There have been a lot of studies onthe differences and variations in lodging resistance among different rice varieties, but few studies involving the combined effects of nitrogen rate and transplanting density on lodging resistance of a certain hybrid varieties at different planting areas. In order to study the relationship between lodging resistance and physical and chemical characteristics of rice culm and the effects of nitrogen rate and transplanting density on the physical and chemical c haracteristics and lodging resistance of hybrid rice culm, a split plot field experiment was conducted w ith h ybrid rice Jinyou 527 at Ya’an which altitude is about 600 m and Xichang which altitude is about 1 600 m . The experimental results were as follows. With the increasing of nitrogen rate and transplanting density, the plant height and length of basal internodes increased, the diameter of stem and the wall thickness of culm reduced, and the culm phenotype index decreased. High nitrogen rate and planting density lowered the contents of starch, cellulose and lignin of culm. The contents of N, K, Si, Ca, Mg, Fe, Zn, Cu, and Mn of culm were also influenced by nitrogen rate and transplanting density. As a result, high nitrogen rate and transplanting density reduced the breaking strength and lodging resistance of rice culm. The lodging index positively correlated to plant height g ravity center height, length of basal internodes and contents of N and Mg, and negatively correlated to diameter of stem, wall thickness of culm, ratio of weight to length of stem, culm phenotype index, contents of K, Ca and starch, cellulose, lignin of culm. However, the relationship between lodging index and Si content of culm was quadratic function. The optimum Si content for high lodging resistance of rice culm was 4.5 – 4.8 mg kg -1 . There were some differences in lodging resistance and sensitivities to nitrogen rate and transplanting density between Ya’an and Xichang, so the suitable techniques for high yield and high lodging resistance of culm should depend on the planting area. It was found that the critical lodging index for hybrid rice Jinyou 527 was 200.

以杂交稻金优 527 为材料，分别在中低海拔地区雅安 ( 600 m ) 和高海拔地区西昌 ( 1 590 m ) 进行了以氮肥水平为主区，栽插密度为副区的田间裂区试验。结果表明 , 随施氮量和栽插密度的增加，茎秆基部节间变细长，茎壁变薄，秆型指数降低 ， 茎鞘中淀粉、纤维素、木质素含量降低，充实度变差； 氮肥水平和栽插密度还影响茎秆中氮、钾、硅、钙、镁、铁、锌、铜、锰等矿质元素的含量，从而影响茎秆的倒伏指数和抗倒伏能力 。 水稻基部茎秆的倒伏指数与株高、重心高度和基部各伸长节间的长度及氮、镁含量正相关，与茎粗、茎壁厚、比茎重、秆型指数及淀粉、纤维素、木质素和钾、钙含量负相关，与茎秆硅含量呈二次函数关系，适宜的硅含量为 4.5 ~ 4.8 mg kg -1 。 由于生态条件不同， 两试点 水稻 茎秆 抗倒能力和受氮肥水平与栽插密度影响的程度存在一定差异，高产、抗倒栽培要因地制宜。金优 527 基部节间的临界倒伏指数为 200 。

摘　要： 以杂交稻金优527为材料,研究施氮量和栽插密度与水稻植株抗倒能力的关系。结果表明：随施 氮量或栽插密度的增加,金优527的倒伏指数均增大,抗倒伏能力下降。穗后21d是金优527易倒伏时期。在高肥高密水平下基部节间秆长,壁薄,横切面积 小而易倒伏。倒伏指数200可作为金优527的临界倒伏指数。

The material characteristics of 7 varieties with different lodging-resistance at 2 nitrogen levels and 2 planting thickness were determined.The results showed that there were great differences in breaking moment value M among varieties. M value of all new

对7个抗倒伏性有差异的水稻品种在2个施肥水平、2种栽培密度条件下，测定了茎秆的材料学特性。结果表明。品种间的基节折断弯矩M差异很大，新育成高产品种的基节折断弯矩均高于对照品种辽粳5号，原因是构成茎秆材料数量的增加。低氮处理使茎秆材质强度BS增加；稀植导致构成茎秆材料的数量增加。不同品种的茎秆材料学特性对稀植的反应存在明显差异。

The mechanic characteristics of 6 varieties with different lodging-resistance at 3 nitrogen levels and 3 planting densities were determined．The results showed that in the same density, as the amount of nitrogen increased, bending stress, plant height, the basal internode moment are gradually increasing; but the Lodging index reduced at first, and then increased, that is, in middling fertility area, the smallest lodging index ,the least possibility of lodging. At the same level of nitrogen, as the planting density decreased, the basal internode moment, secontion modulus and lodging index increased after the first reduced, bending stress increased and then decreased, while breaking moment has increased significantly. That is, in the appropriate level of fertilization, planting should not be too thin nor too dense. In high fertility area planted thinly and in low fertility area planted densely, which may reduce the lodging index. Sparse conditions, the changes of the basal internode moment only depend on the number of stem materials to be achieved; in dense-planting conditions, the changes of the basal internode breaking moment are through the changes of section modulus and bending stress two factors together to be acheieved. In the actual production, the amount of nitrogen can neither too high nor too low, further more, different types of species, require different volume of nitrogen and planting density. The improvement of the quality stem of existing high-yield varieties may be an effective means of further improved lodging -resistance of rice.

以6个抗倒伏性有一定差异的中籼稻品种为材料，设置了3个氮肥水平、3个栽插密度，分别测定了各处理下的茎秆力学特性，分析了氮肥用量和栽插密度对水稻茎秆力学特性的影响。结果表明：在同等密度下，随着施氮量的增加，弯曲应力，株高，基节弯矩，都逐渐增大；而倒伏指数先降低再升高，即中肥区倒伏指数最小，倒伏的可能性最小。在同一施氮水平下，随着栽插密度的减小，基节弯矩，断面模数和倒伏指数先减小后增大，弯曲应力先增大后减小，而折断弯矩却明显增高。即在适宜的施肥水平下，栽插不宜过稀也不宜过密。高肥水平下稀植，低肥水平下密植，都有可能降低倒伏指数。稀植条件下，基节折断弯矩的变化单靠构成茎秆材料的数量来实现；密植条件下，基节折断弯矩的变化是通过断面模数和弯曲应力两因素共同实现的。实际生产中，施氮量既不能过高，也不能过低，而且不同类型的品种，对施氮量和栽插密度的要求有所不同。改进现有高产品种茎秆的质地可能是进一步提高水稻抗倒性的有效途径。

黑龙江农垦水稻高产攻关出现了小面积折合稻谷产量超过14.7t/hm2的高产典型.从品种、土壤、栽培技术和气候条件等方面,采取与其它地区高产典型对比的方法,分析了寒地气候条件下出现这种高产典型的原因.分析了产量构成各项指标的特点及高产攻关研究的现实意义.指出综合栽培技术应该是高产攻关研究的要点.提高我国水稻单产,不仅要重视生产技术创新,还要重视生产机制创新.黑龙江农垦总局大面积水稻获得高产经验值得深入总结.

Two cold region japonica  rice varieties Longjing 20 (more tillers and curved panicle type, MCP) and Longjing 21 (few tillers and halferect panicle type, FEP) were used as materials to study the effect of rowspacing on canopy structure, morphological  traits and yield. The  productive tiller percentage reduced first and then increased as rowspacing widened   and followed  a quadratic regression. Leaf area index (LAI) at later tillering stage and the  highest stem number per unit area  followed a quadratic regression,  increasing first and then reducing. The effect of rowspacing on primary rachis  branch was larger than on  secondary  rachis branch    in Longjing 20 and the trend of Longjing 21 was reverse. The rowspacing showed a negative correlation with seed setting rates  of secondary  rachis branch and  panicle.  The correlation between rowspacing and yields of Longjing 20 and Longjing 21 was positive  and significantly negative, respectively. The morphological  traits of MCP were more easily affected by rowspacing and the rowspacing showed positive   correlation with flag leaf length, flag leaf width,  the 1st internode length from the top, the 2nd internode length from the top  and panicle length. Otherwise，the  morphological  traits of FEP were not significantly affected by rowspacing. The wide rowspacing was propitious to accumulate dry matter of panicle, stem and leaf and to form yield in MCP (the best rowspacing of Longjing 20 was 30 cm), the narrow rowspacing was suit to Longjing 21 which has few tillers and half erect panicle (the best rowspacing of Longjing 21 was 21 cm). It was suggested that wide rowspacing was benefitial  to improving population environment of MCP and narrow rowspacing   was favorable to increase space  utilization of FEP.

以寒地粳稻龙粳20(多蘖弯穗型)和龙粳21(少蘖半直立穗型)为试材，研究了行距对两个不同类型水稻品种冠层结构、形态和产量的影响。结果表明，行距与两种类型水稻成穗率呈先降后升的二次回归关系，与分蘖末期叶面积指数和单位面积最大茎蘖数呈先升后降的二次回归关系。行距对龙粳20一次枝梗的影响大于二次枝梗，而龙粳21则相反；行距与参试品种的二次枝梗结实率和穗结实率均呈负相关，其中与龙粳20二次枝梗结实率呈极显著负相关。行距与龙粳20产量呈正相关，但相关不显著，与龙粳21的产量呈极显著负相关。多蘖弯穗型品种的株型性状更易受到行距的影响，其中行距与龙粳20的剑叶长、剑叶宽、倒1节间长、倒2节间长和穗长均呈显著或极显著正相关，而与龙粳21的各株型性状相关均不显著。较宽行距有利于多蘖弯穗型品种穗、茎、叶干物质积累和产量的形成，龙粳20的最佳行距处理为30 cm，而少蘖半直立穗型品种龙粳21，窄行距更佳，最佳行距为21 cm。分析认为宽行距移栽有利于改善多蘖弯穗型品种的群体生态环境，窄行距有利于提高少蘖半直立穗型品种的空间利用。

[目的]研究氮肥总量及氮肥配置对寒地水稻产量及产量构成因素的 影响.[方法]采用多元二次旋转回归正交组合设计试验,研究3个施肥时期的氮肥用量、调节氮肥施用时间及穴距对粳稻垦鉴稻10号产量及产量构成因素的影 响.[结果]施氮总量与产量间存在最适值(纯氮126 kg/hm2左右),后期粒肥用氮比率与产量之间也同样存在最适值(即纯氮10 kg/hm2左右).[结论]在一定范围内增大施氮总量可提高单位面积穗数和穗粒数,而提高产量方面,氮肥配置对产量的影响较大,在总氮量一定条件下,在 一定限度内,增加前期用氮比率可通过提高穗数获得高产,同时降低中期穗肥用氮比率也可提高水稻产量.

To investigate the effects of dosage of nitrogen (N) fertilizer at early stage (ES), middle stage (MS) and late stage (LS), of application time of the regulating fertilizer (RF) and of row space (RS) on the source-sink relationship of the conventional japonica rice variety Kengjiandao10, the field experiment with multiple factors quadratic rotational-regressive-orthogonal combination design was conducted in cold area of China. The results showed that the amount of N-fertilizer applied at early stage had significant positive correlation with the maximum leaf area index (LAImax) and with the spikelets per unit area; the application time of RF had negative correlation with fertile glume numbers per unit area; and the RS had a quadratic curve relationship with LAImax and with the fertile glume numbers per unit area. It can be concluded that fertile glume numbers could be improved by increasing the amount of N-fertilizer at early stage or by interaction between N-fertilizer application and other cultivation measures (N-fertilizer amount at ES being 140 kg/hm2, N-fertilizer amount at MS and LS being 0 kg/hm2, RF being applied at 6.7 leaf stage, RS being 12 cm), thus improve the rice yield.

采用多元二次旋转回归正交组合设计试验，研究3个施期(基肥和蘖肥、穗肥、粒肥)的氮肥用量、调节肥施用时间及穴距等5个因素对粳稻垦鉴稻10号源库关系的影响。结果表明，基肥和蘖肥用氮量与最大叶面积指数及单位面积结实颖花数呈显著正相关；调节肥施用时间与单位面积结实颖花数呈负相关；穴距与最大叶面积指数及单位面积结实颖花数呈极显著二次曲线关系。说明通过适当加大前期用氮量或协调前期用氮量与种植密度等栽培措施的互作，可在适当范围内(即基、蘖肥用氮量达到140 kg/hm2，穗肥，粒肥用氮量为0 kg/hm2, 调节肥施用时期6.7叶，穴距12 cm)提高群体结实颖花数并最终提高产量。

摘　要： 为探明寒地水稻肥密因子对水稻分蘖及产量的影响,采用多元二次旋转回归正交组合方法,研究粳 稻垦鉴稻10号在不同时期的施氮量、调节肥施用时期及穴距对其分蘖及产量的影响.结果表明：对分蘖状况影响最大的因子是前期氮肥用量,其次是穴距和调节肥 施用时期,再者是前期用氮量与其他因子的互作;与此同时,对分蘖状况各因子与产量的相关分析表明,有效蘖率〉蘖穗率〉最高蘖数〉有效蘖率与群体成穗率互 作〉最高茎数与群体成穗率互作.因此,根据生产实际,尤其在低温地凉年份,适当加大前期氮肥用量并配合适当的密度以及其他农艺措施促使分蘖早生快发是提高 寒地水稻产量的有效途径.

2009年早、晚季以常规超级稻桂农占为试验材料，研究不同插植密度和栽插苗数对产量、产量构成和植株抗倒力的影响。结果表明，（1）栽插密度对晚季水稻产量具有极显著的影响，高密度有利于高产，但对早季水稻产量的影响不显著；插植苗数对早、晚季的产量影响较小，未达显著水平。（2）栽插密度对单位面积的有效穗数、每穗总粒数、每穗实粒数和群体颖花量影响较大，对结实率和千粒重影响较小；插植苗数对单位面积的有效穗数、每穗总粒数、每穗实粒数影响较大，对群体颖花量、结实率和千粒重影响较小。（3）丛、株抗倒力随插植密度的增大和插植苗数的增多而下降。综上所述，对于常规超级稻品种桂农占在高肥力稻田、适宜的施N量和合理的N肥运畴条件下，早季插植密度以24万丛/hm2、每丛插3苗，晚季插植密度以30万丛/hm2、每丛插4苗，能较好兼顾高产、高效和有效防止倒伏。

In order to identify the suitable planting density and high-yielding charcteristices of mechanically transplanted pot seedlings of rice (PS) with different panicle types, and clarify the effect of planting density on plant type and loding resitance, a field experiment was conducted using rice cultivar with three panicle types in 2012 and 2013. By setting high, medium and low planting density treatments and using mechanically transplanted carpet seedling as control (CK), we investigated yield and its components, panicle traits, canopy leaf system configuration, physical properties of culm and lodging resistance. Resluts showed as follows: (1) With decreasing planting density, yield of three density treatments in the large panicle cultivar increased firstly and then reduced which was higher than that of CK;,and yield of three density treatments reduced progressively for the medium and small panicle cultivar. With decreasing planting density, number of panicles in all cultivars reduced significantly, and spikelets per panicle increased markedly, but there was no significant difference in grain-filled percentage and 1000-grain weight. (2) With decreasing planting density, in all cultivars with PS, panicle length, grain density, grain weight per panicle, No. of primary branch, No. of secondary branch, No. of grains of primary branch and No. of grains of secondary branch showed a tendency of increase, and were higher than those in CK, but it showed a decreasing tendency in ratio of No. of primary branch to No. of secondary branch and ratio of No. of grains of primary branch to No. of grains of secondary branch. (3) Leaf length, leaf width, leaf basal angle, drooping angle of top three leaves and specific leaf weight from flag leaf to the 3rd leaf in all cultivars with PS were enhanced with decreasing planting density, and were higher than those in CK except for leaf basal angle and drooping angle. (4) With decreasing planting density, length of basal 1st, 2nd, and 3rd internodes were shortened, and culm diameter, culm wall thickness, dry matter weight per unit internode of basal inernodes, neck internode length, stalk length, plant height and gravity center height were increased. (5) The breaking resistance and bending moment of basal 1st, 2nd and 3rd internodes were increased with decreasing planting density, but lodging index was decreased. Therefore, for increasing yield with PS, the large panicle cultivar should reduce planting density appropriately, and increase grain number per panicle; the medium panicle cultivar should coordinate number of panicles and spikelets per panicle, getting a large amount of the total spikelets; the small panicle cultivar should depend on number of panicles. When the plant density reduced in PS, panicle traits and top three leaves area could be improved, but leaf basal angle and drooping angle could be increased; meanwhile, it was benefical to shorten the length of basal internodes and increase culm diameter, culm wall thickness and dry matter weight per unit internode, resulting in enhanced breaking resistance and reduced lodging index.

选用3种穗型水稻品种，设置3种钵苗机插密度，以毯苗机插为对照(CK)，系统研究钵苗机插不同密度对水稻产量及其构成、穗部性状、冠层叶系配置、茎秆物理特性和抗倒伏的影响，旨在探明水稻钵苗机插配套不同穗型品种适宜栽插规格及其增产特点；同时，阐明钵苗机插不同密度下水稻株型特征和抗倒伏特性。结果表明: (1) 3种钵苗机插密度处理下，大穗型品种产量随密度降低呈先增后降的变化趋势，但均显著高于CK；中、小穗型品种产量有随着密度降低而下降的趋势。不同穗型品种穗数随着密度降低而显著减少，每穗粒数显著增加，结实率和千粒重无明显变化规律。(2)钵苗机插下不同穗型水稻品种的穗长、着粒密度、单穗重、一次枝梗数、二次枝梗数、一次枝梗粒数和二次枝梗粒数均随密度降低而增加，且高于CK；一、二次枝梗数比值和一、二次枝梗粒数比值随密度降低而呈下降趋势。(3) 钵苗机插下不同穗型水稻品种的上三叶的叶长、叶宽、叶基角、披垂度和比叶重随着密度降低而呈增加趋势；且上三叶的叶长、叶宽和比叶重高于CK。(4)随着密度降低，不同穗型品种钵苗机插水稻基部N1、N2、N3节间长度减少，茎秆粗度、茎壁厚度和节间干重增加，穗下节间长、秆长、株高、重心高增加，而相对重心高有减小趋势。(5)不同穗型品种钵苗机插水稻基部节间N1、N2、N3抗折力和弯曲力矩随着密度降低而增加，倒伏指数呈下降趋势，且低于CK。说明水稻钵苗机插配套大穗型品种宜适当降低密度，增加每穗粒数以获高产；中穗型品种需兼顾穗数和每穗粒数，提高群体颖花量而增产；小穗型品种依靠穗数而提高产量。水稻钵苗机插降低密度能改善穗部性状和增加上三叶的叶面积，但增大了叶基角和披垂度，同时利于缩短基部节间长度，增加基部节间粗度、茎壁厚度和充实度，从而提高抗折力，降低倒伏指数。