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1.
Genetic diversity between parents is important for hybrid breeding and for maximum usefulness of a cross in pure line breeding. However, wide crosses may suffer from poor adaptation in the target environments and recombination losses owing to disruption of favourable epistatic gene combinations. In this study we investigated the importance of various gene effects for different traits in the parents and generations F1 to F5 derived from 99 intra- and inter-pool crosses among 20 lines of the Minor, Major, and Mediterranean germplasm pools of faba bean in Mediterranean and German environments. Yield performance of parental inbreds and progenies of crosses in different selfing generations was high in the region of adaptation of the respective germplasm pool. Heterosis for yield was greatest in interpool crosses of Minor × Mediterranean germplasm, amounting to 106% in Mediterranean and 72% in German environments. Interpool crosses exhibited significantly greater heterosis compared with intrapool crosses in both mega-environments. Generation means analysis revealed the importance of additive gene effects and dominance × dominance epistasis in Mediterranean and German environments. Dominance effects and additive × additive epistasis for yield were negligible in most crossing groups. Since intrapool crosses of Mediterranean germplasm in Mediterranean environments and crosses of Minor and Major germplasm in the German environments were most promising, we suggest crosses among adapted germplasm for hybrid breeding and for establishing new base material in line breeding in faba bean. 相似文献
2.
Combining ability of seed vigor and seed yield in soybean 总被引：4，自引：0，他引：4
Studies have shown no consensus in relationships between seed yield and vigor in soybean [Glycine max (L.) Merrill]. The lack of information regarding the inheritance of seed vigor prompted this study to determine the types
of gene action and combining ability estimates for seed vigor and its related traits. Five high and six low seed vigor soybean
genotypes were crossed in a diallel, and selfed to produce 55 F2 progenies, which were examined, along with the parents, for seed vigor, yield, and seed weight. Significant genotype and
environment effects were found for seed vigor and yield. General combining ability (GCA) effects for seed vigor and seed yield
were significant (p≤ 0.01) and larger than specific combining ability (SCA) effects. Significant GCA and SCA effects were found for seed weight,
indicating that both additive and non additive genetic effects were involved in conditioning seed weight. The ratios of mean
square, 2GCA / (2GCA+SCA), were 0.96 for seed vigor and 0.93 for seed yield. These ratios indicated that additive gene effects
were more important than non additive gene effects for seed vigor and seed yield in these crosses. Mean seed vigor(83.8%),
as determined by accelerated aging germination, and mean seed yield (2,155 kg ha-1)in high vigor × high vigor crosses were higher than the high vigor × low vigor and low vigor × low vigor crosses. Mean percent
accelerated aging germination rates in F2 populations from diallel crosses were significantly related to mid-parent seed vigor(r2 = 0.52**) and midparent seed size (r2 = 0.31**). These results indicated that levels of seed vigor can be improved through breeding, while maintaining high yields because
of the predominance of GCA effects in both seed vigor and seed yield.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
Summary The relationship between the genetic distance of parents and both the heterosis of F1 hybrids and the variance of F5 lines was investigated in 72 crosses of pea (Pisum sativum L.). The genetic distance between each pair of parents was estimated, using isozyme (GDi), morphological (GDm) or quantitative (GDq) markers and finally a combination of isozyme and morphological markers (GDi+m). GDm was poorly correlated with the other measures of genetic distance, which in turn were strongly correlated with each other. Genetic distance was moderately correlated with the level of heterosis for yield over midparent in the F1 generation, with the highest correlation obtained from GDi+m. GD was not significantly correlated with heterosis for yield over the better or best parent but it was significantly correlated with all three measures of heterosis for pods per plant and hundred seed weight. There was no correlation between genetic distance and the level of heterosis for yield and total dry matter in the F2 generation, but GDi, GDi+m and GDq were predictive for the level of inbreeding depression in grain yield and total dry matter. When parents were high in genetic distance, crosses produced highly transgressive segregants for basal branches per plant, hundred seed weight, harvest index and onset of flowering. Genetic distance between parents was thus a useful measure for predicting a portion of hybrid performance and also of the variance of derived inbred lines. It was concluded that when choosing parents for a cross, consideration should be given to their genetic distance as well as their overall adaptation and their yield. There is considerable potential for optimising choice of parental combinations in the development of improved pea cultivars. 相似文献
4.
大豆杂种产量的主-微位点组遗传分析 总被引：1，自引：1，他引：0
选用来源于中国黄淮和美国的熟期组II~IV的8个大豆品种,按Griffing方法II设计,配成36个双列杂交组合(28个杂种组合+8个亲本)于2003-2005年进行田间试验。应用基于数量性状主基因+多基因遗传模型的主-微位点组分析法,解析8个大豆亲本产量的主、微位点组遗传构成及其效应,估计主、微位点组对产量杂种优势的贡献。结果表明,8个大豆亲本间产量由6个主位点组加微位点组控制,主位点组、微位点组分别解释表型变异的75.98%和10.81%。6个主位点组加性效应(aJ)分别为140.10、259.65、1.95、151.35、–32.70和45.00 kg hm–2,显性效应(dJ)分别为177.15、314.25、105.75、75.90、242.85和171.00 kg hm–2。杂种遗传构成包括主位点组杂合显性效应、主位点组纯合加性效应、微位点组杂合显性效应和微位点组纯合加性效应4部分,相对重要性依次递减,以显性效应为主,加性效应为辅。亲本间主、微位点组及其遗传效应的解析阐释了各杂种组合的遗传特点,还提供了进一步挖掘遗传潜力进行优势改良的基础。 相似文献
5.
Summary Broadening agronomic adaptation will improve yield stability in the grain legume Vicia faba L. We gathered information on the adaptation of European and Mediterranean material to European and Mediterranean environments. The material comprised 20 inbred lines (12 European and 8 Mediterranean lines) and 99 intra- and interpool-crosses in generation F1. These were evaluated in 9 environments: two spring-sown Southern German environments (SGermE), and seven autumn-sown Mediterranean environments (MedE) in Sicily, Puglia, Andalucia and South Africa. Standard ANOVA, stability analyses and AMMI analysis were performed. Mean yield in F1 was 257 g/row, the overall parental mean was 144 g/row. The range of environmental means was from 94 g/row to 411 g/row. The average regression coefficient in F1 was b
i
=1.07, being significantly greater than for the parents (b
i
=0.68). The opposite was true for the relative magnitude of the deviations from the regressions, which were highly correlated to the AMMI-PC1-results. The AMMI analysis clearly separated the SGermE from the MedE, as well as the germplasm pools. Though the superiority of the F1-hybrids over their parents was striking, their pattern of interactions with the environments strictly reflected that of their parents. A number of promising crosses was identified as a nucleus of a widely adapted faba bean genepool. 相似文献
6.
Successful identification of a desirable segregant depends partly on the parents chosen to make the crosses. This experiment was conducted to compare performance and genetic variability for seed yield, yield components, agronomic traits and harvest index of lines derived from low- and high-yielding flax (Linum usitatissimum L.) crosses, and to identify important yield components for flax seed yield improvement. The lines chosen as high yielding parents for this experiment were‘Linott’and 'Summit; and the low yielding parents were‘Grant’and Ci2395. The high-yielding lines produced significantly more seeds per boll and had a higher harvest index than the low-yielding lines. Evaluation of 161 F2:6 lines from four crosses among these lines showed that the greatest genetic variability, highest cross average, and highest F6 line seed yield occurred in the low x high cross,‘Grant’x‘Linott’. All low X high crosses exhibited higher genetic variances for seed yield than the high x high crosses. The high x high cross 'Summit’x‘Linott’had low genetic variance for seed yield. Number of bolls per area was determined by linear regression, path coefficient analysis, and stepwise multiple regression analysis to be the most important component of seed yield. This study showed that hybridization of low and high-yielding flax lines may be useful to increase genetic variability and obtain high-yielding flax lines. 相似文献
7.
New sources of partial resistance to Fusarium head blight (FHB) in wheat have been identified over the past decade; however,
little is known of their breeding value. A 20 parent partial diallel that included resistant genotypes from the U.S., Europe,
China and South America was used to evaluate the potential of these sources of resistance as parents in wheat breeding programs.
Eight plants replication−1 of each of 190 crosses and 20 parents were point-inoculated with Fusarium graminearum under greenhouse conditions in two replicated experiments. Both general (GCA) and specific combining ability (SCA) were significant.
Most of the variance for FHB severity was associated with additive genes; however, estimates for SCA ranged from highly negative
to highly positive in both resistant × resistant and resistant × susceptible crosses which suggest that improving FHB resistance
through gene pyramiding strategies based on additive genetic variation may be complicated by interaction effects that condition
FHB resistance. 相似文献
8.
Heterosis and heritability in crosses among Asian and Ethiopian parents of hot pepper genotypes 总被引：1，自引：1，他引：0
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. 相似文献
9.
Tsuneki Tanaka Hiroyuki Tamaki Kazunori Ashikaga Hiroki Fujii Toshihiko Yamada 《Plant Breeding》2013,132(2):144-148
Molecular marker technologies may provide a tool to overcome the forage yield plateau in timothy (Phleum pratense L.). Therefore, a study was designed to investigate the relationship between marker‐based genetic distance (GD) estimates and yield. Genetic distances were estimated using Dice coefficients framed by 28 simple sequence repeat markers. In Experiment 1, parents with high general combining ability (GCA) from two contrasting first‐generation synthetic strains (exhibiting high and low yields) were compared. Average GDs of each strain were 0.74 (high) and 0.68 (low). These differences indicated that GD may be partially the basis for contrasting yields. In Experiment 2, GDs among 40 parents of a polycross were used for calculating general genetic distance (GGD), which is indicative of their allelic complementation. Analyses revealed a significant (P < 0.01) moderate correlation (r) between GGD and GCA for yield (r = 0.45) and a significant (P < 0.01) residual mean square for the regression of yield on GGD, suggesting that considerable non‐additive effects were associated with GCA. The results are indicative of the potential use of GD estimation for yield improvement in timothy. 相似文献
10.
Grain yields of seven barley cultivars (Hordeum vulgare L.) and 398 doubled-haploid lines derived from their diallel crosses were evaluated in hill plots at two locations in Ontario. Additive × additive epistasis and linkage disequilibrium were detected in the seven cultivars. Additive × additive genetic variance was significantly greater than zero but additive genetic variance was not significantly greater than zero. The narrow-sense heritability on the basis of line means was intermediate (0.33). It was predicted that 13.1% yield improvement could be realized in the next recurrent selection cycle using the doubled-haploid method. 相似文献
11.
W. Link B. Schill A. C. Barbera J. I. Cubero A. Filippetti L. Stringi E. von Kittlitz A. E. Melchinger 《Plant Breeding》1996,115(5):352-360
Two recently detected, promising CMS systems in faba bean have opened up new possibilities in hybrid breeding. This study was conducted to determine hybrid performance and heterosis of 33 intra-pool and 66 inter-pool crosses from a factorial of six European small-seeded (Minor), six European large-seeded (Major), and eight Mediterranean faba bean lines. The parent lines and F1 crosses were evaluated at two German and seven Mediterranean environments for anthesis, maturity, yield, yield components and plant height. Yield in the Mediterranean environments was 60% of that in the German environments. European Minor lines and their intra-pool crosses were unadapted to Mediterranean environments and yielded only 31 % compared with the Mediterranean lines and their crosses, whereas European Major genotypes yielded 58%. In German environments the European crosses yielded 107% of the Mediterranean crosses. Heterotic yield increase over the parental mean was largest for European Minor x Mediterranean inter-pool crosses, amounting to 95% in the Mediterranean and 73% in German environments. Our results confirmed the expectation of an increased heterosis in inter-pool over intra-pool hybrids and poor adaptation of European genotypes in Mediterranean environments. In the latter, Mediterranean intra-pool hybrids were the most promising, whereas in Germany inter-pool hybrids of the European Minor × Mediterranean type were most promising. 相似文献
12.
The Libusta (Coffea canephora P. × C. liberica B.) programme initiated in the seventies in Côte d'Ivoire aims at improving the quality of coffee grown in low altitudes, with a yield comparable to current commercial C. canephora clones. The second generation of back‐crosses to the C. canephora (CAN) parent, BC2, are now likely to be commercially exploited as far as yield is concerned. The best BC2 progeny yielded 1386 kg of green coffee/ha/y, averaged over five harvest years. On average, the genetic gain for yield from BC1 to BC2 reached 22%. In a factorial mating design, no interaction was observed between BC1 and CAN parents, while both main effects were highly significant. This explained that observed genetic gains and further genetic gains may be achieved with appropriate strategies. 相似文献
13.
Genetic analyses were carried out with B. napus lines that differed in total content of individual glucosinolates (GSLs), as well as in their profile. Inheritance of total GSL content was studied with a complete F1 diallel mating of eight doubled haploid (DH) lines (5–120/μmol GSL/g dry seed) as well as with the segregating populations of two crosses between DH lines. Most of the genetic variability was caused by gca effects; heterosis was not important; heritability of GSL content was high (h2b, = 0.95, h2n= 0.87). For GSL contents below 20/μmol/g seed, heritability values reached h2b, = 0.69 and h2n, = 0.66. Low total GSL content was found to be controlled by 4–5 recessive genes with additive gene action. Alkenyl GSL profiles studied in F2 from resynthesized rapeseed lines were determined by four loci, two that are responsible for the elongation of the butenyl to pentenyl GSLs and two that are responsible for hydroxylation of alkenyl GSLs. Initial genetic studies of indolyl GSL contents from 0.1–4.5/μmol/g show that two or three genes may be involved. The frequency distribution of F2 phenotypes was virtually continuous due to both segregational and environmental variation. Genotypes with low alkenyl and low indolyl GSL contents were selected after crossing parents with low alkenyl/high indolyl and high alkenyl/low indolyl GSL content. The alkenyl GSL profiles are discussed with regard to the parental diploid species B. oleracea and B. campestris. 相似文献
14.
Summary A diallel cross population was created from five clones that were randomly selected from five commercial ultivars of alfalfa (Medicago sativa L.). It was planted out at Edmonton and was studied for forage yield, vigor, growth habit, days to flower, plant height and frost tolerance in 1972 and 1973. Results showed that genetic difference between the five parents were large since the general combining ability (GCA) was more important than specific combining ability (SCA) and reciprocal effects (RE) for all the six characters. Greater genetic variance for forage yield, vigor, growth habit and plant height were observed in the second year of growth rather than in the year of establishment. Thus selection for these characters in the second year would be most effective. Genotype x environment interaction was significant for all characters and was relatively more important in the case of vigor and plant height. A study of the GCA effects showed that this source of variation was due to changes in the order of ranking for GCA effects over the environments. Genotypic correlation of the six characters revealed strong genetic association between forage yield, vigor, growth habit, plant height and frost tolerance in this population of alfalfa. 相似文献
15.
Ângela de Fátima Barbosa Abreu Magno Antonio Patto Ramalho Daniel Furtado Ferreira 《Euphytica》1999,108(2):121-127
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. 相似文献
16.
棉花三系杂交种不同生态区遗传效应及优势表 现简 总被引：2，自引：2，他引：0
选用3个核背景不同的恢复系材料和7个不同的哈克尼西棉胞质不育材料作为亲本,根据NCⅡ遗传交配设计,配置了21个杂交组合,分别在黄河流域棉区河南安阳、黄淮流域棉区河南西华和长江流域棉区安徽无为3个生态区试点种植,通过性状调查与室内考种,采用朱军的ADE模型,进行数据分析。结果表明,子棉和皮棉产量主要受到加性、显性、加性与环境互作效应的影响,衣分和铃数主要受加性、加性与环境互作效应的影响,而铃重则只受加性与环境互作效应的影响;对于纤维品质性状,纤维长度、马克隆值、比强度和整齐度受到加性效应的影响,同时,纤维长度和马克隆值还与加性与环境互作效应相关;遗传率分析与遗传方差分量分析表现一致;产量及产量性状之间有一定的遗传相关,而纤维品质性状之间的遗传相关则较小,产量和纤维品质性状之间也存在着较少的遗传相关;杂交组合的产量竞争优势表现为安阳试点>西华试点>无为试点,说明与生态环境有关。在3个不同的生态区,研究了21个杂交组合的遗传效应及优势表现,研究结果对三系杂交组合选配有一定的指导意义。 相似文献
17.
Wheat breeders rarely apply population improvement schemes or select parental sources according to combining ability and heterotic patterns. They rely on pedigree selection methods for breeding new cultivars. This experiment was undertaken to assess the advantages of using diallel crosses to define combining ability and understand heterosis in a broad‐based wheat‐breeding population across different environments affected by yellow rust. Sixty‐four genotypes derived from a full diallel mating scheme were assessed for grain yield in two contrasting growing seasons at two locations for two consecutive years. Parental genotypes showed significant combining ability for grain yield that was affected by yellow rust and genotype‐by‐environment (GE) interactions, both of which affected heterosis for grain yield. Significant GE interactions suggested that decentralized selection for specific environments could maximize the use of this wheat germplasm. Cultivar effects and specific heterosis were the most important factors influencing grain yield. Some crosses capitalized on additive genetic variation for grain yield. This research shows the power of available quantitative breeding tools to help breeders choose parental sources in a population improvement programme. 相似文献
18.
Gene action controlling yield and yield‐related traits among tef (Eragrostis tef [Zucc.] Trotter) populations under drought‐stressed and nonstressed conditions 
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下载免费PDF全文 This study was aimed to determine gene action for grain yield and yield‐related traits of newly developed tef populations under drought‐stressed and nonstressed conditions to improve drought tolerance. Ten crosses, along with the parents, were evaluated in the F2 generation under drought‐stressed conditions at Hastebo and Adigdad sites in 2015 and Dura site in 2016 and under nonstressed conditions at Dura site in 2016. Additive gene action predominantly controlled the inheritance of the grain yield and majority of the yield‐related traits under drought‐stressed and nonstressed conditions. Under both test conditions, the genotypes DZ‐Cr‐387 and 9415 were the best general combiners for increased grain yield and morphological traits. Conversely, genotype 222076 was the best general combiner for reduced maturity period only. The selected parents are novel genetic materials for tef breeding programmes to improve grain yield and morphological traits with reduced days to maturity for drought tolerance breeding. The family of the cross DZ‐Cr‐387 × 222076 was selected for high grain yield and early maturity in both the drought‐stressed and nonstressed environments. 相似文献
19.
A. Elgersma 《Euphytica》1990,51(2):163-171
Summary Seed yield in perennial ryegrass is low and unpredictable. Spaced-plant traits suitable for indirect selection for total seed yield in drilled plots would be very useful. The objectives of this investigation were to evaluate genetic variation for seed yield components and other traits among clones from three perennial ryegrass cultivars differing in seed yield and their open-pollinated progenies. Per cultivar, a random set of 50 genotypes was cloned and on each genotype seed was generated by open pollination. Clonal ramets of the parents were observed for 17 traits in 1986 at two locations. In 1987 and 1988, parents and progenies were observed as single plants in a randomized complete block design with two replications. There was little cultivar-environment interaction for most traits. The parents differed significantly for almost all traits. Half-sib (HS) families differed for only three to five traits. Broad-sense heritabilities (h2
b), based on variance components of the parents, were moderate to high; earliness had the highest hb
2. Narrow-sense heritabilities (h2
n), based on variance components among HS-families, were low to moderate and mostly not significant; for most traits h2
n estimates varied between years and cultivars. Flag leaf width and date of first anthesis showed the highest h2
n. Narrow-sense heritability estimates from parent-offspring regressions (h2
nPO) ranged from non-significant to high, depending on year and cultivar; they were generally higher than the corresponding h2
n estimates. Generally, h2
nPO was highest for earliness, flag leaf width, ear length and the number of spikelets per ear. Breeding methods that capitalize on additive genetic variance, such as mass selection, should result in improvement for these traits. 相似文献
20.
Molecular markers and protein quantities as genetic descriptors in maize. II. Prediction of performance of hybrids for forage traits 总被引：1，自引：0，他引：1
J. Burstin A. Charcosset Y. Barriére Y. Hébert D. de Vienne C. Damerval 《Plant Breeding》1995,114(5):427-433
As it is related to the variability in genome expression, variability in protein quantities revealed by two-dimensional electrophoresis was proposed for describing phenotypic diversity. The objective of this study was to compare the predictive power of different genetic distances derived from molecular markers and from protein quantitative variations in a diallel of 210 hybrids among 21 maize inbred lines (Zea mays L.) of various origin. The lines were characterized for: 1. 142 markers resulting from the analysis of enzyme, RFLP, and protein-structure polymorphism; and 2. The variation in relative quantities of 190 proteins. The hybrids were evaluated for six forage traits in four environments. Correlations between the genetic distances computed for 142 marker loci and hybrid performances were moderate to high in diallels using crosses between related lines. Genetic distances based on protein quantities showed, in most cases, similar or lower correlations. Distance measures were not useful as predictors of hybrid performance for crosses between unrelated lines. Protein quantities were better for revealing specific genotypes. 相似文献