In the corn planted area of Yellow Huai Hai, introducing local resources. besides, choosing fine varieties, being suitable to broadcast time, the reasonable planting density, to adopt the measure of effective prevention natural disaster and the nimble harvest time is the guarantee of high-yield cord, and put forward the related proposal to existing problems.

在黄淮海玉米种植区域内，介绍了该区域自然资源特点。选用优良的品种、适宜的播期、合理的种植密度、采取有效的预防自然灾害的措施及灵活的收获时间，是获得玉米高产的保证，并对其存在的问题提出了相关的建议。

摘　要： 玉米已成为当前中国种植面积最大且总产量最高的第一大作物，发展玉米生产对保障国家粮食安全具有重要战略意义。全面阐述了改革开放以来中国玉米生产的发展历程及各发展阶段的生产特点，并重点从自然资源分布、农田基础设施、玉米品种与种子质量、栽培技术、生产经营方式、收储流通等方面深入分析了当前中国玉米生产存在的主要问题。在此基础上，从增加科研投入、加强基础设施建设、强化政策扶持、加强技术服务、加大高产创建力度和改善产后储运流通等方面提出了促进中国玉米进一步增产的政策建议，以及加强玉米新品种选育、抗旱节水、保护性耕作、提高播种质量和群体整齐度、机械化栽培和病虫草害防治等技术措施。

It is difficult to increase grain yield (above 15 tha -1 ) in irrigated plain of Inner Mongolia because of unclearness in exploring the productivity potential of high-yield spring maize colony. To solve this problem, we analyzed the yield components the yield performance parameters, and the effects of plant density on yield performance of different hybrids in split plot designs for 52 high yield maize colonies in four years,. The result showed that ear number and grain number per ear were the main factors affecting the yield of maize colony (above 15 tha -1 ). The yield components of high yield colonies (above 15 t ha -1 ) were as follows: 7.08×10 4 –9.60×10 4 ears per hectare, 477–654 grains per ear, 324.7–388.7 g per 1000-grains and 168.9–234.0 g per ear. The rational indexes for high yield maize colony (above 15 t ha -1 ) included the maximum LAI (leaf area index ) of above 6.5, the MLAI (mean of leaf area index) of about 5.0, and the LAI at harvest stage was above 3.5. However, different hybrid cultivars demonstrated different rational yield components: cultivars with high stalk and large ear (yield over 15 tha -1 ) should have 67 500–75 000 ears per hectare, 610–640 grains per ear, about 380 gram per 1000-grains, and 220–240 gram per ear; cultivars with medium or little ear on medium stalk (yield above 16.5 tha -1 ) should have 75 000–97 500 ears per hectare, 520–600 grains per ear, 340–355 gram per 1000-grains, and 180–220 gram per ear. Enhancing plant density increased yield by high MCGR (mean of crop growth rate) and TGN (total grain number), but the decline in net assimilation capacity per plant resulted in remarkable reduction of GN (grain number) and thus restricted TGN potential. Adjusting population structure by increasing plant density brought about high yield above 15 tha -1 , which results from the compensation of population yield gain for individual productivity loss. Individual productivity in structure-optimized colony should be improved to break the limit of individual sink, and synchronous improvement in colony structure and individual function is the important approach to further raise yield of spring maize.

针对内蒙古平原灌区春玉米 高产 (15 t hm -2 以上)群体产量进一步提高难度大，产量挖潜途径不明确的问题，采用产量构成因素分析与产量性能参数分析相互验证的方法，在4年52点 次高产 (15 t hm -2 以上)群体产量构成因素分析的基础上，设计不同品种密度试验，研究增密对不同品种群体产量性能的影响，明确不同类型玉米品种的增产途径和栽培调控的主攻方向。结果表明，穗数和穗粒数是决定高产(15 t hm -2 以上)群体产量的主要因素。实现 15 t hm -2 以上 群体的产量结构为：穗数(7.08~9.60)×10 4 穗，穗粒数477~654粒，千粒重324.7~388.7 g，穗粒重168.9~234.0 g。其合理群体结构衡量指标是LAI max 在6.5以上，平均LAI在5左右，收获期LAI在3.5以上。高秆大穗型品种理想的产量结构是：67 500~75 000穗 hm -2 ，每穗610~640粒，千粒重380 g左右，单穗粒重220~240 g，产量大于15 t hm -2 ；株高适中的中小穗型品种，理想产量结构是： 75 000~97 500穗 hm -2 ，每穗520~600粒，千粒重340~355 g，单穗粒重180~220 g，产量在16.5 t hm -2 以上。密度增加促进平均作物生长率(MCGR)和单位面积总籽粒数(TGN)的增加进而提高产量，但增密后平均净同化率(MNAR)降低导致穗粒数显著降低并限制了TGN的提高潜力。通过增密为主的结构性挖潜，使得群体功能的增益大于个体生产性能的降低，实现 高产 (15 t hm -2 以上)，属于“得失性补偿增产”；在优化群体结构的基础上，提高个体生产能力，突破个体库容降低的限制，进行功能性挖潜，实现群体结构和个体功能协同增益的“差异性补偿增产”，是产量进一步提高的重要途径。

The studies on main maize varieties used popularly from 50′s to 90′s in China showed tyat the canopy apparent photosynthesis rate (CAP)rose, percentage of declined CAP and the rate of respiration in total CAP reduced, with the renew of maize varieties. The CAP of middle-base leaves in modern maize

对50年代以来生产上大面积推广的主要玉米品种的研究表明： 随着玉米品种的更替， 群体光合速率增强， 群体光合衰减率降低， 呼吸消耗所占总光合的百分率下降。 灌浆期当代品种中、 下部叶片的群体光合速率明显高于老品种。 种植密度是影响玉米群体光合速率的主要因素， 在高、 中、 低三种密度条件下， 当代品种均有较高的

A field experiment was conducted to investigate the effect of plant growth regulator brassinolide (BR) on the regulation of physiological activities of ear leaf, the grain filling and yield in spring maize ( Zea mays L., cv. Zhengdan 958). Husks and ear leaves were treated with BR at 15 days after anthesis by foliar spraying. The results showed that the chlorophyll content, photosynthetic rate and activities of PEP carboxylaes, RuBP carboxylase, sucrose synthase and sucrose phosphate synthase in ear leaf as well as source content in kernel were significantly reduced, while starch accumulation and dry weight of kernel were increased during grain filling. BR significantly increased the content of chlorophyll and photosynthetic rate , enhanced the activities of PEP carboxylaes and RuBP carboxylase, definitely resulting in enhanced CO 2 assimilation. BR markedly increased the activities of sucrose synthase and sucrose phosphate synthase in ear leaf. And in kernel, the accumulation of sucrose and starch as well as the grain filling rate were accelerated by BR. BR treatment significantly reduced the length of ear barren tip, and increased the number of kernels per ear, which led to higher yield. These results suggest that BR treatment at filling stage may be a good strategy to get a high yield in maize, by enhancing activity of resource, delaying sencence and stimulating the ?ow of assimilate from the source to the sink.

以玉米品种“郑单 ”为材料，在大田条件下，采用植物生长调节物质油菜素内酯 ， 对苞叶和穗位叶喷施处理，研究了 对玉米穗位叶功能、籽粒灌浆及产量的调控作用。结果表明，灌浆期随生育进程，玉米穗位叶叶绿素含量、光合速率、磷酸烯醇式丙酮酸羧化酶 、 二磷酸核酮糖羧化酶 以及蔗糖磷酸合酶和蔗糖合酶的活性均显著下降。同时，籽粒蔗糖含量显著降低，但淀粉含量和粒重均显著增加。与对照相比， 处理显著增加玉米穗位叶叶绿素含量，提高光合速率，增强 、 、蔗糖磷酸合酶和蔗糖合酶的活性。 处理显著增加籽粒蔗糖和淀粉积累，提高玉米籽粒干物质积累。在产量构成上， 显著缩短秃尖长度，增加穗粒数和千粒重，显著提高产量。本研究说明，灌浆期喷施 可提高玉米叶源的活性，延长叶片光合功能持续期，促进籽粒灌浆和物质积累，从而实现增产。

摘　要： 【目的】阐明不同生态区及品种条件下玉米源库协调性、碳氮代谢的差异表现及其与产量的关系。【方法】在东北（吉林省农安）、京津唐（北京昌平）和黄淮海（河南省浚县）3个生态区各设一个试验点,以6个高产、稳产的优良品种为试验材料,在稀植条件下（密度45 000株/hm2）比较不同生态区和不同品种玉米的产量和产量构成、叶面积指数（LAI）和粒叶比、干物质和氮素分配转运、可溶性糖和C/N等指标。【结果】3个试验点的产量表现为农安〉浚县〉昌平;6个品种中产量最高的是先玉335,最低的是京单28,其它品种间差异不显著。在不同生态区和品种条件下,玉米产量与穗粒数的相关性明显大于千粒重;吐丝期最大LAI与产量的相关性不显著,而粒叶比则与产量成正相关;吐丝后干物质生产量与籽粒产量呈极显著正相关。低产生态条件下,茎鞘内富集了大量的可溶性糖,反映了源-库-流的不协调。在不同生态条件下,C/N与产量呈负相关。根据籽粒氮素的来源可将不同品种归为3类：（1）对后期吸氮（61.0%—68.4%）的依赖高于器官转运氮（39.7%—46.0%）;（2）后期吸氮量与器官转运氮量相当;（3）后期吸氮（42.5%—45.3%）低于器官转运氮（57.2%—61.7%）。【结论】适宜生态条件下,玉米源库关系更加协调,表现在粒叶比高、收获指数（包括氮素收获指数）大、灌浆期干物质积累量和氮素吸收量大、茎鞘可溶性糖含量适宜、C/N值相对较低。而粒叶比高、籽粒灌浆期干物质积累量和氮素吸收量大也是高产品种的重要特点。

Kernels at the upper position of a maize ear usually show slower filling rate and lower weight than those at the basal and middle positions. The mechanism is little understood. The objective of this study was to understand if changes in carbohydrate accumulation and activities of the enzymes involved in starch synthesis in the kernels at different positions on a maize ear were associated with grain filling. A maize cultivar Denghai 11 was planted in spring and summer. Contents of the soluble sugar, sucrose and starch and the activities of the adenosine diphosphoglucose pyrophosphorylase (AGPase), starch synthase (StS), and starch branching enzyme (SBE) in kernels at different positions on an ear and their relationships with grain filling rate were determined. The results showed that kernel number per ear, 100-kernel weight, and grain yield were more or higher for the spring maize than for the summer maize. Although the grain yield was different between the spring maize and the summer maize, the maximum kernel filling rate, mean kernel filling rate, 100-kernel weight, the contents of both soluble sugar and sucrose in kernels, the maximum starch accumulation rate and mean starch accumulation rate in kernels all exhibited an order of basal position > middle position> upper position. The activities of AGPase, StS and SBE in kernels at different positions on an ear showed the changes of single peak curves, and the peak and mean enzymatic activities in kernels at the upper position were significantly lower than those at both middle and basal positions. The starch accumulation rate and kernel filling rate were very significantly and positively correlated with activities of AGPase, StS and SBE in kernels. The results suggested that a smaller starch accumulation rate and lower weight for the kernels at the upper position on a maize ear are mainly attributed to lower activities of the enzymes involved in starch synthesis in these kernels. A higher kernel weight for the spring maize is closely associated with its stronger ability of starch synthesis in the kernels.

玉米果穗顶部籽粒通常较中、下部籽粒充实差，粒重轻，其机制不清楚。本研究旨在探明玉米果穗不同部位籽粒淀粉合成相关酶活性变化及其与籽粒灌浆的关系。以玉米品种登海11为材料，分别进行春播和夏播试验，观察果穗不同部位籽粒中可溶性糖、蔗糖和淀粉的含量及淀粉合成相关酶活性变化。结果显示，与夏播玉米相比，春播玉米具有较多的每穗粒数、较高的百粒重和产量。虽然产量在春播和夏播间有差异，但两季玉米籽粒的最大灌浆速率、平均灌浆速率、百粒重、可溶性糖和蔗糖含量、最大淀粉积累速率、平均淀粉积累速率均表现为果穗下部籽粒>中部籽粒>上部籽粒。灌浆期果穗不同部位籽粒腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)、淀粉合酶(StS)和淀粉分支酶(SBE)活性变化均呈单峰曲线，果穗上部籽粒AGPase、StS和SBE活性峰值和平均值均显著低于果穗中、下部籽粒。相关分析表明，淀粉积累速率、籽粒灌浆速率与AGPase、StS和SBE活性均呈极显著正相关。说明玉米果穗顶部籽粒较低的AGPase、StS 和SBE活性是其灌浆较差、粒重较低的重要原因。春播玉米粒重较高，与其灌浆期较强的淀粉合成能力有关。

以郑单958为对照,设置春播(5月14日)和夏播(6月13日)两个播期处理,研究玉米品种京单38在不同生态条件下的子粒灌浆特性。结果表明,京单38的百粒干物重高于对照品种郑单958,春、夏播条件下增幅分别为14.74%和20.26%,春播百粒干物重较夏播高1.87%。京单38的子粒灌浆速率高于郑单958,春、夏播最大灌浆速率分别较对照高42.27%和49.50%,夏播最大灌浆速率较春播高9.42%。相关和通径分析表明,最大灌浆速率与粒重呈极显著正相关,与郑单958相比,京单38子粒灌浆速率高且灌浆速度快,春、夏播条件下均可获得较高的粒重。

Located mainly in the dryland areas, the Loess Plateau is an important region for crop production with winter wheat (Triticum aestivum L.) as a major crop all over the lands. In cropping systems, winter wheat cultivars play an important role. For obtaining high and stable wheat yields in the region, it is of significance to select the most suitable variety of winter wheat for practical use and reveal the differences of dry matter accumulation and translocation of the winter wheat cultivars with various-yielding levels for understanding of their internal characteristics. For this purpose, a field experiment was conducted from 2008 to 2009 in a site where no fertilizer had been received for six years before the trial. Two factors were included in the experiment: wheat cultivars and fertilization. Nine wheat cultivars with different yield levels released and widely adopted in the region were utilized as testing materials and each was planted at three nitrogen and phosphate input rates with four replications. During plant growth period, plants were sampled at flowing and harvest stages and the total dry matter amounts and the dry matter accumulation pre- and post-anthesis were measured so that the differences of dry matter translocation, dry matter transported amount and rate, transferred efficiency as well as the contribution of the transferred dry matter to grains could be evaluated for those winter wheat cultivars. In addition, the leaf area, SPAD value and photosynthetic rate were also determined at some stages for further illustrating the yield-forming traits. The leaf area was measured at booting stage by LI-3000A leaf area instrument, the SPAD at both booting and grain filling stages by SPAD device, and photosynthetic rate at grain filling stage by LI-6400 portable photosynthetic instrument.The results showed that dry matter, dry matter accumulation during pre-anthesis and post-anthesis, dry matter transferred efficiency and the contribution of transported dry matter to grain yield were significantly different for different winter wheat cultivars. Compared to the control without fertilization, the total accumulation productions of the high, middle and low yielding cultivars were 29%, 22% and 6% increased for the low fertilizer input treatment, and 46%, 39% and 23% for the high fertilizer input treatment, respectively. With the increase of fertilizer rate, the dry matter accumulation in the post-anthesis was increased for the different yielding cultivars whereas, the dry matter translocation, transferred efficiency and the contribution of the transferred dry matter to grain yield were decreased. At the grain filling stage, the SPAD value of their functional leaves or flag leaves of high, middle and low yielding cultivars was 20.7, 17.5 and 13.7 for the low fertilizer input treatment, while 35, 26.1 and 16.8 for the high fertilizer input treatment, respectively. The photosynthetic rate of high yielding cultivars (Xinong 88) was 6.0 μmolCO 2 ·m -2 ·s -1 whereas the average photosynthetic rates of middle and low yielding cultivars were 4.3 and 4.0 μmolCO 2 ·m -2 ·s -1 , respectively. The high-yielding variety was characterized with high levels of total dry matter production and also with high dry matter accumulation after anthesis. The high dry matter increase after anthesis might be related with the high SPAD value and high photosynthetic rate of the functional leaves during the grain filling stage. In summary, the higher level of SPAD value, photosynthetic rate and dry matter accumulation after anthesis was one important reason for wheat cultivars with high grain yields on drylands of the Loess Plateau. Therefore, selecting qualified wheat cultivars, adopting adequate cropping measures as general, and especially maintaining a high dry matter accumulation during post-anthesis through the regulation of nutrient management could be regarded as the essential ways for further improvement of winter wheat yield production in the area.

旱地小麦高产栽培中品种起着重要作用,研究不同产量水平旱地冬小麦品种干物质累积和转移的差异,对黄土高原旱区作物高产稳产有重要意义。以9个旱地冬小麦品种为材料,通过田间试验研究了不同产量水平旱地冬小麦品种的生物量、花前花后干物质累积量、干物质转移量、转移率及转移干物质对籽粒的贡献率、叶面积、SPAD值以及光合速率的差异。结果表明,不同小麦品种的生物量、花前花后干物质累积量、干物质转移量、转移率及转移干物质对籽粒的贡献率均存在明显差异。与不施肥相比,高、中、低3个产量水平小麦品种在低养分投入时,成熟期生物量分别提高29%,22%和6%,高水平时分别提高46%,39%和23%,高产品种的生物量及其对养分投入的敏感程度明显高于低产品种。不同品种的花后干物质累积量随养分投入水平提高而增加,但花前营养器官中储存物质的转移量、转移率和对籽粒的贡献率却明显随之下降。功能叶(旗叶)在灌浆期高、中、低3个产量水平品种的SPAD值在低养分投入条件下分别为20.7、17.5和13.7;高养分投入时,分别为35、26.1和16.8。高产品种西农88的光合速率为6.0 μmolCO 2 ·m -2 ·s -1 ),中产和低产品种的平均光合速率分别为4.3 μmolCO 2 ·m -2 ·s -1 和4.0 μmolCO 2 ·m -2 ·s -1 ,高产品种功能叶(旗叶)在灌浆期能保持较高的SPAD值和光合速率,因而花后能生产较多的干物质,但其花前干物质转移量、转移率及转移干物质对籽粒的贡献率均没有明显优势。可见,花后较高的叶绿素水平、光合速率和干物质累积是旱地小麦品种高产的重要原因。选择优良品种,采取合理的栽培措施, 特别是通过养分调控保持花后具较高的干物质累积量是西北旱地进一步提高冬小麦产量的重要途径。

选用3个具有高产潜力的玉米杂交种京单28、登海601与陕单8806,采用75 000株/hm~2的密度大田种植,测量不同生育期的叶面积与各器官的干物质积累量.结果表明:3个高产玉米杂交种京单28、登海601与陕单8806产量均可达到11 200 kg/hm~2以上,成熟时叶面积系数均在3.5以上,花后干物质再分配分别占籽粒产量的15.25%、14.67%和10.72%,是籽粒增产的主要来源.高产玉米品种的保绿性较好,叶片衰老缓慢,光合功能期长,花后干物质转移对籽粒增产的贡献较大,在高产栽培调控中如何促进花后干物质向籽粒的转移是进一步获得高产的重要途径. Abstract： This experiment selected three maize cultivars( JD28、SD8806、DH601) which had high yield potential, planted them at 75 000 plants/ hm~2 randomly in the farmlands. Measured dry matter of different organs, leaf area index at different growth stages. The results showed that the yield of JD28、SD8806 and DH601 achieved 11 200 kg/hm~2 above; LAI maintained 3.5 at mature stage; The contribution rate of dry matte distribution from organs to grains were 15.25%、14.67% and 10.72% respectively. Dry matte distribution was the main source of the increased part of the grain yield. The leaves of high-yielding maize varieties were good at keeping green, so leaf senescence was slow and the photosynthetic period was long, and the dry matter distributions played a big role in production increasing of high-yielding maize varieties,so one of the important measures to obtain the high yield was to promote the dry matter distribution rate in the high yield-planting process.

【Objective】It is very important to study photosynthesis of super high-yielding maize hybrids, so a field trail was conducted to research the relation to photosynthetic traits and yield of over-15000 kg ha-1 summer maize hybrids during grain filling period. 【Method】Three summer maize hybrids (XY335, DH3632 and DH3806) were planted at 78000 plants ha-1 in National Corn Project Technology Research Center (Shandong) randomly. Above-ground biomass partitioning and photosynthetic characteristics of ear leaves were investigated to evaluate yield formation of three super high-yielding maize hybrids during grain filling period.【Result】Yields of three-type maize hybrids were over 15000 kg ha-1, and yield of XY335 was higher than that of DH3632 and DH3806 significantly (P＜0.05). Characteristic of grain filling analyzed by Richards equation showed XY335 had the higher grain-filling rate, the longer active growing period, and it reached the maximum grain-filling rate earlier than DH3632 and DH3806. The result indicated grain-filling traits like XY335 was favorable to high yield in the experiment. The leaves’ photosynthetic physiology quantity of XY335 was highest of the three-type hybrids. XY335 had high net photosynthetic rate (Pn), PEPCase activity, RuBPCase activity and chlorophyll a/b value after anthesis, and the leaf area index (LAI) and soluble protein content decreased slowly from 20d and 30d after flowering, respectively. 【Conclusion】To obtain 15000 kg ha-1 of super high-yielding breeding and cultivation in practice, we need to improve the leaves photosynthetic physiology quantity to maintain high grain-filling rate and long active growing period after anthesis, enhance the solar energy use efficiency.

【目的】探讨产量15 000 kgha-1以上夏玉米籽粒灌浆期的光合特性及其与产量形成的关系。【方法】在多年高产试验基础上，选用3个具有高产潜力的玉米杂交种，采用78 000株/ha的密度大田种植。以地上生物量及其分配、果穗叶的光合特征参数来评价产量15 000 kgha-1以上的夏玉米光合生理活性；以Richards模型拟合籽粒灌浆过程。【结果】3个玉米杂交种均可实现15 000 kgha-1以上的高产，以先玉335（XY335）产量最高。对籽粒产量形成的Richards解析表明，籽粒灌浆启动快且高灌浆速率持续时间和生长活跃期（50 d以上）长的杂交种更容易实现高产。产量15 000 kgha-1以上3个杂交种表现出灌浆前期净光合速率、PEPCase活性和RuBPCase活性较高，后期净光合速率、叶面积指数和可溶性蛋白含量下降缓慢的特点，整个灌浆期间叶绿素a/b比值始终较高。3个杂交种中XY 335叶片光合生理活性最高，净光合速率和叶面积的高值持续期分别达50 d和60 d以上。【结论】在玉米高产高密度栽培条件下，重视叶片的光合生理活性的改善可提高光能利用效率，维持较高灌浆速率和较长活跃生长期，实现15 000 kgha-1以上的高产目标。