辣椒DH群体果实性状的分离及与F2群体的比较

为分析DH群体的遗传稳定性及其DH群体内性状分离与同来源的F2群体之间异同，本研究利用辣椒花药培养技术，构建一个由“羊角椒(97403)×方灯笼甜椒(97410)”的杂交而成的牛角椒组合作为供体的且由103个DH系组成的DH群体，对该DH群体进行单果重等5个主要果实性状的遗传表现进行分析，并与同来源的F2群体进行比较。结果表明：原供体及其双亲的5个果实性状的变异系数均较小，三者之间的各性状均存在显著差异，说明原供体及其双亲的整齐一致性；对DH群体和F2群体各性状的平均值、变异系数及其性状分离区间的分析和对比结果表明，5个果实性状均是受多基因控制的数量性状，且由于基因重组无论是DH群体还是F2群体均能产生正向和负向两个方向的超亲基因型。但DH群体与F2群体比较各性状的分离区间明显增大，超亲分离类型明显增加，且获得的各DH系均为稳定遗传的自交系，提高了花培育种的选择效率。     

Graft-induced change in fruit shape in Capsicum annuum L. I. genetic analysis by crossing

Summary Characteristics of fruit shape in the progeny from a graft-induced change were analysed. Non-pointed, typically inverted-blunt (two-lobed) fruit apex was observed in chimeric state within a scion of Yatsubusa grafted onto Spanish Paprika (inverted-blunt, three-or four-lobed fruit). This frequency of change in fruit shape was unstable in an early generation on the graft.     

花药培养在小麦耐盐育种上的应用研究

在小麦花药培养中，采用加入一定浓度ＮａＣｌ（０．１％、０．３％、０．５％）的筛选培养基，用恒定浓度筛选法和逐渐增加浓度筛选法，可筛选出耐盐变异体，获得耐盐花培株系。两种筛选方法比较，逐渐增加浓度筛选法可以明显提高筛选效率。经５个有性世代的鉴定表明，耐盐变异体的耐盐特性可以稳定遗传给后代。经筛选的花培株系中，耐盐特性能够稳定遗传的株系比例约占１／４。在育种实践中，经多点试验鉴定，已选育出一批有实用价     

基于RAPD标记与形态标记的辣椒自交系间亲缘关系的比较研究

为了更加准确地测定辣椒亲本间的亲缘关系,提高辣椒育种效率。利用RAPD标记技术对60份辣椒自交系进行了基因组多态性分析,并将形态学聚类和分子鉴定加以对比。结果表明：（1）对60个辣椒自交系的12个数量性状进行了聚类分析,遗传距离在4.8时,将其分为5类。（2）利用RAPD标记对60份辣椒自交系进行了基因组多态性分析,遗传距离D值在0.35处,将辣椒的3个变种基本分开。（3）RAPD标记计算的遗传相异系数矩阵和形态学计算的遗传距离矩阵做相关性分析,其相关系数为0.26,达到极显著。因此,在研究辣椒自交系亲缘关系时,可将两者相结合进行遗传相似性的分析,提高其准确性。     

MAGIC群体的遗传特征及其在作物耐逆研究上的应用

多亲本高世代互交（multi-parent advanced generation intercross,MAGIC）群体是近年来发展起来的新一代遗传作图及育种群体。MAGIC群体最初是以研究动物及人类复杂性状遗传基础为目标而构建的基于多亲本的重组近交群体,随后将其构建方法衍生到植物中应用。MAGIC群体应用于作物遗传育种,可以建立包含无限多株系的群体,主要的优势是拥有大量可利用的多样性遗传基因池。亲本可选用育种中性状优异的材料,通过多次重组创造大量的遗传变异。群体中选出的优良株系可用作育种中间材料或直接组配新品种,也可灵活应用于数量性状位点（quantitative trait locus,QTL）的精确遗传定位分析,真正做到育种群体和定位群体的有机整合。作物耐逆性大多是由QTL控制,因此,主要围绕MAGIC群体的定义、构建流程、遗传特征及其在作物耐逆性研究上的应用和发展前景作综合性阐述。     

辣椒属栽培种主要表型性状的评价与相关分析

为掌握辣椒表型性状变化特点及其相互关系,对辣椒属5个栽培种96份材料的14个表型性状进行了评价和相关分析,结果表明：14个表型性状具有较高的遗传多态性,其变异系数（CV）范围在14.0%（叶形指数）~135.0%（单果重）之间;果实性状与株型性状之间存在较为复杂的相关关系,因此,在辣椒遗传改良中,应根据育种目标对表型性状进行合理的选择。     

茄子花培后代的观察与应用

对从长茄杂交种“牟尼卡”（编号06-1001）进行花药培养获得的花培品系二代（DH2）和三代（DH3）的主要植物学性状进行了观察与比较。结果表明,从同一接种材料可以获得不同类型的花培品系,其始花节位、果形指数和单果重变异幅度很大,15个二代品系中,有46.7%的品系始花节位与接种材料达到显著或极显著差异标准,有40.0%的品系果形指数与接种材料达到显著或极显著差异标准,有33.3%的品系单果重与接种材料达到显著或极显著差异标准。同一品系不同世代间始花节位、果实横径、果实纵径、果形指数和单果重能稳定遗传;品系内个体间始花节位、果实横径、果实纵径、果形指数和单果重变异系数较小(<10%),系内整齐一致。此外,初步选育的花培品系“06-139”和以花培品系为亲本的杂交组合“05-203”开始在农业生产中应用。     

Estimation of genetic parameters and prediction of breeding values in an autotetraploid blueberry breeding population with extensive pedigree data

The strategy for breeding blueberries has been based on phenotypic selection without accounting for pedigree correlation information. A central premise of classical quantitative genetics is that through knowledge of the relationships among individuals in a population, we can make inferences about breeding values (BVs), estimate genetic parameters, and support phenotypic selection. Genetic evaluations using best linear unbiased prediction (BLUP) and restricted maximum likelihood (REML) are founded on pedigree information and have been the standard method used in livestock and forest breeding. Despite theoretical and practical benefits, their application in blueberry breeding programs remains unexploited. The objective of this study was to evaluate the use of REML/BLUP in the University of Florida blueberry breeding program in order to estimate genetic parameters and predict BVs of primary selection traits. To do this, we collected phenotypic data for eight selectable traits (yield, flower bud density, fruit weight, fruit firmness, fruit diameter, fruit soluble solids, fruit pH, and fruit scar diameter) from 1996 individuals. The highest narrow-sense heritabilities were found for fruit weight, scar diameter, and yield. The majority of genetic correlations between traits were under 0.20. The largest genetic gain was achieved when selections from early stages were used as parents and the top 5% of the population was selected. Compared to traditional phenotypic selection, our results are evidencing of the importance of implementing REML/BLUP to estimate genetic parameters that help and support the breeding strategy and maximize genetic gains.     

辣椒果实维生素C含量性状的遗传分析

为了解辣椒果实中维生素C(Vc)含量的遗传规律,对辣椒果实Vc含量进行遗传分析。选用Vc含量差异显著的‘L5’(高Vc含量)和‘L158’(低Vc含量)2个品种分别作为杂交的母本和父本,从而构建了3种世代群体。同时测定和分析辣椒果实Vc含量及与其他果实相关性状的相关性。结果表明:果实中Vc含量呈连续性变化趋势,受多基因控制。Vc含量与单果平均重呈显著正相关,与果肉厚呈显著负相关。Vc含量与可溶性固形物、果横径、果纵径不相关。辣椒Vc含量属于数量性状,受控于多个基因,属于C-O模型,即加性-显性-上位性多基因混合遗传模型。     

3个辣椒花药培养再生株群体主要农艺性状及苗期抗病性研究

对3个辣椒花药培养再生株DH-R2群体的主要农艺性状,包括株高、株幅、首花节位、叶色、单果质量、商品果横径、商品果纵径、果形指数、老熟果色等进行了较详细的测量和统计分析。结果表明:辣椒花药培养再生株群体的农艺性状存在基因型偏性;再生株群体的单果质量、商品果纵径、果形指数这3个性状都表现为低于供体,株高、株幅、首花节位、商品果横径这4个性状都表现为近似于供体;通过单倍体培养途径可以得到不同颜色层次的老熟果色的辣椒纯系,证明了该途径是多基因控制性状育种的有效途径;对耐TMV和CMV的亲本与感病亲本的杂种进行花药培养,获得了兼具TMV和CMV抗性的株系,证明了单倍体培养途径可以创造新的超亲抗病种质。     

Relationship between heterosis and genetic distance based on morphological traits and AFLP markers in pepper

Genetic diversity is considered as one of the criteria for the selection of parents for hybrid breeding. The present study was undertaken to evaluate genetic divergence among seven pepper cultivars and to assess the relationship between heterosis and parental genetic distance. Twenty‐one F₁ hybrids and seven parents were evaluated for 15 morphological characters in a greenhouse and in the field. The parents were examined for DNA polymorphisms using six amplified fragment length polymorphism (AFLP) primer combinations. Cluster analysis using two genetic distance measures grouped the seven parents differently. Mid‐parent and high‐parent heterosis was observed for most characters. Most hybrids outperformed the parental lines for fruit yield, earliness and plant height. Morphological and AFLP‐based distance measurements were efficient enough to allocate pepper genotypes into heterotic groups. The correlations of morphological distances with mid‐parent heterosis were significant for days to flowering and maturity, suggesting earliness can be predicted from morphological distances of parental lines. However, the correlations of AFLP‐measured genetic distances with mid‐ and high‐parent heterosis were non‐significant for all characters, except for fruit diameter, and proved to be of no predictive value.     

优质、抗逆甜玉米群体配合力及 遗传潜势分析

为了充分利用新近合成的优质、抗逆甜玉米群体,同时加速育种进程。试验采用不完全双列杂交设计,以2个自育超甜玉米骨干系作测验种,与63个穗行的75个单株杂交,配制组合150个,通过杂交组合鉴定试验、株系的食用品质及抗性等的鉴定评价,对群体配合力及遗传潜势进行了分析,结果发现在75个被测株中,36个株系的单株产量一般配合力为正,而通过对其产量相关性状、商品性及农艺性状一般配合力分析也发现,其GCA表现较好的株系比例接近或超过50%。结合株系自身表现,筛选获得9个苗头株系;同时根据杂交组合鉴定结果,获得8个苗头组合。综合群体内株系的配合力及群体自身表现,初步认为该群体优良基因频率较高,遗传变异较为丰富,具有较大利用潜力。     

Phenotypic Variation in a Germplasm Collection of Pepper (<Emphasis Type="Italic">Capsicum chinense</Emphasis> Jacq.) from Korea

A total of 47 core collections of pepper (Capsicum chinense Jacq.) conserved in National Agrobiodiversity Center (NAC) were studied under field condition at Jeonju over two consecutive years (2015 and 2016). All accessions were characterized for their 14 qualitative and 16 quantitative characters. Results revealed that both qualitative and quantitative characters exhibited wide variation among the studied germplasm. Distribution of fruit characters (fruit length, width, and fruit wall thickness) among the accessions was positively skewed. Of the 47 accessions evaluated, 38.3% accessions had conical shaped fruits and mature fruit color was predominantly red (51.1%), orange (21.3%) and yellow (14.9%). Principal component analyses revealed that (i) 56.64% of the qualitative (fruit shape, color and fruit surface) variation and (ii) 89.42% of the quantitative (plant width, height and fruit maturity days) variation were explained by the first two components. Clustering revealed two groups and dendrogram revealed morphological variation among accessions. The phenotypic diversity exists in this core collections provide valuable information to improve agronomic traits in pepper breeding program.     

基于SNP分子标记的泰山/泰科麦系列小麦遗传解析

对不同年份育成的21个小麦品种（系）进行全基因组扫描,通过分析遗传距离和染色体区段/位点,明确其亲缘关系远近和遗传差异。分析可知,获得的2029个SNP基因位点在B基因组拥有较高的遗传多样性,其次是A和D基因组;在7个同源群中,第3和第6同源群呈现出较高的遗传多样性,而第1和第4同源群的遗传多样性较低;21条染色体中,3A、1B、6B染色体的遗传多样性较高,而1A、6A的遗传多样性偏低。对21份供试材料依据审定（育成）年份分析其群体的平均遗传距离,不同年份品种间的平均遗传距离先增大后减小,遗传多样性逐渐降低;21份供试材料间的遗传相似系数在0.69~0.99之间,大致可聚为4个类群,同一年份的品种一般聚在一起,与其系谱关系吻合。构建并分析供试材料的基因型图谱发现,00s、10s和现在育成的小麦品种（系）共有SNP和共有染色体区段分别主要在A、D和B基因组,对应已发表性状同不同年份育种目标吻合。同时发现21份供试材料均含有25个共同SNP位点,分布在1A、5A、6A、7A、2B、3B、6B、1D、2D、3D和7D染色体上,且每条染色体上分布的SNP位点数目均不相同,通过对应已发表性状进一步证实在品种（系）组配与选育过程中注重产量、株高、分蘖数、抽穗期、灌浆速率和抗病等性状的选择。以上研究结果可为今后小麦新品种组配和选育提供参考依据。     

辣椒砧木种质资源对疫病的抗性及遗传初步分析

以从国外引进的辣椒砧木种质资源为研究对象,采用游动孢子灌根法对幼苗进行疫病抗性鉴定;选择不同抗性水平且抗性表型稳定的5份砧木种质进行完全双列杂交,鉴定F1代对疫病的抗性,以病情指数为表型指标分析抗性杂种优势,通过Griffing法分析抗病性的配合力和遗传参数,探讨砧木种质抗病性状的数量遗传特点.结果表明:15份供试辣椒砧木种质中,3份种质对疫病表现中抗,其余种质均表现感病;20个F1杂交组合中,有2个杂交组合对疫病表现中抗,有3个组合表现杂种优势;辣椒砧木种质抗疫病性状符合“加性-显性-上位性”数量遗传模型,且加性效应占主导地位,同时可能受细胞质基因的影响,表现核质互作效应.本研究筛选出3份辣椒砧木种质和2个F1杂交组合对疫病表现中抗,其中种质D15可作为抗疫病育种骨干亲本,研究结果可为合理利用辣椒砧木种质开展抗疫病育种提供参考.     

不结球白菜形态性状及SSR遗传多样性关联分析

分析不结球白菜遗传多样性,筛选与形态性状相关联且具有多态性的标记位点,为不结球白菜的分子辅助育种选择、种质资源的利用和新品种选育提供依据。本研究以类型差异大、有南方特色的54份种质资源为材料,对其6个质量性状和5个数量性状进行3次田间调查,从40对引物中筛选出25对SSR引物进行遗传多样性分析,结合形态性状对54份不结球白菜种质资源进行统计分析。结果表明:6个质量性状间具有丰富的多样性,5个数量性状间有显著的差异性,其中SA变异系数最大,FC与L、W和SA呈显著正相关;25对SSR引物共检测到72个多态性位点,平均每对SSR引物产生2.88个多态性位点,PIC平均值为0.3831,说明不结球白菜SSR具有丰富的遗传多样性;54份不结球白菜的遗传相似系数变化范围为0.492~0.963,平均为0.742,在遗传距离0.6处可将供试材料划分为3个类群;通过关联分析发现5个与数量性状关联的标记位点,各标记的表型变异解释率在0.4657~0.6329,平均为0.5393。本试验获得的5个标记位点可为不结球白菜分子标记育种提供依据。     

Genetics,genomics and breeding of groundnut (Arachis hypogaea L.)

Groundnut is an important food and oil crop in the semiarid tropics, contributing to household food consumption and cash income. In Asia and Africa, yields are low attributed to various production constraints. This review paper highlights advances in genetics, genomics and breeding to improve the productivity of groundnut. Genetic studies concerning inheritance, genetic variability and heritability, combining ability and trait correlations have provided a better understanding of the crop's genetics to develop appropriate breeding strategies for target traits. Several improved lines and sources of variability have been identified or developed for various economically important traits through conventional breeding. Significant advances have also been made in groundnut genomics including genome sequencing, marker development and genetic and trait mapping. These advances have led to a better understanding of the groundnut genome, discovery of genes/variants for traits of interest and integration of marker‐assisted breeding for selected traits. The integration of genomic tools into the breeding process accompanied with increased precision of yield trialing and phenotyping will increase the efficiency and enhance the genetic gain for release of improved groundnut varieties.     

Heterosis and heritability in crosses among Asian and Ethiopian parents of hot pepper genotypes

Hot pepper is the most important worldwide grown and consumed spice and vegetable crop. Though hybrid breeding has been proposed for genetic improvement in the crop, but there is lack of information on heterosis in crosses among crop genotypes in Ethiopia. Twelve genotypes (nine Asian and three Ethiopian parents) of hot pepper were crossed in 2003 cropping season in a half-diallel fashion to fit Griffing’s fixed effect model analysis. An open field experiment was conducted in 2004/2005 to investigate heterosis for fourteen traits in 66 F₁ hybrids grown together with their 12 selfed parents. Highly significant genotypic differences were observed for all the traits except for leaf area. Variance component due to specific combining ability (dominance) were larger than that due to general combining ability (additive) for each of the studied traits with few exceptions. Broad sense heritability (H _b²) for fruit traits were more than 60% and with wide gap from narrow sense heritability (h _n²) for most of the important traits like number of fruit per plant (H _b² = 88.3% and h _n² = 46.0%), days to maturity (H _b² = 87.2% and h _n² = 23.1%) and dry fruit yield per plant (H _b² = 72.6% and h _n² = 14.6%). Maximum heterosis over mid-parent and better-parent, and economic superiority of hybrid over standard check were recorded, respectively for dry fruit yield per plant (163.8, 161.8 and 92.1%), number of fruits per plant (104.4, 79.6 and 136.4%) and days to maturity (−29.8, −31.5 and −23.6%). These observations suggested a possibility of utilizing dominance genetic potentiality available in diverse genotypes of the crop by heterosis breeding for improving hot pepper to the extent of better economic return compared to the current commercial cultivar under production in the country. Low narrow sense versus very high broad sense heritability for days to maturity and dry fruit yield per plant could be a sign for achievability of earliness and high fruit yield using heterosis in hot pepper. The maximum heterobeltiosis were recorded either from F₁s obtained from Ethiopian and Asian crosses or from within Asian crosses, suggesting the possibility of maximizing heterosis by considering genetically diverse parental genotypes. The manifestation of highest heterosis in hybrids from among Asian lines indicated existence of genetic diversity among Asian genotypes and the potentiality for improvement of hot pepper using genotypes from different regions of the world along with elite inbred lines from local cultivars.     

食用向日葵产量与籽粒主要性状配合力及遗传分析

选用4份分枝型恢复系和6份雄性不育系材料作亲本,按照不完全双列杂交（NCII）设计配制24份向日葵杂交组合,对组合的小区产量、单株产量、单盘实粒数、百粒重、籽仁率、籽粒长度和籽粒宽度7个性状的亲本配合力、遗传参数及竞争优势进行分析。结果表明,24份组合的7个性状存在真实性的遗传差异。在亲本不育系一般配合力（GCA）选择的基础上,应注意组合特殊配合力（SCA）的选择,GCA效应值高的亲本育种潜力较大,组配出优势组合的概率大;籽粒长度和籽粒宽度的狭义遗传力较低,分别为7.91%和14.89%,不宜进行早代选择;GCA较高的不育系为亲本A和亲本D,其中亲本A在各性状上均为正向GCA效应值,且在供试不育系中,其GCA效应值最大,其次为亲本D;组合1×A小区产量的SCA效应值及竞争优势最高,为本试验中的最优组合,其他籽粒性状与对照相比也均有提升。     

Genetic and QTL analyses of yield and a set of physiological traits in pepper

An interesting strategy for improvement of a complex trait dissects the complex trait in a number of physiological component traits, with the latter having hopefully a simple genetic basis. The complex trait is then improved via improvement of its component traits. As first part of such a strategy to improve yield in pepper, we present genetic and QTL analyses for four pepper experiments. Sixteen traits were analysed for a population of 149 recombinant inbred lines, obtained from a cross between the large-fruited pepper cultivar ‘Yolo Wonder’ (YW) and the small fruited pepper ‘Criollo de Morelos 334’ (CM334). The marker data consisted of 493 markers assembled into 17 linkage groups covering 1,775 cM. The trait distributions were unimodal, although sometimes skewed. Many traits displayed heterosis and transgression. Heritabilities were high (mean 0.86, with a range between 0.43 and 0.96). A multiple QTL mapping approach per trait and environment yielded 24 QTLs. The average numbers of QTLs per trait was two, ranging between zero and six. The total explained trait variance by QTLs varied between 9 and 61 %. QTL effects differed quantitatively between environments, but not qualitatively. For stem-related traits, the trait-increasing QTL alleles came from parent CM334, while for leaf and fruit related traits the increasing QTL alleles came from parent YW. The QTLs on linkage groups 1b, 2, 3a, 4, 6 and 12 showed pleiotropic effects with patterns that were consistent with the genetic correlations. These results contribute to a better understanding of the genetics of yield-related physiological traits in pepper and represent a first step in the improvement of the target trait yield.