【作者】 吴文革；

【导师】 张洪程； 戴其根；

【作者基本信息】 扬州大学 ， 作物栽培学与耕作学， 2011， 博士

【摘要】 本研究以最新认定的超级杂交中籼稻品种为试验材料,一般产量的杂交中籼稻为对照,布点于江苏、安徽两省的不同生态区,研究超级稻的产量潜力、库容特征以及形态生理特性,在此基础上探索超高产栽培途径,旨在阐明超级稻超高产形成规律及其生理、形态基础,揭示超高产本质,提出超高产栽培途径,并明确进一步高产的调控方向,以期为超级稻育种与超高产栽培提供理论依据与实践指导。主要结果如下：1、超级稻最大库容可达870kg/667m2以上,实际产量可达750kg/667m2以上。超级稻群体颖花量增加直接导致产量的提升,超高产对应的群体颖花量为3500×104/667m2左右；穗、粒共同作用促进了群体颖花量的扩增,但对于不同产量等级,两者的贡献是不同的,从中产→高产,靠穗数和粒数的协同贡献(穗数的贡献率为47%、粒数为53%),从高产→超高产,主要依赖于穗型增大(粒数的贡献率78.8%,穗数为21.1%)。培育大穗是通过两种途径协调实现的：一是增加一次枝梗数及其上的平均着粒数；二是增加二次枝梗数并稳定二次枝梗上的平均着粒数,以后者为主。超级稻具有极强的颖花形成能力,同时还具有充实度高的优势,并集中体现在单穗重上(超级稻单穗重≥4.0g,比对照增加10.9%)。大穗和单穗重高是超级稻库容构成特点。2、超级稻干物质生长与积累具有明显优势,产量随成熟期物质积累量的增加而提高(r=0.886*,r0.05=0.811),而收获指数相对稳定在0.50-0.55的范围。超级稻的物质生长优势始于拔节期,并随生育进程而逐渐增强,开花以后群体生长率(CGR)明显提高,使得花后的干物质积累极显著提高;超级稻中后期群体叶面积指数(LAI)下降慢,显著提高了群体光合势(LAD)；超级稻的叶面积指数(LAI)及群体光合势(LAD)的提高促进群体生长率(CGR)的显著提高,大田期平均群体生长率(CGR)比对照高出302.8g m-2·d-1。3、超级稻剑叶硝酸还原酶活性(NR)高,具有明显的N素吸收利用的优势,大田期N素吸收积累总量较对照增加11.3%。超级稻N素吸收利用优势始于拔节期,并随着生育进程而扩大,抽穗以后吸收N素能力显著高于对照,穗后25d以后仍具有一定的吸收能力(24g N·667m-2·d-1)。超级稻拔节～孕穗阶段对N吸收速率最强,平均为245.3gN·667m-2·d-1。花后吸收利用N素能力增强,提高了花后功能叶的含N率,减缓了叶面积的衰减,延长了的叶片光合功能期和高值持续期。适应超级稻后期氮代谢活跃、吸收量大的这种特性,超高产栽培更应注意增加其后期的N素供应。4、超级稻孕穗期群体最大叶面积指数达7.5—8.0,比对照提高3.4%,而且花后叶面积衰减慢,比较优势扩大,灌浆中期和成熟期分别比对照提高13.8%和16.9%。抽穗后功能叶光合色素含量提高,这可能与超级稻后期N吸收能力较强有关；整个灌浆期叶绿素Chla+b的含量均高于对照,而且Chla/b的值在灌浆早期明显低于对照,这是超级稻光合生理的一个明显特征指标。生育后期超级稻叶片超氧化物歧化酶(SOD)活性较高,清除氧自由基能力增强,减缓了叶片表面有害物质(MDA)的积累而延缓了叶片早衰。功能叶后期的净光合效率(Pn)有所提高,因而超级稻生育后期的叶源量(LSC)显著提高,群体光合生产能力也得以显著提高。5、超级稻具有与生理特性相协调的形态特征—理想的株形、优化的冠层结构及强劲稳健的支撑系(1)超级稻具有较为理想的株型剑叶适中短偏、倒2叶、倒3叶加长,功能叶叶长排列有序,宽而内卷,上三叶叶基角和披垂角小；叶干重和比叶重也明显提高,保证了叶形和叶姿的稳定；叶片形态指标随时间后移而与对照的比较优势扩大；良好的株型提高群体内部叶层透光率,降低了群体消光系数。据此提出了超级稻更高产的理性株型指标。(2)超级稻的冠层结构优化超级稻单茎最大叶面积达330—350cm2(比对照高出10%),其中高效叶面积占70%：基部叶片因为株型的改善,寿命延长,光合功能期增加26.6%。叶面积和干重均高于对照,花后下降平缓,与对照的比较优势随着时间而扩大,灌浆中后期比叶重(SLW)提高。茎秆基部节间短、而穗下节长,株高适度增加,为群体生物学产量的提高奠定形态基础,并优化了叶系配置。鞘包茎度高、鞘壁增厚,增粗了茎秆,且比较优势随时间的后移而扩大。明确了超级稻更高产的冠层形态指标。(3)超级稻具有结构与功能相协调的稳健支撑系抽穗期以后超级稻鞘和茎的干重均明显高于对照；花前储藏在茎、鞘中的干物质在灌浆过程中的输出以鞘为主,茎较稳定,鞘和茎的表观输出率分别为44.9%和14.3%,同比对照降低6个和5个百分点；但鞘输出量的绝对量超级稻高于对照。超级稻鞘和茎的充实度高,基部节间的充实度显著高于对照,且随着时间的后移比较优势加大；鞘的充实度高,有利于其上叶系面积和光合功能的稳定,也增强了包茎壮秆作用,是支撑系一个更为重要的构件。灌浆后期鞘的充实度及包茎度可以作为更高产超级稻选择的形态依据之一。稳健的支撑系既增强了承重、抗倒伏能力,又有利于后期光合功能的稳定提高,是超级稻最重要的形态生理特征。6、比较分析了不同栽培模式对产量形成及群体质量的影响,提出了“补偿”途径,并系统分析了补偿途径的栽培原理及增产机理。(1)通过基本苗和氮肥试验,探明了超级稻超高产的适宜群体起点结构为稀植适苗、适宜施氮量为17.5kg/667m2；通过途径试验并经示范验证,比较不同栽培途径对超级稻产量形成及群体质量的影响,提出了补偿超高产栽培途径。(2)阐述了补偿途径的栽培原理,揭示了补偿途径的增产机理,明确了“补偿”的核心意义在于“提高后期功能—补偿花后群体光合势”。对第三期超级稻(目标产量900kg/667m2)的产量构成、形态生理基础以及更高产的途径进行了讨论。更多还原

【Abstract】 This research take middle-season indica super hybrid rice of new determination as experiment materials, and general yield level of middle-season hybrid rice as control, studied on the yield potential, characteristics of storage capacity, physiological and morphological characteristics in Anhui and Jiangsu province, further exploration of approaches for more higher grain yield, aimed at elucidating the physiological and morphological basis of formation regularity of super high-yielding, revealing the approaches for super high-yielding, discussing the regulating directions for more higher yield, provide theoretical basis for super rice breeding and super-high-yielding cultivation, and the results showed that:1. The gross storage capacity of super hybrid rice is above870kg/667m2,and the actual yield could reach over750kg/667m2.The higher number of population spikelets was a major and direct factor resulting in higher yield, and its corresponding population spikelets is about3500×104/667m2; Combined action of panicle and grain lead to increasing of population spikelets, however, the contribution of this two characters were different in different stage. From middle yield to high yield, panicles and grain numbers contribution were47%and53%, respectively, while, from high yield to super high yield is benefit from larger panicles based on enough panicle number, and the contribution of grain number and panicle number were78.8%and21.1%, respectively. The large panicle was constructed by means of two ways:the first increased the number of primary branches(PB) and its number of grain-setting per PB. The other, the number of secondary branch(SB) was enhanced based on the stable number of grain-setting per SB, in which, the increment of number of SB and total number of grain-setting per plant was a key measure. Super hybrid rice have higher spikelets forming ability, meanwhile, higher glumness is superiority, the centralized reflection is higher single panicle weight; The single panicle weight could be over4.0g,10.9%higher than control; Large panicle and higher single panicle weight are structure peculiarities of storage capacity of super hybrid rice.2. Super hybrid rice have significant superiority of dry matter accumulation, grain yield increased with increase of dry matter accumulation at maturity stage(r=0.886*, r0.05=0.811), while the range of harvest index is about0.5-0.55. Super hybrid rice have higher dry matter accumulation after jointing stage, and the growth rate(CGR) is increasing with the plant growth. After flowering stage, significant higher dry matter accumulated because of higher CGR than control. At the middle and later growth stage, leaf area index(LAI) decreased slowly, which lead to significant higher population leaf area duration(LAD). With the increasing of LAI and LAD, CGR increased significantly, the CGR is302.8g m-2·d-1higher than control in field period.3. Super hybrid rice had high activity of nitrate reductase(NR) and obvious advantages of nitrogen accumulation and utilization, the total amount of nitrogen absorption and accumulation was11.3%more than control. The advantages of nitrogen absorption and utilization of super hybrid rice started from jointing stage and enlarged with growing process, the nitrogen absorption ability of super hybrid rice after heading stage was significantly higher than control, after heading for25d, the rice plant still had certain ability of nitrogen absorption (24g N-667m-2·d-1). Super hybrid rice had the strongest nitrogen absorption efficiency (average at245.3g N·667m-2·d-1) during jointing-booting stage, which was significantly higher than control. The strong ability of nitrogen absorption and utilization after flowering stage increased the N content in functional leaves, slowed down the descending rate of leaf area and prolonged the photosynthetic function duration and high value duration of leaves. In order adapt to the characteristics of nitrogen active metabolism and large absorption amount in later growth stage of super hybrid rice, nitrogen supply should be increased in later stage for super-high-yielding cultivation.4. At booting stage, maximum population leaf area index could reach7.5-8.0, which increased3.4%than control, and the decrease of leaf area after flowering stage slowed down, increased the comparative advantages, at middle grain filling stage and maturity stage, the super hybrid rice had13.8%and16.9%higher LAI than control, respectively. The higher ability of nitrogen absorption is the possible reason of increasing of photosynthetic pigment content (PPC) in function leaf at the later growth stage. During grain filling stage, the content of chla+b is higher than control, and the ratio of chla/b is lower than control at early filling stage, this is a remarkable physiological characteristic of photosynthesis. At the later growth stage, super hybrid rice leaf had higher activities of superoxide dismutase, improved ability of scavenging oxygen free radicals in later stage, which decreased the content of malondialdehyde (MDA) and slowed down leaf presenility, improved the net photosynthetic rate of functional leaves in later stage, and the leaf source capacity increased significantly, so as to significantly improved the ability of photosynthetic production.5. Super hybrid rice had coordinated development of morphological characteristics and physiological characteristics:comparatively ideal plant type, optimized canopy structure, strong and stable supporting system.(1) Super hybrid rice has comparatively ideal plant type:flag leaf has moderate length or little short, longer length of top2nd and3rd leaf, orderly arrangement of function leaves, wide and involution, small basic angle and drooping angle of top three leaves; Dry matter weight of leaves and specific leaf weight is higher significantly, ensure the steady of leaf shape and leaf position; With the plant growth, compared with control, comparative superiority of morphological index is increasing. Good plant type could improve transmittance and decrease extinction coefficient of population. On the basis of above results, ideotype index for more higher grain yield was proposed.(2) Super hybrid rice has optimized canopy structure:the maximum leaf area index could reach330-350cm2per single-stem(10%higher than control), and70%of it is high effective leaf area; Photosynthetic function duration of bottom leaves is26.6%longer than control which caused by improved plant type; Leaf area and dry matter weight are all higher than control, and deceased gently, comparative superiority is increased with plant growth, special leaf weight increased at middle grain filling stage. Shorter basal internode, longer rachis internode, and little higher plant height are the morphological foundation of biological yield, and optimized the leaves structure and position; Higher leaf sheath phimosis degree, and thick wall of leaf sheath are the reasons of stem grow sturdily, and the degree increasing with plant growth; Make sure the index of canopy structure and morphological characteristics for more higher grain yield. (3) Super hybrid rice has strong supporting system:dry matter weight of leaf sheath and stem are higher than control significantly, at grain filling stage, the dry matter which stored in leaf sheath before flowering stage are transformed more than stored in stems, apparent export percentage of leaf sheath and stem are44.9%and14.3%, respectively, and6%and5%decreased than control. However, absolute amount of output from leaf sheath of super hybrid rice is higher than control. Meanwhile, the filling degree of basic internodes is higher than CK significantly, and the degree is increasing with plant growth, especially higher filling degree in leaf sheath is benefit to stabilized leaf area and photosynthetic function, it’s a more important factor for supporting system. The filling and sheath phimosis degree of leaf sheath at the later grain filling stage could as the morphological index for more higher grain yield. Stabilized supporting system enhance the bearing ability and resistance to fracture, and it’s benefit to improve the photosynthetic function at the later growth stage, that’s the most important characteristics of super hybrid rice.6. It compares and analyzes the effect on yield formation and population quality of super hybrid rice in different cultivation patterns, and summarizes the approaches of compensated cultivation for super high yield, and analyzed cultivation principle and yield-increasing mechanism.(1) The suitable beginning population structure confirmed by experiments of seedlings and nitrogen management are follows:sparse planting and proper seedling number and the appropriate N level is17.5kg/667m2; By experiment demonstration and verification, the effects on yield formation and population quality in different cultivation patterns was compared, and bring compensated cultivation for super high yield.(2) It explained cultivation principle of compensated cultivation, revealed yield-increasing mechanism and expounded the core meaning of this approach is to compensate the population leaf area duration, improve the population function after flowering stage.Based on the3rd target yield(900kg/667m2) of super hybrid rice, yield components, physiological and morphological basis, and regulation approaches for getting more higher yield were discussed.更多还原