不同生态区烤烟δ^(13)C值与光合色素及化学成分的关系

The Relationship of Tobacco δ^(13)C Value and Photosynthetic Pigment and Chemical Constituents in Different Ecological Zones

为研究不同生态区烟叶香气风格形成的生态原因,选云南、福建和河南3个不同生态烟区大田种植烤烟‘K326’,各地的取样时段,为各地移栽后70天,采集烤烟第7叶位叶片,此后每间隔12天,依次取第10、13和16 4个不同叶位生理成熟叶片,对3地烟叶的δ13C值与光合色素和化学成分的动态变化进行研究。结果表明:3地烟叶δ13C值、叶绿素a、b、类胡萝卜素含量及叶绿素总量均呈负相关。福建和云南烟叶的δ13C值与叶绿素a和叶绿素总量负相关均达显著水平(P<0.05)。河南烟叶的δ13C值与叶绿素/类胡萝卜素比值、叶绿素a/b比值呈弱正相关,而福建和云南的δ13C值则与叶绿素/类胡萝卜素比值呈正相关,与叶绿素a/b比值呈负相关。福建和云南相同叶位叶绿素a含量、叶绿素b含量、叶绿素总含量及除第13叶位外的类胡萝卜素含量间均没有显著差异(P>0.05)。δ13C均值与化学成分中的烟碱、总氮和钾呈正相关,与总糖、还原糖和氯呈弱负相关。分别对3地的烟叶化学成分进行直观比较,河南的总糖、还原糖、总氮及钾与福建、云南的差异明显,而福建和云南间则差异不明显。以δ13C值比较,河南的值最小,4个不同叶位的平均值仅为-29.67‰,与福建的-26.32‰、云南的-25.6‰相比差异显著,而福建和云南间其值差异仍不显著。总体来看,3地烟叶δ13C值地区间存在的差异,不但与光合色素含量变化规律大致相同,还与化学成分有相似的趋势。3地烟区δ13C值与光合色素和化学成分在地域间表现存在的趋同或差异,为以烟叶δ13C值作为判定不同生态区烟叶香气风格形成的阈值提供了思路。

To study the formation of tobacco aroma style in different ecological zones, we chose flue-cured tobacco‘K326＇which was planted in three different ecological zones（Yunnan, Fujian and Henan） as the test sample. The first sampling was processed after 70 days from tobacco transplanting by collecting mature leaf in 7 th position. Then after every 12 days, we collected mature tobacco leaves in position #10, #13, and #16 successively. δ13^C value, photosynthetic pigment and chemical constituents variation of tobacco leaves were analyzed in our experiments. The results showed that δ13^C value with chlorophyll a/b and carotenoids content with chlorophyll were negatively correlated. The δ13^C value of Fujian and Yunnan had significant negative correlation with the total chlorophyll a and chlorophyll（P〈0.05）. The δ13^C values of Henan had weak positive correlation with chlorophyll carotenoids ratio and chlorophyll a/b ratio. The same value in Fujian and Yunnan were positively correlated to chlorophyll and carotenoids ratio, while negatively correlated to the chlorophylla/b ratio. In Fujian and Yunnan chlorophyll a content, chlorophyll b content, overall chlorophyll content and carotenoid content（except leaves in position 13th） had no significant differences（P〉0.05）. The average δ13^C value was positively correlated to nicotine, nitrogen and potassium, and had weak negative correlation with total sugar, reducing sugar and chlorine. Intuitive comparison of total sugar, reducing sugar, nitrogen and potassium among samples from three areas showed that Henan＇s was significantly different from Fujian＇s and Yunnan＇s, while no obvious difference was found between Fujian＇s and Yunnan＇s. As to δ13^C value, Henan＇s was the minimum（the average value of four leaf position was-29.67‰）, which was significantly different from Fujian＇s（-26.32‰） and Yunnan＇s（-25.6‰）. Meanwhile the value was not significantly different between samples from Fujian and Yunnan. Generally speaking, the δ13C values were different among regions, not only changed roughly identical with photosynthetic pigment content, but also had similar trends with chemical composition. δ13C value, photosynthetic pigment and chemical composition of tobacco leaf from three different regions had different styles. This conclusion provided idea that using δ13C as threshold we could determine planting districts of tobaccos with different aroma style.