【作者】 张馨文；

【导师】 李雁鸣；

【作者基本信息】 河北农业大学 ， 作物栽培学与耕作学， 2007， 硕士

【摘要】 为挖掘超高产冬小麦群、个体光合生产潜力，进而提高产量，在节水栽培及每公顷9吨左右的超高产条件下，对冬小麦全生育期叶片的光合速率、叶面积、叶面积持续期等光合性能的变化动态及物质生产特性进行了系统的研究。主要研究结果如下：1．超高产小麦冬前各个叶片的光合速率，均在叶片全部展开时达到最大，然后随着叶片衰老及温度降低逐渐下降。在春生叶片中，倒2叶、倒3叶的光合速率在孕穗期，旗叶在开花后20天达到最高值。不同部位叶片光合速率相比较，开花期以后，四个品种均以旗叶光合速率最高，倒2和倒3叶次之，倒4和倒5叶最低。越到后期，这种差距越大。这表明，超高产小麦光合速率最大值出现时间后延，即后期光合速率较高，有利于灌浆盛期光合产物的生产和向籽粒的转移，并提高其本身的平均光合速率，提高整体的光合性能。2．超高产小麦不同叶位间比较，冬前的各个叶片的最高光合速率随叶位的提高而降低，叶片功能期亦随叶位提高而缩短，光合面积以第3叶最大，综合光合性能表现最好的叶位也为第3叶。春季光合能力表现最强的叶位为倒2叶和旗叶，开花后以顶三叶的光合速率高、功能期长，尤以旗叶最为明显。3．超高产小麦单株光合性能在全生育期的变化表现为：单株叶面积在起身期后均逐渐提高，至孕穗期达到高峰，之后逐渐下降。单株全部叶面积的平均光合速率则是起身、拔节期较高，之后稳定一个时期即开始下降，下降幅度不大。说明在影响作物单株干物质生产或单株光合速率的因素中，单株叶面积起着重要作用，且超高产小麦叶面积高峰出现时间略晚，单株光合速率高峰期出现也相应较晚，利于单株后期产量形成过程中光合产物的生产。4．超高产小麦的最大LAI在7～8之间，且高效LAI持续时间长，衰降速度慢，开花后10天仍能维持在4.5以上。各个阶段光合势较大，春后总光合势在290万m^-2·d^-1·hm^-2以上，且花后光合势大于88万m^-2·d^-1·hm^-2，为花后光合产物的制造打下了基础。全生育期的总干物质积累量高达19000 kg·hm^-2以上。花后干物质总量占的比例大，尤其是石新828和石麦12占1／3左右。达到超高产(9000kg·hm^-2以上)的小麦品种的经济系数为0.44～0.48。可见，在保证总茎数的基础上，维持花后绿色叶片面积，防止叶片早衰，进而增强单株及群体光合性能，提高总干物质积累量和花后比例，提高经济系数，应是小麦超高产的核心。更多还原

【Abstract】 In order to exploit the photosynthetic potentiality of super high-yield winterwheat, and then improve grain yield, a study was conducted in the fields of winterwheat with a grain yield about 9 t/ha for four varieties under limited irrigation. Thedynamics of net photosynthetic rate (P_n) of leaves, leaf area, leaf area duration anddry matter production were measured during winter wheat growing period. The mainresults were summarized as follows.1. The net photosynthetic rate (P_n)of all pre-winter leaves on the main stem ofwheat reached the maximum values when the leaves were fully expanded, thendecreased gradually with leaf senescence and the decrease of temperature. Forspring-growing leaves, the P_n of the second and the third leaves from top reached thehighest values at booting stage, and the P_n of flag leaf reached the maximum at 20days after anthesis. Comparison on the P_n among different leaves of all the fourvarieties tested after anthesis showed that, the P_n of flag leaf was the highest, thenthose of the second and third leaves from top, with those of the fourth and fitch leavesfrom top the lowest. And the differences of P_n among the different leaves obovebecame more significant during late growing period. These results showed that, themaximum values of P_n appeared later in super high-yield winter wheat, and that wasbenificial to dry matter production during grain filllig and the transportation ofassimilates to grains, then improve the average photosynthetic rate and totalphotosynthetic performance.2. Comparion of photosynthetic performance among different leaves in superhigh-yield winter wheat showed that, the highest photosynthetic rate decreased, andthe leaf area duration shortened with the leaf position from base to top before winter.The area of the third pre-winter leaf was the biggest, and the general photosyntheticperformance of the third leaf was also the best. During the growth period after winteruntil maturity, the general photosynthetic performance of the second leaf from top andflag leaf was the best. After anthesis, the top three leaves, especially flag leaf, hadhigher P_n and longer photosynthetic duration than other leaves.3. The changes of photosynthetic performance for individual plants of super high-yield winter wheat were that, the leaf area per plant increased gradually after"getting-up stage" (about double ridge stage of the spike differenciation), and reachedthe maximum values at booting stage, then decreased. The average photosyntheticrate for a plant was higher at getting-up and jointing stages, and kept the higher valuefor a longer period, then decreased. The leaf area per plant played a more importantrole in photosynthetic production per plant comparing with other components such asthe average P_n. The maximum values of leaf area for super high-yield wheat appearedlater, and then the maximum values of photosynthesis per plant were also later, whichwas beneficial to the dry matter production during late stage of grain yield formation.4. The maximum leaf area index (LAI) of super high-yield wheat was 7～8, andthe duration with higher LAI was longer and decreased slower. The LAI maintainedmore than 4.5 at 10 days after anthesis. Loaf area duration (LAD) was larger at eachstage, the total leaf area duration was more than 2.9×10~6 m~2·d/ha, and attained 8.8×10~5 m~2·d/ha after anthesis, provided the basis for assimilation after anthesis. Totalamount of dry matter accumulation of super high-yield wheat reached 19000 kg/ha,and the percentage of biomass after anthesis was high, especially the two varieties,Shixin 828 and Shimai 12, counted about 1/3. The harvest indices of the varietiesreached super high-yield (yielded≥9000 kg/ha) were 0.44～0.48. The results aboveshowed that, on the basis of enough total culms (main stems and tillers) per hectare,the basic practices of supper high-yield was to keep larger leaf area and prevent leavesfrom early-senescence after anthesis, improve the photosynthetic performance onplant and crop levels, increase population dry matter accumulation after anthesis, andimprove harvest index.更多还原