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1.
R. Ortiz 《Plant Breeding》1997,116(5):487-491
The objective of this work was to determine intraclass correlations for growth and yield traits, as well as associations between them, in segregating hybrids. Diploid, triploid and tetraploid hybrids were obtained from triploid-diploid crosses between plantains and bananas. These hybrids were evaluated as plants and as ratoon crops on a humid forest site. Significant differences between ploidy within crosses were observed for most traits. The tetraploids were taller, had longer production cycles but a shorter fruit filling time, and heavier bunches than the diploids. There were significant differences between clones of the same ploidy within crosses. Hence, individual selection within ploidy will be effective for the improvement of plantain. Most of the bunch and fruit traits were positively and significantly associated, especially at the tetraploid level. Selection for large fruit at the diploid and tetraploid levels may lead to heavy fruits, thereby resulting in hybrids bearing heavy bunches. Significant and positive correlations between plant height and bunch weight at the tetraploid level suggest that selection of dwarf plantains with heavy bunches may be difficult. 相似文献
2.
Elizanilda Ramalho do Rêgo Mailson Monteiro do Rêgo Fernando Luiz Finger Cosme Damião Cruz Vicente Wagner Dias Casali 《Euphytica》2009,168(2):275-287
The aim of this work was to estimate the general and specific combining ability of peppers by measuring fruit quality and yield traits. This experiment was carried out on the garden field from Universidade Federal de Viçosa (UFV), Minas Gerais State—Brazil. Eight lines of Capsicum baccatum belonging to the UFV Horticultural Germplasm Bank were chosen based on their broad genetic and phenotypical background variation and then they were crossed in a complete diallel way. The F1 seeds of the 56 hybrids and eight parents were planted in the field in a randomized complete block design. The data were submitted to ANOVA and the means were grouped by Scott–Knott test (P ≤ 0.01). Significant variation for fruit quality and yield components was observed among parents and F1 generation. Analysis of variance for the combining ability showed that GCA effects exhibited significant difference and SCA effects of the crosses were significant, except for the height of first bifurcation. For almost all characters both additive and non-additive effects influenced the performance of hybrids. 相似文献
3.
为了明确玉米果穗相关性状的配合力及其遗传效应,按NCⅡ遗传交配设计,对参试的20个玉米自交系(9个母本,11个父本)的9个性状的一般配合力、特殊配合力、广义遗传力、狭义遗传力进行分析。结果表明,5个自交系JZF5、JZF2、JZM10、JZM5、JZM3在穗粒重等多个性状上兼具一般配合力(GCA)有益的显著或极显著值。穗粒重特殊配合力(SCA)排名前5的杂交组合JZF5×JZM4、JZF2×JZM1、JZF8×JZM5、JZF6×JZM5、JZF7×JZM5,它们的亲本之一穗粒重GCA为极显著正值,提示在杂交种组配时应兼顾GCA和SCA效应。穗长、秃尖长、行粒数、穗行数、水份含量加性遗传方差占比大于70%,穗粒重的加性遗传方差占比为35.7%,主要由非加性遗传方差构成。广义遗传力上,水份含量>秃尖长>穗行数>穗长>穗粒重>行粒数>穗轴重>穗宽>百粒重,其中秃尖长、穗行数的广义遗传力大于60%,水分含量的广义遗传力大于70%。狭义遗传力上,秃尖长>水份含量>穗行数>穗长>行粒数>穗轴重>穗宽>百粒重>穗粒重,其中秃尖长、水份含量和穗行数的狭义遗传力大于50%,适宜在早代进行选择；百粒重和穗粒重的狭义遗传力最低,分别是22.8%和19.7%,不宜在早代进行选择。本研究的果穗部分性状供试特性偏向父本,建议关注父本对玉米杂交种果穗相关性状的重要影响。 相似文献
4.
5.
Flower bud thrips, Megalurothrips sjostedti is the most severe field pest of cowpea that causes massive flower abortion which eventually results to substantial yield reduction in Africa. There is paucity of information on the mode of gene actions controlling inheritance of resistance to flower bud thrips in cowpea in the literature. The objectives of study were to assess the genetic variability for thrips resistance among the cowpea germplasm, determined the mode of inheritance of genes that conferred resistance and both broad and narrow-sense heritability estimates for the inheritance of thrips resistance in cowpea. Twelve cowpea lines were used in crosses in the screen house at IITA, Ibadan. The mating was accomplished using North Carolina design II to generate 48F1 hybrids, which were eventually evaluated with the parents. Data on number of peduncles, number of pods and number of thrips per flower were recorded and subjected to analysis of variance using random model by SAS 9.2. Significant variability was observed for most agronomic and thrip-adaptive traits among the cowpea germplasm, parental-lines and F1 genotypes evaluated. General combining ability (GCA) and specific combining ability (SCA) mean squares were significant (P < 0.01) for number of pods per plant and other traits under the research environment. The GCA effect accounted for 68.82–80.07% of the total variation among hybrids for all traits except days to flowering; SCA explained less than 50% of the total variation. Narrow-sense heritability estimates ranged from 7.53 (days to flower) to 63.92% (number of peduncles per plant). Additive gene action largely controlled the inheritance of yield components and other traits under thrips infestation and these traits were moderately heritable. 相似文献
6.
The combining abilities for physical-quality traits in peanut were examined to understand the type of gene action governing
these traits, and to identify peanut genotypes suitable for use as parents in breeding for quality improvement. The F1 hybrids including reciprocals from a six-parent diallel cross along with the parents were evaluated in a randomised complete
block design. Data were recorded on five quality traits in peanut viz., shelling outturn, 100-pod weight, 100-seed weight, Count and proportion of sound mature seeds. Substantial genetic variability
was observed among the hybrids for the traits studied. Diallel analysis indicated that expression of majority of the quality
traits is regulated predominantly by additive gene action suggesting possibility of early-generation selection, while non-additive
gene action also plays an equally important role in the control of seed size. Significant reciprocal effect for all the traits
denoted role of maternal parent in the expression of quality traits and importance of parental selection in quality breeding.
Genotypes ICGV 86564 and TPG 41 were good combiners for seed size, while J 11 was a good combiner for improvement of shelling
outturn and proportion of mature seeds. Association between general combining ability (GCA) effects and mean performance suggested
that the performance per se of the genotype should be a good indicator of its ability to transmit the desirable quality attributes
to its progenies. Though performance of crosses was found to be independent of parental GCA status, it is evident that at
least one of the parents used in hybridisation should have large pods and seeds for obtaining better segregants. 相似文献
7.
Marília Caixeta Franco Sérvio Tulio Cassini Valter Rodrigues Oliveira Clibas Vieira Siu Mui Tsai Cosme Damiao Cruz 《Euphytica》2001,118(3):265-270
Ten F1's obtained from crosses among five common bean genotypes of Andean (WAF 15, Mineiro Precoce and Batatinha) and Middle American
(BAT 304 and Ouro) gene pools were assessed for their combining abilities for root nodulation with Rhizobium tropici strain CIAT 899. The plants were grown under controlled conditions and evaluated for number of nodules per plant (NN), nodule
dry weight (NDW), mean nodule weight (MNW) and plant fresh weight (PFW). The subdivision of the treatment effects on the general
(GCA) and specific combining effects (SCA) were performed according to Griffing's diallel analysis method 2, model 1. The
analyses of variance and estimates of quadratic components showed that non-additive gene effects were more important in the
expression of NN and PFW, whereas additive gene effect was predominant for NDW and MNW. A close association was observed between
high number of nodules and GCA. Generally, crosses involving parents of different gene pools yielded hybrids with high positive
estimates of SCA for all assessed traits. The genotypes of Andean origin WAF 15 and Mineiro Precoce are the most promising
parents for breeding programs to increase NN and NDW in common beans.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
以陆地棉的5个抗黄萎病品种为父本,4个感病品种为母本,采用不完全双列杂交配制20个组合,进行黄萎病抗性配合力研究。结果表明,冀122、中植棉2号在发病率、病情指数、相对病情指数3个性状上均具有较高的一般配合力（GCA）效应,而冀棉616、豫棉112、徐棉18号则为负向效应。通过特殊配合力（SCA）效应分析,有9个组合具有正效应,而11个组合为负效应。通过估算3个性状的GCA方差和SCA方差,表明这些性状主要受加性基因效应控制。通过遗传力分析,3个性状广义遗传力较大,可在早代选择。 相似文献
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10.
Hamidreza Nooryazdan Hervé Serieys Jacques David Roberto Bacilieri André J. Bervillé 《Euphytica》2011,178(2):159-175
The genetic base of sunflower elite lines is very narrow, due to many years of selection and breeding. To broaden the genetic
diversity of the cultivated sunflower, in 1995 73 wild sunflower populations were crossed with 3 cultivated lines (Testers),
and 219 hybrid offspring’s were evaluated in the field. GCA and SCA effects were computed suggesting for all traits a genetic
potential for improvement through selection. Study of the hybrids revealed that the wild accessions bear different genetic
abilities to combine with the testers for traits of morphological architecture, phenology and yield (seed weight and seed
oil). The variance due to GCA and SCA showed that gene action was additive for days to flowering, branching and plant height.
Genotypes derived from the same geographic origin may have either good or poor general combing ability. The correlation between
GCA and per se genotype performance was positive for all traits except for seed oil content. This was the first attempt to evaluate wild-cultivated
hybrids in sunflower on a large scale and will be the starting point for the management of hybrid Helianthus annuus populations for breeding. GCA and SCA estimations will facilitate the definition of strategies to manage and exploit the
natural diversity for this crop. 相似文献
11.
Seed is an important input in production of field crops. The successful production of sugar from sugar beet depends on high
yielding varieties, optimum plant establishment after sowing and good agricultural practices. Therefore, seed with the highest
germination ability and vigour is necessary to ensure an early and high level of field emergence. Knowledge of the genetic
control of seed characters may help breeders to efficiently select for improved germination. In this research, variance components
and inheritance of sugar beet seed characteristics were studied. Five monogerm diploid O-Type lines were crossed with 15 monogerm,
diploid cytoplasmic male sterile (CMS) lines on the basis of North Carolina Design II (Factorial Design), and 75 F1 hybrids
(single crosses) were produced. The hybrids were then compared in three completely randomized designs of 25 entries each.
Eight seed traits of F1 hybrids were evaluated in the laboratory in three replications. Based on genetic analysis, the additive
variance for rootlet length, hypocotyle length, uniformity of germination and 1,000-germ weight was significant at 5% probability
level. Also, the dominance variance was significant at 1% probability level for all the seed traits measured except for germination
percentage. Narrow-sense heritabilities of rootlet and hypocotyle lengths were significant at 5% probability level. Correlation
analysis showed that germination speed and hypocotyle length were positively and negatively correlated with germination uniformity,
respectively, at 1% probability level. These results indicated that there was a remarkable genetic variation for the seed
traits which could be exploited by selection and heterosis breeding. 相似文献
12.
陆地棉配合力与杂种优势、遗传距离的相关性分析 总被引：6，自引：2，他引：4
用10个陆地棉亲本进行不完全双列杂交,共配置了45个组合,计算亲本的一般配合力（GCA）、特殊配合力(SCA)、杂种优势,并结合SSR标记研究了陆地棉亲本配合力与杂种优势、遗传距离之间的相关关系。配合力分析发现,10个亲本的一般配合力和特殊配合力存在显著或极显著差异。分析亲本配合力、杂种优势和遗传距离的相关性发现,子棉产量、皮棉产量、衣分的一般配合力和杂种优势呈显著或极显著相关,纤维长度、比强度、麦克隆值、株高、果枝数、单株铃数、铃重、子棉产量、皮棉产量、衣分的特殊配合力和杂种优势均呈极显著正相关,而与遗传距离相关均不显著。单株铃数、铃重、子棉产量、皮棉产量、衣分的杂种优势与遗传距离均为正向显著或极显著相关。在育种实践中这些显著或极显著相关的性状可能具有较高的改良潜力。 相似文献
13.
Maize hybrids that are tolerant to drought at the seedling stage are needed to boost productivity in the rainforest agro-ecology of West Africa. Genetics of tolerance of maize seedling to drought stress is not well understood and is poorly documented. The objectives of this study were to screen early-maturing maize lines for seedling drought tolerance, determine the inheritance and the combining ability of selected inbred lines, and evaluate the performance of seedling drought-tolerant hybrids under field conditions. Forty-nine early maize lines were screened for drought tolerance at the seedling stage. Ten drought-tolerant and two susceptible inbred lines were selected and used in diallel crosses to generate 66 hybrids. The twelve inbred lines and their hybrids were evaluated under induced drought at seedling stage in the screen house and under marginal growing conditions on the field for two seasons. Data collected were subjected to analysis of variance using the DIALLEL-SAS program. Mean squares for both GCA and SCA were significant for most traits in all research environments, indicating that additive and non-additive gene actions are controlling seedling traits under stress conditions. However, for most traits, SCA was preponderant over GCA in all environments, indicating overdominating effect of non-additive gene action. Which in turn implied that the best improvement method for the traits is hybridization. Inbred TZEI 7 had the best GCA effect for seedling traits under screenhouse conditions and for grain yield and other agronomic traits under drought conditions in the field. Hybrids TZEI 357?×?TZEI 411 and TZEI 380?×?TZEI 410 showed superior SCA effects under screen house conditions. In conclusion, the study established wide genetic variability for drought tolerance at seedling stage among tropical early-maturing maize germplasm however, the non-additive gene action was more important for most seedling traits. 相似文献
14.
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
15.
Grain yields of maize in the lowland tropics are generally limited by short days and high temperatures that minimize durations of incident light. Little has been published on the effects of this limiting environment on the genetics of grain filling rate (GFR), and grain filling period (GFP) in tropical maize germplasm. This study sought to address these limitations. A set of 8 elite maize inbreds of tropical origin and their 28 diallel hybrids were grown in three seasons at Waimanalo, Hawaii, USA. Seasonal differences included > 100% differences in values of photosynthetic active radiation (PAR) during grain formation. Information was sought on the performance variations and the genotype by season interactions for GFR, GFP, days to mid-silk (DTS), kernel weight, with estimates of general (GCA) and specific combining ability (SCA) and their interactions with seasons. Significant differences occurred for inbreds, hybrids, and genotype by season interactions, GCA and SCA effects and their interactions with seasons, which could be attributed primarily to the differences in PAR values among seasons in Hawaii during grain filling. Additive genetic effects predominated for GFR and GFP. Breeding approaches that take advantage of additive gene effects including hybrid breeding with evaluations in multiple Hawaii seasons may be used to alter GFR and GFP. 相似文献
16.
Heterosis and combining ability for grain yield and other agronomic traits in winter triticale 总被引：1，自引：0，他引：1
Hybrid breeding is a widely discussed alternative for triticale. Heterosis as well as general (GCA) and specific combining ability (SCA) effects were estimated for eight agronomic traits. The experiment comprised 24 F1 hybrids, produced by a chemical hybridizing agent, together with their six female and four male parents, grown in drilled plots in two locations. In comparison with the mid‐parent values, hybrids averaged a 6.4 dt/ha (10.1%) higher grain yield, 8.4% more kernels per spike, a 6.8% higher 1000‐kernel weight, 9.7% lower falling number (FN) and 4.4% greater plant height. SCA effects for grain yield were significant and ranged from 4.5 to 6.9 dt/ha for grain yield. Together with GCA x location interactions, they explained most of the variation. For 1000‐kernel weight, GCA effects were predominant. SCA and interactions with location accounted for most of the variation in FN, whereas interactions were negligible for plant height. Correlations between mid‐parent and hybrid performance and between GCA and per se performance of parents were tight for all traits except grain yield, which allows for pre‐selection of parental lines. Although the amount of heterosis in triticale at present is closer to wheat than to rye, by selecting parents for combining ability and identifying heterotic patterns, grain yield heterosis of up to 20% appears sufficiently encouraging to embark on hybrid breeding. 相似文献
17.
Summary Head blight caused by Fusarium culmorum and F. graminearum is damaging in all winter rye (Secale cereale L.) growing areas. For hybrid breeding, the relative magnitude of general (GCA) and specific combining ability (SCA) is a crucial parameter for developing appropriate selection procedures. Forty single-cross hybrids were produced by crossing six and seven inbred lines of the Petkus and Carsten gene pool, respectively, in a factorial design. Hybrids were evaluated in two years with artificial F. culmorum inoculation. Resistance traits were head blight rating and grain weight relative to the non-inoculated control. Both resistance traits were closely correlated across both years (r-0.8, P=0.01). Significant genotypic variation was found for both traits with medium to high estimates of heritability (h2=0.6-0.8). Components of variance for GCA were, across years, 10 and 6 times larger than those for SCA for head blight rating and relative grain weight, respectively. Significant SCA effects were found for 15 to 20% of all cross combinations across both traits in each year. SCA effects were, however, inconsistent over years leading to a high SCA-year interaction. In conclusion, resistance to Fusarium head blight among the interpool hybrids tested was conditioned mainly by additive gene action that could be utilized by recurrent selection in multi-environment trials.Abbreviations GCA
general combining ability
- SCA
specific combining ability 相似文献
18.
Evaluation of genetic variances, heritabilities, and correlations for yield and fiber traits among cotton F2 hybrid populations 总被引：4，自引：0，他引：4
Summary F2 hybrid cultivars continue to occupy a small portion of the cotton (Gossypium hirsutum L.) production are in the United States, but occupy a larger proportion of the production area in some other countries. Sixty-four F2 hybrids resulting from crosses of four commercial cultivars and 16 pest-resistant germplasm lines were evaluated for five fiber and four yield traits in four environments at Mississippi State, MS. An additive-dominance genetic model was employed for these traits. The minimum norm quadratic unbiased estimation (MINQUE) method was used with a mixed model approach for estimating genetic variance and covariance components and for predicting genetic correlations. This study investigated genetic variances, heritabilities, and genetic and phenotypic correlations between agronomic and fiber traits among these 64 F2 hybrid populations and discussed the usefulness of these populations for use as hybrids or for selections for pure lines.Dominance variance accounted for the major proportion of the phenotypic variances for lint yield, lint percentage, and boll size indicating that hybrids should have an advantage for these traits compared to pure lines. A low proportion of additive variance for fiber traits and the significant additive x environment variance components indicated a lack of substantial useful additive genetic variability for fiber traits. This suggests that selections for pure lines within these F2 populations would have limited success in improving fiber traits. Genetic and phenotypic correlation coefficients were of comparable magnitude for most pairs of characters. Fiber strength showed a positive additive genetic correlation with boll weight. Dominance genetic correlations of fiber strength with elongation and 2.5% span length were also significant and positive; however, the additive genetic correlation of length and strength was zero.Contribution of the USDA-ARS in cooperation with the Mississippi Agric. and Forestry Exp. Stn. 相似文献
19.
转Bt基因棉杂种优势及性状配合力研究 总被引：45，自引：19，他引：26
采用NCⅡ设计方法,选用我国构建的Bt(Bacillus thuringiensis)基因棉GK3和美国构建的Bt基因棉新棉33B等Bt基因棉为父本,配制杂交组合,分析了含Bt基因杂交棉组合的性状优势表现及配合力效应。性状优势分析表明,组合的中亲优势和竞争优势明显,皮棉产量中亲优势率达100％,竞争优势率达86．7％,多数品质性状较对照为优,表明转Bt基因棉品系与常规品种间杂种优势利用潜力较大;通径分析表明,在增产因素中,铃重和铃数所起贡献较大;配合力分析表明,父本间和母本间的GCA均方值均达显著或极显著水平,组合的SCA均方值除子、皮棉声量性状外,其余均不显著,在F1性状的遗传中,各性状的加性效应起主导作用;F1的性状表型值与父、母本的GCA呈高度正相关,并达显著水平,表明选配含Bt基因杂交组合时,选择GCA值大的亲本较为可靠。 相似文献
20.
Summary Diallel crosses were made between 15 tomato genotypes with varying performance under a low energy regime. It appeared that differences between genotypes for 11 vegetative and generative plant characters are determined mainly by additive genetic variation. For breeding cultivars adapted to low energy conditions, crossing genotypes with a high GCA for weight of trusses and fruits (WTF) and genotypes with a high GCA for weight of vegetative plant parts (WVP) seems most promising. Complications may arise from the negative correlation between GCA values for WTF and WVP, and the strong positive correlation between GCA values for fruit number and WTF, causing small fruits. 相似文献