【作者】 杨琼；

【导师】 罗建新；

【作者基本信息】 湖南农业大学 ， 植物营养学， 2011， 硕士

【摘要】 烟叶含钾量低一直制约着我国烟叶的品质。由于我国钾资源匮乏,钾肥利用率低,且通过增施钾肥提高烟叶含钾量的效果不显著,因此,选育高钾基因型的烤烟(株系),是提高烟叶含钾量的一条有效途径。本试验采用砂培试验,以导入了外源富钾基因的K2、K3、K5、K7、K9等5个高钾基因型烤烟(株系)和K326(CK)为供试材料,研究了2个供钾水平(0.6mmol/L和6.0mmol/L)下,不同钾基因型烤烟(株系)的生长表现和对介质溶液中钾的吸收、积累、分配等方面的差异,探讨了高钾基因型烤烟(株系)与K326对钾吸收利用的差别。主要研究结果如下：1.在不同供钾水平下,5个不同高钾基因型烤烟(株系)的株高、叶面积、叶长宽比和叶间距等农艺性状指标都明显优于对照K326,其中以K7和K9表现最佳,K2和K5次之,K3最小；高钾基因型烤烟(株系)的干物质量均大于K326,其中K5、K7和K9的干物质量较大,表明高钾基因型烤烟(株系)的农艺学性状比K326具有明显的优势,且干物质量也随着生长优势的凸显而增大。2.由于受烟株干物质和钾积累强度的综合影响,不同高钾基因型烤烟(株系)的烟叶含钾量的变化各不相同。在烟苗移栽25d,与高供钾水平相比,低供钾水平下高钾基因型烤烟(株系)含钾量的降幅大于K326,降幅在83.81%～88.83%；而在移栽45d,K5的钾吸收积累量的降幅小于K326,其它4个高钾基因型烤烟(株系)的钾吸收积累量的降低幅度均大于K326,其降幅为89.62%～92.85%,但各株系间的差异不显著。因此,随着烟株生长发育的推进,K5在移栽45d能维持较高的钾水平,对提高烟叶的含钾量有利。在低供钾条件下,烟苗移栽25d,高钾基因型烤烟(株系)的钾吸收积累量均大于K326；而到移栽45d,K2和K7的钾吸收积累量显著小于K326。移栽45d与移栽25d相比,K326、K2和K7的钾吸收积累量均有下降,但K2和K7的降低幅度均小于K326,而K3、K5和K9的钾吸收积累量呈上升趋势。说明K3、K5和K9具有良好的吸钾能力和吸钾潜力。3.高供钾水平下,高钾基因型烤烟(株系)的根系活力高,其中尤以K9的优势最为明显。在低供钾条件下,移栽25d,各基因型烤烟(株系)的根系活力均大于高供钾水平,而根体积、根系总吸收面积和活跃吸收面积均小于高供钾水平；移栽45d,各不同基因型烤烟(株系)的根体积和根系活力均低于高供钾水平,而K9根系总吸收面积和活跃吸收面积高,分别比高供钾水平下高9.22%和70.08%；K2和K7根系活跃吸收面积也增大,增幅分别为：15.87%和75.90%,说明在生育后期,在钾素营养供应水平较低的生长环境中,K2、K7和K9都能维持良好的根系吸收特征,从而加强烟株对钾的吸收与积累。4.高钾基因型烤烟(株系)与K326相比,其根系的最大吸收速率(Vmax)值大,对钾的亲和力(Km)和钾最低吸收浓度(Cmin)值小,表明其对钾的亲和力较强,不仅能在低钾的环境中更好地吸收利用介质中的钾,而且能在高钾的环境中,快速地吸收利用介质中的钾。在不同的高钾基因型烤烟(株系)中,以K7和K9的根系Vmax值最大,Km最高,Cmin最小,其次是K2和K5,K3则较差。因此,不同高钾基因型烤烟(株系)对钾的吸收动力学特征存在明显的差异,这些差异,可以作为品种筛选的依据之一。更多还原

【Abstract】 The low potassium content in tobacco leaves has constantly restricted the quality of tobacco in our country. As the potassium resource scarcity and the poor utilization efficiency of potash fertilizer, breeding the high K genotypes of flue-cured tobacco is an efficient way to enhance the potassium content in tobacco. The experiment applied the sand cultivate way, tested materials are 5 flue-cured tobacco named K2、K3、K5、K7、K9 which,imported K-rich gene and the check sample is K326. The materials was cultivated under the two potassium levels,0.6mmol/L and 6.0mmol/L, the growth characteristics of different genotypes tobacco and the absorption of potassium in soil solution, accumulation, distribution and the differences between the K-rich potassium genotypes and K326 in absorbing and utilization efficiency were studied. The main results are as follows:1. Under all potassium levels, the plant height, leaf area, leaf aspect ratio and leaf spacing of high-K genotypes tobacco are all greater than K326, in which K7 and K9 perform best, K2 and K5 ranking second,and then the K3. Meanwhile, the amount of dry matter of high-K genotypes tobacco is also higher than K326, among which K5, K7 and K9 are comparatively higher. It showed that the high-K genotype tobacco having an advantage than K326 on the agronomic characteristics, and the dry mass is increased along with the phenotype advantages.2. Influenced by dry mass and potassium accumulation intensity, the main range of variation on potassium content of tobacco leaves of different potassium efficient genotypes tobacco are different.25 days after transplanting, compared with the high potassium level, K-rich potassium genotypes decline more than K236 under the low potassium level, the range is between 83.81% to 88.83%.45 days’after transplanting, the declining of accumulation of potassium in the K-rich potassium genotypes to the exclusion of K5 are slower than K326, decreased by 89.62% to 92.85%, and the difference is unsignificant. Therefore, with the growth and develepment of tobacco plant, K5 can keep the high potassium level 45 days after transplanting, which helps to improve the cointent of potassium in tobacco.. On the conditions of low K, the accumulation of potassium in the K-rich potassium genotypes is more than K326 25 days after transplanting, moreover, the accumulation of potassium in K2 and K7 is obviously less than K326 25 days to 45 days after transplanting. Comparing in transplanting 45 days with 25 days, the accumulation of potassium in K326, K2 and K7 is declined, and the decreasing extent of K2 and K7 is less than K326, and that the accumulation of potassium in K3,K5 and K9 is increased. It shows that K3,K5 and K9 have a good ability and potential of absorbing potassium. 3. On the condition of high K, potassium efficient genotypes tobacco have higher root activity, and K9 is the best. After 45 days’transplanting,on the low potassium levels, the root activity of different genotypes tobacco is higher than the high potassium levels, and the root volume, root total and active absorption area of different genotypes tobacco are lower than the high potassium levels. After 45 days’transplanting on the low potassium levels, the root volume and root activity of different genotypes tobacco is lower than the high potassium levels, and K9 got larger root total and active absorption area, which is respectively larger by 9.22% and 70.08% than the high potassium level.K2 and K7 got larger root active absorption area, by 15.87% and 75.90% respectively. It indicates that K2、K7 and K9 possess characteristic of root morphology which is beneficial for the absorption and accumulation of potassium in the low potassium environment in latter growth period.4. Compared high-K genotypes of flue-cured tobacco with K326, the root of the former has a bigger Vmax value, the smaller Km and Cmin value. It indicated that the potassium efficient genotype have the higher affinity to potassium, it can absorb and utilize patassium under any potassium level. In different high-K genotypes of flue-cured tobacco, K7 and K9 have the biggest Vmax value, the highest affinity to potassium (Km) and the lowest concentration absorption of potassium the smallest (Cmin), secondly, the K2,K5. and K3 are minimal.So,it indicated that the absorbing dynamics of potassium of potassium efficient genotypes tobacco is distinct to screen high potassium genotypes flue-cured tobacco.更多还原