不同生育期弱光胁迫对烤烟生长和品质的影响

2004、2005年在四川凉山烟科所通过盆栽试验,用遮阳网在烟草不同生育期(生根期、旺长期和成熟期)营造不同的光照强度(自然光、减弱50%光强和减弱75%光强),研究了不同生育期弱光胁迫对烟株生长发育和烤后烟叶品质的影响。结果表明:弱光胁迫增加了株高、节距和叶面积,降低了干物质积累、根冠比和干鲜比,增加了叶片平衡含水率和含梗率,降低了叶片的单叶重、叶片厚度、叶质重和叶片密度,增加了叶片总氮、烟碱和钾离子含量,降低了总糖和还原糖含量。总体的来看,每个生育期弱光胁迫对烟草的生长和品质都会有很大影响,在生育中后期弱光胁迫的影响要比在生育前期的影响要大,且弱光胁迫程度越大影响越大。

Effects of Weak Light Stress at Different Growth Stages on the Growth and Quality of Flue-cured Tobacco

The pot-culture experiments were carried out on the effects of different weak light stress at different growth stages on growth, physical property, chemical composition of flue-cured tobacco during 2004 and 2005. The results indicated that: tobacco growth rate was slower, the plants were taller, and leaf area was bigger under shade conditions. Dry matter accumulation, root/top weight, dry/fresh weight, leaf Chl.a content were reduced, growth stage was delayed and leaf Chl.b and Chl.a Chl.b content, ration of Chl.b/Chl.a were increased for shading treatments. Compared with control, shading reduced leaf weight, thickness, intensity, and increased stem content, moisture content. Weak light stress increased total nitrogen, nicotine and potassium content, decreased total sugar and reducing sugar content in cured tobacco leaf. In all, the effects of weak light stress at all growth stages were serious; the effects of at middle and later growth stages were more than that at earlier growth stage.