【作者】 张喜娟；

【导师】 徐正进；

【作者基本信息】 沈阳农业大学 ， 作物栽培学与耕作学， 2009， 博士

【摘要】 实现水稻超高产对保障我国粮食安全有重要作用,超高产水稻的生理特性和遗传基础是实现水稻超高产的理论依据。沈农265和沈农6014是沈阳农业大学水稻研究所培育出来的直立穗型超高产水稻品种,它们推动了粳型超高产水稻育种研究的深入和超高产水稻品种种植面积的扩大。本文从多方面研究了超高产水稻沈农265和沈农6014的生理特性及沈农265的遗传基础。研究内容包括:1)以辽粳294和辽粳371为对照,研究了超高产水稻沈农265和沈农6014的产量性状、光合特性、维管束性状和籽粒灌浆充实特性;2)以12个不同穗颈弯曲度的北方粳稻品种为试材,研究了直立穗型与弯曲穗型水稻抗倒伏能力的差异,沈农265和沈农6014为直立穗型试材;3)利用沈农265/丽江新团黑谷的176株F₂群体,对超高产水稻沈农265的产量、穗部、穗颈维管束以及抗倒伏性状进行了QTL分析。研究结果如下:1沈农265和沈农6014产量水平高。沈农265比对照辽粳294和辽粳371分别增产7.96%和14.16%,沈农6014比对照分别增产9.50%和15.80%。从产量构成因素分析,沈农265和沈农6014通过适当降低单位面积穗数和千粒重、大幅度地提高穗粒数及保持较高的结实率来获得高产。从穗部性状特点来看,沈农265和沈农6014的穗长中等、穗着粒密度大、一二次枝梗数及粒数多、一二次枝梗着粒密度大且结实率较高、一二次枝梗千粒重较小、穗型指数较大。从穗部性状与产量及产量相关性状的相关分析来看,穗着粒密度和一二次枝梗着粒密度大、一二次枝梗数和粒数多、一次枝梗结实率高是两超高产水稻品种获得高产的重要因素,这些特点可以作为北方水稻育种的重要参考指标。2沈农265和沈农6014光合生产和光合产物转运能力强是其获得高产的生理基础。它们的光合特点有:1)叶面积指数相对较小,但上三叶叶面积所占比例较高,上三叶叶长适中,但叶宽和比叶重较大,空间配置较好;2)剑叶叶绿素含量高、叶绿素a/b的值低,剑叶衰老缓慢,适应环境变化的能力强,在弱光及低CO₂浓度下有较强的同化能力,光合“午休现象”较轻,耐光氧化能力强,叶片净光合速率高;3)分蘖成穗率高,光合产物浪费少,整个生育期干物质积累量优势不大,但齐穗后干物质积累优势明显,经济系数高,光合产物分配到穗部的量多,茎鞘中储藏物质转运率较高。3沈农265和沈农6014维管束性状和籽粒灌浆充实特点有:剑叶、穗颈和穗下部一二次枝梗维管束系统发达,说明两超高产水稻品种光合产物运输系统比较发达;由于穗粒数多,尽管光合生产和光合产物转运能力强、维管束系统发达,沈农265和沈农6014籽粒的灌浆起始势、最大灌浆速率、平均灌浆速率和达最大灌浆速率时间等灌浆特性并没有优势,而各粒位和穗位籽粒仍表现了较高的结实率和充实度。相关分析表明:改善剑叶、穗颈和枝梗维管束性状,不仅利于增加穗粒数和形成大穗,还能使各粒位和穗位的结实率、充实率提高,说明穗粒数与结实率和充实率间的矛盾,可以通过改进维管束系统来协调;由剑叶、穗颈和枝梗维管束性状改善所引起的穗粒数增多、灌浆速率降低及灌浆期延长,可以通过提高枝梗小维管束韧皮部面积占维管束面积的比例来解决。此外,剑叶、穗颈及枝梗维管束性状间存在着一定的正相关,剑叶和穗颈维管束性状对枝梗维管束性状改善有促进作用,作用大小表现为:穗下部＞穗中部＞穗上部,提高穗颈小维管束韧皮部所占比例有利于提高枝梗小维管束韧皮部所占比例。4直立穗型粳稻穗下第1节间（N₁）、第2节间（N₂）、第3节间（N₃）和第4节间（N₄）的弯曲力矩与弯曲穗型品种差异不显著,但N₁、N₂、N₃的抗折力却显著提高,从而使N₁、N₂、N₃的倒伏指数显著或极显著低于弯曲穗型粳稻,说明其中上部节间抗倒能力明显增强。进一步分析直立穗型与弯曲穗型粳稻茎杆解剖结构、化学成分以及它们与茎杆抗折力的相关性发现,直立穗型粳稻N₁、N₂、N₃抗折力强的主要原因是:（1）茎壁厚度和茎壁面积增大,节间抗折的物理性状明显提高;（2）大小维管束数目多,大小维管束、韧皮部、木质部面积增大,节间内部组织的结构明显改善:（3）纤维素含量高,支持细胞壁结构的物质含量多。茎壁厚度、茎壁面积、维管束性状及纤维素含量可以作为选育抗倒伏品种的主要参考指标。就北方粳稻而言,培育直立穗型品种,更容易获得抗倒性强的品种。5对沈农265/丽江新团黑谷的F₂群体的产量、穗部和穗颈维管束以及抗倒伏性状进行了QTL分析。1)共检测到17个控制产量相关性状的QTL,分布在6条染色体上,其贡献率差异较大,在12%～65%之间,其中有4个QTL的贡献率超过25%,分别是控制穗长的qPL9、每穗颖花数的qSPP4-1、着粒密度qSD9和结实率的qRG12。2)共检测到37个控制穗部和穗颈维管束性状的QTL,它们分布在水稻的第1、2、3、4、5、6、7、8、9和12号染色体上,单个QTL对性状表型贡献率在11%～65%之间,其中大于20%的有15个。这些QTL分别位于第3、4、6、9和12号染色体上,以6个QTL簇（QCR）的形式存在。说明紧密连锁或成簇分布是穗颈维管束性状和穗部性状高度相关的遗传学基础之一。3)共检测到18个控制基部第二节间机械强度及其相关性状的QTL。其中控制基部第二节间抗折力的QTL检测到4个,位于第4、7、9和10号染色体上,可解释遗传变异的12%～23%,其正效等位基因均来自沈农265。在第4染色体上的相同区间上还同时检测到了控制茎粗、茎壁厚度、单个大维管束面积、单个大维管束木质部面积、单个小维管束面积和单个小维管束木质部面积的QTL,贡献率在12%～21%之间。在第7染色体与控制基部第二节间抗折力的QTL相同的位置上,检测到控制茎粗的QTL,贡献率为13%,说明这两个位点是控制基部第二节间机械强度的重要区域,也是茎壁性状、维管束性状与机械强度高度正相关的遗传学基础。更多还原

【Abstract】 The realization of super-high-yielding of rice has a great significance for food security of China.The physiology characteristics and genetics basis of super-high-yield rice is its theoretical basis.Shennong 265 and Shennong 6014,developed by Rice Research Institute of Shenyang Agricultural University,are erect panicle type Japonica super-high-yield rice varieties.These two rice varieties promoted the in-depth research in breeding of Japonica super-high-yield rice and the expansion of cultivated area of Japonica super-high-yield rice. The physiology characteristics of Shennong 265 and Shennong 6014 and the genetics basis of Shennong 265 were studied from various aspects in this PhD thesis.The research contents were as follows:1)The characteristics of yield,photosynthetic,vascular bundle and grain-filling of Shennong 265 and Shennong 6014 were studied by using Liaojing 294 and Laojing 371 as check varieties;2)The lodging resistance of erect panicle type rice（EPT）and curved panicle type rice（CPT）were studied by using 12 japonica rice cultivars as materials, Shennong 265 and Shennong 6014 were used as samples of erect panicle type among them;3) QTLs controlling yield traits,panicle characteristics,panicle base vascular bundle traits and lodging resistance traits were detected in 176 F2 population derived from a cross between super japonica rice Shennong265 and japonica rice Lijiangxintuanheigu.The major results were as follows:1 The yield of Shennong 265 was 7.96%and 14.16%higher than that of Liaojing 294 and Liaojing 371 respectively.The yield of Shennong 6014 was 9.50%and 15.80%higher than that of Liaojing 294 and Liaojing 371 respectively.Yield components analysis demonstrated that Shennong 265 and Shennong 6014 achieving high yield through increasing spikelet number per panicles and seed setting rate,but decreasing effective panicle number and 1000-grain weight moderately.The panicle characteristics of Shennong 265and Shennong 6014 can be summarized as follows:medium panicle length,higher spikelets density,a larger number of primary（PB）and secondary branches（SB）and grains on primary and secondary branches,higher seed setting rate of PB and SB,less 1000-grain weight of PB and SB,and bigger panicle trait index.The correlation coefficient between panicle traits,yield and its components showed that the important factor of these two varieties in high-yield can be summarized as:higher spikelets density of PB and SB,a larger number of PB and SB and grains on PB and SB,and higher seed setting rate of PB.The high-yield characters of Shennong 265 and Shennong 6014 can be used as an important reference for Northern rice breeding. 2 The photosynthetic capacity and photosynthate transport capacity of Shennong 265 and Shennong 6014 were better than those of Liaojing 294 and Liaojing 371.These characters were the physiological basis for these two varieties to achieve high yield.Compared with Liaojing 294 and Liaojing 371,the photosynthetic capacity and photosynthate transport capacity of Shennong 265 and Shennong 6014 can be summed up as follows,1)they had a little lower in the leaf area index（LAI）,but much higher percentage of efficient LAI,and they had moderate length and larger width and specific leaf weight of top 3 leaves.2)The chlorophyll content and the Ch1 a/b value in flag leaves of Shennong 265 and Shennong 6014 were higher and decreased slowly after heading,and its had stronger ability to adapt to the environment;Shennong 265 and Shennong 6014 had an ability of keeping high level photosynthesis and Pn under high or low light intensity,high temperature and low CO₂ concentration,and its also had stronger light oxidation ability.3)Percentage of productive panicle of Shennong 265 and Shennong 6014 was higher,so that it’s had less photosynthate waste;Shennong 265 and Shennong 6014 had higher photosynthetic productivity and dry matter accumulation superiority and harvest index,and it also had high export amount and transformation of the mater in stems and sheathes.3 The vascular bundles traits and grain-filling characteristics of Shennong 265 and Shennong 6014 were investigated and summarized as follow,their vascular bundles trait of flag leaf and neck-panicle and primary and secondary branches on the lower panicle were better than that of check varieties,which indicated that these two super-high-yield rice had efficient transporting system in photosynthetic products;Although Shennong 265 and Shennong 6014 had stronger photosynthetic capacity and photosynthate transport capacity, but its also had more spikelets per panicles,so that they did not have advantage in grain-filling characteristics,but they still had higher seed setting rate and filled-grain percentage on different panicle part eventually.Correlation analysis showed that improving on vascular bundle traits of flag leaf,panicle neck and branches was not only beneficial to got an increase in the number of spikelets per spike but also beneficial to got an improving on seed setting rate and filled-grain percentage on different parts of panicle.Correlation analysis also indicated that improvement of the ratio of total phloem area of small vascular bundle （SVB）to total area of SVB of branches was beneficial to ameliorate grain-filling characteristics.Besides,there is a positive correlation between flag leaf,panicle neck and branches on vascular bundle traits.Improving on vascular bundle traits of flag leaf and panicle neck was beneficial to improving on vascular bundle traits of branches on panicle,the positive correlation was in order of lower panicle＞middle panicle＞upper panicle.Improving on the ratio of total phloem area of small vascular bundle（SVB）to total area of SVB of panicle neck will help to improve the ratio of branches.4 There was no significant difference in bending moment of the 1st,2nd,3rd and 4th internodes between erect panicle type rice and curved panicle type rice（CPT）.But EPT had greater breaking resistance of the 1st,2nd and 3rd internode than CPT.So that the lodging index of the 1st,2nd and 3rd internode of EPT was lower than that of CPT.The correlations between the breaking resistance of culm and its morphological traits,anatomical features, chemical components were further studied.There were many reasons for the breaking resistance of 1st,2nd and 3rd internode of EPT increased.Firstly,EPT had thicker culm wall and larger culm wall area than CPT.Secondly,the mummer of vascular bundles,the area of vascular bundles,the area of phloem and the area of xylem of EPT were lager than those of CPT.Thirdly,EPT had higher cellulose content in comparison with CPT.TO select lodging resistant cultivars,one should consider these characterized includeing thicker culm wall, larger culm wall area and better vascular bundle characters with high cellulose content in their stems.In northern of China,breeding erect-panicle cultivars would be an effective way to improve lodging resistance of japonica rice5 QTLs for yield,panicle and panicle base vascular bundle characteristics and lodging resistance related characteristics were identified by using a population of an F₂ population derived from a cross between japonica rice Shennong265 and Lijiangxintuanheigu.1)A total of 17 QTLs for yield traits which distributed on 6 chromosomes.The variances explained by each QTL from 12%⁶5%.There were 4 QTL explaining more than 25%of total phenotypic variation individually,which were qPL9 conferring PL,SPP4-1 conferring SPP,qSD9 conferring SD and qRG12 conferring RG.2)A total of 37 QTLs controlling 24 panicle and panicle base vascular bundle characteristics were detected,which distributed on chromosome 1,2,3,4,5,6,7,8,9 and 12.The phenotypic variations explained by individual QTL were ranged from 11.0%to 65.0%,among which 15 QTLs explained VE by more than 20%.These QTLs showed cluster forms on chromosome 3,4,6,9 and 12.All the information suggests that the closed linkage between genes and phenotypes and clusters of QTLs in genome highlight the correlation of panicle and panicle vascular bundle characteristics,as the important genetic basis.3)A total of 18 QTLs for 14 traits were detected for basal second internodes’ culm mechanical strength and related traits,including 4 for the breaking resistance of the basal second internode on chromosome 4,7,9,and 10.The variances explained by each QTL from 12%²3%.For all loci,the Shennong265 alleles increased Culm’s breaking resistance.The QTLs controlled Stem diameter,Wall thickness,Area of large vascular bundle,Xylem areas of large vascular bundle,Area of small vascular bundle and Xylem areas of small vascular bundle characteristics were detected on the same area on chromosome 4.The phenotypic variations explained by individual QTL were ranged from 12%～21%.The QTLs controlled Stem diameter and QTLs controlled the breaking resistance of the basal second internode were detected on the same area on chromosome 7.The qSD7 explained about 13%of the total phenotypic variation in the F₂ population.All the information suggests that these QTLs are important for the breaking resistance of the basal second internode,and as the important genetic basis of the positive correlation of culm,vascular bundle and stem strength characteristics.更多还原