| Tobacco is an important economic crop in China, and potassium has a great impact on the yield and quality. Resources of potassium in china are deficiency.To screen the tobacco germplasm of efficient, to study its mechanism is one way to alleviate the demand for tobacco potassium.166genotypes provided in the test, collected from Chongqing Tobacco Institute, screening identified by nutrient solution culture and field cultivation, to do research in nutritional mechanism of high and low tobacco potassium genotypes, the main results are as follows:1Screening to get high and low tobacco potassium genotypesFrom seedling, initial screening by hydroponic experiments on the166tobacco genotypes, to get twenty high tobacco potassium genotypes and fifteen low tobacco potassium genotypes, and for further screening in the field, finally get three high tobacco potassium genotypes, NC89, Dianjiang bud seed, HB030and three low tobacco potassium genotypes, NC628, dry stone soil Fuling smoke, Yunyan1.2Hydroponic screening of different tobacco genotypes, to explore the physiological differences in seedling under different potassium levelsUnder different potassium treatment, seedling growth performance in different genotype, firstly, at external morphology. In hypokalemia treatment, the lower leaves of tobacco seedlings appear typical of potassium deficiency symptoms. Symptoms appear late in efficient genotypes, cotyledon off more slowly, more leaves.In the early seedling growth, the uptake of potassium is smaller, so the potassium treatment, the rapid root development, biomass accumulation and more. With the growth of tobacco seedlings, the demand for potassium increased, so deal with the latter, often under the Tobacco Potassium better root growth, biomass accumulation increased rapidly.3Different levels of potassium on effect of agronomic traits in the two inefficient genotypesFrom30days after processing to90days, each genotype, the plant height, stem girth, maximum leaf length, leaf width showed the biggest growth trend, for45days to60days, tobacco plant are growing fastest, plant height reached maximum at75days, then basically stopped state; stem girth change little after60days;60days after treatment before the maximum leaf length increased considerably, after slow growth; maximum leaf width in the treatment30days to75days, showing growth trends,75days to90days showed a downward trend, the maximum in transplanting75days. Overall, under low potassium stress conditions, the plant height and maximum leaf length are bigger in low potassium treatments, the maximum leaf width and stem circumference did not differ much. Over the processing time under low potassium stress conditions, the main agronomic traits of each genotype showed a distinct disadvantage. Under low potassium stress, root length of each genotype, total root surface area, total volume of roots and root activity has decreased in varying degrees.4Different levels of potassium on effect of physiological indices in the two inefficient genotypesUnder conditions of low potassium stress, potassium efficient genotypes NC89, Dianjiang bud seed, HB030photosynthetic pigments and potassium inefficient genotype NC628, dry stone soil Fuling smoke, Yunyan1differences mainly in the60days of treatment, potassium efficient genotypes NC89Dianjiang bud seed, HB030containing chlorophyll a, chlorophyll b, carotenoids activity than potassium inefficient genotype NC628, dry stone soil Fuling smoke, Yunyanl. Research on the function of nitrogen metabolism of sugar leaf cells showed that under low potassium stress, elevated amylase activity, relative to potassium inefficient genotype, the K efficient genotypes NC89, Dianjiang bud seed, HB030elevated more; protein content, sucrose synthase, nitrate reductase activity decreased less efficient genotype, the potassium protein content fell more efficient genotypes, sucrose synthase, nitrate reductase activity decreased less. Research shows that the function of cell membrane, under low potassium stress, MDA, SOD, POD activity increased compared to low potassium genotype, the increase in the amount of potassium more efficient genotypes.5Different levels of potassium on effect of photosynthesis parameters in the two inefficient genotypes The experimental results show that the net photosynthetic rate for60Telsda to the maximum, under conditions of low potassium stress at this time, three K efficient genotypes net photosynthetic rate than the three K inefficient genotypes overall net photosynthetic rate of56.08%higher; Rooms feature leaves the maximum CO2concentration in the treatment75days, then three potassium efficient genotypes up7.51%in the intercellular carbon dioxide concentrations than potassium potassium treatment often under duress, while the three K inefficient genotypes up47.01%; NC89, HB030treated in various periods under different potassium, transpiration rate was significantly greater than other genotypes; NC628, dry stone soil Fuling smoke clouds after the1st treatment Potassium Stress, down64.01%, a decrease large, much larger than the efficient genotype NC89, Dianjiang bud seed, HB030decreased10.00%.6Different levels of potassium on effect of leaf chemical constituents in the two inefficient genotypesUnder stress conditions potassium content, chlorine reactive nitrogen to nicotine, nicotine ratio of sugar to rise, nitrogen content changed little, other indicators have different degrees of decline, the coordination chemistry of genotypes have different degrees of decline into. Under constant K treatment, NC89, Dianjiang bud seed, HB030potassium content, nicotine high content and low content of reducing sugars, NC628, dry stone soil Fuling smoke, low clouds and potassium on the1st content, content low nicotine, sugar content low. Under low potassium stress, NC89, Dianjiang bud seed, HB030potassium content than NC628, dry stone soil Fuling smoke clouds on the1st of potassium in potassium normally active; NC89, dry stone soil Fuling content chlorine smoke, nitrogen content decreased content of sugar rose; NC628, Dianjiang bud seed, HB030content chlorine, nitrogen content increased sugar decreased content; clouds on the1st of chlorine content, the content changed little sugar, nitrogen increased content; Dianjiang bud seed nicotine content increased slightly, the other genotypes decreased.7Potassium efficient gene expression in different genotypesMore NtAKT1-1relative expression levels in the lower leaves of the NC89; potassium in the regular treatment, relative to Dianjiang bud seed and HB030, NtAKT5, NtNKT-2, NtKCl of the NC89roots in the relative expression of large amounts; NtNKT1in NC89the relative expression of large amounts of roots in potassium often treated HB030stems, leaves parts of the relatively large amount of expression; NtNKT-1, NtNKT2NC89stems in large amounts relative expression; under low potassium stress conditions, NtTPK1-1at the root of the relative expression levels of more HB030.8Potassium efficient gene expression in different parts of tobaccoNtAKT1-1, NtAKT5, NtKUP2, NtSKOR, NtTPK1-1in the roots and leaves have relatively large amount of expression; NtKAT in the roots, stems, leaves the middle of the relative expression of many; NtTPK1-2in the roots, stems, leaves the upper the relative expression of large amounts; NtHAK5, NtKCO1in relative expression of the upper leaves more; NtTORK1in the upper part, the relative expression of middle leaves more in the roots, stems, lower leaves almost no expression; NtHAKl expression mainly in the leaves, roots, stems smaller amount relative expression.9Potassium efficient gene expression between different treatmentUnder low potassium stress, NtNKTI, NtTPK1-1in NC89, Dianjiang bud species, relative expression levels in various parts of HB030decreased; NtTPK, NtTPK1-1by low potassium stress treatment, which significantly increased the relative expression levels of various parts of the; NtAKT1-1, NtHAK1, NtKUP2by low potassium stress treatment, no significant change in their relative expression levels of each part. Under conditions of low potassium stress, NtAKT5, NtHAK1, NtKAT, NtKCl, NtNKT-2at the root of the decline in the relative expression; NtNKT-1, the amount of relative expression NtNKT2decline stems; relative expression NtKAT amount stems rise; NtHAK5, NtKAT, NtKCOl, NtKC1, NtTORK1, NtSKOR rise in the relative expression amount of leaves. |
