苦瓜数量性状遗传距离与杂种优势关系的研究

6个苦瓜高世代自交系分成两组,按不完全双列杂交设计配制9个杂交组合。利用11个数量性状计算主成分遗传距离。以遗传距离为自变量,杂种优势为依变量,进行回归分析。结果表明：产量和果长杂种优势与遗传距离之间分别为显著和极显著直线关系,回归方程分别为Y=7.5718+3.2272X和Y=-5.8529+1.5946X。单果质量和果径杂种优势与遗传距离之间无相互关系。分析认为单果质量为产量的重要构成性状,而叶柄长、节间长为果长的重要构成性状。对遗传距离预测杂种优势的应用问题进行了讨论,认为遗传距离预测杂种优势可进一步进行研究。     

库尔勒香梨部分果实性状遗传的研究

库尔勒香梨是中国久负盛名的梨果佳品。却存在着果个小、果心大的缺陷。为了传承香梨品质优势,克服其弱点,本课题组于1971年开始香梨为亲本的杂交育种工作。以6个梨的杂交组合、351株实生树为试材,进行了各组合亲本和后代的性状分析,探讨了各主要性状的遗传趋势。结果表明,杂交后代果实形状、肉质遗传倾向于亲本,倾亲率分别为68.09%和51.38%。梨果实大小为数量性状,杂种后代果个分离广泛,杂种后代果实普遍变小,各组合的遗传传递力在68.91%~117.51%之间,平均遗传传递力为93.11%。梨果实可溶性固形物含量呈数量性状遗传,杂种后代分离较广,其组合传递力平均为97.49%。     

黄瓜数量性状遗传距离与杂种优势关系的研究

探讨数量性状遗传距离与杂种优势的关系,为黄瓜新品种的选育提供理论依据。选择5份黄瓜自交系材料作为母本,6份黄瓜自交系材料作为父本,按半双列杂交法配制出29个杂交组合,对11份黄瓜自交系材料的7个数量性状进行杂种优势分析和聚类分析,并研究数量性状遗传距离与杂种优势的关系。研究结果表明,各数量性状均有不同程度的正向杂种优势,其中株高、结瓜数和单株产量的杂种优势最为明显,而单果重、主蔓20节内雌花数、果实长和果实粗的杂种优势比较微弱。11份黄瓜自交系被分为3大类群,地理远近与遗传距离之间并不存在必然的联系。结瓜数的中亲优势指数和杂种优势指数、果实长和果实粗的中亲优势指数及单株产量的超亲优势指数与亲本遗传距离之间存在显著的相关关系,而株高、单株产量的中亲优势指数和杂种优势指数与亲本遗传距离之间存在极显著的相关关系,大部分数量性状的杂种优势都随着遗传距离的增大而增大。在进行黄瓜种质资源评价时,不能以地理关系作为唯一标准;在进行黄瓜杂交育种时,可根据育种目标,适当选择较大的遗传距离来获得杂种优势。     

西瓜6个农艺性状的杂种优势及其遗传表现的分析

选用10份西瓜亲本材料,按照双列杂交法配制了45个杂交组合,田间测定其开花期、果实发育期,坐果指数、小区产量,单瓜重、中心可溶性固形物等性状上的杂种优势.结果表明:约70％的组合在上述6个性状中表现出超中优势;分别有65.91％、29.54％、43.18％、31.82％、34.09％、40.09％的组合在开花期、果实发育期、坐果指数、小区产量、单瓜重、中心糖上表现出超亲优势,超亲优势达到显著水平的比例在4.45％～11.36％之间.44个杂交组合在6个性状上总体表现倾向于早熟或高亲亲本.     

蓝靛果忍冬杂交亲和力及杂交浆果性状分析

以俄罗斯引进品种、野生优良单株为杂交亲本,开展蓝靛果忍冬杂交育种试验,对其杂交亲和力和杂交浆果性状进行调查与分析。结果表明,15个杂交组合均获得成功,平均坐果率可达50%以上,以野生优1与俄罗斯品种的杂交亲和性较大,各杂交组合的坐果率差异显著。不同组合杂交当代浆果表型性状存在显著差异,以单果重的变异幅度最大。其中,格尔达×堪察加、野生优1×格尔达、野生优1×堪察加、野生优50×格尔达、野生优1×蓝色黑风、野生优7×洛火泰这6个组合的杂交浆果的纵横径、平均单果重等性状优于母本,表现良好,为超亲组合。     

花生巢式群体的脂肪含量遗传分析

巢式群体可以利用多个亲本解析复杂性状的遗传机制。本研究利用1个共同亲本与6个基础亲本所配置巢式组合F_2:3家系的种子脂肪含量数据,分析了花生脂肪含量的遗传模型,旨在探明不同的基础亲本组合中脂肪含量性状的遗传差异,为制定脂肪含量遗传改良的亲本选配和后代选择策略提供依据。6个组合的共同亲本为高脂肪含量的普通型大果品种豫花15号,其他6个基础亲本为不同脂肪含量和不同植物学类型的品种。结果表明,在不同杂交组合中脂肪含量的遗传模式有所不同,6个组合分别符合无主基因模型、1对主基因加性显性模型和2对主基因等显性模型3种遗传模式。各种遗传效应的估计值也各不相同,主基因遗传力从32%到80%,说明不同杂交组合中,控制脂肪含量的基因位点差异及其重组和分离方式不同。高脂肪含量双亲杂交后代的高脂肪含量个体较多,但主基因遗传力较低,不宜在早代实施表型选择;双亲脂肪含量差异较大的后代脂肪含量变异幅度更大,能够选择到不同脂肪含量的类型。本研究也表明,巢式组合具有较丰富的脂肪含量变异类型,揭示出脂肪含量性状遗传的复杂性和多基因调控的特点,为较全面地了解脂肪含量的遗传提供了基础。该巢式群体也将有助于进一步开展脂肪含量的QTL定位研究。     

二倍体苜蓿主要性状配合力及杂种优势分析

以3份花药离体培养单倍体苜蓿与2份扁蓿豆材料作为亲本,组配10个杂交组合,分析7个主要农艺性状的配合力,探究苜蓿与扁蓿豆的杂种优势与亲本一般配合力(GCA)、特殊配合力(SCA)和遗传距离之间的相关关系。结果表明,节间长受加性效应和非加性效应共同影响,株高、节间数、单株产量其遗传主要受加性效应影响较大。各性状的杂种优势在不同组合间差异较大。在二倍体苜蓿与扁蓿豆种间杂交组合中,XJ-3×CY-5和CY-35×HB各农艺性状特殊配合力的效应值适宜,杂种优势强,可作为优良杂交组合进行利用。研究表明,可通过组合间的SCA与杂种优势来提高亲本的选配效率,但利用SRAP标记遗传距离预测苜蓿杂种优势还有待进一步研究。     

枇杷果实育种目标性状在杂种后代中的表现

对黄金块与解放钟为亲本的有性正反交后代的果实进行分析,研究了育种目标性状：单果重（60g以上）、果皮色泽（橙红色）、可溶性固形物含量（12%以上）、可食率（72%以上）在杂种后代中的表现。结果表明：杂种后代单果重、果皮色泽、可溶性固形物含量、可食率达到育种目标后代分别占总数14.93%、53.73%、20.90%、47.76%;同时达到四个育种目标性状的杂种后代数量为1株。     

草莓果实若干数量性状的遗传分析研究

对8个草莓杂交组合F_1的181个株系的果实主要数量性状进行了测定和统计分析,研究和探讨了草莓果实主要数量性状的遗传倾向.结果表明:果实一级序果果重、二级序果果重、最大果重、可溶性固形物含量、果实硬度、维生素C含量均为多基因控制的数量性状,呈连续变异.F_1果实一级果重、二级果重、最大果重、果实可溶性固形物含量、维生素C含量都呈现出趋小变异,果实硬度呈现出增大的趋势,趋向变大.     

不同品种小果型西瓜的品质综合评价

为筛选出适合江苏设施栽培条件下的精良小果型西瓜品种,对春季设施条件下10个不同品种小果型西瓜进行品质分析和综合评价。依据品鉴标准由品鉴人员品尝后对西瓜打分,依次对西瓜的外观品质、内在营养品及经济性状进行测定及记录,利用主成分分析法对包含品鉴得分在内的18项指标进行分析,获得10个西瓜品种的综合得分及最终排名。从品鉴结果看,‘苏梦107-446’的评分最高,表现最好;从西瓜果实经济性状方面比较,‘苏梦108-020’的单瓜重和横径最大,‘早春红玉’的果实纵径、果皮厚度和果形指数表现最高,与其他品种差异显著;内在品质中可溶固形物方面‘,苏梦107-446’的中心和边际可溶固形物含量最大;其他内在品质指标方面,‘早春红玉’的蔗糖含量最高,‘苏梦111-034’的柠檬酸含量最高,‘苏梦107-409’的莽草酸含量最高。利用主成分分析法对18项指标进行分析并提取5个主成分,5项主成分的累积贡献率为89.7%,能够解释89.7%的原始数据信息。10个供试小果型西瓜的品质综合得分由高到低为‘苏梦107-409’‘、苏梦111-032’‘、苏梦111-034’‘、苏梦108-020’‘、早春红玉’‘、...     

高品质棉与抗虫棉杂交株型性状的遗传及与产量性状的关系

采用增广NCⅡ设计,以5个高品质陆地棉品种（系）为母本,5个转基因抗虫棉品种（系）为父本组配的25个杂交组合为材料,研究主要株型性状的遗传效应、杂种优势及与产量性状的相关性。结果表明,株高、始果枝高、果枝数和果节数的平均中亲优势较小,但不同组合间差异较大,均符合加性遗传模型。遗传相关分析表明,株高与株铃数、单株皮棉重呈极显著正相关;果枝数与株铃数呈极显著正相关,与铃重呈极显著负相关;果节数与株铃数、衣分和单株皮棉重呈显著正相关。株型性状与产量性状间的关联性主要是由果节数与株铃数、铃重的相关引起。研究结果为高品质抗虫棉理想株型性状的选育与调控具有一定的指导意义。     

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.     

Genetic diversity of oilseed Brassica napus inbred lines based on sequence-related amplified polymorphism and its relation to hybrid performance

Significant heterosis for seed yield in oilseed rape has created interest in the development of hybrid cultivars. The DNA‐based marker protocol, sequence‐related amplified polymorphism (SRAP) was used to determine genetic diversity among oilseed rape maintainer and restorer lines. This measure was used in an attempt to establish an association between genetic distance and heterosis in hybrids for various agronomic traits. A total of 118 polymorphic loci were generated by 18 SRAP primer combinations. Based on the polymorphism generated by the markers, calculated similarity index values ranged from 0.46 to 0.97. Cluster analysis grouped 10 maintainer and 12 restorer lines into three groups, with the exception of two maintainer lines, PM5 and PM9, which fell outside these groups. The grouping of the lines was largely in agreement with the available pedigree data on their origin and agronomic performance. Analysis of variance among inbred lines and their resulting F₁ hybrids over two locations revealed significant differences for plant height, days to maturity and seed yield, but not for oil content. Substantial mid‐parent heterosis was observed only for seed yield, and ranged from 26% to 169%. All hybrids surpassed their respective inbred lines for this trait, except for a single cross combination of related lines. In general, crosses of lines located in different clusters yielded more than those from the same clusters. Regression analysis revealed a statistically significant relationship between the genetic distance of the parents and seed yield in their hybrid, and their derived mid‐parent and high‐parent heterosis. The correlation coefficient between genetic distance and yield (0.64) indicated a moderately strong relationship, so it is possible that some of the SRAP markers might be linked to quantitative trait loci for seed yield.     

黄瓜早熟及丰产性与主要农艺性状的相关性分析

通过对黄瓜杂种一代苗期及成株33个性状的性状值、超中优势、超亲优势进行了全面系统地研究,分析了黄瓜丰产及早熟两个性状的主要构成因素及与其他性状间的相关性。结果表明,总瓜条数、单瓜重、主枝瓜重量、主枝单瓜重、主枝瓜条数、侧枝瓜条数、侧枝单瓜重、侧枝瓜重量、茎粗和生育天数等性状是决定总产量最为重要的因素并具有较强的杂种优势,无论在性状值、超亲还是超中优势中均达到极显著相关。前期产量主要决定于第一雌花节位和雌花节率及主侧枝瓜条数和瓜重、株高、叶面积等性状,达到显著水平,其中第一雌花节位和雌花节率在性状值、超亲和超中优势中都呈极显著相关性,说明这两个性状是决定黄瓜早熟性的决定性的因素并具有较强的杂种优势。根据试验结果分析了在黄瓜育种和生产过程中为达到早熟高产目的应当注意的几个主要问题。     

近等基因背景下对玉米胚乳突变基因ae的遗传效应研究

采用8个生产上常用的常规玉米自交系以及它们的ae近等基因系各组配16个组合进行裂区试验。测定等基因背景各对组合的直链淀粉含量、千粒重、小区产量及其它农艺性状。结果表明,纯合aeae的组合与同型马齿型组合相比千粒重、小区产量普遍降低而直链淀粉含量显著提高,遗传背景对ae基因的表达有重要影响,自交系和杂交种中可能     

Inheritance mode of fruit traits in melon: Heterosis for fruit shape and its correlation with genetic distance

Fruit quality traits were studied in 12 exotic accessions and their hybrids with a “Piel de Sapo” inodorus melon cultivar. The genetic relationships among these genotypes were assessed with 16 microsatellite markers, which agreed with the classification of Cucumis callosus, C. pubescens and C. trigonus as accessions within C. melo. There were very large differences between all the exotic accessions and “Piel de Sapo” genotype for fruit traits. When the hybrids were analysed, three different situations regarding mid parent heterosis were found, depending on the trait: no heterosis (soluble solid concentration), highly variable, from negative to positive (fruit weight and fruit diameter) and general positive heterosis (ovary shape, fruit length and fruit shape). Best parent heterosis for fruit shape was also common among hybrids. A highly significant correlation (r = 0.81) was detected between fruit shape and fruit length heterosis, suggesting that fruit shape heterosis is caused mainly by the enlargement of the fruit longitudinally. A highly significant correlation (r = 0.84) between heterosis for fruit shape and genetic distance, as estimated with microsatellites, was also found. These results, together with the previously reported observation that melon fruit shape is polygenic and highly heritable, makes the genetics of melon fruit shape a suitable system for dissecting the genetic and molecular basis of heterosis.     

玉米不同基因型气孔特征和叶温差的研究

为了探讨玉米不同基因型和杂种优势在气孔及蒸腾上的特征，对3个高产杂交种(农大108、农大103和中原单32)及其所有亲本进行了气孔形态、气孔频率和叶温差的观察与测量。结果表明，3个玉米杂交种在气孔特征及叶温上都表现出显著的杂种优势，其中农大108和农大103的杂交种气孔长度都表现正向超亲，杂种优势率分别为10．55％和9．30％，但气孔频率为负向超亲(杂种优势率分别为39．25％和20．43％)；中原单32的杂交种在气孔长度和气孔频率都表现正向超亲，杂种优势率分别为9．47％和16．48％；但从3个杂交种组合均值看，气孔长度为正向超亲，气孔频率为负向超亲。3个玉米杂交种的叶温差都表现正向超亲。相关分析表明，气孔长度与气孔频率呈显著负相关(r=-0．6460^*)；气孔长度与叶温差呈正相关，而气孔频率与叶温差呈负相关，但都不显著。     

‘富士’苹果果实品质与海拔的相关性分析

为明确苹果果实品质与海拔的相关性关系,以河北省44个果园的‘富士’苹果为试材,采用成熟期采样、测定和相关性分析的方式,研究果实外观品质、内在品质、质构特性与海拔高度的相关性。果园平均海拔247.77 m,在果实外观品质方面,果实单果重与海拔呈显著负相关(r=-0.33,P<0.05),着色指数与海拔呈极显著正相关(r=0.43,P<0.01),裂果指数与海拔呈极显著负相关(r=-0.64,P<0.01);在果实内在品质方面,果实可溶性固形物含量与海拔呈显著正相关(r=0.37,P<0.05),硬度、可滴定酸、固酸比均与海拔无显著相关性;在果实质构特性方面,果实粘附性与海拔呈显著负相关(r=-0.30,P<0.05),内聚性与海拔呈显著正相关(r=0.34,P<0.05),脆裂性与海拔呈显著正相关(r=0.30,P<0.05),胶粘性与海拔呈显著正相关(r=0.30,P<0.05),咀嚼性与海拔呈显著正相关(r=0.32,P<0.05),弹性与海拔无显著相关性。海拔高度在700 m以下时,较高的海拔能够显著提高果实的外观品质和可溶性固形物含量,海拔高度与果实质构特性显著相关。