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1.
杂交籼稻组合演替过程中植株农艺性状的变化   总被引:1,自引:0,他引:1  
以大面积推广的23个杂交籼稻组合为材料,研究了品种更替过程中农艺性状的演变特征。结果表明,在杂交籼稻组合的演替过程中,单株有效穗数下降,单株产量和生物量降低,单茎的茎鞘、叶片、穗重增加,抽穗后叶片的光合能力增强。相关分析和通径分析表明,生物量是影响单株产量的主要因素。在杂交稻的育种和栽培中,强调单个有效穗的大穗优势的同时,必须注重品种的分蘖发生能力,建立适宜的群体密度以获取高产。  相似文献   

2.
吉林省不同年代育成大豆品种某些农艺性状的变化   总被引:2,自引:1,他引:2  
两年来对吉林省1923~2005年生产上主推的16个大豆品种的生物量、产量、收获指数以及种子蛋白质、脂肪含量的研究表明:大豆植株的生物量从苗期到R6期逐渐增加,R6期达到最大值,然后下降,老品种比现代品种下降速度快。大豆品种的生物量、产量和收获指数均随育成年代呈线性增加,其中产量和收获指数平均每年分别增加14.84kg/hm2(1.27%)和0.23%。种子脂肪含量随育成年代增加,平均每年增加0.04%;而蛋白质含量随年代降低,平均每年下降0.06%。产量与生物量和收获指数呈显著正相关(P<0.05);与种子脂肪含量呈正相关,与蛋白质含量呈负相关,但不显著。本文结果表明,大豆育种工作者以高产为选择目标的同时使生物量和收获指数得到提高。生物量和收获指数可以作为高产品种选育的指标。  相似文献   

3.
两年来对吉林省1923~2005年生产上主推16个大豆品种的生物量、产量、收获指数以及种子蛋白质、脂肪含量的研究表明:大豆植株的生物量从苗期到R6期逐渐增加,到R6期达到最大值,然后下降,老品种比现代品种下降速度快。大豆品种的生物量、产量和收获指数均随育成年代呈线性增加,其中产量和收获指数平均每年分别增加14.84kg/hm2(1.29%)和0.09 %。种子脂肪含量随育成年代增加,平均每年增加0.87%;而蛋白质含量随年代降低,平均每年下降1.52%。产量与生物量和收获指数呈显著正相关(P<0.05);与种子脂肪含量呈正相关,与蛋白质含量呈负相关,但不显著。本文结果表明,大豆育种工作者以高产为选择目标的同时使生物量和收获指数得到提高。生物量和收获指数可以作为高产品种选育的指标。  相似文献   

4.
以培杂泰丰、粤晶丝苗和天优998为材料,分别设置不施氮、中氮和高氮3个不同的氮肥水平(即施纯氮0、120和180kg/hm2,依次记为NN、MN、HN),研究始穗期遮荫(分别为双层遮荫、单层遮荫和不遮荫,依次记为DS、SS、CK)对不同基因型水稻产量及一些生理特性的影响。结果表明,与不施氮处理相比,遮荫处理结束后恢复5d高氮显著增加水稻叶面积指数、茎鞘干质量、总干质量、茎鞘物质输出量和茎鞘物质转运率,水稻剑叶的光合速率和气孔导度也显著提高。高氮处理下水稻的收获产量、有效穗数和每穗总粒数显著高于不施氮处理,而结实率和千粒重却显著降低。与不遮荫相比,双层遮荫处理水稻叶面积指数、茎鞘干质量、总干质量、剑叶的光合速率和气孔导度显著降低,双层遮荫处理水稻的收获产量和有效穗数也显著降低。氮肥和遮荫的互作效应对水稻叶面积指数、茎鞘干质量、总干质量、有效穗数以及收获产量的影响也达到显著水平。在单层遮荫条件下,增施氮肥可以减轻遮荫对水稻叶面积指数、叶片干质量、茎鞘干质量、总干质量、有效穗数和收获产量的不利影响。对不同品种而言,超级杂交稻天优998受到氮肥和遮荫的影响更大。  相似文献   

5.
种植方式对水稻和陆稻氮素吸收利用的影响   总被引:11,自引:0,他引:11  
 以武香粳99-8(水稻)和中旱3号(陆稻)为材料,研究了种植方式对水稻和陆稻生育后期N素吸收利用的影响。与水种稻(对照)相比,中旱3号覆膜旱种时产量显著低于对照,武香粳99-8覆膜旱种时和对照没有显著差异,裸地旱种产量均为最低。覆膜旱种和裸地旱种抽穗期植株的含N率较低,抽穗至成熟期植株含N率下降速率为水种>裸地旱种>覆膜旱种。抽穗和成熟期植株吸N量大小为水种>覆膜旱种>裸地旱种。旱种稻成熟期茎鞘中的N素分配显著高于对照,籽粒显著低于对照,品种间叶片有所不同。抽穗期旱种稻的N素物质生产效率显著高于对照。成熟期覆膜旱种N素物质生产效率最低。旱种稻N素籽粒生产效率(中旱3号覆膜旱种除外)和N素收获指数较对照增加,大小为裸地旱种>覆膜旱种>水种。与武香粳99-8相比,中旱3号抽穗后植株含N率下降快,植株N素积累量较小,叶片和籽粒中N素分配比例高,茎鞘低;N素物质生产效率(成熟期)、N素籽粒生产效率和N素收获指数高,产量低。  相似文献   

6.
《杂交水稻》2017,(1):52-61
以杂交中籼稻F优498为材料,采用3因素裂区设计,研究不同秧龄、水肥管理模式和穴插苗数对水稻不同层级茎蘖干物质生产特性和产量的影响。结果表明:除抽穗期穗部干物质积累量外,抽穗期和成熟期各器官及整株的干物质积累量以及抽穗至成熟期穗部和整株的干物质增加量均与产量极显著正相关;各处理1次分蘖对产量的贡献均最高,除35 d秧龄下穴插2苗处理主茎的产量高于2次分蘖外,其它处理均是2次分蘖的产量高于主茎;分别与35 d秧龄处理和穴插2苗处理比较,65 d秧龄处理和穴插单苗处理抽穗期和成熟期主茎、1次分蘖和全株的干物质积累量显著降低,2次分蘖的干物质积累量则显著提高;65 d秧龄处理各级茎蘖的茎鞘物质转运率和贡献率均显著低于35 d秧龄处理,2次分蘖的茎鞘物质转运率和贡献率显著低于主茎和1次分蘖;适龄移栽有利于高产,而在长秧龄条件下,应在拔节之前移栽,穴插单苗,同时采用干湿交替灌溉对其有效调控。  相似文献   

7.
以水稻新品种"盐粳218"为材料,采用小区对比方法,探讨了不同栽插密度对水稻生长发育及产量的影响。结果表明,栽插密度为31 cm×15 cm,每穴栽插4本株条件下盐粳218叶绿素含量较高、且生育后期下降幅度最小,分蘖提早、有效穗数增加,单茎茎鞘物质输出率、茎鞘物质转换率、收获指数较高,产量结构合理、产量水平较高。  相似文献   

8.
以桂华占、八桂香为材料,不同播期调控下,研究不同播期下优质稻花后植株碳氮流转与籽粒生长及品质的相关性.结果表明:(1)花后茎鞘、叶片干物质运转速度和运转率都与籽粒起始灌浆势呈正相关.籽粒活跃灌浆期、持续灌浆时间与花后茎鞘、叶片干物质运转速度和运转率呈极显著正相关.(2)播种期推迟不利于茎鞘碳同化物向穗部流转,茎鞘碳同化物转运对籽粒的产量和淀粉产量的贡献率表现为淀粉>可溶性糖>蔗糖,茎鞘碳同化物对籽粒产量及淀粉产量的贡献率远高于叶片.可溶性糖转运对籽粒产量和淀粉产量贡献率表现为SD1>SD2>SD3;蔗糖、淀粉对籽粒的产量贡献率表现为SD1>SD2>SD3.茎叶可溶性糖积累量的减少与籽粒直链淀粉含量和积累量增加是同步的,并且,茎叶可溶性糖积累量快速递减期(花后3~12 d)与直链淀粉含量和积累量快速递增期(花后6~12d)同步.(3)播种期推迟减少茎鞘和叶片总氮的积累,籽粒氮收获指数降低,但是播种期的推迟却增加茎鞘和叶片器官蛋白氮积累,有利于籽粒蛋白质含量提高.  相似文献   

9.
施氮对不同小麦品种干物质分配、氮素吸收和产量的影响   总被引:2,自引:0,他引:2  
为了解不同小麦品种对氮肥的敏感性,以西农979和小偃22为参试品种,对其分别进行了五个水平的施氮处理,并分析了不同施氮量处理对两个品种营养器官干物质对籽粒的贡献率、各器官含氮量、分蘖成穗和产量的影响。结果表明,随着施氮量的增加,两个品种茎鞘、穗轴+颖壳、叶中干物质转运量及干物质对籽粒贡献率均呈减少的趋势,施氮后西农979干物质对籽粒贡献率平均减少14.23%,小偃22平均减少18.50%;两品种器官含氮量均以籽粒最高,茎鞘最低,且随施氮量的增加呈增加趋势;随着施氮量增加,两品种千粒重降低,穗数、穗粒数以及产量均呈先增加后减少的趋势。与小偃22相比,西农979花前各器官干物质转移量及其对籽粒的贡献率均较低,但其具有更强的花后同化能力;施氮后,西农979在冬春分蘖与穗数增加方面均优于小偃22,产量提高幅度也相对较大,在施氮180 kg·hm-2时产量最高,说明西农979对氮肥反应较小偃22敏感。  相似文献   

10.
目的 探明不同类型水稻品种产量和氮素吸收利用对FACE(大气CO2浓度增高)响应的差异。方法 以常规粳稻、杂交籼稻、常规籼稻共6个品种为供试材料,研究FACE对不同类型水稻产量、氮素吸收利用的影响。结果 1)FACE处理极显著提高了水稻产量,平均增加24.17%, 常规籼稻增幅最大,FACE和对照均以杂交籼稻最高;2)FACE处理显著增加了单位面积穗数,常规粳稻增幅最大,并显著增加了杂交籼稻和常规籼稻每穗粒数;3)FACE处理显著提高了成熟期吸氮量和氮素籽粒生产效率,成熟期吸氮量平均增加21.23%,杂交籼稻增幅最大, FACE和对照均以常规籼稻最高;氮素籽粒生产效率平均增加7.33%,杂交籼稻增幅最大,FACE和对照均以杂交籼稻最高。成熟期吸氮量对产量促进作用略大于成熟期氮素籽粒生产效率;4)FACE处理降低了植株含氮率,成熟期平均下降0.105个百分点,常规粳稻降幅最大。FACE处理极显著提高植株干物质量,成熟期平均增加23.95%,常规籼稻增幅最大;FACE处理显著提高常规籼稻和杂交籼稻成熟期单穗吸氮量,分别增加10.79%、13.93%,但常规粳稻下降了9.60%;FACE处理显著提高了成熟期群体吸氮强度,平均增加22.29%,杂交籼稻增幅最大。FACE处理对水稻全生育期天数无显著影响;FACE处理显著提高茎鞘、叶片、穗各器官吸氮量,叶片增幅最大,平均增加51.86%,杂交籼稻增幅最大;FACE处理显著提高了不同生育阶段吸氮量,抽穗-成熟阶段增幅最大,平均增加108.90%,杂交籼稻增幅最大;5)植株干物质量、单穗吸氮量、吸氮强度、穗吸氮量、抽穗-成熟阶段吸氮量对成熟期总吸氮量的促进作用分别大于植株含氮率、单位面积穗数、生育天数、茎鞘叶吸氮量、移栽-分蘖和分蘖-抽穗阶段吸氮量;6)FACE处理显著提高了氮肥偏生产力,降低了每百千克籽粒需氮量,前者平均增加24.16%,常规籼稻增加最多;后者平均降低4.7%,常规籼稻降幅最大。结论 FACE处理可显著提高水稻产量和氮素吸收利用效率,但品种间差异较大。  相似文献   

11.
To understand the changes in yield, harvest index (HI) and biomass of aboveground parts of rice, 33 japonica rice cultivars released from 1958 to 2005 were planted. During the 47 years, the grain yield increased from 9 118.36 to 15 060.1 kg/hm2 and HI from 0.46 to 0.55. In the genetic improvement, the total number of tillers per plant decreased, and the biomass per unit area slightly increased at the harvest stage. The increases of yield and HI resulted from the increased biomasses of effective tillers and single stem, and the increase of biomass per stem was related to the increased biomasses of different organs along with the genetic improvement. The stem and sheath biomass at heading and the leaf biomass at 30 days after heading showed the highest increase, up by 75.17% and 49.94%, respectively. The biomasses of leaf and stem-sheath at 10 days after heading, and biomass per stem at 30 days after heading were obviously correlated with the yield. The results indicate that the genetic improvement has resulted in the increase of yield and HI. This increase is correlated with the decrease of total tiller number per plant, and increase of biomasses of effective tillers and single stem. The leaf biomass after heading and the stem and sheath biomass at 10 days after heading can be used as selection criteria for breeding high yielding rice cultivars.  相似文献   

12.

Background

Harvest index (HI) in rice is defined as the ratio of grain yield (GY) to biomass (BM). Although it has been demonstrated that HI is significantly related to yield and is considered as one of the most important traits in high-yielding rice breeding, HI-based high-yielding rice breeding is difficult due to its polygenic nature and insufficient knowledge on the genetic basis of HI. Therefore, searching for rice varieties with high HI and mapping genes associated with high HI can facilitate marker-assisted breeding for high HI in rice.

Results

Yuexiangzhan, a popular indica cultivar with good reputation of high HI was crossed with Shengbasimiao, an indica cultivar with lower HI to develop a recombinant inbred line population, and QTL mapping for HI and its component traits was conducted. In total, five QTLs for HI, three QTLs for GY, and six QTLs for BM were detected in two-year experiments. Among the three GY QTLs, one co-located with the HI QTL on chromosome 8, while the other two co-located with the two tightly-linked BM QTLs on chromosome 3. The co-located QTLs in each of the chromosomal regions produced additive effects in the same direction. Particularly, the HI QTL on chromosome 8, qHI-8, could be detected across two years and explained 42.8% and 44.5% of the phenotypic variation, respectively. The existence of qHI-8 was confirmed by the evaluation of the near isogenic lines derived from a residual heterozygous line, and this QTL was delimitated to a 1070 kb interval by substitution mapping.

Conclusion

In the present study, the detected GY QTLs overlapped with both HI QTL and BM QTL, suggesting a positive relationship between GY and HI or BM, respectively. With an understanding of the genetic basis for grain yield, harvest index and biomass, it is possible to achieve higher yield through enhancing HI and BM by pyramiding the favorable alleles for the two traits via marker-assisted selection (MAS). As qHI-8 has a large phenotypic effect on HI and expresses stably in different environments, it provides a promising target for further genetic characterization of HI and MAS of high HI in rice breeding.
  相似文献   

13.
The source-sink relationship determines the ultimate grain yield.We investigated the genetic basis of the relationship between source and sink and yield potential in rice.In two environments,we identified quantitative trait loci(QTL)associated with sink capacity(total spikelet number per panicle and thousand-grain weight),source leaf(flag leaf length,flag leaf width and flag leaf area),source-sink relationship(total spikelet number to flag leaf area ratio)and yield-related traits(filled grain number per panicle,panicle number per plant,grain yield per plant,biomass per plant,and harvest index)by genome-wide association analysis using 272 Xian(indica)accessions.The panel showed substantial variation for all traits in the two environments and revealed complex phenotypic correlations.A total of 70 QTL influencing the 11 traits were identified using 469,377 high-quality SNP markers.Five QTL were detected consistently in four chromosomal regions in both environments.Five QTL clusters simultaneously affected source,sink,source–sink relationship,and grain yield traits,probably explaining the genetic basis of significant correlations of grain yield with source and sink traits.We selected 24 candidate genes in the four consistent QTL regions by identifying linkage disequilibrium(LD)blocks associated with significant SNPs and performing haplotype analysis.The genes included one cloned gene(NOG1)and three newly identified QTL(qHI6,qTGW7,and qFLA8).These results provide a theoretical basis for high-yield rice breeding by increasing and balancing source–sink relationships using marker-assisted selection.  相似文献   

14.
水分管理对免耕抛秧水稻根系生长及产量的影响   总被引:11,自引:2,他引:9  
研究了水分管理对免耕水稻根系生长和产量的影响。结果表明,干湿交替灌溉对根系的伸长、生长、生理及分布具有较大影响,水稻各生育期干湿交替灌溉处理水稻单株根干质量、单株生物量、根半径、根表面积、总根数、根系活力、超氧化物歧化酶活性均显著高于淹水淹灌。干湿交替灌溉处理实收产量显著高于淹水淹灌,增产主要因子是有效穗数、每穗粒数和结实率。灌浆盛期干湿交替灌溉处理单株生物量、根半径、根表面积、总根数、超氧化物歧化酶活性均显著高于湿润淹灌,水稻产量差异则不显著。  相似文献   

15.
我国水稻品种遗传改进在增产中的贡献分析   总被引:14,自引:2,他引:12  
在建立水稻品种改良在增产中的科技贡献分析模型的基础上,计算了我国水稻生产过程中科技进步、品种改良、化肥投入和经营管理等措施引起的产量变化。结果表明,1985~1994年的10年间,在科技进步对产量增产的平均贡献中,品种改良占29.2%,化肥投入占43.2%,经营管理水平占27.6%。在水稻生产发展过程中,形成了3种水稻增产科技要素组合类型,即以化肥为主的要素组合类型、以良种为主的要素组合类型和综合管理型要素组合类型。在此基础上,提出了进一步提高我国水稻产量的合理途径。良种对增产的贡献是一种最为经济有效的增产因素之一,国家应进一步加强对该领域的投资和研究,以维持并提高良种科技进步对增产的贡献份额。同时,应通过品种改良、肥料投入和经营管理相结合的综合技术管理,提高水稻生长的资源利用效率。  相似文献   

16.
Rice crop growth and yield in the north Iran are affected by crop duration and phenology.The purpose of this study was to calibrate and validate the ORYZA2000 model under potential production based on experimental data for simulating and quantifying the phenological development,crop duration and yield prediction of rice crop influenced by different seedling ages.In order to calibrate and validate the crop parameters of ORYZA2000 model,a two-year field experiment was conducted under potential growth conditio...  相似文献   

17.
For adapted cultivars under normal crop densities, biological yield is largely determined by the pool of available resources, e.g. water, nutrients and photosynthetically active radiation, while the nature and intensity of intraspecific competition plays an important role in determining the magnitude of harvest index (HI). Water deficits can drastically reduce the HI from its genetic potential to zero. This study was conducted to determine the effect of drought-weighted intraspecific competition on the HI and, consequently, the grain yield in spring wheat populations along a natural moisture gradient in northwestern China. Along the natural moisture gradient (annual mean rainfall decreased 328→204→185 mm per year, supplemented with 70 mm of irrigation), culm size inequality (as measured by the Gini coefficient of above-ground biomass per culm) always increased, and Lorenz curves were more concave. HI decreased significantly in 1999 (0.364→0.345→0.307) and 2000 (0.341→0.303→0.251). There was a significant negative correlation between the Gini coefficient and the HI of spring wheat along the moisture gradient (R2=0.92, P<0.01). These results suggested that size hierarchies in spring wheat populations are closely correlated with the water regime in the field, and that under greater drought stress there are relatively more smaller plants with lower HI (size-dependent reproductive allocation). Size inequality is an index of competitive status in plant populations under stress environments. Agriculturally, greater size inequality may result in a competitive cost for energy and photosynthetic products, in other words, growth redundancy, which is detrimental to reproductive allocation and consequently, grain yield. The results support the view that stand uniformity in field crops is an important mechanism for increasing grain yield.  相似文献   

18.
为了探明轻简栽培方式对中稻+再生稻产量构成特征和经济效益的影响,以黄华占和金农丝苗为材料,于2017年在四川泸州进行不同栽培方式(翻耕移栽、翻耕直播、免耕移栽)的大田试验,分析了中稻-再生稻干物质生产特性、产量、产量构成和经济效益.结果表明,不同栽培方式间头季稻产量差异不显著.翻耕直播头季稻产量较翻耕移栽平均增加3.5...  相似文献   

19.
Enhancing rice yield in upland rice systems through genetic improvement remains a major challenge in the tropics. This review aims to provide the trends on upland rice cultivation over the last 30 years and recent distribution of upland rice in the tropics, and to report progress in studies on genetic improvement for enhancing productivity in Africa, Asia, and Latin America. While upland rice cultivation area has reduced in Asia and Latin America over the last 30 years, the area in Africa has increased. The current share of upland rice area in total rice area is related to rainfall and gross national income per capita, especially in Africa, and higher share is associated with lower rice self-sufficiency at national level. Breeding programs in Asia and Latin America have developed high-yielding varieties using indica materials as parents. In Africa, New Rice for Africa (NERICA) varieties were developed from crosses between improved tropical japonica and Oryza glaberrima. However, recent studies report that there is scope for improving existing NERICA using upland indica materials from Asia. In highlands of Africa, there are ongoing breeding programs using japonica varieties, such as the Nepalese Chhomrong Dhan. Key important plant traits used in the breeding programs are not largely different across regions, especially intermediate plant height and tillering capacity (which may be related to weed-suppressive ability), and high harvest index. In conclusion, we propose an international network for breeding upland rice with accelerating seed exchange across regions that could enhance upland rice productivity through genetic improvement.  相似文献   

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