以旅大红骨群自交系为父本的玉米杂优组合F1杂种优势研究

以5个来源不同的玉米自交系组成的杂交组合为材料，对旅大红骨群自交系为父本的F。产量等性状的杂种优势进行了初步研究，结果表明：旅大红骨群与Reid，PA，PB群组合的F。的杂种优势均随性状不同而有所差异；在种质改良过程中PA×旅组合后代的杂种优势较强，从抗旱性角度来看Reid×旅组合具有显著优势；旅大红骨群自交系作为父本对后代在多个性状上的影响大于母本自交系，在利用不同性状对后代进行改良时应注重旅群与其他群不同组合模式的应用。     

对我国玉米主产区主要种质遗传类群划分与利用分析

根据系谱关系和配合力(杂种优势)将我国玉米主产区主要自交系分为Reid、唐四平头(四平头)、旅大红骨(旅红)、Lancaster、金皇后、获嘉白马牙(获马)以及其他7个种质类群。     

热带玉米与温带玉米种质杂交农艺性状的差异

以热带玉米和温带玉米为亲本,系统地研究了不同种质玉米杂交后代农艺性状的差异。结果表明:苗期全株干物质积累量温×温>热×热>热×温,地上部干物质量热×热>热×温>温×温,地下部分表现趋势与地上相反;生长初期株高温×温>热×温>热×热,随着生长进程的推移,组合间株高呈现出相反的趋势;不同种质间杂交后代苗期叶片数和出叶速率没有明显差异;杂交组合中含热带种质的比例越高,最大面积叶片出现的高度越高,面积较大的叶片数相对较多;热带种质所含比例越大,后代雄穗分支数越多。热带种质带来的株高增加,主要源于植株中下部节间的伸长。     

普通玉米种质及双回交对爆裂玉米改良效果初报

对5个普通玉米自交系与4个爆裂玉米自交系组配的20个普×爆组合F3、BC11F2、BC12F2的膨爆特性及其与两类亲本关系的研究结果表明:普通玉米种质对普×爆后代的膨爆特性影响显著,选择适宜的普通玉米种质、恰当组配普×爆组合,对于普通玉米种质在爆裂玉米育种中的有效利用起着关键性的作用;普×爆组合F3的膨爆特性均较差,一代回交可使其显著提高,最高分别为F3的750,2200,1100,基本达到对爆裂玉米膨爆特性的要求指标;双回交世代间差异不显著。     

改良Reid类群种质及组配的杂交种在河南省的应用状况

河南省生产上大面积应用的玉米杂交种其亲本的主要来源于瑞德黄马牙、旅大红骨、塘四平头,近年来又从省外引入和选育一批78599等改良种(P群)。重点介绍了改良Reid类群种质的特征特性和应用概况。通过改良Reid类群种质与塘四平头、旅大红骨、P群及其他类群组配的杂交种分析,阐述了改良Reid类群种质的杂交优势模式及该类群种质在河南省玉米育种和杂交种生产中所起的重大作用。     

以旅大红骨群自交系为父本的玉米杂优组合F1杂种优势研究

以5个来源不同的玉米自交系组成的杂交组合为材料,对旅大红骨群自交系为父本的F1产量等性状的杂种优势进行了初步研究,结果表明:旅大红骨群与Reid,PA,PB群组合的F1的杂种优势均随性状不同而有所差异;在种质改良过程中PA×旅组合后代的杂种优势较强,从抗旱性角度来看Reid×旅组合具有显著优势;旅大红骨群自交系作为父本对后代在多个性状上的影响大于母本自交系,在利用不同性状对后代进行改良时应注重旅群与其他群不同组合模式的应用。     

玉米自交系铁98033-1的杂种优势研究

本文以自选系铁98033-1和其他8个国内常用的优良玉米自交系为亲本,按griffing4双列杂交模式设计,对其杂种优势进行研究。结果表明:铁98033-1具有明显的降低杂交组合株高的作用,所配组合具有较强的抗倒伏性和抗病性(大斑病、小斑病、丝黑穗病)。铁98033-1与旅大红骨种质和唐四平头种质之间具有很强的杂种优势,而与瑞得种质、兰卡斯特种质及PN种质之间优势不大,可用来进行种质改良和创新。     

美国玉米种质改良系主要农艺性状的配合力及杂种优势分析

试验采用NCⅡ遗传交配设计,以分属于5个杂种优势群的自交系吉853、S122、龙抗11、铁C 8605-2、丹599为测验种,与5个美国玉米种质改良系组配25个杂交组合,分析5个美国玉米种质改良系的主要农艺性状的配合力及杂种优势.结果表明,自交系WY1和WY3单株产量及相关性状一般配合力表现较好,在玉米育种中有较大的利用潜力;组合WY 3×龙抗11、WY5×吉853、WY4×S122是产量及相关性状特殊配合力综合表现优良的前3个组合;WY3×S122、WY1×S122、WY1×丹599、WY4×S122、WY1×吉853是单株产量总配合力和杂种优势表现突出的组合;美国玉米种质改良自交系可与旅大红骨、塘四平头、温带Ⅰ群类群的玉米自交系杂交组配出强优势的玉米杂交种.     

黑龙江省玉米主要杂交优势利用模式的研究

利用从初步确定的黑龙江省主要玉米种质四大优势类群中各选取2个自交系，按Griffing4模式配制得到28个双列杂交种，并用这8个自交系与其它类群的3个自交系按NC-Ⅱ设计进行不完全双列杂交，得到24个杂交组合。试验结果表明，长3群×Mo17群为长穗、大粒、熟期适宜类型，是适于黑龙江省生态条件要求的杂优模式。Mo17群×唐四平头群为大穗、大粒型、中晚熟杂种优势利用模式。长3群×红玉米群为稳产、早熟杂种优势利用模式。长3群×唐四平头群及甸11×唐四平头群、吉818×Mo17群具有较高的产量杂种优势，目前生产上无这几种杂优模式品种应用，值得进一步研究。`     

先锋玉米种质改良系的配合力分析

采用NCII设计,在6万株·hm-2密度下,对5份先锋玉米种质的遗传改良系和旅大红骨群自交系组配的25个玉米杂交组合进行穗部性状配合力分析,总结了这5份先锋玉米改良系的利用价值和改良成效。结果表明:JK 18和JK 20的单株产量一般配合力高,由此2自交系共组配出4个高产组合,有极大的增产潜力。JK 80单株产量一般配合力低,但有1个高产组合,可以进一步改良,发掘利用。先锋种质改良系×旅大红骨组配模式较国内Reid×旅大红骨组配模式的耐密性有所改良,有较大的应用潜力,可在高产密植型杂交种选育中进行应用。     

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.     

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.     

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.     

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。     

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.     

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。     

Blood,timber, and the state in West Kalimantan,Indonesia

Abstract: West Kalimantan (West Borneo) has a history of violent communal conflict.¹ It also has extensive forests that have been looted for decades. The argument will be that these two are linked, but not by the grievances of the forest dwellers. Except in its first few days, the two main episodes of 1997 and 1999 were not driven mainly by grievances among marginal groups. Rather, explanations based on the ‘resource curse’ carry more weight. These focus attention on the contested nature of the state, rather than on rebellious activities of marginal groups. When state institutions were thrown into disarray by the sudden resignation of President Suharto in 1998, Dayak militants already close to state power rewrote the rules of local politics by demonstratively ‘cleansing’ certain areas of an unpopular immigrant minority. This theatrical manoeuvre impressed political rivals sufficiently to allow Dayaks to gain control over several timber‐rich districts, which had a thriving black economy. Malays later imitated these techniques to stem the tide.