小麦黄淮冬麦区北片国家区试品种产量构成因素变异分析

利用2015-2018年黄淮冬麦区北片国家区试中32个小麦品种,对产量及产量构成三因素的性状进行变异性分析、回归分析和通径分析,探讨产量构成三因素对产量的影响。变异性分析表明,产量构成三因素的变异性为有效穗数>千粒重>穗粒数;相关分析表明有效穗数、穗粒数和千粒重均与产量呈正相关,有效穗数和千粒重与产量呈极显著正相关;三因素与产量相关性大小为:有效穗数>千粒重>穗粒数,有效穗数对产量的影响最大,对小麦产量提高贡献最多,其次是千粒重,有效穗数(X1)、穗粒数(X2)和千粒重(X3)与小区产量(Y)的多元回归方程为Y=-21261.89+15.77X1+274.67X2+232.81X3。通径分析的结果与相关分析的结果一致,也是有效穗数对产量的作用最大(Py=0.864),千粒重作用次之(Py=0.714.),穗粒数作用最小(Py=0.626)。     

云南文山12个小麦品种（系）生产力水平分析

对12个小麦品种(系)的形态、经济性状、抗逆性和适应性进行分析,研究各品种(系)在云南省文山市的生产力水平,为品种审定和推广应用提供依据。结果表明：(1)有效分蘖数,有效穗数,穗粒数与千粒重是造成产量形成的原因,且穗粒数与千粒重是提高产量的重要因素;(2)参试的12个品种(系),仅有一个品种(系)蜀麦1619相对于对照品种(系)云麦56减产,其余均有不同程度的增产;(3)文D6-8植株整齐,长势良好,千粒重较高,籽粒大,饱满度较好,抗病性强,且产量最高,属于理想品系;(4)玉15-1株型紧凑,长势好,有效穗多,穗粒数较多,籽粒饱满,千粒重高,产量仅次于文D6-8;(5)易2011-1植株长势好,整齐度较好,穗大粒多,饱满度较好,千粒重较高,抗倒伏,产量居第三位。     

杂交稻不同穗粒结构品种的增产因素分析

为探索不同穗粒结构杂交稻品种高产栽培的增产因素,以在生产上大面积推广、穗粒结构不同的杂交稻汕优63、Ⅱ优838、丰两优四号3个品种为试验材料,根据3个品种参加区试的产量构成,进行有效穗、每穗粒数、结实率、千粒重4个产量构成因素与产量的相关分析、4个产量构成因素间的相关分析、4个产量构成因素与产量的通径分析。结果表明,穗数多、每穗粒数中等的汕优63,高产栽培增产的主要因素是提高有效穗与每穗粒数,对增产的贡献率分别为37.3%和38.1%,提高结实率对增产的贡献率为24.1%;穗数中等、每穗粒数较多的Ⅱ优838,高产栽培增产的主要因素是提高有效穗,对增产的贡献率为62.2%,提高每穗粒数对增产的贡献率为26.2%;穗数较少、每穗粒数多的大穗型品种丰两优四号,高产栽培增产的主要因素是提高有效穗和每穗粒数,对增产的贡献率分别为49.2%和44.8%。可见,穗数多、每穗粒数中等的品种高产栽培的增产因素是提高有效穗与每穗粒数,同时提高结实率;穗数中等、每穗粒数较多的品种高产栽培的增产因素是提高有效穗,同时提高每穗粒数;穗数较少、每穗粒数多的大穗型品种高产栽培的增产因素是提高有效穗和每穗粒数。     

小麦品种淮麦33产量构成因素分析及增产途径探讨

利用2015-2017年江苏省连云港市小麦高产创建万亩示范片33个点次试验资料,对小麦品种淮麦33产量构成因素进行分析。相关分析表明,穗粒数、千粒重与产量呈极显著正相关(r=0.6453**,r=0.7059**),穗数与产量呈微弱正相关(r=0.0712)。籽粒产量与穗数、穗粒数、千粒重的多元回归方程为:Y=-22151.30+15.85X1+270.48X2+261.70X3。通径分析表明,穗粒数对籽粒产量的作用最大(直接通径系数Py=1.0632),其次是穗数(直接通径系数Py=0.7327),千粒重的作用相对较小(直接通径系数Py=0.3303)。淮麦33的高产栽培技术应在适宜群体的基础上,主攻穗粒数,同时兼顾粒重的提高。     

晋南旱地小麦区试品系农艺性状相关分析

为了解晋南旱地小麦育种发展趋势,对2006—2015年晋南旱地小麦区试参试的121份品系进行农艺性状比较分析、相关分析和通径分析。结果表明:单位面积产量变异系数最大(29.74%)。产量三因素变异系数顺序为有效穗数穗粒数千粒重。单位面积产量与有效穗数(0.869**)、株高(0.878**)、穗粒数(0.775**)、有效分蘖率(0.735*)、千粒重(0.593**)、穗长(0.519**)和最高总茎数(0.371**)极显著正相关,与基本苗(0.191*)显著正相关,与生育期(-0.291**)极显著负相关。有效穗数、穗粒数、千粒重、株高、有效分蘖率和生育期对单位面积产量的直接贡献较大,依次为有效穗(0.591)穗粒数(0.373)千粒重(0.266)株高(0.093)有效分蘖率(|-0.069|)生育期(0.059),它们决定了单位面积产量97.65%的变异。2006—2015年山西省南部旱地小麦品种产量的提高是在保证穗数的基础上,通过增加穗粒数和提高千粒重来实现的。     

宁春50号产量构成及产量形成分析

宁春50号是宁夏农林科学院农作物研究所育成的高产优质广适小麦新品种,用品种鉴定、品比试验、区试试验、生产试验以及大面积生产示范、农田生产等多年多点试验示范对该品种进行了产量形成及稳定性分析,以期为当前高产小麦育种栽培提供借鉴.结果表明,宁春50号较对照宁春4号表现出了较高的产量;宁春50号稳定性与宁春4号相当,在2007年区试中宁春50号丰产稳产性都高于宁春4号,在稳定性产量上还有提高的潜力;在不同区域条件下,宁春50号和宁春4号产量及产量构成变化幅度基本一致,变化幅度最大的为穗粒数,千粒重次之,穗数最低;宁春50号产量及产量构成平均值较宁春4号都高,表明宁春50号具有较好的遗传特性,增产潜力明显;产量达到8 000 kg/hm2以上,平均穗数达到669.8×10 4穗/hm2,平均穗粒数为30.9粒/穗,千粒重为42.8 g,在5 000 kg/hm2到1 000 kg/hm2产量水平变化过程中,穗数、千粒重都呈现明显的递增趋势,而穗粒数变化趋势不明显;宁春50号产量增加与穗数、千粒重关系密切,相关系数分别为0.37、0.34,达到了极显著水平,与稳粒数关系未达到显著水平.宁春50号增产要提高穗数和千粒重,并采取相应的栽培管理措施.     

不同类型小麦品种产量构成因子分析

通过对春性小麦品种和半冬性小麦品种区试资料的分析摸清了两种不同类型小麦三个产量构成因子与产量关系的密切程度，即小表产量构成因子对产量的作用，春性小麦为穗粒数＞千粒重＞单位面积有效穗数，半冬性小麦为单位面积有效穗数＞穗粒数＞千粒重，且三者之间存在强烈的交互作用，相互矛盾，相互补偿。     

感温型三系杂交水稻特优2278农艺性状与产量相关性和通径分析

感温型三系杂交水稻特优2278是玉林市农业科学院选育的水稻品种,为挖掘增产潜力和探索高产栽培技术,通过分析5个县市田间试验数据,对其齐穗期、全生育期、有效穗数、株高、穗长、总粒数、实粒数、结实率、千粒重、产量等10个农艺性状进行了相关性分析和通径分析。结果表明,特优2278的10个农艺性状变异系数从大到小依次为总粒数有效穗数结实率实粒数产量株高全生育期齐穗期穗长千粒重,其变化范围为3.05%～9.39%;与产量的相关性从大到小依次为实粒数(0.951)千粒重(0.615)总粒数(0.602)全生育期(0.544)穗长(0.466)齐穗期(0.163)结实率(0.044)有效穗(-0.542)株高(-0.632);根据通径分析可得到通径系数大小顺序为千粒重(0.689)全生育期(0.512)结实率(0.195)有效穗数(-0.533)。     

长江中下游中籼杂交稻区试品种产量成因性状分析

基于2008—2012年南方稻区国家水稻品种区试数据,运用相关分析、通径分析和主成分分析方法,分析了长江中下游地区中籼杂交水稻5年220个参试品种的农艺性状与产量形成的关系,结果表明,有效穗数、每穗总粒数与结实率对产量显著正相关,其中对产量贡献最大的是结实率,千粒重与产量极显著负相关。在长江中下游杂交稻育种过程中,应以每穗总粒数和结实率为中心兼顾有效穗数和千粒重,协调优化产量构成因素的关系,建立良好的群体结构,发挥中籼品种产量的潜力。综合各种分析及结合长江中下游杂交中籼的9t/hm²以上的的高产组合,得出其产量结构是：有效穗数达到255万/hm²左右,株高在122cm以下,每穗总粒数达到180~200粒,结实率80%以上,千粒重27g左右。     

黄淮冬麦区旱地区试小麦产量与产量三因素通径分析

对1997~1998年度参加全国旱地区试的16个冬小麦品种产量三因素与产量进行相关和通径分析,结果表明三因素都与产量具有正相关关系,其相关系数大小顺序为：穗粒数＞千粒重＞公顷穗数;直接通径系数大小顺序为：穗粒数＞公顷穗数＞千粒重。因此在选育旱地小麦品种时应注重协调好产量三因素之间的关系,在取得一定的群体穗数的基础上,以千粒重和穗粒数为重点性状。     

The origin,evolution, cultivation,dissemination, and diversification of Asian and African rices

Summary Available evidences drawn from biosystematics, evolutionary biology, biogeography, archaeology, history, anthropology, paleo-geology and paleo-meteorology are pooled to reconstruct the series of events that led to the cosmopolitan cultivation of the Asian cultivated rice (O. sativa) and the regionalized planting of the African cultigen (O. glaberrima) in West Africa. The genus Oryza originated in the Gondwanaland continents and, following the fracture of the supercontinent, became widely distributed in the humid tropics of Africa, South America, South and Southeast Asia, and Oceania. The two cultivated species have had a common progenitor in the distant past. Parallel and independent evolutionary processes occurred in Africa and in Asia, following the sequence of: wild perennialwild annualcultivated annual. The weed races also contributed to the differentiation of the cultivated annuals. The corresponding members of the above series are O. longistaminata Chev. et Roehr., O. barthii A. Chev., O. glaberrima Steud., and the stapfii forms of O. glaberrima in Africa; O. rufipogon Griff., O. nivara Sharma et Shastry, O. sativa L., and the spontanea forms of O. sativa in Asia.The differentiation and diversification of the annuals in South Asia were accelerated by marked climatic changes following the last glacial age, dispersal of plants over latitude or altitude, human selection, and manipulation of the cultural environment.Cultivation of rice began in many parts of South and Southeast Asia, probably first in Ancient India. Cultural techniques such as puddling and transplanting were first developed in north and central China and later transmitted to Southeast Asia. Wetland culture preceded dryland culture in China, but in hilly areas of Southeast Asia, dryland cultivation is older than lowland culture. The planting method progressed from shifting cultivation to direct sowing in permanent fields, then to transplanting in bunded fields.Widespread dispersal of the Asian cultigen led to the formation of three eco-geographic races (Indica. Sinica or Japonica, and Javanica) and distinct cultural types in monsoon Asia (upland, lowland, and deep water). Varietal types changed readily within the span of a millenium, largely due to cultivators' preferences, socio-religious traditions, and population pressure. Genetic differentiation developed parallel to the ecologic diversification process.The African cultigen developed later than the Asian cultigen and has undergone less diversification. The wild races in South America and Oceania retain their primitive features mainly due to lack of cultivation pressure or dispersal.Both the African and Asian rices are still undergoing evolutionary changes at habitats where the wild, weed, and cultivated races co-exist.     

Cities,Skills, and Inequality

ABSTRACT The surge in U.S. wage inequality over the past several decades is now commonly attributed to an increase in the returns paid to skill. Although theories differ with respect to why, specifically, this increase has come about, many agree that it is strongly tied to the increase in the relative supply of skilled (i.e., highly educated) workers in the U.S. labor market. A greater supply of skilled labor, for example, may have induced skill‐biased technological change or generated greater stratification of workers by skill across firms or jobs. Given that metropolitan areas in the U.S. have long possessed more educated populations than non‐metropolitan areas, these theories suggest that the rise in both the returns to skill and wage inequality should have been particularly pronounced in cities. Evidence from the U.S. Census over the period of 1950 to 1990 supports both implications.     

Resources,representation, and authority in Jharkhand,India

Abstract: Jharkhand is at the centre of India's struggles to define ‘the environment’ and ‘economically relevant natural resources’. Although cultural labels are applied by leaders who seek influence in these struggles as well as by many of those people who listen, an ethnonational analytic frame does not help answer the questions: How, why and when has the political idea of environment changed in India? When and why has the Jharkhand movement chosen violent tactics? When and why has the Jharkhand statehood movement realised electoral success? Or, why was Jharkhand state formed? To address such questions, a long range historical‐institutional approach is much more fruitful.     

Interdependence,Rules, and Rural Development

This paper explores land use conflicts between non-farm neighbors and farmers to illustrate the usefulness of the concepts of interdependence, rules, and property rights when doing rural development. Recognizing interdependence and its implications helps economic analysis focus on and understand the types of rules and institutions having the most influence on economic behavior, and thus identify policy alternatives. The resolution of land uses conflicts, for example, unavoidably changes the bundle of rights associated with land, andinfluences who can impose costs of whom; it makes a difference if a large farm has the right to produce odors, flies, or noise that reduces their neighbors' abilities to enjoy theneighbors' own land, or if instead, neighbors have the right to use their property without experiencing farm-produced odors, flies or noise the farm may be unable to use its own land for agriculture without being inconvenienced.     

Unemployment,Growth, and Trade Unions

This paper develops a two‐sector endogenous growth model with a dual labor market caused by the operation of trade unions. Trade unions strive for the extraction of rents from the growth generating imperfectly competitive primary sector. This union behavior results in a non‐competitive wage differential between the primary and secondary (perfectly competitive) sector. How the relationship between growth and unemployment depends on the institutional details of the labor market is analyzed. In general, growth and unemployment are intimately related for two reasons. Unemployment affects the scale of operation of the economy and thereby the growth rate. Growth affects inter‐temporal decisions of workers about where to allocate on the labor market once they are laid off, and thereby it affects equilibrium unemployment.     

Potato genetics,genomics, and applications

Potato has a variety of reproductive uniquenesses besides its clonal propagation by tubers. These traits are controlled by a different kind of genetic control. The reproductive information has been applied to enable interspecific hybridization to enhance valuable traits, such as disease and pest resistances, from the tuber-bearing Solanum gene pool. While progress has been made in potato breeding, many resources have been invested due to the requirements of large populations and long time frame. This is not only due to the general pitfalls in plant breeding, but also due to the complexity of polyploid genetics. Tetraploid genetics is the most prominent aspect associated with potato breeding. Genetic maps and markers have contributed to potato breeding, and genome information further elucidates questions in potato evolution and supports comprehensive potato breeding. Challenges yet remain on recognizing intellectual property rights to breeding and germplasm, and also on regulatory aspects to incorporate modern biotechnology for increasing genetic variation in potato breeding.     

薏苡氮磷钾养分吸收分配及利用特征

旨在为薏苡科学施肥及高产潜力挖掘提供理论依据。以4个薏苡品系为试验材料,于2018—2019年进行大田试验,分析其在不同生育时期氮磷钾(NPK)元素的吸收、分配及利用规律。结果表明,4个薏苡品系的全株总生物量干重在20.5~24.7 t/hm²,地上部分生物产量干重在18.4~22.6 t/hm²之间,但是籽粒产量相对偏低,产量为1969.2~3109.1 kg/hm²。从薏苡抽穗至籽粒成熟,整个植株对NPK元素的吸收和积累量均有增加;N元素在抽穗至扬花期主要分布在茎鞘和叶片,至完全成熟籽粒中N素积累及分配均高于其他部位,而PK元素则主要分配在茎鞘部位。薏苡植株总NPK的吸收量平均为183.93 kg/hm²、62.57 kg/hm²和320.56 kg/hm²,平均吸收比例为N: P: K=2.94: 1: 5.12。薏苡NPK元素的籽粒生产效率和收获指数相对偏低,每100 kg籽粒对NPK养分需求量分别为5.6~7.3 kg,1.7~2.4 kg,8.0~15.0 kg。4个薏苡品系整体物质累积能力强、生物量大,但籽粒对NPK吸收分配和利用效率相对较低,高产潜力的挖掘仍有很大的提升空间。     

不同花生品种氮磷钾钙硫吸收、分配和利用的差异

通过大田随机区组试验,研究优化施肥条件下,不同花生品种氮磷钾钙硫吸收、分配和利用的差异,旨在为豫南花生产区不同品种花生合理施用氮磷钾钙硫肥提供技术支撑。结果表明,花生仁中氮(N)、磷(P)、硫(S)含量最高,其中,‘驻花1号’的N、‘开农71’的P、‘冀花13’的S含量最高,分别为5.150%、0.558%、0.277%;花生茎叶中钾(K)、钙(Ca)含量最高,其中‘中花16’茎叶中K、‘中花24’茎叶中Ca含量最高,分别为1.637%、0.940%。花生仁中N、P、S积累量最高,其中,‘豫花40’花生仁中N、P、S积累量最高,分别为288.436、25.505、15.263 kg/hm²;花生茎叶中K、Ca积累量最高,其中‘豫花37’、‘中花24’茎叶中K、Ca积累量最高,分别为80.760、54.084 kg/hm²。每形成100 kg荚果需求的N、P₂O₅、K₂O、CaO、S养分量分别3.920~5.042、0.905~1.293、1.626~2.721、0.777~1.150、0.270~0.343 kg。本试验条件下,每形成100 kg荚果,‘豫花22’需求的氮最低,‘中花24’需求的磷最低,‘商花5号’需求的钾、钙、硫最低;‘驻花1号’需求的氮最高,‘开农71’需求的磷、钾、硫最高,‘中花24’需求的钙最高。