水稻分蘖成穗率的遗传变异研究

以水稻弯穗型辽盐２号第３个品种为母本,直立穗型辽粳３２６等４个品种为交本,研究了水稻分蘖成穗率的配合力和遗传力。结果表明,辽粳３２６一般配合力相对效应值最高为９．０,辽盐２８２次为５．０,特殊配合力以辽盐２８２／辽粳２９４最高为５．８;分蘖成穗率的广义遗传为８２．５％,狭义遗传力为６５．３％。     

水稻分蘖成穗率的遗传变异研究

以水稻弯穗型辽盐2号等3个品种为母本,直立穗型辽粳326等4个品种为父本,研究了水稻分蘖成穗率的配合力和遗传力。结果表明,辽粳326一般配合力相对效应值最高为9．0,辽盐282次之为5．0,特殊配合力以辽盐282／辽粳294最高为58;分蘖成穗率的广义遗传力为825％,狭义遗传力为65．3％。     

烯效唑干拌种对不同群体小麦分蘖成穗的调控

以绵阳26为供试材料,采用烯效唑干拌种研究了不同浓度(0、10、20、40 mg/kg)对不同播种密度(90×10~4、180×10~4、270×10~4/hm~2)下小麦分蘖成穗的影响。结果表明,烯效唑处理后,公蘖前期(出苗50d内)烯效唑浓度越高,达到最大分蘖速度的时间越早,低节位分蘖特别是第1、第2分蘖的发生加快;分蘖后期(出苗50 d后)分蘖速度减慢,高浓度处理(40 mg/kg)的分蘖发生比低浓度提早10 d结束。烯效唑提高了孕穗后期单位面积的茎蘖数、分蘖成穗率、单株穗数和单位面积有效穗,其中以20 mg/kg最优。密度不同,烯效唑提高分蘖成穗率的效果有差异,以高密度下的效果更佳。     

水稻分蘖的发生,控制与茎蘖成穗率的提高

如所周知,水稻产量可以分解成4个要素：单位面积穗数、每穗总粒数、结实率和粒重,中间两个要素,也可用其乘积每穗实粒数来表达。单位面积穗数是产量构成要素中最活跃也是最基本的一个要素。穗数多少在很大程度上受制于分荣的发生量,但又不是越多越好。以往产量还不高的时候,或者目前的一些中低产地区,增加分菜数量,增多穗数,能显著提高产量;在产量水平已经比较高的今天,尤其是高产地区,就并不是靠再增多穗数能提高产量了。可以说穗数的潜力已经或者接近到了极限,而增大穗形的问题却变得越来越重要了。于是"稳穗增粒"便成为当前…     

略论提高水稻成穗率的意义和途径

本文通过对丰产方和大面积苗情资料及辅助试验结果分析，明确了适宜穗数和成穗率是水稻高产群体质量的最主要形态指标。指出在适宜穗数的基础上，提高成穗率，有利于攻大穗，提高高效叶面积率，粒叶比，增加齐穗期单茎茎鞘重，促进灌浆期干物质生产量和籽粒产量的提高，据此，提出了在适宜穗数的基础上，把成穗率提高到８０％以上，是优化中，后期群体质量的核心。同时，对生产实践中如何提高成穗率进行了探讨。     

不同寄秧密度对杂交水稻分蘖成穗率的影响

通过不同寄秧密度对杂交水稻秧苗素质的影响，以及对移栽本田后的生育效应分析，明确在本试 验设计条件下，较稀的寄秧密度，其秧苗单株带蘖多，干物重大，移栽后分蘖成穗率高，ＬＡＩ大，干物质积累多， 每穗粒数多，从而为高产创造条件。     

水稻生长发育的化学调控讲座（6）——水稻倒伏的化学控制

60年代以前，稻麦倒伏曾是世界性的技术难题。矮壮素的研究成功解决了小麦的倒伏问题。之后，我国植物生理学家也曾研究应用矮壮素和缩节安防止水稻倒伏．但水稻对这两种物质控长效应的反应十分迟钝。随着水稻品种的矮秆化，倒伏已非我国稻作生产上的普遍问题。     

水稻抛秧与插秧分蘖成穗规律研究初报

１９９６年我们对水稻盘育秧抛秧和湿润育苗插秧的两种栽培方式的叶龄、发育进程和分蘖成穗进行了跟踪调查，结果表明：抛秧水稻比插秧在本田里主茎出叶速度快０．５－１个叶；抛秧分蘖成穗集中在４０／－７／０节位上；插秧集中在５／０－８／０节位上；随着分蘖位次的升高，每穗实粒数依次减少。     

杂交水稻不同时期分蘖成穗率与群体穗型质量和产量的关系

通过前期基蘖肥与后期穗粒肥的氮肥运筹比例的试验研究，阐明了杂交稻秧田和大田期的分蘖成穗规律及其在产量形成中的作用，并提出了适宜的前后期氮肥运筹比例为６：４。     

旱育秧不同搁田始期对水稻成穗率的影响

水稻旱育稀植高产栽培技术是一项以培育适龄水秧,稀植浅播和合理运筹肥水为主要内容的综合栽培技术。福建省自1992年引进,经过多年的试验示范,确认其具有秧苗素质好,耐寒性强,旱播早熟,高产低耗,操作简便等特点,是水稻栽培史上的一项重大技术革新,目前在生产上已得到大面积推广,收到了显著的增产效果。但近年来,个别地方在此项技术的推广过程中,未能正确把握适时搁田,造成无效分库增多,影响其增产效果。为此,1997年组织了水稻旱育秧不同搁田始期对水稻成穗率影响的试验,现总结如下：一、材料与方法（一）试验地点与材料试验…     

不同调控技术对水稻成穗率的影响

总结了不同调控技术途径对水稻茎蘖成穗率影响的试验结果.表明:当大田茎蘖数达到预定的80%左右时烤田成穗率可提高15.68和23.91个百分点.不同密植和施肥水平对成穗率影响不明显,而基追肥比例不同则成穗率差异显著.采用宽行窄株栽培、喷施"九二GA996"等均有利于提高成穗率.     

重穗型杂交稻新组合Ⅱ优辐819高产制种技术

Ⅱ优辐819是福建省南平市农科所用Ⅱ-32A与南恢辐819配组育成的重穗型杂交稻新组合.该组合2000～2001年参加福建省水稻新组合区域试验,比对照汕优63增产7.58%,增产达极显著.米质经农业部稻米及制品检测中心测定:米质12项指标中有11项指标达二级以上优质米标准.2003年1月通过福建省农作物品种审定委员会审定.建阳市2003～2004年制种136hm2,平均每666.7m2产量200.8kg.其中制种户林建生制种0.47hm2,生产种子2 133.3kg,平均每666.7m2产量302.6kg.现将其高产制种技术介绍如下:     

水稻再生分蘖的萌发成穗规律研究

受顶端优势的控制,再生分蘖至头季黄熟前3d才萌发,穗子较小,而且荫发成穗毕随节位下移丽降低。提高再生季产量的关键,是在头季高桩收割保留高萌发率的倒2芽基础上,采取拈抗顶端优势的措施,提高下部冉生分蘖的萌发率,从而形成比头季更多的穗数,以多穗补小穗的不足。     

Genetic control of panicle architecture in rice

Rice panicle architecture affects grain number per panicle and thereby grain yield. Many genes involved in control of panicle architecture have been identified ...     

水稻带耙田开沟培土机械直播技术及应用效果

根据国内外直播稻技术发展趋势,针对我国南方直播稻生产中存在的关键问题,研究提出水稻带耙田开沟培土机械水直播技术。该项技术具有种子“土中”发芽出苗、田间稻苗有序分布和生育以及农艺农机配套、工效肥效高等技术优势;明显提高直播稻的发芽出苗稳定性和成苗率,有效控制直播稻生育中期无效分蘖的发生,改善田间群体质量,促进深根壮秆,提高了直播稻的成穗率和穗型整齐度,增强了水稻后期的抗倒伏能力。在较大面积上示范应用,取得了显著的省工节本、增产增收效果和经济、社会、生态效益。     

N applications that increase plant N during panicle development are highly effective in increasing spikelet number in rice

Efficient use of nitrogen fertilizer is critical in improving yield stability in rice. The objective of this study was to determine the effect of nitrogen (N) top-dressing on the number of total spikelet (fertile plus sterile) production and evaluate the effect among rice cultivars. We analyzed 136 sets of experimental data on growth and spikelet production for three lowland cultivars, grown under various regimes of N over 10 seasons at Kyoto, Ibaraki and Kanagawa, Japan. In each season, one to three of the lowland cultivars, Nipponbare (japonica), Koshihikari (japonica) and Takanari (indica), were studied. In 1986, 1995 and 1999-2001, the N regimes included basal application only, light basal and heavy top-dressing from the panicle initiation stage onward, heavy basal and heavy top-dressing from the spikelet formation stage onward, and no applications. In 2002 and 2005-2008, we set up experimental plots with varied time of N top-dressing, with or without N basal application. Takanari had the largest spikelet number averaged over all plots and was considered better efficient in spikelet production per applied N than the other cultivars. Although the trend is not clear, the effect of time of top-dressing on spikelet number was generally the greatest when N was top-dressed from 35 to 30 days before heading. The variation of observed spikelet number was analyzed with a linear regression of plant N 14 days before heading and by a model that estimates spikelet production accounting for plant N 14 days before heading and crop growth rate (CGR) during the 14-day period preceding heading. For the variation of spikelet number within each cultivar, the linear function model expressed the observed spikelet number than the two function model with R² 0.43** versus 0.13*-0.28** for the former and later models, respectively. When the results of all cultivars were combined, the two function model was much better for estimation of spikelet number than the linear function model (R² = 0.36** vs. 0.20*). This indicates that yearly and varietal variation of spikelet number was caused mainly by plant N status at the late spikelet differentiation stage. The varietal variation in spikelet production efficiency is explained by CGR during this 14-day period. We concluded that N applications that increase plant N 14 days before heading is highly effective in maximizing spikelet production among cultivars.     

The difference in amylose content within a panicle as affected by the panicle morphology of rice cultivars

The variation of amylose content (AC) among grains within a panicle and its relation to panicle morphology were investigated using 44 japonica rice cultivars differing in grain density (GD), panicle bending degree (BD) and palatability. Morphological traits of the rice panicle were poorly associated with mean grain AC on the average of the whole panicle, but closely related to AC variation and spatial distribution within a panicle, with the compact-panicle cultivars (GD>6.5 grain/cm and BD< 30°) having greater variation than loose-panicle cultivars (GD<6.0 grain/cm and BD>70°). The extent of AC differences among the rachides within a panicle was also cultivar-dependent, and greater differences were found between middle and top rachides for the compact-panicle cultivars, and between middle and bottom rachides for the loose-panicle cultivars. The difference in spatial distribution of AC variation between Bing110 (a compact-panicle cultivar) and XS11 (a loose-panicle cultivar) indicated that grains with low AC were principally distributed on interior rachis of middle branches for Bing110, but on bottom-rachis for XS11. Such a distribution is basically associated with the difference in the timing procedure of floret initiation and development, and final grain weight.     

不同浓度沼液浸种对杂交水稻种子发芽率、成秧率的影响

高活力的新种采用沼液原液浸种比清水浸种发芽率提高4．2％,成秧率提高10．7％,且出苗快,苗壮根粗,叶色浓绿。秧苗素质明显比对照好,是一项新型的种子处理技术,且技术简便、安全、效果好,值得大力推广。