马铃薯新型栽培种在实生种子选育中的应用研究

本文研究比较了马铃薯实生种子选育中,新型栽培种(Neo-tuberosum)利用的6类不同组合方式产生的杂种实生种子在群体生产力和一致性上表现的差异,结果表明:①不同组合方式形成的具有不同Neo-tubersum基因频率的实生种子,群体间生产力表现极显著的差异。这一差异主要表现在产量构成因素上,商品薯数量和小薯数量对构成群体产量均有极显著的作用;小薯数量的增加对提高群体的商品薯率有极显著的负作用,即块茎数量越多,块茎越小。后代商品薯率取决于S.tuberosum种质,而块茎数量主要由Neo-tuberosum决定,并找出其生产力表现的优先顺序。②S.tuberosum×Neo-tuberosum组合表现的一致性水平在株高、薯形、皮色和芽眼深浅等性状上与S.tuberosum自交群体相似,没有显著差异,是利用新型栽培种进行实生种子选育的最佳组合方式。     

马铃薯实生种子优良杂交组合评价

本文研究了国内最新配制的马铃薯实生种子9个杂交组合,通过试验,分析和比较了F_1实生苗世代主要经济性状的表现,综合评价了各个杂交组合在杂种优势利用中的价值,筛选了可用于商品生产的优良组合.对主要亲本的配合力进行了估计,为实生种子利用提供科学依据并研究优良自交系.试验结果表明:W_4×NS_(79-12-1),W_5×NS_(79-12-1)和肯德×8342-36为优良杂交组合,W_4×NS_(79-12-1)可用于实生种薯生产.自交系NS_(79-12-1)和8342-35为优良自交系,后者在提高单薯重量降低单株结薯个数上有较高的配合力.本文还讨论了我国马铃薯实生种子选育和杂种优势利用的进展和发展潜力.     

马铃薯近缘栽培种种间杂种优势及配合力的研究

本试验用新型栽培种(A)、普通栽培种(T)和能产生2n花粉(FDR)的二倍体杂种(D)以不完全双列杂交设计配制杂种并产生5个杂种群体(TA、TD、AD、AA及TT).这些群体的无性系按完全随机区组设计种植.对总产量等主要性状进行了研究.在5个群体中,TA群体在产量和单株块茎数上有显著的杂种优势,其超过中亲值平均分别为15.18和26.51%.在群体平均产量上TA显著地高于TD、AD、TT和AA;在其它产量构成性状及经济性状上超过或与这4个群体无差异.种间杂种TD和AD的产量等性状在以中亲值为比较的杂种优势上有显著的杂种优势,并与TA无差异甚至高于TA,但在实际群体产量上都低于其四倍体亲本的均值,甚至与种内品种间杂种TT和AA无显著差异.AD除在产量和平均块茎重的优势高于TD外,其它性状无差异.相同杂交组合其实生苗世代与无性一代在产量、淀粉含量和单株块茎数上呈显著的正相关.因此,在实生薯利用中以组合为单位的群体选择是有效的.配合力分析表明,马铃薯单株产量和平均块茎重在亲本选配中一般配合力和特殊配合力是同等重要的,而在单株块茎数和淀粉含量上以一般配合力为主.     

马铃薯实生种子优良杂交组合评价

本文研究了国内最新配制的马铃薯实生种子９个杂交组合，通过试验，分析和比较了Ｆ１实生苗世代主要经济性状的表现，综述评价了各个杂交组合在杂种优势利用中的价值，筛选了可用于商品生产的优良组合。     

北方杂交粳稻亲本籼粳成分与杂种产量和稻米品质性状的关系

以北方杂交粳稻骨干亲本及其组合为材料,采用程氏指数法和微卫星分子标记法,对亲本籼粳成分与杂种产量和稻米品质性状的关系进行了研究。杂交粳稻骨干亲本的程氏指数为13.5～19.3,偏籼系数为0.12～0.38,采用程氏指数和分子标记法对亲本进行籼粳分类的结果并不完全一致。父本程氏指数与产量杂种优势和杂种性状的相关性强于母本,而对于偏籼系数则相反。亲本程氏指数差异与产量杂种优势和杂种性状的相关性强于分子标记差异。亲本籼粳成分及其差异与多数杂种性状和产量杂种优势呈明显的二次曲线关系,存在临界极值;亲本籼粳成分及其差异与杂种产量性状和稻米品质性状的相关性相反。因此,要获得产量杂种优势和杂种表现最佳、高产与优质相结合,父母本籼粳成分应适度搭配。     

马铃薯近缘栽培种间杂种育种价值的研究

本文对普通栽培种(Solanum Tuberosurm)×新型栽培种(S.Neotuberosum)(T×A)和普通栽培种×2倍体杂种(普通栽培种的双单倍体×S.phureja)(T×2n杂种)两种类型组合后代的主要经济性状,如茎色、株高、单株重、商品薯率、淀粉含量及产量等性状的分离幅度和杂种优势表现进行了比较研究。结果表明,在杂种后代诸性状的表现上,T×2n杂种类型的后代表现分离幅度小,杂种优势强。但由于2倍体杂种自身经济性状不好,使T×2n杂种类型子代的绝对产量低于T×A类型。因此,在现阶段,在育种和实生种子利用上,利用T×A类型的组合更有实际意义。     

芝麻杂种优势研究

芝麻杂种F_1的产量优势,不同组合差别很大。本试验以地理远缘的品种作亲本配制了77个组合,对杂种优势现象作进一步的探索.杂种F_1的产量分别为双亲平均,优亲及当地推广种的-6.9～252.7％,-24.8～141.1％和-37.1～67.6％ .选择产量差异较大的品种作亲本,F_1具有较强的优势.遇过试验,发现了若干产量优势较强的杂交组合.对全部杂交种及亲本的主要经济性状与产量的关系进行了相关性分析,以供今后选配杂交组合参考.     

水稻杂种优势表现与双亲遗传差异

 用广亲和恢复系中413与“Lemont × 特青”重组自交系群体(RIL)杂交,构建中413测交F₁群体（ZTP）和分子标记连锁图谱。研究了中413基因组组成、F₁杂种产量性状优势表现以及杂种优势表现与亲本间遗传差异的关系。双亲性状优良往往能获得好的F₁代,但并非所有组合都是如此。低值亲本与中413杂交亦可产生高值后代,表现较强的杂种优势。双亲遗传差异与杂种优势表现呈正相关,当母本（RILs）的粳型成分（Lemont 基因组含量）达到80%左右时,杂种的籽粒产量最大,优势最强。杂种的生物学产量亦表现随母本的粳型成分增加而继续增加的趋势。     

水稻不同类型亲本杂种F2产量性状表现及遗传参数分析

通过对盐粳68/密阳50、盐粳68/盐粳34、盐粳68/一目惚3个不同类型水稻杂交组合F2群体产量性状表现及遗传参数估算,分析了水稻不同类型亲本杂种后代与亲本的关系。结果表明,产量性状的表现及其遗传参数因亲本类型的不同而有明显差异。籼、粳亚种间杂交组合F2群体产量性状变异幅度大、遗传力较高、遗传进度也较大,因而有广泛的选择潜力。     

大麦杂种优势与苗期酯酶同工酶的相关性研究

本文通过对４ 个核质互作型杂种大麦及其亲本的酯酶同工酶、单株产量构成要素及主要农艺性状的分析研究,初步认为：核质互作型杂种大麦杂种优势的大小与亲本之间的酯酶同工酶的谱带差异程度和互补程度密切相关。可根据双亲的酯酶谱带差异程度选配杂交组合;苗期的酯酶同工酶类型可作为预测不同组合杂种优势大小的指标之一。     

马铃薯4x×2x杂种无性一代产量及产量性状的表现

产生２ｎ花粉的Ｎｅｏ－ｔｕｂｅｒｏｓｕｍ双单倍体×Ｓｏｌａｎｕｍｐｈｕｒｅｊａ的二倍体杂种以及其与Ｎｅｏ－ｔｕｂｅｒｏｓｕｍ双单倍体的回交后代与普通马铃薯（Ｓ．ｔｕｂｅｒｏｓｕｍｓｓｐ．ｔｕｂｅｒｏ ｓｕｍ品种东农３０３进行了杂交。４ｘ杂种在株高方面表现出了很强的杂种优势。商品薯产量与４ｘ亲本无显著差异，但两个杂种群体的最高值分别超４ｘ亲本的２６０ｇ／株和６０ｇ／株。总产量杂种优势明显，但杂种单株结薯数多，平均块茎重小，这些是限制４ｘ×２ｘ杂种利用的不利因素，需要进一步地改善。     

基于“华占”的强优势杂交组合的株高与主穗长遗传分析

株高与穗长是水稻品种的关键性状,有效利用水稻性状间的杂种优势是培育高产品种的关键技术手段。以“华占”配制的‘天优华占’‘恒丰优华占’‘五丰优华占’3个杂交组合为供试材料,构建了包含P₁、P₂、F₁、F₂、BC_1-1、BC_1-2等6个遗传世代群体。采用植物数量性状“主基因+多基因”混合模型分析了株高和主穗长的遗传方式。结果表明：3个杂交组合的株高和主穗长遗传均符合MX2-ADI-ADI遗传模型。在“华占”为遗传背景中,3个群体F₂、BC_1-1、BC_1-2的株高均以多基因控制为主,多基因遗传率变幅分别为72.11%~75.42%、76.92%~86.28%和68.13%~75.13%,育种后代中应在高世代选择。3个群体F₂代中的主穗长主基因遗传率分别为81.99%、68.95%和90.01%,多基因遗传率分别为12.16%、23.78%和3.52%;在回交群体中,3个组合的主穗长主基因和多基因遗传率与回交亲本密切相关,育种上应根据群体遗传特性进行相应的选择策略。     

Genetic variance estimates in a heterogenous potato population propagated from true seed (TPS)

Genetic variances were estimated for 11 traits in a potato breeding population propagated from true seed (TPS). Means were high and no genetic variability was found for seed germination and transplant survival. Additive variance and heritability were high for TPS production which was positively correlated with tuber yield. No additive variance was found for uniformity of tuber size, but heritability estimates for other component traits of tuber uniformity and yield were relatively high. The results indicated that index selection should be effective for improvement of yield and tuber uniformity.     

Use of random amplified polymorphic DNA markers to estimate heterosis and combining ability in tomato hybrids

Random Amplified Polymorphic DNAs (RAPD) were used to estimate genetic distances and determine the correlation between genetic distance and hybrid performance of 29 tomato lines that were the parents in a diallel mating design. Among 97 observed bands, 69 showed polymorphism and were used for establishing genetic distances based on the Nei coefficient between parents. A UPGMA dendrogram and Multi-Dimensional Scaling (MDS) analysis based on Nei genetic distances clearly clustered each group, confirming the variation at a molecular level. Correlations between genetic distances of the parents and performances of hybrids were established for various quantitative traits. Significant correlations were found between RAPD markers estimated genetic distances and MPH, HPH, SCA for some traits. The low correlation between parental genetic distances and hybrid performances for some quantitative traits suggested that RAPD markers have low linkage to Quantitative Trait Loci (QTLs) or have inadequate genome coverage for these traits. The results indicated that RAPD markers can be used as a tool for determining the extent of genetic diversity among tomato lines, for allocating genotypes into different groups and also to aid in the choice of the superior crosses to be made among tomato lines, so reducing the number of crosses required under field evaluation.     

四倍体杂交冰草AFLP遗传连锁图谱的构建

为给冰草抗性及产量等重要性状QTL定位及分子标记辅助育种等研究奠定基础,以四倍体杂交冰草的347个F2代单株及其亲本为材料,利用AFLP分子标记技术构建四倍体冰草的分子遗传连锁图。结果表明,本研究首次成功构建出1张密度较高的四倍体杂交冰草分子遗传连锁图谱,该图谱包含14个连锁群,572个标记,各连锁群长度范围为129.75~214.90cM,覆盖基因组总长度2 266.59cM,标记间平均间距4.13cM。     

Pollen fertility in relation to open pollinated true seed production in potatoes

The cost and difficulty of producing hybrid true potato seed (TPS) currently limits their use for commercial production. Twelve clones, selected in preliminary trials for low pollen stainability but high fruit and seed set, initially seemed promising for inexpensive production of mostly hybrid open-pollinated (OP) TPS. However, in subsequent tests, pollen stainability of these clones appeared to be highly variable and fruit and seed set were not as high. Bumblebees favored the most fertile clones, especially during periods when pollen stainability was the highest. Amounts of OP fruit and seed set correlated with maximum observed pollen stainability levels of the clones. Most of the OP seeds produced by these clones were probably the result of self-pollination; therefore, other methods must be used to obtain hybrid TPS.     

Estimation of genetic parameters for characters related to potato propagation by true seed (TPS) in an andigena population

Genetic variances were estimated for a population ofSolarium tuberosum L. subsp.andigena, selected for adaptation to north temperate climatic conditions. Estimates for 15 traits, including some unique to true seed (TPS) propagation, were obtained from trials conducted under short day conditions in Peru. Only non-additive variance was found for yield, but heritability estimates were relatively high for tuber number and tuber size. The results indicated that yield could be increased through selection utilizing additive variance for the component traits, especially tuber size. Estimates of genetic variability for tuber uniformity were low. TPS yield was positively correlated with most other traits except tuber number.     

Male fertility and 2n pollen production in haploid-wild species hybrids

Hybrids (2n = 2x = 24) from crosses between Group Tuberosum haploids (2n = 2x = 24) and 24-chromosome, wild species must be fertile and produce 2n gametes if they are to be used in breeding schemes involving sexual polyploidization. Male fertility of the 2x hybrids depends primarily on the species parent. Hybrids involvingS. berthaultii, S. chacoense, S. kurtzianum, S. spegazzinii, andS. tarijense as parents are male fertile. The haploid parents are male sterile, so the species not only contribute genetic diversity and desirable traits, but also genes necessary for male fertility.S. infundibuliforme, S. raphanifolium, andS. sanctae-rosae parents produced male sterile hybrid progeny, while use ofS. boliviense, S. bukasovii, S. canasense, S. microdontum, andS. sparsipilum results in families containing both fertile and sterile plants. Sterility may be due to interactions between Tuberosum cytoplasm and dominant nuclear genes from the species. Genetic male sterility and environmental conditions may also be responsible for low pollen stainability in some hybrids. Many fertile, 2x hybrids produce 2n pollen. Selection for 2n pollen in the species is fast and efficient, but meiotic analysis is required in male sterile haploids. Fortunately, selection in the species parent alone results in a large number of 2n pollen-producing hybrids. These 2x hybrids have been used to generate tetraploids via 4x × 2x crosses.     

32份茶树地方群体种资源的遗传多样性和群体结构分析

选取均匀分布于茶树15个连锁群上的30对SSR引物,对来自12个省份的32份茶树群体种资源进行遗传多样性和群体结构分析,以期为茶树杂交育种亲本选择和演化路线推断提供参考。研究共获得149个等位基因,平均每个SSR标记检测到5.96个等位基因,引物多态性信息含量均值为0.660。32个茶树群体Shannon’s多样性指数范围为0.691～1.089,平均数为0.954;观测杂合度的范围为0.253～0.633,平均数为0.510;期望杂合度范围为0.430～0.653,平均数为0.590。供试茶树群体遗传分化系数(Fst)均值为0.205,遗传分化水平较高。基于Nei’s遗传距离的聚类和群体结构分析结果一致,供试种质可划分为四大类型,具有明显的地域分布规律。