【作者】 杨世民；

【导师】 马均；

【作者基本信息】 四川农业大学 ， 作物栽培学与耕作学， 2011， 博士

【摘要】 试验于2006至2009年在生态条件差异较大的四个生态点进行,生态点分别是温江、雅安、汉源、西昌,海拔高度分别约为530m、550m、1055m、1500m,在杂交水稻生育期间和生殖生长关键时期,各生态点的温度、光照和降水条件差异明显。试验主要从杂交水稻的形态学变化、功能与代谢变化、激素含量和蛋白表达差异、物质生产能力和产量等多个方面对杂交水稻的适应性及其机理进行了研究,试验由以下三个部分组成：第一部分是杂交水稻生态适应性的研究,于2006年进行,比较研究了18个杂交水稻品种在温江、汉源、西昌三个生态点的生态适应性,并进行综合评价,从中筛选综合适应能力和对光照的适应能力有差异的品种进行下一年的试验；第二部分是两类生态条件下不同类型杂交水稻始穗期的遮光试验,于2007年分别在温江和进行,研究了弱光胁迫下3种同类型的6个杂交水稻品种在两类生态条件下的适应性和适应机理；第三部分为不同类型水稻秧田期遮光试验,于2009年在雅安四川农业大学农场进行,研究了在2007年研究基础上确定的不同类型的4个杂交水稻品种的适应性和适应机理。主要研究结果如下：1.在不同生态条件下,杂交水稻齐穗期的单株叶面积和剑叶面积差异极显著,杂交水稻的叶面积调节能力较强；杂交水稻的叶绿素含量、叶绿素a/b比值、类胡萝卜素含量、光合速率差异显著,杂交水稻品种在汉源生态点能形成优良的光合性能；杂交水稻可以通过合成叶绿素和类胡萝卜素、降低叶绿素a/b比值、防止叶绿素被强光氧化等生理变化,增强生态适应能力,尤其是对强光或弱光的适应能力,不同生态环境的不同光照刺激,可使杂交水稻启动不同的适应方式。不同生态条件下杂交水稻的干物质积累、茎鞘物质输出率、产量构成因素和产量也差异显著,其中对产量影响较大的因素是单株干重、结实率、千粒重。对所有15项测试指标进行主成分分析表明,与杂交水稻生态适应性关系密切的指标有：光合速率、相对电导率、剑叶面积、有效穗、单株叶面积、叶绿素含量、光氧化率、单株干重、产量、输出率、类胡萝卜素含量,说明在试验生态环境下,应重点改善杂交水稻的光合性能和增强抗逆性,才能达到提高产量的目的。2.不同品种的光合速率、电导率、千粒重、单株干物质重、光氧化率、输出率等有明显的差异,不同的杂交水稻品种可能有共同的生态适应方式,也各自有不同的特殊生态适应方式,改变叶面积是杂交水稻的共同适应方式,特殊的适应方式有：增加叶绿素、叶绿素b和类胡萝卜素含量、降低光氧化率、减少叶片的物质输出、增强抗逆性。采用主成分分析对各品种的生态适应性进行了综合评价,将18个品种分为广适品种、普适品种、特适品种三种类型,生态适应性较强的品种有：壹丰8号、红优2009、D优7511、金优188、川江优3号、C优725、汕优63、Ⅱ优363、冈优725、协优93083.在杂交水稻始穗期遮光(遮光率约85%),在两生态点均表现一致的结果是：杂交水稻可以通过增加叶绿素含量和叶绿素a/b比值,来抵御弱光对光合作用的影响,维持光合速率的相对稳定；遮光使叶绿素光氧化率有增加的趋势,遮光是以促进叶绿素合成而非阻止其分解的方式来增加叶绿素含量的,尤其使其合成更多的叶绿素b。遮光对水稻上三叶和单株叶面积无显著影响,但能增加剑叶着生角度,显著减少倒3叶的鲜重。遮光可以改变杂交水稻的有机物质分配规律,尽管遮光提高了茎鞘物质的输出率和转换率,但却因减少了叶片有机物质的输出,导致杂交水稻的结实率和千粒重的显著降低,产量也大幅降低,说明杂交水稻始穗期以后的光合生产能力对产量形成具有重要作用。总体而言,遮光对不同抗逆特性品种的形态特征、光合生理特性、抗逆性、物质生产与运输分配和产量构成因素及其构成因素的影响不同。广适性品种壹丰8号和红优2009、耐荫品种倍丰3号和冈优527,在弱光下能保持光合特性、生物膜结构、SOD酶活性、物质生产与分配特性、产量形成能力的稳定,甚至可以启动弱光抵御机制,如改变剑叶着生角度、增强SOD活性、增加叶绿素b含量、减少叶片有机物质输出、甚至大幅降低产量来维持叶片正常的生理功能和生长。4.在秧田期对杂交水稻进行不同程度的遮光(遮光67%和86%)处理,显著影响不同耐荫性品种秧苗的分蘖数,随着弱光胁迫强度的增大,分蘖数呈显著降低趋势；适当的遮光强度能促进耐荫性水稻品种秧苗增高、叶面积增大,过度遮光使秧苗苗高及叶面积显著降低。耐荫性强的品种在高强度遮光条件下,可溶性糖含量及C/N比呈明显升高,随着遮荫强度的增加叶绿素a、b和叶绿素总量均呈不同程度的增加趋势,叶绿素b增幅高于叶绿素a,使Chl a/b比值降低,而耐荫性较弱的品种则无这样的变化趋势。秧田期遮光可以诱导抗逆激素ABA增加,对生长促进类玉米素(ZT)和赤霉素(GA)含量的影响,则因品种不同有差异。遮光可诱导杂交水稻在分子量为33kD左右的位置产生新的蛋白质谱带,耐荫性较强的品种倍丰3号在蛋白谱e(26-33kD)的表达明显增强于其它品种。耐荫性较强的品种相对电导率变幅较小,MDA含量增大的比例也相对较小,SOD酶活性随遮光强度的增加增幅加大,但脯氨酸(Pro)含量变化显著。5.作者根据本研究结果和前人的相关研究,对杂交水稻生态适应性的概念和评价体系进行了新的考量,初步提出：杂交水稻的生态适应性评价至少应该考虑生存需要的适应性和生产需要的适应性两个重要方面。在评价指标中,应重点选择针对性强的指标,回避一些具有共同性和瞬时变化的生理指标；应进行多年多点试验；还应采用合理的生物统计方法,对试验结果进行综合评定。更多还原

【Abstract】 The experiment was carried out from 2006 to 2009 year, in quite different conditions of the four ecological sites. The altitude is approximately 530m,550m, 1055m and 1500m. During the critical period in the growth and reproductive growth of hybrid rice, there are significant differences of temperature, light and precipitation. In this paper, we conducted some studies on the adaptability and mechanism of hybrid rice such as morphological changes, function and metabolism, hormone levels and the differences of protein expression, matter production and yield. The study consisted of three parts, the first part was the ecological adaptability of hybrid rice. In 2006, we comparative studied on the ecological adaptability of the 18 hybrid rice varieties in Wenjiang, Hanyuan and Xichang. Meanwhile, we conducted a comprehensive evaluation and screened some varieties which had differences on the comprehensive adaptive capacity and ability to adapt to light for the next year trial. The second part was the shading test at initial stage of panicle emerging of hybrid rice varieties in two different types of ecological conditions. In 2007, we studied the adaptability and adaptation mechanism in the two types of ecological prerequisites of 6 hybrid rice varieties under low light stress at Wenjiang and Hanyuan. The third part was the shading test about different types seedling rice, in 2009, Yaan, the farm of Sichuan Agricultural University. Based on the study in 2007, we investigated the adaptability and adaptation mechanism of 4 hybrid rice varieties which had different types. The main results were following.1. In the different ecological conditions, there were significantly differences in leaf area and flag leaf area of hybrid rice full heading stage, hybrid rice had a strong ability for regulating leaf area; there were significantly differences in chlorophyll content, ratio of chlorophyll a/b, carotenoid content and photosynthetic rate of hybrid rice, hybrid rice varieties could form an excellent photosynthetic performance in Hanyuan ecological site; hybrid rice could reduce some physiological hanges such as synthesizing chlorophyll and carotenoid, reducing chlorophyll a/b ratio for increasing the capacity of ecological adaptation, especially it could increase the adaptability about glare and low light. Because of different light stimuli in different ecological environments, hybrid rice could start to adapt in different ways. In the different ecological conditions, there were significantly differences in dry matter accumulation, output rate of stem and sheath, yield components and yield of hybrid rice, the factors which had greater impact on yield were dry weight per plant, seed setting rate and thousand-grain weight. The 15 indicators of principal component analysis showed that the indexes which had larger contribution on ecological adaptability of hybrid rice were photosynthetic rate, relative conductivity, flag area, leaf area per plant, dry weight per plant, effective panicle, chlorophyll content, photo-oxidation rate, carotenoid content, grain yield and output rate, these phenomena showed that we should focus on improving photosynthetic performance and enhancing resistance of hybrid rice for increasing production in the test environment.2. The photosynthetic rate, conductivity, thousand-grain weight dry matter weight, photo-oxidation rate, output rate of different hybrid rice was different distinctly. Different varieties of hybrid rice might have a common way of ecological adaptation, also might have their own different special way of ecological adaptation. such as the common way:changing the leaf area of hybrid rice, the special way: increasing the chlorophyll, chlorophyll b and carotenoid content, reducing photo-oxidation rate, decreasing the material output of leaf and enhance stress resistance. The 18 varieties of hybrid rice was divided into wide suitable varieties, pervasive varieties, especially suitable varieties using comprehensive evaluation method of principal component analysis. The varieties of ecological adaptability strongly were Yifeng8, Hongyou2009, Dyou7511, Jinyou188, Chuanjiangyou3, Cyou725, Xianyou63,Ⅱyou363, Gangyou725 and Xieyou9308.3. Hybrid rice showed the same result by shading (about 85%) in initial heading stage in two ecological sites. Hybrid rice could resist the effects of low light on photosynthesis and maintain the relative stability of photosynthetic rate by adding more chlorophyll content and chlorophyll a/b ratio. Chlorophyll photo-oxidation rate tended to increase by shading, shading was promoting the chlorophyll synthetic rather than stopping the decomposition to increase the chlorophyll content, especially chlorophyll b. Shading on rice could increase the angle of flag leaf and reduce the fresh weight of upper 3 leaves significantly, but had no significant effect on trilobites and leaf area. Shading on hybrid rice could change its distribution rule of organic matter, although increase transformation rate and export rate of the matter in stem-sheath, but reduce the leaf decomposition of organic material, which lead to reduction of the seed-setting percentage and thousand-grain weight significantly and production was greatly reduced, and it showed that Photosynthetic capability after initial heading stage of hybrid rice was important to yield formation. Overall, the effect of shading on the morphological characteristics, characteristics of photosynthetic characteristics, resistant, material production and transport distribution yield and its formation factors of different varieties of resistance were different. In low light, Wide adaptability varieties of yifeng8 and hongyou2009, low light resistance varieties of beifeng3 and gangyou527 could keep stable of the photosynthetic characteristics, bio-membrane structure, SOD activity, material production and distribution characteristics and the ability of yield formation, they could even start against mechanism of low light, such as changing the flag leaf Angle, enhancing SOD activity, increasing the chlorophyll b content, reducing the organic material output and even dramatically reducing production to maintain normal physiological function and leaves growth. Low light intolerance varieties of gangyou527 could not keep stable.4. The different degree of shading (about 67% and 86%) on hybrid rice in seeding period could significantly influenced tiller number of different varieties of Low light resistance. Tiller number tended to reduce significantly along with the increase of low light stress. The result shows that proper degree of shading on hybrid rice in seeding period could increase the plant height and the leaf area, but excessive degree of shading could significantly decrease the plant height and the leaf area of low light resistance. The high degree of shading is good for improving the content of soluble sugar and the ratio of C and N on the strong varieties of low light resistance. The degree of shading is good for improving the chlorophyll a, b and content of chlorophyll on the strong varieties of low light resistance, the content of chlorophyll b more than chlorophyll a, the ratio of chlorophyll a and chlorophyll b decreased. The shading treatment is good for improving the content of ABA, ZT and GA in nursery period, the result shows that different degree of effecting on different varieties. The shading treatment could produce new protein spectral bands on 33 kD position of hybrid rice, the protein spectral bands e (26-33kD) expressed the strongest variety is 3 number of Bei-Feng on the strong varieties of low light resistance. The result shows that increasing degree of shading can improve the active of SOD on the strong varieties of low light resistance.5. The author according to the test results combine with other research results suggested that:Ecological adaptability evaluation should consider the adaptability of survival and the adaptability of production; Evaluation index should choose important indexes or exclude intercommunity and instantaneous of physiological indexes; Comprehensive evaluation should use suitable the method of statistical analysis for all indexes of test result of years.更多还原