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181.
182.
Optimization of DH-line based recurrent selection procedures in maize under a restricted annual loss of genetic variance 总被引:1,自引:0,他引:1
Doubled haploid (DH) lines are increasingly being used in commercial hybrid maize (Zea mays L.) breeding. They allow for various quantitative genetic and logistic advantages provided that they are implemented in efficient
and optimally allocated breeding procedures. In the present study, a new software was applied to optimize two recurrent selection
(RS) schemes for hybrid maize breeding based on DH lines under a restricted annual budget and an upper limit for the relative
annual loss of genetic variance. This software maximizes the expected gain from selection in general combining ability by
means of quantitative genetic model calculations. Optimization results are compared for one, two, and three stages of testcross
selection under different assumptions regarding the evaluation of lines per se and the annual budget. Results show that the
optimum allocation of technical and budget resources to the individual steps of an RS program and the efficiency of alternative
RS procedures are decisively determined by the number of selection stages. Under standard assumptions, one-stage selection
was superior to two- and three-stage selection. Thus, shortening the length of an RS scheme considerably increases its efficiency.
By intercrossing a reduced number of selected lines for starting a new RS cycle, the short-term response to selection may
be increased, but the population size and, thus, the selection limits in the long run are diminished. Therefore, fair comparisons
of alternative RS procedures require to define the intended time span for maximizing the genetic gain from RS and to restrict
the relative annual loss of genetic variance accordingly. 相似文献
183.
Brito Giovani G. Concenço Germani Costa Vladimir E. Fagundes Paulo Ricardo R. da Silva-Filho João Luis Parfitt José Maria B. Magalhães Ariano Silva Giovana T. Jardim Thaís M. Luccas Nathália Furtado Scivittaro Walkyria B. 《Journal of Crop Science and Biotechnology》2022,25(1):19-32
Journal of Crop Science and Biotechnology - Phenotyping is the major bottleneck in the effort to develop varieties of rice (Oryza sativa L.) suitable for growing under a water-saving irrigation... 相似文献
184.
This paper empirically examines the key factors driving UK direct investment in the Spanish regions over the period 2000–2016 and, consequently, tries to unveil its main motivation. Applying a spatial Durbin panel model to capture spatial linkages, the results point to the existence of complementarity between the FDI received by a region and that of the remaining ones. This outcome, along with a positive and statistically significant spillover effect of market potential, reveals that complex-vertical FDI motivation with agglomeration economies prevails among UK MNEs investing in Spain. Additionally, our findings unveil the role played by some other FDI drivers, such as wages and infrastructure. Furthermore, the paper is unique in decomposing the average direct and spillover effects by region and pairs of regions, so that remarkable differences can be identified. This breakdown has strong significance from a policy perspective since it can guide regional policy makers. In short, our findings point out to the fact that FDI policy should be jointly designed by those regions presenting strong bilateral spillover effects. Thus, greater cooperation among policy makers would be welcome. 相似文献
185.
András Cseri Mátyás Cserháti Maria von Korff Bettina Nagy Gábor V. Horváth András Palágyi János Pauk Dénes Dudits Ottó Törjék 《Euphytica》2011,181(3):341-356
In the present study, allele mining was conducted on a panel of drought related candidate genes in a set of 96 barley genotypes
using EcoTILLING, which is a variant of the targeting induced local lesions in genomes (TILLING) technology. Analyzing approximately
1.5 million basepairs in barley a total number of 94 verified unique haplotypes were identified in 18 amplicons designed for
9 genes. Overall, 185 single nucleotide polymorphisms (SNPs) and 46 insertions/deletions (INDELs) were detected with a mean
of 1SNP/92 bp and 1INDEL/372 bp genomic sequence. Based on overlapping haplotype sequences, markers were developed for four
candidate genes (HvARH1, HvSRG6, HvDRF1, HVA1), which allows distinguishing between the main haplotypes showing either differences in amino acid sequence or which have
larger INDELs in the promoter region. As “proof of concept”, the HvARH1 and HvSRG6 haplotypes were tested for the level of abscisic acid-induced gene expression in subsets of genotypes belonging to different
haplotype categories. An integrated database was developed to contain information about the genes, genotypes, and haplotypes
analyzed in this study. The database supplies profound information about the natural variation in the tested drought related
candidate genes providing a significant asset for further mapping studies dealing with this highly polygenic trait. 相似文献
186.
José Wilacildo de Matos Oliveiro Guerreiro-Filho Wallace Gon?alves Daniel Alves Ramiro Bárbhara Joana dos Reis Fatobene 《Euphytica》2011,181(2):253-260
The coffee leaf miner, Leucoptera coffeella, is the most important pest of Coffea arabica plantations in Brazil, and all cultivars are susceptible to the insect. However, distinct reactions have been observed in
other species, such as C. congensis and C. canephora. In this work, the occurrence of antixenotic response was surveyed in individuals of Coffea species, selected for resistance to the leaf miner at both field and laboratory conditions. Tests performed on young plants
from C. arabica cultivars Icatu Precoce IAC 3282, Mundo Novo IAC 515-20, Tupi IAC 1669-33 and Catuaí Amarelo IAC 62 demonstrated that these
were preferred for oviposition when pooled with seedlings from C. canephora cv. Apoat? IAC 2258. Apoat? was also preferred over C. racemosa for oviposition. Similar results were observed in tests using detached leaves, and higher amount of eggs was counted in the
cv Obat? IAC 1669-20 and Catuaí Vermelho IAC 81, and lower oviposition frequency was observed in C. canephora cv. Guarini IAC 1598. C. congensis showed an oviposition frequency between C. arabica and C. canephora. Also, the results suggest that the frequency of oviposition is co-related with the plant resistance level, during larvae
infection. 相似文献
187.
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
188.
Genetic relationships among 18 accessions, including 16 of Ananas and two of Pseudananas, were investigated using RAPD molecular markers. The procedure for DNA extraction was adapted from the method of Dellaporta
et al. (1983) where an incubation in proteinase K and a purification step were included. From the total of 148 markers scored,132
(89.2%) were polymorphic. The similarity matrix was used for cluster analysis. The phenogram developed from the RAPD bands
showed that for most of the cases, the accessions within a species grouped together. Nevertheless, a moderate infraspecific
genetic variation was observed. For example, DNA data grouped all A. comosus accessions with a mean similarity coefficient of 0.85. Comparable results were obtained with all other species investigated.
The highest genetic divergence was found withinA. lucidus where the mean similarity coefficient among accessions was0.75. A similar level of genetic polymorphism was observed among
species,therefore, a definition about which species were involved in the constitution of A. comosus genotypes was not possible. These results agree with the breeders standpoint suggesting that all Ananas species belong to the primary gene pool of pineapple.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
189.
190.