高密育种及自交系的选育途径

本文阐述了高密度在玉米育种中的应用状况及玉米在高密的下的表现,并对高密育种中自交系的选育途径进行了探讨。     

河北农业大学创建日期及其历史沿革的考证

根据翔实的历史资料对河北农业大学创建的时间、地点、等级、主要负责人、学生等方面进行了充分的考证，从而充分论证了河北农业大学创建于公元1902年，并且创建时即为农学高等程度。     

特用大豆品种选育新进展

本文报道了黑龙江省农业科学院作物育种研究所,利用野生大豆及优异种质资源选育出黑大豆、小粒大豆、青大豆等特用大豆新品种,为发展特色农业及加工企业提供了优良品种和优质原料.     

Kin selection and the evolution of monogamy

A two-locus genetic model is studied in which one locus controls the tendency of individuals to act altruistically toward siblings and the other locus controls the mating habits of females. It is demonstrated that genetic variation at the altruism locus is often sufficient to induce an increase in the frequency of genes that cause females to produce all of their offspring with a single mate. This occurs because of nonrandom associations that develop between genes that cause altruism and those that affect female mating behavior. The results provide a new explanation for the evolution of monogamy, and they suggest a previously unexplored mechanism for the evolution of a variety of other behavioral traits as well.     

甘蔗有性杂交育种亲本选配

对江西甘蔗杂交亲本研究作了总结,对已鉴定品种和20世纪90年代后进入品比试验的品种进行了组合和育成品种亲本利用次数归类;总结了亲本选配的主要经验,提出今后亲本选配应多选用新CP、Roc、CO品种和赣14号、赣17号、赣南95/108等品种,并注意选用野生种F2-F5代材料,利用其抗逆强的优势进行杂交组配。     

基因组选择及其在猪育种中的应用

基因组选择(Genomic Selection,GS)实际上是全基因组范围内的标记辅助选择(Marker Assisted Selection,MAS)。基因组选择能大大提高畜禽育种的遗传进展,同时还能降低群体的近交量,是近年畜禽育种界的研究热点。综述了基因组选择的研究进展,并分析了基因组选择在猪育种中的应用前景和面临的挑战。     

筛选和培育镉低积累水稻品种的进展和问题探讨

推广镉低积累品种是重金属污染农田安全利用的前提,筛选和培育镉低积累水稻品种已经成为水稻育种家的一个重要任务。近年来人们对镉低积累品种的筛选和培育工作投入较大的精力,但是由于稻米镉积累是一个复杂性状,受环境和基因型共同调控,人们对重金属低积累品种的定义、特征、筛选认定方法等并没有形成一致意见。本文主要介绍了最近几年国内外在镉低积累水稻品种筛选和定向培育方面的最新成果。在此基础上,从遗传学和农学角度提出了我们对镉低积累品种的定义及其特征的理解:镉低积累品种是指在相同环境条件下稻米镉积累量相对较低的品种,其在高镉(有效态)背景下稻米镉含量相对较低,中低镉背景下能达标,而低镉土壤背景下不超标。虽然稻米镉积累受环境和遗传因素共同调控,但镉积累特性遗传率高,降低稻米镉积累量不影响水稻的生育期、产量及其他必需微量元素的含量。镉低积累品种和镉高积累品种稻米镉积累量的差异随环境变化而变化,在高镉背景下相差较大,而在低镉土壤背景下差异变小。因此筛选认定镉低积累品种时,我们建议先在高镉背景下比较不同品种的相对镉含量,筛选镉积累相对较低的品种,然后在低镉条件下评价其产品的达标频率,确定其安全生产所需的环境条件。     

Energetic and fitness costs of mismatching resource supply and demand in seasonally breeding birds

By advancing spring leaf flush and ensuing food availability, climatic warming results in a mismatch between the timing of peak food supply and nestling demand, shifting the optimal time for reproduction in birds. Two populations of blue tits (Parus caeruleus) that breed at different dates in similar, but spatially distinct, habitat types in Corsica and southern France provide a unique opportunity to quantify the energetic and fitness consequences when breeding is mismatched with local productivity. As food supply and demand become progressively mismatched, the increased cost of rearing young pushes the metabolic effort of adults beyond their apparent sustainable limit, drastically reducing the persistence of adults in the breeding population. We provide evidence that the economics of parental foraging and limits to sustainable metabolic effort are key selective forces underlying synchronized seasonal breeding and long-term shifts in breeding date in response to climatic change.     

Reduced egg investment can conceal helper effects in cooperatively breeding birds

Cooperative breeding systems are characterized by nonbreeding helpers that assist breeders in offspring care. However, the benefits to offspring of being fed by parents and helpers in cooperatively breeding birds can be difficult to detect. We offer experimental evidence that helper effects can be obscured by an undocumented maternal tactic. In superb fairy-wrens (Malurus cyaneus), mothers breeding in the presence of helpers lay smaller eggs of lower nutritional content that produce lighter chicks, as compared with those laying eggs in the absence of helpers. Helpers compensate fully for such reductions in investment and allow mothers to benefit through increased survival to the next breeding season. We suggest that failure to consider maternal egg-investment strategies can lead to underestimation of the force of selection acting on helping in avian cooperative breeders.     

Natural selection and developmental constraints in the evolution of allometries

In animals, scaling relationships between appendages and body size exhibit high interspecific variation but low intraspecific variation. This pattern could result from natural selection for specific allometries or from developmental constraints on patterns of differential growth. We performed artificial selection on the allometry between forewing area and body size in a butterfly to test for developmental constraints, and then used the resultant increased range of phenotypic variation to quantify natural selection on the scaling relationship. Our results show that the short-term evolution of allometries is not limited by developmental constraints. Instead, scaling relationships are shaped by strong natural selection.     

基因组选择及其在作物育种中的应用

基因组选择(GS)利用所有可利用的分子标记构建预测模型,并基于此模型估计个体的育种价值,是一种新型的、针对数量性状由微效多基因控制这一育种问题更高效的、具有广阔前景的分子辅助育种方法。概述了GS的原理和常用方法,并基于GS的影响因素探讨了提高其准确性的各种方法,展望了GS在作物育种中的应用,提出构建GS平台的思路。     

同源四倍体茄子育种的选择Ⅱ.株形 指数的遗传多样性及其相关选择

同源四倍体茄子育种选择的较底世代(C5代)株形和结果正常的植株比例很低(9.19%).3个不同母本系的12个株系株形指数平均为0.4779,株形指数的广义遗传率h2B=96.39%±3.52%,株形指数与植株平均结果数呈极强的负相关性,遗传相关系数rs=-0.9989,相关遗传力hxy=95.22%.随着轮回选择世代的增加以及选系遗传稳定性的增强,株形指数不仅与植株总产量呈现强的直线正相关性(rg=0.8871,hxy=86.18%)而且也与早熟性--前期产量呈现强的正相关性(rg=9592,hxy=93.64%).植株高度、茎粗、株幅、叶形指数、始花节位等表型性状与株形指数间存在着极显著的遗传相关性,其相关遗传力及间接选择效率:叶形指数＞株幅＞始花节位＞茎粗＞株高.其中株高、茎粗及始花节位为负值,叶形指数与株幅为正值,与选择方向相同.     

综合指数法在番鸭选育中的应用

应用综合指数选择法对白番鸭父系、母系进行继代选育.结果表明:第3世代父系10周龄公母鸭体重比母系公母鸭分别重280.18g(P<0.05)和242.91g(P<0.05).父系经2世代选择,公母鸭26周龄体重比0世代分别增加330和80g;而母系经2世代选择,公母鸭26周龄体重增加不显著(P>0.05).父系经2世代选择,其母鸭56周龄蛋重比0世代重3.41g,每只母鸭平均产蛋量增加3.86枚.母系经2世代选择,其56周龄产蛋量比0世代增加8枚,蛋重增加0.45g.可见应用综合指数选择法连续2世代选育能明显提高白番鸭的生产性能.     

玉米杂交种中种868号的选育

中种868生育期128 d,需≥10℃积温2 700℃,属中晚熟玉米杂交种,具有高产、稳产、多抗等特点,适宜在吉林省、黑龙江省、内蒙古、辽宁省等地区种植,种植密度以4.2万~4.5万株/hm2为宜;制种时,母本与1/2父本同期播种,另外1/2父本在父母本出芽以后播种,种植比例1:4.     

棉花品种选择和播期确定的动态知识模型

基于献资料和研究成果，利用生态学原理和多目标决策方法，建立了棉花种植制度和品种选择的定量知识模型，进一步提出了与品种、产量目标、种植方式等相适应的播期确定动态知识模型。利用南京、安阳、石河子和太原等生态点的不同品种和产量目标资料对所建知识模型进行了检验。结果表明，知识模型对品种选择和播期设计具有较好的决策性和适用性。