黑穗醋栗优良杂交亲本筛选及组配试验

以“J96-16-5”、“y96-9-4”、“B98-2-4”和“B98-2-7”为试材,“奥依宾”为对照品种,对4个黑穗醋栗优良品系进行综合性状的比较与评价.结果表明:优质丰产性状突出的品系为“J96-16-5”、“Y96-9-4”和“B98-2-4”.选择“J96-16-5”作为母本,“晚丰”、“Y96-9-4”、“奥依宾”、“B98-2-4”作为父本,配置杂交组合,进行杂交试验.4个组合坐果率均正常,获得了较理想的杂交种子数量.     

籼型杂种稻谷品质性状的杂种优势表现

以3个野败型雄性不育系（A）和10个恢复系（R）为材料，配成3×10=30个A×R杂种，研究籼型杂种稻谷9个品质性状的杂种优势表现。结果表明：（1）杂种的平均表现，在精米率(HP)、粒长(GL)、垩白度(CS)、直链淀粉含量(AC)和胶稠度(GC)上，都介于雌亲和雄亲平均数之间；在粒宽(GW)、粒重(WG)和碱扩值(ASV)上既大于雌亲又大于雄亲     

Genetic variation for resistance to Phytophthora fragariae var. rubi in red raspberries

Summary The inheritance of root rot resistance in red raspberry, caused by Phytophtora fragariae var. rubi, was investigated using two experimental breeding designs. Design A was not randomly mated and genetic parameters could not be calculated. Design B was therefore randomly mated to make it possible to do such estimations. Considerable genetic variation was associated with the recorded traits on seedlings tested in a glasshouse. Disease index and % survival were both found to be highly heritable with broad sense heritabilities (H²) close to 0.9 in each design. Estimates of narrow sense heritability (h²), indicated that progress towards resistance would be moderate. In the first design the cultivars Festival, Asker, Boyne and Sentry and the clones N85-02-13 and N85-06-140 had high general combining abilities. Some crosses had a high specific combining ability indicating the presence of non-additive genetic variation.     

Number of crosses and population size for participatory and classical plant breeding

In the breeding of self-pollinating crops, crossing creates variation upon which selection is exerted. If the value of crosses cannot be predicted then this uncertainty means that many crosses need to be made. However, since there is a limit to the capacity of a breeding programme, more numerous crosses result in each cross having a small population size, fewer progenies in later generations and a lower probability of recovering good genotypes from each cross. Published theory on the optimum number of crosses in a plant breeding programme, for a predominantly self-pollinating crop, usually assumes that all crosses are equal value. This overestimates the number of crosses required. When the optimum size of a population in a favourable cross is considered, theory predicts that very large populations are desirable. The required population size is even larger if linkage of loci controlling different traits is also considered. Hence, in an inbreeding crop, one possible strategy is to select a small number of crosses that are considered favourable and produce large populations from them to increase the probability of recovering superior genotypes. In an out breeding crop, the analogy is a few composites with large population sizes. This low-cross-number strategy is ideally suited to the particular constraints and advantages of participatory plant breeding. Such an approach, although not essential, may still be advantageous in classical breeding. When a breeding programme is based on few crosses, which parents are chosen is crucial and farmer participatory methods are highly effective in narrowing the choice. Modified bulk population breeding methods, and recurrent selection are desirable strategies in the participatory plant breeding of self-pollinating crops when combined with a low-cross-number approach. This revised version was published online in August 2006 with corrections to the Cover Date.     

木荷1代育种群体遗传多样性分析

木荷为我国亚热带地区主要的珍贵优质阔叶用材树种和生态防护树种.利用筛选的14对多态性强的SSR引物,对木荷1代育种群体中来自15个产地133个亲本进行遗传多样性分析,为其优异种质资源保存、杂交亲本选配及新种质创制提供科学依据.结果表明:14对引物共扩增86个位点,每对引物检测到的等位基因数(Na)变异范围为2～11个,平均等位基因数(Na)为6.14个,平均有效等位基因数(Ne)为3.23个,平均观察杂合度(Ho)为0.572 0,平均Shannon信息指数(I)和平均Nei's基因多样性指数(Nei)分别为1.224 7和0.599 0,说明木荷1代育种群体具有丰富的遗传多样性,其中,福建建瓯产地遗传多样性最高,浙江遂昌产地遗传多样性最低.木荷1代育种群体中成对亲本间遗传距离为0.023 3～1.633 8,平均为0.6067.不同产地遗传多样性与纬度呈显著的负相关关系(r=-0.5162,p=0.048 9).通过UPGMA聚类,可将133个育种亲本分成3个类群,其中,类群3又分为4个亚类群.木荷亲本选配时,应充分考虑优树的产地来源.     

化杀杂种小麦优势表现分析

利用化学杂交剂ＳＣ２０５３ 诱导的小麦不育系为母本,与４ 个品质优良的丰产品种配制组合１０８ 个,研究了２９ 个组合各性状的优势表现。结果表明,Ｆ１ 各性状的杂种优势依次为主穗长＞ 千粒重＞ 主穗粒数＞ 主穗结实小穗数＞ 公顷穗数＞ 株高。通过试验,筛选出６ 个强优势组合。     

中国本土割手密血缘创新亲本材料的利用潜力分析

 以云割F1,F2,崖城71-374（F2）及其后代与国内外常用亲本配成的30个杂交组合为研究材料,分析其有性世代主要性状的遗传效应。结果表明：母本、父本及选配方式的不同后代的主要性状均表现极显著差异（P<001）,平均遗传力依次为：组合（896%）＞父本（764%）＞母本（706%）;后代主要性状的遗传力大小顺序为锤度＞有效茎＞茎径＞株高＞蔗产量＞糖产量;云割F197-105,云割F197-147,云割F203-7,云割F203-78,云割F180-189,云瑞05-458,云割F203-72等7个材料做父本的一般配合力优于优良亲本崖城71-374,可作为优良创新种质、亲本材料重点利用;云蔗99-155,云割F203-315,云蔗89-7,桂糖92-66,内江00-118可作为高糖亲本利用;德蔗93-88×云割F203-7,CP65-357×云割F180-189,粤糖93-159×云割F180-189可作为高产、高糖优良创新组合重点利用;CP65-357×云割F197-105,粤糖93-159×云割F197-147,云瑞05-344×云割F197-105,Q141×云割F197-105,云瑞05-189×云割F203-78,云瑞05-344×云瑞05-458,农林03-1×云割F197-105等可作为高生物量能源甘蔗育种优良创新组合重点利用。     

黑龙江省主要玉米品种及其亲本光温反应特性研究 Ⅰ12个玉米品种及其亲本的光反应特性

以黑龙江省12个常用玉米品种及其亲本为试验材料,研究其光反应特性,通过对材料的每日阶段遮光处理的结果分析,缩短光照直接影响玉米品种的生育阶段.其中出苗至抽雄期遮光处理与正常光照的叶龄值差异显著,可作为衡量光反应特性的指标性状.缩短光照后使大部分玉米杂交种及自交系的花期提前,其中四早六、龙单21、绥玉7号、1134、龙系85、H172、4F1对光敏感;海玉4号、四单16、本育9号、合344、434、706、446光反应迟钝.遮光处理对品种形态性状株高、穗位高、叶片数及雄穗分枝数都有不同程度的影响.其影响大小程度依次为:穗位高>株高>雄穗分支>叶片数.     

基于SSR和RSAP的龙须菜作图群体多态性标记 开发与亲本间遗传距离的估计与比较

遗传连锁图谱的构建是实现分子标记辅助育种与数量性状定位的必要手段,为构建龙须菜(Gracilariopsis lemaneiformis)遗传连锁图谱提供多态性分子标记,本实验共采用400对SSR引物和91对RSAP引物对组合,对龙须菜两个F1代配子体作图群体的亲本进行了多态性标记筛选,并对4个亲本间的遗传距离进行了评估.得到的SSR多态性标记在GL-F3/GL-M8间为15个,GL-F6/GL-M9间为8个;多态性RSAP标记在GL-F3/GL-M8间为88个;GL-F6/GL-M9间为93个.分析了基于SSR、RSAP技术的两对亲本间的遗传距离,SSR结果显示GL-F3/GL-M8间遗传距离为0.071 2,GL-F6/GL-M9间的遗传距离为0.043 6;RSAP结果显示GL-F3/GL-M8间遗传距离为0.228 4,GL-F6/GL-M9间的遗传距离为0.253 7.结果表明,在引物组合平均覆盖的位点和引物组合平均产生的多态性方面,RSAP均远高于SSR,在GL-F3/GL-M8间RSAP分别是SSR的4.48与12.13倍,在GL-F6/GL-M9间RSAP分别是SSR的5.81与25.5倍,RSAP标记更适合应用于龙须菜的遗传距离估计和资源的遗传多样性研究.本研究揭示出作图群体亲本间遗传多样性特征,SSR与RSAP分子标记的开发为龙须菜遗传连锁图谱的构建奠定了基础.     

安徽农村留守儿童与非留守儿童成长问题的差异性分析

对安徽省农村儿童进行访谈,获取有效问卷245份,重点分析了安徽农村留守儿童和非留守儿童在学习状况、生活满意度、品德行为、心理健康的差异性。研究显示,安徽农村留守儿童和非留守儿童在学习状况、生活满意度和心理健康3方面存在显著差异,且非留守儿童好于留守儿童;在品德行为方面,二者不存在显著差异。