【作者】 李国生；

【导师】 杨建昌；

【作者基本信息】 扬州大学 ， 作物栽培学与耕作学， 2007， 硕士

【摘要】 土壤水分和氮素营养是影响稻米品质的重要因子。阐明土壤水分和氮素营养对稻米品质的影响及其互作效应,对指导水稻高产、优质、高效栽培有重要意义。本研究以中籼杂交稻汕优63和中粳稻武育粳3号为材料,种植于大田、盆钵或土培池,观察了在不同氮素水平和土壤水分条件下的稻米品质变化特点。主要结果如下:1、在大田试验条件下,施氮量从0 g N/m~2到40 g N/m~2,对稻米的出糙率、精米率、粒长/粒宽、透明度和直链淀粉含量无显著影响。稻米蛋白质含量随施氮量的增加而增加。汕优63施氮量从0 g N/m~2到16 g N/m~2,武育粳3号施氮量从0 g N/m~2到24 g N/m~2,整精米率、最高黏度、崩解值随施氮量的增加而增加;稻米的垩白粒率、垩白度和消解值则随随施氮量的增加而降低。汕优63施氮量从16 g N/m~2到40 g N/m~2,武育粳3号施氮量从24 g N/m~2到40 g N/m~2,整精米率、最高黏度、崩解值随施氮量的增加而降低;稻米的垩白粒率、垩白度和消减值则随施氮量的增加而增加。说明施氮量为160 kg N/hm~2和240kg N/hm~2可分别作为籼稻汕优63和粳稻武育粳3号优质稻米生产的氮肥施肥量指标。2、在盆栽试验条件下,结实期土壤水水势从0kPa到-60kPa,对稻米的出糙率、精米率、粒长/粒宽、直链淀粉含量和粗蛋白含量无显著影响。汕优63土壤水势为-15kPa和-30kPa处理以及武育粳3号土壤水势为-15kPa的处理的整精米率与对照(土水势为0)无显著差异。汕优63土壤水势为-45kPa和-60kPa处理以及武育粳3号土壤水势为-30kPa、-45kPa和-60kPa的处理的整精米率、胶稠度、碱消值较对照显著降低。汕优63土壤水势为-15kPa和-30kPa处理以及武育粳3号土壤水势为-15kPa处理的垩白米率、垩白度和消减值较对照显著降低,淀粉谱的最高黏度和崩解值则显著增加。两品种土壤水势为-45kPa和-60kPa处理的垩白米率、垩白度和消减值显著高于对照,最高黏度和崩解值则显著低于对照。表明土壤水势为-15kPa～-30kPa和-15kPa可分别作为汕优63和武育粳3号结实期节水灌溉的低限土壤水势指标。3、在土培池试验条件下研究了结实期土壤水分和氮素营养对稻米品质影响的交互作用。在各施氮水平(粒肥为0、4.5、9.0 g N/m~2)下,稻米的出糙率、精米率和整精米率均以土壤水分轻度落干处理(土壤水势为-25 kPa)的最高,垩白米率和垩白度均以土壤轻度落干处理的最低。在低氮水平(0 g N/m~2)下,土壤重度落干处理((土壤水势为-50 kPa)降低了稻米碾磨品质、外观品质和食味品质;在中氮(4.5 g N/m~2)或高氮(9.0 g N/m~2)水平下,土壤重度落干处理的稻米的碾磨品质、外观品质和食味品质与保持水层处理的差异不显著或显著优于保持水层处理。说明氮素营养和土壤水分对稻米品质的形成存在着明显的互作效应,结实期土壤水势为-25 kPa、粒肥的施氮量为45 kg N/hm~2,稻米的品质较优。更多还原

【Abstract】 Soil moisture and nitrogen (N) nutrient are the principal factors affecting rice quality. Elucidation of their influences and coupling effects on the quality would have great significance in conducting the cultivation for high yielding, good quality and high efficiency. In this study, a typical indica hybrid Shanyou 63 and a japonica cultivar Wuyujing 3 were used as materials, and were field-, pot- or tank-grown. The effects of N levels and soil moisture during grain filling and their coupling effects on rice qualities were investigated. The main results are as follows:1. The plants were field-grown. The amount of N, ranged fron 0 to 40 g/m~2, showed no significant effect on brown rice percentage, milled rice percentage, kernel length/kernel width, and amylose content. The protein content was increased with the increase in the amount of N application. The head rice percentage, peak viscosity, and values of breakdown in rapid viscosity analyzer (RVA) profiles were increased, whereas chalky grain percentage, chalkiness, setback values were reduced, when the amount of N application was from 0 to 16g/m~2 for Shanyou 63 and from 0 to 24 g/m~2 for Wuyujing 3. The head rice percentage, peak viscosity, and values of breakdown decreased, whereas chalky percentage, chalkiness, setback values were increased, when the amount of N application was from 16 to 40g/m~2 for Shanyou 63 and from 24 to 40 g/m~2 for Wuyujing 3. The results indicate that the amount of N at 160 kg/hm~2 and 240 kg/hm~2 could be as an index of N application for Shanyou 63 and Wuyujing 3, respectively, in the production for the good quality of rice. 2.Under the pot experiments, soil water potentials, ranged from 0 to -60 kPa, had no significant effect on brown rice percentage, milled rice percentage, kernel length/kernel width, amylose content, and protein content. There was no significant difference in the head rice percentage between treatments of the keeping flooded (control) and soil water potentials at -15 and -30 kPa for Shanyou 63 or at -15 kPa for Wuyujing 3. The head rice percentage, gel consistency, and alkali spreading values significantly decreased when soil water potentials at -45 and -60 kPa for Shanyou 63 or at -30, -45, and -60 kPa for Wuyujing 3. The chalky grain percentage, chalkiness, and setback values significantly decreased, while peak viscosity and values of breakdown were significantly increased, when soil water potentials at -15 and -30 kPa for Shanyou 63 or at -15 kPa for Wuyujing 3. The chalky grain percentage, chalkiness, and setback values were significantly grater, whereas peak viscosity and values of breakdown were significantly smaller, than those of the control when soil water potential at -45 and -60 kPa for both cultivars. The results suggest that soil water potential at -15 ~ -30 kPa and -15 kPa could be as low-limit indexes for Shanyou 63 and Wuyujing 3, respectively, in water-saving irrigation during the grain filling period of rice.3. The coupling effects of soil moistures and N levels on rice quality were studied A tank experiment was conducted. Under all the N levels (grain fertilizer at the rate of 0, 4.5, and 9.0 g N/m~2), the brown rice percentage, milled rice percentage and head rice percentage were the greatest, while chalky grain percentage and chalkiness were the lowest, for the moderate soil-drying treatment (soil water potential at -25 kPa). At the low level of N (0 g/m~2), the severe soil-drying treatment (soil water potential at -50 kPa) significantly degraded the milling quality, appearance quality, and eating quality. At the mid (4.5 g/m~2) and high (9.0 g/m~2) N levels, the differences in milling quality, appearance quality, and eating quality between the severe soil-drying and the keeping flooded wee not significant, or those in the former were benter than those in the latter. It could be concluded that the ineraction between soil moisture and N levels affects rice qualities, and that soil water potential at -25 kPa during grain filling and the amount of N at 45 kg/hm~2 as the grain fertilizer benefit the formation of good quality.更多还原