic rate,lower transpiration rate,higher water use efficiency,better photosynthetic performance,and can adapt to high temperature and drought environment.So from the photosynthetic performance,it can be preliminarily concluded that O.C had the potential to be planted in the dry-hot valley of Yunnan.