外源GA_3和IAA对烤烟内源激素调控效应和常规化学成分的影响

为了探究外源GA3和IAA对烟草生长及品质的影响,从激素和基因水平探究外源激素作用机理,探索较优激素浓度配比。采用田间试验,以烤烟品种NC71为实验材料,设置不同浓度配比的外源激素,检测了不同时期烤烟株高、干物质积累、激素含量、相关基因表达量的变化和烟叶品质的变化。结果表明,外源GA3可以显著提高烤烟株高和节距,而外源IAA相对提升较少,烟株的干物质量也随着GA3浓度提高而增大。喷施不同浓度外源GA3和IAA均可提高茎尖GA3和IAA含量并降低ABA含量,其中150 mg/L提升效果最明显,100 mg/L外源GA3和10 mg/L外源IAA次之。外源GA3能够使烟草GAI1基因表达量明显下降,IAA也能降低GAI基因的相对表达量,但效果相对较弱。喷施外源激素的烟叶总糖、还原糖、钾含量都有所增加,而总氮、烟碱、氯含量则有所下降,100 mg/L外源GA3与IAA配合施用的条件下钾氯比和糖碱比最高,品质表现较好,可在移栽后15 d喷施100 mg/L外源GA3和10 mg/L外源IAA。这些结果可以为豫中烟区烤烟喷施外源生长调节剂提供依据。

Effects of Exogenous GA3 and IAA on Growth Regulation and Quality of Flue-cured Tobacco

In order to study the effects of exogenous GA3 and IAA on tobacco growth regulation and chemical composition, the mechanism of exogenous hormones and the optimal hormone concentration were explored based on hormone and gene levelsexplore. Taking the flue-cured tobacco variety NC71 as the experimental material, this paper set different concentration treatments of exogenous hormones to detect the changes of plant height, dry matter accumulation, hormone content, related gene expression and tobacco leaf quality. The results showed that exogenous GA3 could significantly increase the plant height and pitch of flue-cured tobacco, while the relative increase of exogenous IAA was less, and the dry matter quality of tobacco plants increased with the increase of GA3 concentration. Spraying different concentrations of exogenous GA3 and IAA increased the content of GA3 and IAA in shoot tip and reduced the content of ABA and the effect of 150 mg/L was the most obvious, the exogenous GA3 of 100 mg/L and the exogenous IAA of 10 mg/L were the second exogenous. GA3 significantly reduced the expression of GAI1 gene in tobacco, and IAA also reduced the relative expression of GAI gene, but the effect was relatively weak. The content of total sugar, reducing sugar and potassium in tobacco leaves sprayed with exogenous hormones increased, while the contents of total nitrogen, nicotine and chlorine decreased, and potassium in the condition of 100 mg/L exogenous GA3 combined with IAA. The ratio of chlorine to sugar and alkali was the highest, and the quality was better, so 100 mg/L exogenous GA3 and 10 mg/L exogenous IAA were sprayed 15 d after transplanting according to the principle of lessness. These results provided a basis for the application of exogenous growth regulators to flue-cured tobacco in the central part of Henan province tobacco area.