【作者】 蒋光华；

【导师】 周治国；

【作者基本信息】 南京农业大学 ， 作物栽培学与耕作学， 2005， 硕士

【摘要】 本文以美棉33B为材料,通过设置播期试验,使棉纤维加厚发育过程（铃龄25～50d）处于不同的温度条件下,研究相同棉株生理年龄不同温度、相同温度不同棉株生理年龄以及温度与棉株生理年龄协调作用对棉纤维加厚发育及纤维比强度的影响。主要研究结果如下: 1.低温对棉纤维比强度形成生理机制的影响。棉纤维加厚发育期24.0℃左右的日均温是高强纤维形成的最佳温度,内在生理机制表现为棉纤维蔗糖合成酶活性最高,β-1,3-葡聚糖酶活性最低,纤维素的累积量和累积速率均明显高于其他低温条件,纤维超分子结构取向参数角较小,处于优化状态,最终表现为纤维比强度亦最大。低于21.0℃时即对棉纤维加厚发育相关酶活性产生明显影响,纤维比强度降低。当温度降到15.0℃左右时,棉纤维蔗糖合成酶活性显著降低,而β-1,3-葡聚糖酶活性显著升高,同时纤维素累积量和累积速率均显著降低,纤维超分子结构取向参数角明显宽化,棉纤维不能正常发育(铃重仅为3.22g,纤维比强度仅为15.73CN·tex^-1)。 2.棉株生理年龄对棉纤维加厚发育的生理机制及纤维比强度的影响。棉花“三桃”的棉纤维加厚发育及纤维比强度受温度和棉株生理年龄的双重影响,棉株生理年龄是影响伏桃、早秋桃棉纤维加厚发育的主要因子,对棉株上部果枝的伏桃和下部果枝的早秋桃棉纤维加厚发育具有显著影响,铃重、衣分和纤维比强度均明显低于其他部位;棉纤维加厚发育期低温则是影响晚秋桃棉纤维加厚发育及纤维比强度的首要因子,在本试验15.3℃的温度条件下,棉纤维蔗糖合成酶活性显著降低,β-1,3-葡聚糖酶活性显著升高,同时纤维素累积量和累积速率均显著降低,棉花铃重低于2.00g,纤维比强度低于20.0CN·tex^-1。棉株生理年龄对伏桃、早秋桃和晚秋桃纤维比强度的影响作用依次增强。 3.低温与棉株生理年龄的协同作用对棉纤维加厚发育及纤维比强度的影响。在正常温度条件下,棉纤维加厚发育及纤维比强度的形成主要受温度和棉株生理年龄的双重影响,棉株生理年龄是主要因子,当棉纤维加厚发育期日均温为26.0℃（2002）和26.2℃（2003）,中部7-9果枝棉纤维蔗糖合成酶活性最高,β-1,3-葡聚糖酶活性最低,纤维素的累积量和累积速率均高于其他果枝部位,纤维超分子结构取向参数最小,最终表现为纤维比强度亦最大。在低温条件下温度是首要影响因子,温度越低棉株生理年龄的影响越不明显,当日均温低于16.0℃时,蔗糖合成酶活性显著下降,β-1,3-葡聚糖酶活性显著上升,纤维比强度均表现最低,2002年为:17.08CN·tex^-1,2003年为:21.18 CN·tex^-1,不再受棉株生理年龄的影响。 综上所述,低温和棉株生理年龄对棉纤维中可溶性蛋白、内源保护酶、蔗糖合成酶、β-1,3-葡聚糖酶等生理指标的影响是导致纤维素累积量和累积速率、纤维超分子结构取向参数及最终纤维比强度差异的主要原因。提供合成纤维素或胼胝质的前体物更多还原

【Abstract】 By setting different seeding times, which put the thickening development process of fiber (boll age 25 days to 50 days) in the different temperature conditions, the effects of different temperature at the same physiological age of cotton plant, different physiological age of cotton plant at the same temperature, cooperation of temperature with physiological age of cotton plant on the physiological mechanism of fiber thickening development and fiber strength were studied in a cement pool culture experiment by a cotton variety (America cotton 33B) as experiment material.The main results were as follows:1. Effects of low temperature on physiological mechanism of cotton fiber strength forming process. Mean daily temperature within boll age 25 days to 50 days which was 24.0℃ was the feasible temperature to forming the high-strength fiber, and when mean daily temperature was lower than 21.0℃, it would effected obviously the enzymes activity that related to cotton fiber thickening development, and resulted in the fiber strength falling. When mean daily temperature was 15.0℃ right-and-leftly, the fiber sucrose synthetase activity was evidently fall, and the β-1,3-glucanase activity moved up, the cellulose accumulation quantity and accumulation rate reduced obviously, cotton fiber development was abnormal, boll weight was only 3.22g, and fiber strength was only 15.73CN tex-1.2. Effect of physiological age of cotton plant on the physiological mechanism of fiber thickening development and fiber strength. There were double effect of temperature and physiological age of cotton plant on fiber thickening development and fiber strength, the physiological age of cotton plant was the principal factor and there were evidently effect on fiber thickening development of summer boll for the top fruiting branches and early autumn boll for the lower fruiting branches, boll weight and lint percent and fiber strength in these portion were lower than the others. Low temperature in fiber thickening development process was the principal factor that affected fiber thickening development and fiber strength of late autumn boll, under this testing condition of which the mean daily temperature for late autumn boll was 15.3℃, the fiber sucrose synthetase activity was evidently fall, and the β-1,3-glucanase activity moved up, the cellulose accumulationquantity and accumulation rate reduced obviously, boll weight was smaller than 2.00g and fiber strength was less than 20.0CN tex-1.3. Effect of low temperature cooperated with physiological age of cotton plant on the physiological mechanism of fiber thickening development and fiber strength. At the normal temperature conditions, there were double effect of temperature and physiological age of cotton plant on fiber thickening development and fiber strength. When mean daily temperature within boll age of 25 to 50 days were 26.0℃ (2002) and 26.2℃ (2003), at middle position of cotton plant, the fiber sucrose synthetase activity was highest, and the β-1,3-glucanase activity was lowest, the cellulose accumulation quantity and accumulation rate were higher than which of other temperature and position of cotton plant, fiber orientational indexes of super-molecular was least, so fiber strength was most. At the low temperature conditions, temperature was the most influence factor, and influence of physiological age of cotton plant fell with temperature descending. When mean daily temperature under 16.0℃,the fiber sucrose synthetase activity was evidently fall, and the β-1,3-glucanase activity moved up, so fiber strengths were only 17.08CN tex-1 (2002) and 21.18CN tex-1 (2003), and were independent of influence of physiological age of cotton plant.In conclusion, effects of low temperature and physiological age of cotton plant on soluble protein, endogenesis protect enzyme, sucrose synthetase, β-1,3-glucanase are the major reasons for the differences of the cellulose accumulation quantity and accumulation rate, fiber orientational indexes of super-molecular and fiber strength. The dynamic change laws of sucrose synthetase providing former body (UDPG) for synthesizing cellulose or callose and β-1,3-glucanase synthesizing callose by using UDPG are the vital enzymatic reasons for form of fiber strength.更多还原