高粱品系的主要农艺性状评价与综合分析

为探究产量与农艺性状间的关系,客观评价高粱品系,提高性状改良进程。本研究对24个高粱组合的农艺性状和产量进行变异分析、相关性分析、灰色关联度分析、主成分分析和聚类分析。结果表明单穗粒重变异系数和主穗柄长度较大;全生育期与至开花期、穗粒数皆达到极显著正相关,与穗粒数、单穗粒重、糖锤度呈显著正相关,千粒重对产量影响最大;灰色关联度结果也表明千粒重与产量性状关联度最大,其次为单穗粒重、至开花期和主穗长度;主成分分析结果表明,12个性状综合成6个因子,累计贡献率达86.91%,分别为生育期因子和开花期因子、产量因子和穗长因子、株型因子和穗柄长度因子、穗粒因子物质运储因子、产糖因子,排名前6的高粱组合有N_2、N_(20)、N_(19)、N_9、N_8和N_(24)。聚类分析结果表明,在阈值为0.60处,将24个高粱组合分为3类,第Ⅰ类生育期较长,千粒重、穗粒重较好;第Ⅱ类生育期较短且产量较高;第Ⅲ类综合性状较好。     

含CIMMYT种质的改良系的改良效果研究

摘要：本研究将黑龙江省玉米自交系吉846和K10与CIMMYT种质Pob45、Pob46杂交构建半外来群体并从中选育改良系,再按原杂交种的组配形式或配制成若干改良杂交组合,对其产量和其它性状进行测定并与原杂交种进行比较,研究其产量和产量性状的变化特点与规律,分析改良的效果和进一步改良的方向,为更有效地利用外来种质特别是来自CIMMYT的热带和亚热带多数种质改良黑龙江省现有的种质资源提供参考。结果表明从半外来群体吉846×Pob45中选育的吉846改良系与K10组配的杂交组合的产量有高于同熟期对照龙单13和原组合的,部分杂交组合的株高、穗位有所降低,部分杂交组合的雄穗一级分枝数、全株叶面积、出籽率、百粒重也有较明显的改良。从半外来群体K10×Pob46中选育的K10改良系与吉846组配的杂交组合的产量都低于同熟期对照龙单13和原组合,但个别性状如百粒重、出籽率、行粒数、穗长有一定的改良效果。     

秦巴山区玉米杂交组合主要性状与产量间的灰色关联度分析

运用灰色系统理论中杂交组合灰色评判原理与方法,对60个玉米组合的产量和9个产量因素进行灰色关联分析及综合评判,以明确不同玉米杂交组合产量和产量构成因素之间的关系。结果表明:秦巴山区玉米杂交组合产量与主要农艺性状的关联度大小排序为穗粗>百粒重>穗长>穗位高>穗行数>行粒数>出子率>株高>秃顶长。组合46综合性状最好(G=0.881),组合52次之(G=0.861),组合54综合性状最差(G=0.552),综合评判结果与杂交组合在生产实际中表现基本一致。     

杂交粳稻产量性状与品质性状相关性分析

为了探明杂交粳稻的产量性状与品质性状间的关系,以5个千粒重介于23.5~27.4 g之间的BT型不育系和40个千粒重介于18.7~31.2 g之间的三系粳稻恢复系,采用5×40 NCⅡ设计方式,配制200个杂交组合为试验材料,对产量性状、品质性状及其相互关系进行了分析,主要结果表明：单株谷重与单株有效穗数、每穗实粒数、结实率、千粒重均呈极显著正相关（r=0.47**,0.63**,0.53**,0.35**）,与穗长呈显著正相关(r=0.15**);对单株产量贡献最大的是每穗实粒数。垩白粒率和垩白度2个性状是杂交粳稻品质改良的重点,其次是精米率和整精米率;糙米率、精米率、整精米率相互间均呈极显著正相关,糙米率与垩白粒率和垩白度呈极显著正相关（r=0.33**,0.25**）。产量性状对品质性状的影响不大,通过筛选,可以将高产、优质的性状聚合到同一杂交组合中。     

玉米自交系株形和产量性状的遗传改良效果

对60～90年代初我国自育和引进的39个骨干自交系株形和产量性状遗传改良效应的研究表明,随着年代的推移,自交系的穗位高、穗位高/株高比值明显降低,茎粗逐渐增加,株形更趋紧凑,雄穗分枝数和雄穗长度逐渐减少,改良效果显著.在产量性状中穗粗和穗行数的改良效果显著,单株粒重有所增加,但改良效果不明显,其它产量性状改良效果甚微.     

5个玉米人工合成群体主要性状育种潜势分析

对5个玉米人工合成群体主要性状表现、杂种优势以及配合力进行了研究。结果表明，群体内个体间均存在较丰富的遗传变异，群体间主要性状及其配合力差异更为明显，其中群体GP-5和GP-3植株穗位高低适中，主要产量性状及其GCA表现较好，优良个体出现频率较高，比对照高产的组合出现次数较多，具有较大改良利用潜势；群体GP-4虽主要产量性状均值偏低，GCA正向效应值偏小，但植株较矮，穗位较低，比对照高产的组合出现次数较多，通过GCA改良和SCA选择有一定利用前景；群体GP-1和GP-2植株穗位偏高，主要产量性状的GCA均为负值，育种潜力不大。     

不同类型杂交早稻农艺性状的遗传分析

采用6个杂交稻三系不育系和10个杂交早稻父本品种,通过不完全双列杂交配置了60个杂交早稻组合。分析了在相同栽培环境条件下三系杂交早稻亲本及其所配置的杂交早稻组合的12个农艺性状的遗传规律。结果表明：12个农艺性状的遗传以加性效应为主,各性状的狭义遗传力大小顺序依次为千粒重>株高>穗长>穗实粒数>结实率>穗总粒数>生育期>理论产量>实际产量>有效穗>成穗率>最高苗;除穗长外,其余性状受父本的影响较大;理论产量与结实率、穗实粒数、株高、成穗率及有效穗呈正相关,可通过这几个性状对产量进行间接选择;穗实粒数是杂交早稻选择指数中最重要的选择性状。     

杂交粳稻亲本产量性状优异配合力的标记基因型筛选

提高杂交粳稻竞争优势的关键是改良其恢复系产量性状的配合力。为使之更富成效,选用115个SSR引物扩增6个粳稻BT型不育系和12个恢复系的标记基因型,并按NCII遗传设计配制72个F1组合,分析18个亲本的单株日产量、单株有效穗数、每穗总粒数、每穗实粒数、千粒重5个性状的配合力,结合亲本SSR分子标记数据和性状配合力数据筛选了5个性状优异配合力的标记基因型。结果发现20个SSR标记基因型与亲本产量及其构成性状配合力显著相关。其中8个与亲本单个性状配合力相关;6个同时与亲本2个性状配合力相关;4个同时与亲本3个性状配合力相关;2个同时与亲本4个性状配合力相关。同时与多个性状配合力相关的标记基因型,对各性状的作用方向有正有负。RM152-165/170是单株日产量和单株有效穗数优异配合力效应最大的标记基因型,可使F1的相应性状值增加20.6%和12.7%。优异配合力的标记基因型可直接用于粳稻恢复系配合力的分子标记辅助改良。     

两个类型水稻组合主要性状的灰色关联分析

应用恢色关联度分析方法,对重庆三峡农业科学院配组而成的两个类型的籼稻组合主要经济性状与产量的关联度进行了分析,结果表明：穗、粒兼顾型组合产量与各性状的关联度按大小顺序依次为实粒数>结实率>有效穗>千粒重>全生育期,表明每穗实粒数的高低是影响该类型组合产量的主要因素,有效穗及各粒重次之;重穗型组合产量与各性状的关联度按大小顺序依次为有效穗>实粒数>结实率>千粒重>全生育期,表明有效穗是影响该类型组合产量的主要因素,每穗实数次之。     

CIMMYT种质对东农250亲本自交系的改良效果研究

本试验将CIMMYT种质Pob46和Pob45分别导入东农250的父本自交系吉846和母本自交系444中,研究CIMMYT种质对其产量及其他农艺性状的改良效果。结果表明吉846改良系和444改良系所配杂交组合的株高及穗位均有所降低,有利于增强组合的抗倒伏性;百粒重普遍增加但产量普遍降低,仅有个别组合增产;其它性状如雄穗一级分支数和行粒数等,二者改良效果有所不同。     

不同燕麦品种产量及其与构成因素的相关性研究

在内蒙古土默川山前洪积平原水肥条件不同的土壤上,对引进不同燕麦品种的产量及其构成因素进行了相关及聚类分析。结果表明:供试燕麦品种之间的产量有极显著差异。株高只在水肥条件较差的情况下与草产量显著相关。在两种条件下,燕麦的草产量与子粒产量均呈显著相关;子粒产量主要取决于穗重、穗粒数。而在水肥条件较好的情况下,千粒重、穗数、穗重、穗粒数与子粒产量均显著相关。不同品种间,皮燕麦坝莜4号和科燕1号产量较高,坝莜4号的抗逆性较强;裸燕麦比皮燕麦对水肥条件敏感。     

Estimation of variance components and heritability of bunch yield and yield components in the oil palm (Elaeis guineensis Jacq.)

In an experiment involving 24 single-cross progenies of oil palm conducted at the Nigerian Institute for Oil Palm Research, 9-year data of fresh-fruit yield and its two components, annual bunch number and single-bunch weight, were recorded. Means of progenies of each of the three traits obtained from 1–9-year records were used in analyses of variance according to a repeated-measures design. The results were then used to estimate variance components due to progenies and progeny × year interactions. These estimates were then used to estimate heritability for yield and yield components based on progeny means, which were assumed to be calculated from 1–9 years of harvests. The results revealed that heritability estimates of fresh-fruit yield and its two yield components were not reliable based on the first-year harvest data. The single-bunch weight had a slower rate of improvement than the other two traits when more years were used for the estimation. Heritability can be expected to be over 80% for fresh-fruit yield and bunch number based on 1-, 3-, and 4-year means, respectively. Six-year data are required for single-bunch weight to reach the same heritability measure.     

高产小麦品种模式化选育的初步研究

本文探讨了高产小麦品种理想模式的概念、特点和品种模式化选育的理论依据及优点。对37个亩产400公斤以上的高产品种的产量与其构成因素、形态性状、生理性状以及这些性状之间的关系进行了多元和简单相关分析。针对山东的生态条件和品种的现状，优化了亩产600-650公斤的品种模式。探讨了各类性状间的有机联系和协调发展产量潜     

陆地棉染色体片段代换系及F1皮棉产量与产量构成因素的相关和通径分析

探讨棉花染色体片段代换系皮棉产量与产量构成因素之间的相关关系,明确其产量育种的主攻方向,以1套陆地棉染色体片段代换系及F1为材料,采用相关与通径分析的方法,对5种环境条件下代换系亲本及F1的皮棉产量与产量构成因素进行分析。结果表明,产量构成因素的变异系数以铃数最大,铃重次之,衣分最小,且F1产量构成因素的变异系数在所有环境下均比代换系亲本要小。铃数、衣分及铃重与皮棉产量均呈正相关,除个别环境外均达到显著性水平,其与皮棉产量的相关和偏相关系数在代换系亲本中以铃数最大,而F1中则以衣分最大。衣分,铃数与皮棉产量的相关程度受环境影响小,而铃重受环境影响较大。除1种环境外,代换系亲本的直接通径系数以铃数最大,衣分次之,铃重最小,而F1中则以衣分最大,铃数次之,铃重最小;代换系亲本中各因素的间接通径系数均为正值,而F1中铃数与铃重相互之间的间接通径系数均为负值。材料类型和环境条件不同,其产量构成因素与皮棉产量的相关程度及贡献大小也存在较大差异。代换系亲本产量育种的主攻目标前期应该重在衣分,后期重在铃数,而F1则始终以提高衣分为主。     

Estimates of relative contribution of biomass, harvest index and yield components to soybean yield improvements in China

A method was developed to estimate the relative contribution of increased biomass, harvest index and yield components to seed yield gain of soybean. Data from four field experiments conducted in three soybean production regions in China were used to measure the role of different traits (such as harvest index) in seed yield improvement by applying this method. The results indicated that harvest index was a larger contributor to the progress of soybean yield improvements than biomass in China. However, the estimates of improvements of yield components suggested that there could be several strategies for obtaining high yield. High yielding would be achieved by improving all of the three yield components (pods per plant, seeds per pod and seed weight) simultaneously, or significantly improving one or two of the three components.     

Inheritance of yield components and their correlation with yield in cowpea (Vigna unguiculata (L.) Walp.)

Summary The inheritance of yield components was studied in a cross of two varieties of cowpea (Vigna unguiculata), and the relationships among the components and yield were examined in the F₂ of a cross and in a trial of 22 varieties. The main objective was to determine the suitability of using the components as selection criteria for increasing seed yield. All the components appeared to be under polygenic control and transgressive segregation in the F₂ was observed for pod length and number of seeds per pod. Narrow sense heritability estimates ranged from 19.8% for number of pods per plant to 60.3% for pod length. Most of the genotypic correlations between pairs of yield components were significant. Correlation of yield per plant was negative with pod length, but positive with the other components. Number of pods per plant was consistently correlated with yield. However because of low heritability for number of pods per plant, this component may only be used as a preliminary selection criterion while the final selection is based on yield itself.     

Diallel analysis of combining ability and heterosis for yield and yield components in rice by using positive loci

Diallel crosses have been widely used for analysis of general combining ability (GCA), specific combining ability (SCA) and heterosis. In the present research, 12 lines were selected from 60 inbred rice bred by International Rice Research Institute with extremely-high or -low yielding records according to the previous three consecutive seasons of yield trial experiments, to construct a half diallel cross. The genetic distances (GDs) revealed by molecular markers for the 12 lines ranged from 0.2288 to 0.7169, averaging at 0.5882; clustering analysis showed the 12 lines were divided into four groups maintaining the original cluster structure of the 60 lines. The positive loci (PLs) including effective-increasing loci (ILs) and effective-decreasing loci (DLs) were screened. The results showed that hybrids derived from those parents with higher GCA effects had better performance for traits of yield and yield components. The SCA effects were strongly correlated to F₁ performance as well as heterosis; the GDs based on ILs were significantly positive correlated to SCA effects and heterosis for yield and yield components while the GDs based on DLs showed the significant negative correlations. Based on this research, a new conception, i.e. general sum of combining ability (GSCA) was conceived, which is defined as the sum of GCAs for two parents of a hybrid. The GSCA and SCA showed similar correlations with traits of yield and yield components. The results illustrated that ILs could be used for further study on prediction of heterosis for traits of yield and yield components; and GSCA may be another considerable parameter combined with ILs for breeders in selecting elite hybrid.     

基于陆地棉背景的海岛棉染色体片段导入系产量性状QTL定位

棉花产量分为籽棉产量和皮棉产量,其中高皮棉产量总是育种的首要目标。皮棉产量由单株铃数、衣分、单铃重等因素组成。其中衣分在各因素中的遗传率最高,同时也是产量育种中重要的选择指标。育种中利用分离群体对单株铃数、铃重等产量性状选择受环境影响较大。利用染色体片段导入系进行铃数、铃重等产量性状的定位,定向改良产量性状,是棉花分子设计育种的有效方法。本研究利用陆地棉TM-1为轮回亲本和海岛棉海7124为非轮回亲本构建了一套陆地棉背景的染色体片段导入系,并在7个环境的田间试验下,鉴定了它们的产量表现,定位了28个与单株铃数、铃重、衣分和籽指相关的QTL。其中,在Dt亚组染色体上鉴定出的产量性状QTL多于在At亚组染色体上鉴定出的。28个QTL中,加性效应为正的16个,加性效应为负的12个,表明海岛棉不同的导入片段效应不同,有的片段可以提高陆地棉产量,有的则降低陆地棉产量。在6个环境下,导入系IL008(特征标记NAU2573和NAU3576)的衣分均显著高于轮回亲本TM-1,因此IL008可以应用于棉花分子育种,定向改良陆地棉的衣分。     

Morphological Traits above the Flag Leaf Node as Indicators of Drought Susceptibility Index in Durum Wheat

Selection criteria for drought tolerance would be helpful tools for wheat breeding programmes. To assess the usefulness of some morphological traits above the flag leaf node as indicators of yield and the susceptibility index (SI) of Fischer and Maurer, 10 durum wheat genotypes were used in experiments conducted under two water regimes at two latitudes in Spain during 3 years. Morphological traits were measured at anthesis, and yield, yield components and quality traits were evaluated at ripening. Principal components analysis showed associations between morphological traits and yield, yield components and quality, most of them caused by differences between environments. Peduncle weight, spike weight and length and awn length were significantly related to SI within environments. Spike and peduncle weight were the traits more related to yield and SI in all the experiments together and in the rainfed sites, while in the irrigated sites spike length was better. The spike weight and length were negatively associated with SI, while peduncle weight was positively associated to SI. Genotype means across all experiments were associated with SI values. These morphological traits could be selection criteria in breeding programmes to obtain varieties with good yield stability. The genetic variability found suggests opportunity for selection.     

Molecular markers for yield components in Brassica juncea – do these assist in breeding for high seed yield?

A population of 112 F₁-derived doubled haploid lines was produced from a reciprocal cross of Brassica juncea. The parents differed for seed quality, seed color and many agronomic traits. A detailed RFLP linkage map of this population, comprising 316 loci, had been constructed, and was used to map quantitative trait loci (QTL) for seed yield and yield components, viz. siliqua length, number of seeds per siliqua, number of siliques per main raceme and 1000-seed weight. Stable and significant QTLs were identified for all these yield components except seed yield. For yield components, a selection index based on combined phenotypic and molecular data (QTL effects) could double up the efficiency of selection compared to the expected genetic advance by phenotypic selection. Selection indices for high seed yield, based on the phenotypic data of yield and yield components, could only improve the efficiency of selection by 4% of the genetic advance that can be expected from direct phenotypic selection for yield alone. Inclusion of molecular data together with the phenotypic data of yield components in the selection indices did not improve the efficiency of selection for higher seed yield. This is probably due to often negative relationships among the yield components. Most of the QTLs for yield components were compensating each other, probably due to linkage, pleiotropy or developmentally induced relationships among them. The breeding strategy for B. juncea and challenges to marker assisted selection are discussed.