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Abstract：
Comparative measurements of four Vitis vinifera cultivars were undertaken to assess assimilation tolerance to the high growth temperatures currently pervading Australian and other wine growing regions. The cultivars, cvs. Chardonnay, Merlot, Semillon, and Shiraz, were all grown in common growth conditions, and an hypothesis promulgated genotypic variation in assimilation and in the leaf temperature dependency. Assimilation responses to varying light intensity and to varying chloroplast CO2 at a range of leaf temperatures (15-45°C) were measured in leaves of each cultivar in mid-summer. Light response curves revealed marked genotype differences in maximum assimilation, but temperature effects also varied. Semillon leaves were most sensitive to temperature, with marked and steep differences in assimilation at different temperatures while Chardonnay and Merlot were least sensitive, with relatively flat responses. There were also marked cultivar differences in response to CO2 and significant effects of leaf temperature. CO2-saturated assimilation varied markedly, with Semillon and Merlot leaves most responsive to temperature, although there were differences in optimum temperatures and maximum rates. Chardonnay leaves remained least tolerant, with lowest rates of assimilation across most temperatures. Assimilation at 45°C also separated the cultivars and two cultivars had higher rates than at 15°C while Chardonnay and Merlot leaves had higher rates at 15°C. There were no cultivar differences in the temperature dependency of Ribulose 1,5-bisphosphate (RuBP) carboxylation, but Semillon had a much steeper temperature dependency on RuBP regeneration than the other cultivars. All these responses confirmed the hypothesis and concluded the high-temperature tolerance of Semillon and Shiraz and the poor adaptability of Chardonnay and possibly Merlot to perform in the current high-temperature growth conditions.
摘要：
对四个葡萄品种进行了比较测量，以评估对目前遍布澳大利亚和其他葡萄酒种植区的高生长温度的同化耐受性。品种，cvs.霞多丽,梅洛,Semillon,还有Shiraz,都是在共同的生长条件下生长的，和一个假说，揭示了同化和叶片温度依赖性的基因型变异。在夏季中期，在每个品种的叶片温度范围（15-45°C）下，测量了对不同光强和不同叶绿体CO2的同化响应。光响应曲线显示最大同化的明显基因型差异，但温度的影响也各不相同。Semillon叶对温度最敏感，不同温度下的同化差异显著，而霞多丽和梅洛最不敏感，反应相对平淡。对CO2的响应和叶片温度的显着影响也存在明显的品种差异。CO2饱和同化变化明显，Semillon和Merlot的叶子对温度最敏感，尽管最佳温度和最大速率存在差异。霞多丽的叶子仍然最不宽容，在大多数温度下同化率最低。45°C的同化也将品种分开，两个品种的比率高于15°C，而霞多丽和梅洛叶在15°C的比率更高。核酮糖1,5-双磷酸酯（RuBP）羧化的温度依赖性没有品种差异，但是Semillon对RuBP再生的温度依赖性比其他品种高得多。所有这些响应都证实了这一假设，并得出结论：Semillon和Shiraz的高温耐受性以及霞多丽和可能的Merlot在当前高温生长条件下的适应性差。
