大豆亲本杂交方式对后代的遗传变异及品系产量表现的影响 Ⅰ.单交与双交的比较研究

1985—1990年用两套亲本的单、双交组合为材料,比较后代表现及选择效果,以明确双交是否较单交更优越。结果表明:单、双交组合F_2代的株高、主茎节数、单株荚数、单株粒数、百粒重、单株粒重的平均表现、标准差及变异系数无大差异。双交组合多数性状的变异幅度处在两个单交组合之间。除第二套组合双交的主茎节数同时显著少于两个单交外,其余性状均未能同时达到显著水平。按相同育种目标入选的高世代品系在生育期、抗倒伏、抗病性方面,双交均可获得与单交相似的选择效果。两个单交组合与相应的双交组合的F_4、F_5品系平均产量、20％高产品系平均产量、前二名高产品系平均产量的差异未能达到显著水平。看来,对产量进行选择,双交并不比单交更优越。     

南阳盆地直立型豌豆农艺性状与产量相关性及通径分析

采用相关分析和通径分析方法对22份豌豆品种（系）的主要农艺性状和产量进行分析。结果表明：农艺性状与产量的相关程度为：主茎节数＞百粒重＞单株荚数＞株高＞荚宽＞主茎分枝数＞单荚粒数＞荚长;关联顺序为：荚宽＞百粒重＞荚长＞单荚粒数＞主茎分枝数＞主茎节数＞株高＞单株荚数。两种分析结果基本吻合,影响豌豆产量的主要因子为百粒重和单株荚数。通径分析表明百粒重对产量的直接作用大,影响百粒重的直接性状为主茎节数,影响单株荚数的直接性状为单荚粒数和主茎分枝数,因此在筛选培育新品种时应注意考察主茎节数与主茎分枝数,以减少这些性状对产量的不利影响。     

苦荞麦产量与主要农艺性状的相关性及灰色关联度分析

对20个苦荞麦品种(系)9个农艺性状进行了相关性及灰色关联度分析。结果表明:在相关性分析中,全生育期与主茎节数、株高呈极显著正相关,与单株粒数呈显著正相关,株高与主茎节数呈极显著正相关,单株粒数与基本苗呈极显著正相关,与全生育期、主茎节数、株高呈显著正相关,单株粒重与单株粒数呈极显著正相关,与基本苗、主茎分枝数呈显著正相关,株高与千粒重呈显著负相关。所有农艺现状与产量均呈现正相关,其中与基本苗、单株粒数、单株粒重达到极显著水平。灰色关联度分析中,各农艺性状与产量之间的关联度依次为基本苗单株粒数全生育期千粒重单株粒重株高主茎节数主茎分枝数。其中基本苗、单株粒数、全生育期、千粒重和单株粒重等5个性状与产量性状关联度分别为0.763 9、0.763 6、0.756 9、0.749 4、0.746 6,是影响产量的主要因素。     

春大豆主要农艺性状方差分析及相关分析的研究

对引进的9份大豆优良种的11个主要农艺性状进行方差分析，对15个主要农艺性状进行相关分析，研究结果表明：（1）主要农艺性状中的茎粗、单株粒重经方差分析达显著水平，株高、底荚高度、主茎节数、主茎分枝数、单株总荚数、秕荚数、每荚粒数、百粒重等性状经方差分析达极显著水平；（2）主要农艺性状的变异系数大小依次为秕荚数、主茎分枝数、单株荚数、单株粒数、单株产量、底荚高度、每荚粒数、百粒重、株高、茎粗、产量、主茎节数、出苗至开花、开花至成熟、生育期；（3）产量与生育期、秕荚数呈显著正相关，与株高、底荚高度、主茎分枝数、单株产量、每荚粒数、百粒重、开花至成熟的天数呈正相关，与茎粗、主茎节数、单株荚数、单株粒数、出苗至开花的天数呈负相关。因此，要增加产量，首先应考虑百粒重大、单株生产力潜力大的品种，其次考虑底荚高度较低，每荚粒数较多的品种。     

利用混合线性模型分析绿豆主要农艺性状的遗传及相关性

以19个绿豆品种(系)为亲本, 采用非完全双列杂交试验设计及混合线性模型,研究绿豆主要农艺性状的遗传规律及其性状间的相互关系。结果表明, 绿豆全生育日数、株高、主茎节数和百粒重均以加性效应为主, 狭义遗传率较高且达极显著水平;单株荚数、单株产量和总产量的加性效应和显性效应均显著或极显著, 狭义遗传率相对较低;单荚粒数主要受显性效应影响, 广义遗传率较高;播种至开花天数与株高间存在显著或极显著遗传和表型正相关;单株荚数、单荚粒数与百粒重显著或极显著负相关;单株荚数与单株产量、总产量显著或极显著正相关;百粒重与单株产量、总产量相关性不大;针对全生育日数、株高、主茎节数和百粒重的选择可在早期世代进行, 而对产量的选择可以根据单株荚数和单株产量在晚期世代进行。     

绿豆品种农艺性状与产量的相关性及灰色关联度分析

采用相关分析和灰色关联度分析相结合的方法,对28个绿豆品种(系)农艺性状与产量的关系进行综合评价,研究绿豆品种农艺性状与产量的关系。结果表明,生育期、株高、主茎节数、单株荚数与产量呈显著正相关;不同农艺性状与产量的关联度依次为单株荚数荚粒数百粒重主茎节数主茎分枝荚长生育期株高。2种分析方法均表明,单株荚数对产量的影响最大,因此在育种实践中应优先考虑单株荚数这一因素,同时将两种方法相结合,对品种进行综合客观评价。     

大豆遗传资源农艺性状的鉴定和筛选

对来自于中国黄淮海大豆产区、北方大豆产区和南方大豆产区的316个大豆品种的主要农艺性状进行了鉴定和比较。结果表明,育成品种的分枝数、分枝荚数、单株总荚数明显不及农家品种,而其它性状如主茎荚数、单株粒重、单株粒数和百粒重优于农家品种。以育成品种和农家品种分别所作的相关分析表明,主茎荚数、分枝荚数、单株总荚数均与单株粒数和单株粒重呈显著的正相关;主茎节数与株高、主茎荚数、单株总荚数、单株粒重、单株粒数呈显著正相关;分枝数与分枝荚数、单株总荚数、单株粒数和单株粒重呈极显著或非显著正相关,但与主茎荚数呈负向显著相关;单株粒数与单株粒重显著正相关,百粒重与单株粒重正向显著相关,与单株粒数负相关显著。通过比较和分析,就百粒重、生育期和株高筛选出一些具有极端值的品种,可以用作品种选育的亲本和大豆分子育种如转基因受体或分子标记作图群体的遗传材料。     

福建省近年来育成春大豆品种农艺性状的遗传变异、相关性及主成分分析

对福建省11个春大豆品种的10个农艺性状进行了遗传变异分析、相关性分析和主成分分析。结果表明,大豆有效分枝数、主茎节数、单株荚数、单株粒数和单株粒重等变异系数较大;单株粒重与有效分枝数和单株荚数呈显著相关。主成分分析表明,前3个主成分,其累积贡献率为83.78%,分别为荚粒性状因子、产量性状因子和株型性状因子。     

不同肥料组合对高油大豆黑河19品质和产量的影响

研究了9个不同肥料组合对高油大豆黑河19脂肪、蛋白质含量及产量的影响。结果表明:主茎节数和单株粒数在各肥料组合间有显著差异,单株荚数和产量在各肥料组合间有极显著差异,其它性状在各肥料组合间无显著差异。C、E和F等3个肥料组合具有增加大豆主茎节数、单株荚数、单株粒数的作用,能使高油大豆绥农20极显著增产。尤其是F、E两个处理,还具有提高黑河19脂肪含量的作用。     

毛豆品种的农艺性状鉴定及相关性分析

对引进的19份毛豆品种的10个主要农艺性状进行相关性分析。研究表明,1)农艺性状变异系数大小依次为主茎分枝数、百粒重、单株荚数、底荚高、单株粒数、株高、单株产量、主茎节数、茎粗、生育期。2)单株产量与百粒重呈极度正相关,与底荚高、主茎分枝数、茎粗、单株粒数呈正相关,与株高、主茎节数、单株荚数呈负相关。因此要增加单株产量,首先要考虑选择百粒重大的品种,其次是选择茎杆粗壮,主茎分枝数及单株粒数较多的品种。     

三交和双交组合加性-显性-母体效应的遗传模型及蒙特卡罗模拟分析

本文根据广义遗传模型的建模原理,按照三交和双文组合方式的交配设计,分别提出了分析 作物三交和双交组合数量性状的加性－显性－母体效应的遗传模型（ＡＤＭ模型）,给出了不同环境下各 世代群体的遗传效应分量。应用ＭＩＮＱＵＥ（１）法对包括不同世代的三交和双交组合的ＡＤＭ模型进行 了蒙特卡罗模拟分析,结果表明：采用亲本和三（双）交Ｆ_１两个世代分析三（双）交组合的ＡＤＭ模型 时,即可获得方差分量的无偏估计值和遗传效应的无偏预测值;采用包括单交Ｆ_１在内的三个世代联合 分析时,更有利于提高显性等遗传效应方差分量的估算效益。最后讨论了利用单交组合预测三交和双 交组合遗传表现的有关问题。     

三交和双交组合加性-显性-母体效应的遗传模型及蒙特卡罗模拟分析

本文根据广义遗传模型的建模原理, 按照三交和双交组合方式的交配设计, 分别提出了分析作物三交和双交组合数量性状的加性-显性-母体效应的遗传模型(ADM模型), 给出了不同环境下各世代群体的遗传效应分量。 应用MINQUE(1)法对包括不同世代的三交和双交组合的ADM模型进行了蒙特卡罗模拟分析, 结果表明： 采用亲本和三(双)     

小麦群体的基因效应与杂种优势

利用小麦三个单交组合的 P_1、P_2、F_1、F_2,B_1和 B_2六个世代群体以及一套双列杂交材料,根据3种不同模式,估算了各类基因效应、杂种优势和配合力等遗传参数。研究对比了不同遗传模式;分析了各类基因效应,尤其是上位效应的特点。根据基因效应分析了杂种优势的遗传组成,结果认为显性效应及 aa 型上位效应对杂种优势起重要作     

亚洲百合杂交亲和性研究

本实验用常规授粉的方法,对亚洲百合自交、系内杂交和系间杂交亲和性进行了研究,旨在为百合育种研究提供一定的依据。通过试验发现,自交试验中只有‘Mount Duckling’得到膨大的果实;系内杂交试验中共计19个杂交组合,其中13个组合得到膨大的果实,10个组合得到胚;系间杂交试验中以2个东方百合品种为父本,共计12个杂交组合,均未得到胚。通过研究还发现,正反交对结实率也有很大影响。     

The importance of Endosperm Balance Number in potato breeding and the evolution of tuber-bearing Solanum species

Summary Endosperm failure is considered the primary reason for the lack of success in intra-and interspecific crosses. The Endosperm Balance Number (EBN) hypothesis is a unifying concept for predicting endosperm function in intraspecific, interploidy, and interspecific crosses. In the EBN system, every species has an effective ploidy (EBN), which must be in a 2:1 maternal to paternal ratio in the endosperm for crosses to succeed. The knowledge of EBN is very useful in the transfer of genes from exotic germplasm, and in the development of new breeding schemes in potato. The paper describes the strategies for introducing 2x(1EBN), 2x(2EBN), 4x(2EBN) and 6x(4EBN) germplasm into the cultivated 4x(4EBN) potato gene pool. A new methodology for producing 4x(4EBN) and 2x(2EBN) chromosome addition lines is also discussed. EBN has evolutionary importance in the origin of tuber-bearing Solanums. The role of the EBN in the origin of diploid and polyploid potato species, and as a barrier for hybridization and speciation of sympatric species within the same ploidy level is demonstrated. The origin of 3x and 5x cultivated tuber-bearing Solanums may also be explained using the EBN concept. EBN has been reported to exist in other plant species: alfalfa, beans, blueberries, rice, soybeans, squashes, tomato, forage legumes, grasses, ornamentals and Datura stramonium. This indicates that EBN may have broad application and could be useful for germplasm transfer and breeding in other crop species.     

Effects of Pollination Method on Strain Cross Yield in Lucerne

Because of difficulties in pollination, control, F₁ hybrids have not been widely explioted in lucerne’ (Medicago sativa L.). Strain crossing (uncontrolled hybridization between two or more self-fertile populations with seed of the populations combined to product a “strain cross” population) represents a potentially valuable alternative procedure for exploiting heterosis in this species. Strain crosses in lucerne are typically produced using insect pollination in the field. Using hand pollination under glasshouse houses could increase the number of strain crosses available for tests of combining ability. The objective of this study was to determine whether forage yield of strain crosses produced using hand pollination were sufficiently similar to that of insect-produced populations to allow the use of the former in lucerne breeding. Forage yields of eight pairs of hand- and insect-produced strain crosses did not differ significantly in 15 of 16 pairwise comparisons and were positively correlated (r_s= 0.90) for 20 harvests at two locations. Yield amp of band produced strain crosses could be used, with reasonable accuracy to accuracy the eventual performance of strain crosses produced between the same populations using insect pollination.     

Selection potential for seed yield from intra- and inter-racial populations in common bean

Common bean populations from crosses between lines of different races are thought to be more promising for selection of high yield potential than those from intra-racial crosses. Three distinct diallel crosses were made to test this hypothesis and to determine the possibility of substituting diallel crosses for multivariate techniques that estimate genetic divergence. The crosses were between races Mesoamerica × Mesoamerica, Mesoamerica × Durango and Jalisco, and Mesoamerica × Nueva Granada. The parents and the resulting F₄ populations were evaluated at Lavras-MG, Lambari-MG and Patos de Minas-MG, Brazil. The diallel analysis of seed yield was done and the genetic divergence estimated by Mahalanobis distance. Estimates of general and specific combining ability indicated that some inter-racial populations were more promising for selection to increase seed yield than intra-racial populations. However, due to their undesirable seed color and size, and growth habit, especially in a short term breeding program, the chances of obtaining high yielding lines with an acceptable bean is reduced. Genetic divergence was not a good measure to choose the parents because usually, the most divergent groups included were not adapted lines. This revised version was published online in July 2006 with corrections to the Cover Date.     

Identification of primary trisomics and other aneuploids in foxtail millet

A complete set of nine primary trisomics (2n+ 1) for cv.‘Yugu No. 1’of foxtail millet, Setaria italica (L.) Beauv. (2n= 2x= 18), was identified cytologically from progenies derived from crosses between autotriploids(2n= 2x= 27) and their diploid counterparts. Five autotriploid plants were identified from 2100 seedlings derived from 4x-2x crosses; the reciprocal crosses (2x-4x) failed to produce autotriploids. Autotriploids grew vigorously and were morphologically very similar to diploids. Theprimary trisomics (2n= 2x= 19) constituted ?32.5% of the total progeny from the 3x-2x crosses, whereas 59.8% of the descendants were aneuploids with chromosome numbers ranging from 20 (double trisomics and tetrasomics) to 37 (2n= 4x+ 1; or autotetraploid with one additional chromosome). The nine primary trisomics identified were self-fertile; seven had characteristic morphology, whereas trisomics VIII and IX resembled the disomics. The seed set for trisomic V was the lowest (20%), and trisomic VIII the highest (74%). Other aneuploids with 20 or more somatic chromosomes were either self-sterile or partially fertile with various, but low, levels of seed set. Each of the primary trisomics showed its unique transmission rate when self-pollinated; trisomic IX had the highest (45.8%), whereas trisomic V had the lowest (19.6%) transmission rate.     

Number and size of cross progenies from a constant total number of plants manageable in a breeding program

Summary This short paper discusses the optimum number of crosses and size of progenies for a given total population size to minimize the risk of not finding any favourable genotype in the breeding material. It is shown that the number of crosses must generally be as large as possible. In special situations it may be advantageous to include also less promising crosses instead of enlarging the progenies of more promising crosses.