【作者】 张玉烛；

【导师】 袁隆平；

【作者基本信息】 湖南农业大学 ， 作物学， 2011， 博士

【摘要】 超级杂交稻的成功选育与大面积推广对于保障我国粮食安全具有重要作用,然而现实生产中超级杂交稻的产量潜力难以得到充分发挥,不同生态区的产量差异大。为进一步探明超级杂交稻高产机理,实现大面积稳定高产,本研究于2007～2009年设置栽培模式、覆盖方式和水分管理方式3个对比试验,对超级杂交稻高产群体特性、冠层特征和产量形成机理进行了较为系统的探讨。主要结果如下：1.超级杂交稻88S/1128在覆膜旱植和中后期灌水有利于实现高产。不同栽培模式之间表现为覆膜旱植栽培模式总颖花数提高7.4～16.0%,结实率提高3.94～10.08个百分点,千粒重提高了0.10g～0.79g,地上、地下部各时期的干物质积累均具有明显优势,产量比覆膜水植、不覆膜旱植和不覆膜水植模式相比分别提高了167.2kg/hm2、843.9kg/hm2和1125.9kg/hm2；不同水分管理,覆膜和不覆膜栽培下均为全生育期灌水处理产量最高,全生育期湿润处理最低；地膜、稻草和液膜3种覆盖方式的有效穗数、总颖花量和千粒重都高于不覆膜,产量分别提高16.81%、3.65%和9.59%。2.覆膜旱植和中后期灌水提高了冠层覆盖指数、平均叶倾角和直射辐射穿透系数,改善了超级杂交稻的冠层结构。栽培模式之间表现为覆膜旱植明显优于水植不覆膜,水植覆膜和旱植不覆膜介于两者之间,其中冠层覆盖指数的极差达0.28；不同水分管理下,覆膜和不覆膜两种模式均表现为全生育期灌水冠层结构显著优于湿润栽培,中期和后期灌水居中,处理间叶倾角差异覆膜大于不覆膜,齐穗期大于齐穗后20天,有效覆盖指数表现相反；旱植条件下,3种覆盖方式的冠层结构均优于无覆盖栽培,地膜优于稻草和液膜覆盖。3.覆膜旱植具有较高的光合速率和蒸腾速率,净光合速率较旱植不覆膜、水植覆膜和水植不覆膜处理平均提高11.84%、19.92%和14.90%,蒸腾速率较其它3种处理提高12.1%～25.1%,且随着生育期的推进差异加大。荧光动力学研究表明,地膜、液膜和稻草3种覆盖栽培都比不覆盖栽培提高了叶片Fv/Fm和Yield等荧光动力学参数,其中地膜覆盖的提高幅度最大,有利于水稻叶片在生育后期维持较高水平的PSⅡ潜在活性和实际原初光能捕获效率；不同水分管理方式对超级稻叶绿素荧光的影响较小。4.覆膜栽培能显著改善超级杂交稻88S/1128冠层微环境,降低了冠层温度,提高了冠层湿度。对冠层温度和湿度的监测表明,冠-气温差、冠-气湿度差有相同的变化趋势,其中覆膜水植的冠-气日平均温差高达2.07℃,且日变化在上午9时左右出现第一个降温增湿小高峰,冠-气温差达2.27℃,冠-气湿度提高10.93个百分点,晚上8时出现第二个降温增湿高峰,冠-气温差为2.86℃,冠-气湿度提高20.39个百分点。5.覆膜旱植增强了超级杂交稻88S/1128对营养物质的吸收,促进了干物质、Ca和SiO2的积累和转运。覆膜栽培在抽穗到成熟期间灌水,能显著提高水稻茎鞘和叶中钙的吸收和积累,但穗部钙的含量降低了。不同水分管理模式研究结果表明后期灌水显著提高了叶片中钙的含量,中期湿润后期灌水管理能提高茎鞘中钙的含量,后期湿润管理有利于穗中钙的吸收；在覆膜和灌溉双重处理下,植株吸收的SiO2于齐穗期向茎秆转运较多,有利于增强茎秆硬度,对防虫抗倒有积极意义。另外,覆盖栽培增强了旱植水稻对营养元素N、P、K的吸收能力,其中以地膜覆盖处理最为明显。6.覆膜栽培通过改善冠层微环境因子,尤其是通过提高蒸腾增湿降温,促进了超级杂交稻88S/1128对营养物质、干物质的积累及转运,提高了光合速率,有利于高产潜力的发挥。分析超级杂交稻产量构成因子与冠层小气候和光合生理特性之间的关系表明,对产量的影响作用大小依次为每穗总粒数、每穗实粒数、千粒重；齐穗期的光合速率对每穗实粒数影响最大,表现为倒2叶大于剑叶,乳熟期光合速率对千粒重影响最大,表现为剑叶大于倒2叶；在生育后期对光合速率影响最大的冠层小气候因子是冠层与大气的湿度差和冠层与大气的温度差,其中冠-气温差直接影响光合速率,冠气湿度差通过影响冠-气温度差而影响光合速率,且冠层湿度随着倒2叶蒸腾速率的升高而显著升高,同时冠层叶片蒸腾速率还促进了干物质向穗部积累和转运,茎叶对Ca吸收和SiO2向穗部的转运。更多还原

【Abstract】 It is so important for food security in China to successful breeding of Super hybrid rice and extensive promotion, but the yield potential of super hybrid rice is difficult to full play in real production, and the yield is not the same in different ecological area. In order to further prove the high-yield mechanism of Super hybrid rice and achieve stable high yield of large area, between 2007 and 2009, we have designed 3 comparative tests in this study, such as cultivation pattern, mulching modes and water managements, researched of high-yielding population characteristics, canopy characteristics and yield formation mechanism of super hybrid rice. The major results were summarized as follows:1 Plastic film mulching dry-land cultivation and irrigation in the middle and late contributed to high yield of Super hybrid rice 88S/1128. Under different cultivation pattern, total spikelet number increased 7.4～16.00%, seed setting rate increased 3.94%-10.08%, and thousand-grain weight improved 0.10g～0.79g in plastic film mulching dry-land cultivation mode. Dry matter accumulation of aerial part and Underground area had obvious advantages in all periods, and its’ yield were increased 167.2kg/hm2,843.9kg/hm2 and 1125.9kg/hm2 than plastic film mulching waterland cultivation, nude field dry cultivation and conventional cultivation. Under different water managements, the yield of whole growth period irrigation treatments was the highest in the film and nude field cultivation and whole growth period no-water treatments was the lowest. Effective panicle number, total amount of spikelet and thousand-grain weight of 88S/1128 under plastic mulching, straw mulching and liquid film covering were higher than nude field, and its’yield were increased 16.81%, 9.59% and 3.65%.2 Plastic film mulching dry-land cultivation and irrigation in the middle and late increased coverage index, the average leaf angle and direct radiation penetration coefficient, and improved canopy structure of Super hybrid rice. Plastic film mulching much better than the conventional cultivation in different cultivation pattern, and plastic film mulching waterland cultivation and nude field dry cultivation in between, and their canopy coverage index of very poor up to 0.28. Under different water managements, canopy structure of whole growth period irrigation treatments much better than no-water cultivation, the medium-term and late irrigation in between, and leaf inclination angle of plastic film cultivation was greater than nude field cultivation in different treatment, and full heading time is greater than 20 days after heading, but contrary to effective coverage index. Under dry-land conditions, canopy structure of 3 mulching modes are better than nude field cultivation, plastic film is better than covered with rice straw and liquid membranes.3 Plastic film mulching dry-land cultivation had high photosynthetic rate and transpiration rate, in particular, NET photosynthetic rate of plastic film mulching cultivation were higher 11.84%,19.92% and 14.90% than nude field dry cultivation, plastic film mulching waterland cultivation and conventional cultivation, and its’ transpiration rate were higher 12.1%～25.1% than their, and as the growth stages of promoting the difference increased. On the other hand, compare with CK mulching cultivation enhanced fluorescence dynamics parameter-Fv/Fm and Yield, it’s beneficial to potential activity of PSⅡand actual capture rate of luminous energy. Among the treatments of mulching film, straw and liquid film, mulching film was the best one. Otherwise, different water manage has little effect on fluorescence dynamics parameter of super hybrid rice.4 Film mulching cultivation could significantly improve canopy microenvironment of Super hybrid rice 88S/1128, lowered canopy temperature, and increased humidity in the canopy. Canopy temperature and humidity monitoring showed that canopy-air temperature difference and crown-air humidity difference had the same trend. The average daily temperature range of plastic film water cultivation was the most, up to 2.07℃, and diurnal variation appeared the first small cooling humidification peaks around 9 o’clock am, canopy-air temperature difference up to 2.27℃and improved 10.93%. It appeared the second cooling humidification peaks at 8 o’clock pm, canopy-air temperature difference was 2.86℃, crown-air humidity up to 20.39%.5. Calcium absorption characteristics of upland rice were different under different water management. The treatment of later stage irrigation enhanced the content of calcium in leaf, middle stage humidification and later stage irrigation favored calcium absorption of stems, later stage humidification was favorable for spic absorpting calcium. On the other hand, tillering stage to heading stage irrigation was not propitious for calcium absorption of stems and leaf. The treatment of heading stage to maturation stage irrigation enhanced calcium content of stems and leaf obviously, but the spic calcium content was reduced. The research showed that, more SiO2 tansfer to stems at full-heading stage under the treatment of mulching and irrigation,so the stems was more strong and had positive significance for insect resistance and lodging. Otherwise, mulching cultivation enhanced the absorption ability to N, P and K, among them, the treatment of plastic film mulching was most obvious.6. Analysis showed that the effects of yield factors on yield from big to small was total grains per panicle, the grain number per spike,1000-grain weight. At full heading stage the second leaf’s photosynthetic rate effect the grain number per spike, at milk ripe stage flag leaf’s photosynthetic rate effect the 1000-grain weight. Humidity difference and temperature difference between air and canopy were important factor for photosynthetic rate at in late growth stage, among them temperature difference was direct effect, humidity difference was indirect effect. The humidity of canopy increased significantly when second leaf’s transpiration rate was improved. At the same time, transpiration promoted dry matter and SiO2 accumulation of spike, calcium transport to stems and leaf, it was dvantageous to high yield.更多还原