低纬高原气候带分布差异对不同烤烟品种δ13C值的影响

选具有近4个纬度差异，地处2个不同气候带的玉溪市通海县和昭通市鲁甸县2个生态烟区，研究了K326、红花大金元和KRK26烤烟品种在旺长和成熟期的稳定碳同位素（＆13C）分布值对气候环境的响应。结果表明，3个品种烟叶δ13C值的范围为．26．56‰～24．36‰，旺长期烟叶δ13C值表现为通海大于鲁甸，成熟期除KRK26外，巧δ13C值表现为鲁甸大于通海。对比旺长期和成熟期，两地各品种的δ13C值都表现为成熟期大于旺长期，即随着烟叶成熟度增加，分布在2个气候带烤烟的水分利用效率都在逐渐提高。品种间比较表明，无论是旺长期还是成熟期，通海都表现为KRK26的δ13C值最大，鲁甸则表现为红花大金元的巧δ13C值最大。而3个品种下部叶和中部叶δ13C的平均值都表现为通海大于鲁甸，且均与旺长期表现出一致的规律，支持温度较高，日照时数较长，降水量较少，δ13C值越大的结论。

Effects of Distribution Difference in Climatic Zones of Low Altitude Plateau on Carbon Isotope Ratio in Different Tobacco Cultivars

The response of stable carbon isotope （δ13C） distribution of tobacco cultivars K326, Hongda and KRK26 to climate and environment were studied at rapid growth stage and physiological maturity stage by selecting two ecological tobacco growing areas with nearly four latitude difference, located at Tonghai of Yuxi and Ludian of Zhaotong prefecture in two different climatic zones. The results showed thatδ13C value of tobacco leaves ranged from -26.56‰ to-24.36‰. The δ13C values for all of the tobacco varieties at Tonghai were greater than Ludian, except for KRK26. Theδ13Cvalue at Ludian was greater than those at Tonghai in maturity stage. In contrast to the rapid growth and maturity stage, the δ13C value at maturity stage was greater in all varieties for all locations. With the increasing of maturity of tobacco leaves, water use efficiency of the tobacco gradually increased in two climatic zones. Comparison between varieties, for both growth stages, theδ13Cvalue of KRK26 was the largest in Tonghai, the δ13C value of Hongda was the largest in Ludian. The average value ofδ13Cin tobacco of the lower leaves and cutters in Tonghai was greater than Ludian, which support the conclusion that the higher temperature, the longer sunshine hours, the less precipitation, the value ofδ13Cwas larger. The results indicate that temperature, sunlight, precipitation, and variety have significant effect on tobacco δ13C value.