广东烤烟不同区位叶面的pH值差异化分析

Variation Analysis of pH Values among Different Sections of Fluecured Tobacco Leaf from Guangdong

为研究烤烟不同区位叶面的pH值变化规律,选取广东3个产区4个品种的18份初烤烟叶样品,分析从叶尖至叶基10个区位(编号为TL1—TL10)叶面水浸液的pH值变化。结果表明:180个不同区位叶面的pH值介于5.31~5.96,其中73.3%的样品集中于5.49~5.67;叶面pH值与分切区位呈显著正相关关系,从叶尖至叶基的pH值整体呈现先增后降的抛物线变化趋势;广东烤烟pH值在产地、品种、部位间存在显著或极显著差异,尤其是烟叶等级部位与pH值存在极显著相关关系,不同等级部位烤烟的pH值整体上表现为X2F>C3F>B2F。利用基于叶面pH值差异性聚类分析方法,对不同部位烟叶分别确定了最优的三段式分切方案,TL1—TL3叶面区位为第1段,TL4—TL7/8为第2段,其余叶基部位为第3段。

In order to study the variation of tobacco leaf pH values at different cutting locations of flue-cured tobacco in Guangdong Province,eighteen tobacco leaf samples of four flue-cured tobacco cultivars from three regions in Guangdong were selected.And the pH variation behavior of water extracts at ten cutting locations from leaf tip to base area was analyzed.The results showed that,the pH values of180 leaf portions at different locations ranged from 5.31 to 5.96,and 73.3%of the samples were concentrated in the range of 5.49—5.67.There was a significant positive correlation between leaf pH value and cutting location,and the pH value from leaf tip to base showed a parabola trend of first increasing and then decreasing.The pH value of flue-cured tobacco in Guangdong Province showed significant or extremely significant differences among the producing areas,varieties and parts.In particular,a highly significant correlation existed between the tobacco grade and pH value.On the whole,the pH value of flue-cured tobacco of different grade presented the following characteristic:X2F>C3F>B2F.The cluster analysis based on tobacco leaf pH value difference indicated that the three-stage cutting scheme was optimal for different positions of tobacco.The leaf location of TL1—TL3 was the first section,TL4—TL7/8 was the second section,and the rest of the leaf base was the third section.