水稻待测粳型亲籼系花粉育性和小穗育性的遗传研究

目的:弄清粳型亲籼系花粉育性和小穗育性的遗传规律,选育优良水稻品种。方法:3个杂交组合的亲本、杂种F1代和杂种F2代研究了待测粳型亲籼系花粉育性和小穗育性的遗传规律。结果:G2410亲籼并与籼稻的亲缘关系较远,是粳型亲籼系。粳型亲籼系花粉育性和小穗育性受多基因控制,在一个具体组合中,常受1-2个主基因和多个微效多基因控制,各主基因之间的遗传力大小常有不同,控制小穗育性的基因数比控制花粉育性的基因数更多。     

胡萝卜雄性不育株的发现及其形态特征

对田间发现的胡萝卜雄性不育株作了调查与观察,并与可育株作了形态特征比较．结果表明：（1）胡萝卜雄性不育株占群体总株数的0．786％．（2）不育花花瓣为绿色,雄蕊为绿色瓣化型,不完全花瓣状,无花丝、花粉;花柱、柱头及子房完全被花瓣状结构所包裹,不易被发现．可育花花瓣为白色,花丝细长、白色,白色花药肥厚,布满花粉;花柱、柱头及子房明显．并观察到不育株育性对温度具敏感性．     

新型两用系363S在泸州育性表现的初步观察

对两用系新资源材料363S在泸州的育性表现进行了初步观察，结果表明：363S在泸州生态条件下，仍表现出明显的“低温诱导不育高温诱导可育”的特点。该不育系正常染色花粉百分率与其小穗育性表现不一致，以小穗育性为标准，在泸州7月中下旬为不育期，小穗不育度99．5％以上。诱导不育和可育的临界温度指标需进一步研究。     

几个水稻光敏核不育系在绵阳的育性表现初步观察

本文对近两年来引进的几个水稻光敏核不育系的育性表现进行了观察分析,结果表明:两个粳型光敏核不育系双8—2S和农垦58S对温度不敏感,在9月4日以前抽穗的均表现为不育,花粉不育度≥99.8％;几个籼型光敏核不育系对温度都存在不同程度的敏感性,随温度的变化均不同程度表现育性波动;初步探讨了育性和温度、育性和播期的关系以及水稻光敏核不育系在生产上利用的可能性。     

小麦不同类型胞质不育系花药和花粉形态的观察

初步观察了１２ 种小麦不同类型胞质不育系花药和花粉形态特征，结果表明：由于细胞质类型不同，其不育系花药和花粉形态也表现出一定差异．不育系花药形态有短柱形、箭形、扁平形以及雄蕊退化和雄蕊心皮化多种情况，花粉形态异常、败育，有以典败为主、以圆败为主和典败圆败比例大致相等３ 种类型     

大花溲疏的性表达特征及其繁育系统研究

野外实地观测了虎耳草科灌木大花溲疏(Deutzia grandiflora Bge)的开花物候、访花者种类、访花频率和访花行为,并对其花粉的主要营养物质类型、可育率、与胚珠的比(P/O)、活力及柱头可授性进行了检测.结果表明:(1)大花溲疏居群花期约22 d,单花花期约6 d,花两性,雄蕊因长度不同而分成两轮,长雄蕊花药早于短雄蕊花药开裂,短雄蕊花药含花粉数较长雄蕊多,花粉均为淀粉型;(2)长、短雄蕊的花粉育性均达90%以上,长、短雄蕊花药散粉后花粉活力的动态变化基本一致(p0.05),花粉活力均在花药刚开裂时最高,之后明显下降;(3)柱头可授期约为3d,最佳授粉期在开花后3—6 h;(4)P/O值为2998.54±80.71,繁育系统属异交;套袋试验和传粉媒介观察结果表明大花溲疏以异花传粉为主;(5)在大花溲疏上记录到的访花者至少有18种,分属于膜翅目、鳞翅目、双翅目和半翅目,其中,蜂类、蝇类为有效传粉者.     

怎样使蜂群多采槐蜜？

1、多育“采蜜蜂”。刺槐一般在4月底至5月上中旬流蜜。此前，天然花粉很少，应将脱脂大豆粉蒸熟，每千克中加入200克蜂蜜搅匀装脾，用棉花浸水放在蜂路上进行奖励饲喂。同时，用25％哒螨灵逐脾匀喷以杀灭螨虫。还可在     

不同柚品种抗旱性观察

柚属亚热带常绿果树，喜温暖湿润环境，整个生育期需水量大，不耐土壤干旱。但不同轴品种对土壤干旱抗性不同。1995年夏季绵阳市遇高温干旱，5～6月降水量仅为77.6mm，比1994年同期降水量182．6mm低105mm，6月均温为25．57℃，高于1994年同期1．84℃，许多植物表现出干旱受害症状。1995年，我们不失时机地对不同柚品种抗旱性进行了调查研究。1材料与方法供试树为绵阳经专园艺场168株5年生权砧（PoncirustrifoliataRaf）柚树（Citrusgrandis），品种包括晚白柚、梁平柚、沙田柚，园头形树冠，常规管理。试验地为红壤丘陵坡地，土质一般。于…     

一粒小麦小孢子发生过程中的细胞并合

经检测,在正常的一粒小麦(Triticum monococumL.)中有细胞并合发生.细胞并合仅存在于减数分裂的凝线期,核物质从一个花粉母细胞到邻近花粉母细胞的转移是通过胞质通道进行的.细胞并合的发生是自发的,且在花粉母细胞中有方向性本次调查中未观察到花粉败育现象,具细胞并合的植株结实也未受影响.中期Ⅰ一些花粉母细胞的染色体数目有变化,这造成一些花粉母细胞在后期Ⅰ时出现非正常分离.由于异常花粉母细胞很少,孟德尔分离比例仍然成立.这被认为是在常规遗传分析中不能检测出细胞并合的效应的原因.     

36例灯盏花粉针与复方右旋糖酐治疗神经根型颈椎病的疗效观察

目的观察灯盏花粉针与复方右旋糖酐治疗神经根型颈椎病的临床疗效。方法神经根型颈椎病患者36例,静脉注射灯盏花粉针与复方右旋糖酐注射液。结果36例中显效86．1％,有效8.3％,无效5．6％,临床总有效率为94．4％。结论灯盏花粉针与复方右旋糖酐联合应用是治疗神经根型颈椎病有效药物。     

我国省内省外流动人口生育水平差异及原因探析

根据2005年全国1％人口抽样调查、“五普”等资料数据,通过交叉分析和相关性分析对我国省内省外的流动人口生育水平及影响因素进行了描述和探析。研究结果显示：我国省内流动人口比省外流动人口的时期生育水平高,两者的一般生育率分别为45．47‰与34．17‰,总和生育率分别为1．215与0．817,终身生育水平低,省内流动人口的二孩及多孩率低于省外流动人口;因婚姻家庭因素而流动的人口在各年龄段的分布与流动人口年龄结构的错位,是造成省外流动人口时期生育水平低于省内流动人口的根本原因;总和生育率在反映省外流动人口生育水平时,并不能显示省外流动人口因家庭、婚姻化的发展而导致的生育水平上升,所以并不能反映省外流动人口真实的终身生育水平。     

稳定低生育水平战略决策的回顾与前瞻

我国提出计划生育政策和稳定低生育水平的战略决策有深刻的历史背景,是对我国国情的理性判断.而当前我国的人口问题已不同于实行计划生育以前的人口问题,除了人口数量依然需要给予足够的重视外,人口质量、结构、流动迁移等问题比以前更为复杂多样,也需要得到充分关注.如果不能把低生育水平稳定住,各种人口问题会变得更加严峻,因此,稳定低生育水平是我国在人口问题上重大战略决策的继续和完善,是理性的选择.通过节约人口投资、推动城乡改革、提高我国整体实力和国际竞争力、缓解人口对资源环境的压力,为提升两代人的人力资本创造条件.稳定低生育率能促进生产力发展,提高人民生活质量,实现社会的和谐进步.此外,稳定低生育率还为我国庞大的人口转化为丰富的人力资源创造条件.虽然继续稳定低生育率也必将伴随一些负面影响,但总的来说对我国今后经济社会发展利大于弊.生育水平并不是越低越好,根据人口发展的特点,结合我国的实际情况,总和生育率(TFR)稳定在1.8左右在一个时期内是较优的选择.     

马克思的土地肥力观述评

土地肥力是土地的客观属性;土地肥力包括了许多要素;具有肥力的土地是农业基本生产资料;土地自然肥力是自然历史过程的产物;土地经济肥力是人工肥力和自然肥力的统一体;科学技术在土地肥力发展中起着十分重要的作用;自然土壤向农业土壤的转化和发展,是人类生活和生产发展的必然产物。     

上海市生育意愿30年的演变历程

通过对1980年初以来上海开展的数次生育意愿调查结果的回顾与梳理,展现了过去30年上海人口生育意愿(主要是意愿子女数和意愿子女性别)的演变历程:意愿子女数呈不断减少趋势;不同群体间生育意愿数虽存在差异,但都低于2个孩子。同时,总和生育率、孩次率等多项指标显示,上海人口的实际生育已长期处于很低水平。文中历次调查的意愿生育子女数与相应年份总和生育率的纵向比较可表明,在低生育水平社会,人们的实际生育水平一般低于所报告的意愿生育水平。     

Religion, Religiousness and Fertility in the US and in Europe

This article aims to assess the role of religion and religiousness in engendering higher US fertility compared to Europe. Religion is important in the life of one-half of US women, whereas not even for one of six Europeans. By every available measure, American women are more religious than European women. Catholic and Protestant women have notably higher fertility than those not belonging to any denomination in the US and across Europe. In all European regions and in the United States as well as among all denominations the more devout have more children. However, women in Northern and Western Europe who are the least religious have equivalent or even higher fertility than women in the US, and notably higher fertility than those in Southern Europe. This suggests that forces other than religion and religiousness are also important in their impact on childbearing. A multivariate analysis demonstrates that relatively “traditional” socio-economic covariates (age, marital status, residence, education, and income) do not substantially change the positive association of religiousness and fertility. Finally, if Europeans were as religious as Americans one might theoretically expect a small fertility increase for Europe as a whole, but considerably more for Western Europe.     

Value changes and the dimensions of familism in the European community

It is argued in this article that family formation is conditioned not only by economic factors (more particularly, opportunity structures), but also by ideational changes: the economic factors produce period fluctuations that are superimposed on long-term (and often cohort-driven) ideational effects. Value orientations are explored and compared across countries and across age groups using the internationally-comparable data sets provided by the European Values Studies. The analysis indicates the existence of two latent dimensions with respect to familism: tolerance of non-conformism in family formation, and the meaning attached to parenthood. These two dimensions are not completely distinct from each other though, and both are related to religious and political variables (religiosity, ‘post-materialism’, nationalism, leftism, etc.). Theoretical links are made both with Easterlin's hypothesis which implies fluctuating fertility levels and with Simon's thesis concerning the importance of ‘civil religion’ in supporting fertility. The results are, however, largely in line with Ariès' thesis of two successive and quite distinct fertility transitions in the West, and suggest that fertility is very likely to remain at below-replacement levels.     

我国稳定低生育水平影响因素分析

影响我国稳定低生育水平的因素主要有区域生育水平的差异、现行工作机制的滞后、城乡生育水平的差异、群众生育观念与现行生育政策的矛盾等。因此,必须积极采取相应措施,缩小区域之间和城乡之间生育水平的差距,完善计划生育工作机制,从根本上转变群众的生育观念,稳定来之不易的低生育水平。     

水稻幼苗硝酸还原酶与叶绿素和硝态氮的含量及铵态氮吸收的关系

三种蛋白质含量不同的水稻品种,其幼苗的硝酸还原酶的活力不同,叶绿素和硝态氮的含量也不同,凡叶绿素和硝态氮含量高的其硝酸还原酶的活力也高,凡叶绿素和硝态氮含量低的其硝酸还原酶的活力也低,华03的谷粒蛋白质含量高,其幼苗根系对铵态氮的吸收能力也强。上述结果说明,蛋白质含量不同的水稻品种,其生理生化差异在幼苗期已表现对氮的吸收和利用不同。     

Fertility in Advanced Societies: A Review of Research

This paper provides a review of fertility research in advanced societies, societies in which birth control is the default option. The central aim is to provide a comprehensive review that summarizes how contemporary research has explained ongoing and expected fertility changes across time and space (i.e., cross- and within-country heterogeneity). A secondary aim is to provide an analytical synthesis of the core determinants of fertility, grouping them within the analytical level in which they operate. Determinants are positioned at the individual and/or couple level (micro-level), social relationships and social networks (meso-level); and, by cultural and institutional settings (macro-level). The focus is both on the quantum and on the tempo of fertility, with a particular focus on the postponement of childbearing. The review incorporates both theoretical and empirical contributions, with attention placed on empirically tested research and whether results support or falsify existing theoretical expectations. Attention is also devoted to causality and endogeneity issues. The paper concludes with an outline of the current challenges and opportunities for future research.     

Urban versus Rural: Fertility Decline in the Cities and Rural Districts of Prussia, 1875 to 1910

Marital fertility in 54 Prussian cities and 407 Prussian Kreise (administrative areas) is analyzed using unusually rich and detailed socioeconomic and demographic data from eight quinquennial census between 1875 and 1910. Pooled cross-section time series methods are used to examine influences on marital fertility level and on marital fertility decline, focusing particularly on fertility differences according to level of urbanization. Increases in female labour force participation rate and income, the growth of financial services and communications, improvement in education, and reduction in infant mortality account for most of the marital fertility decline in 19th century Prussia. In 1875, rural and urban fertility were similar but by 1910, urban fertility was far lower than rural in part because the values of some of these variables changed more rapidly in the cities, and in part because some of these variables had stronger effects in urban settings.