排序方式: 共有25条查询结果,搜索用时 15 毫秒
1.
Ganeshan Seedhabadee Båga Monica Harvey Bryan L. Rossnagel Brian G. Scoles Graham J. Chibbar Ravindra N. 《Plant Cell, Tissue and Organ Culture》2003,73(1):57-64
The in vitro plant regeneration frequencies for immature scutella, leaf-bases/apical meristems (LB/AM) and mature embryos of four commercially important barley genotypes were compared. Production of shoots from mature embryos or calluses of LB/AM incubated on media containing 1.0 or 2.0 mg l–1 6-benzylaminopurine (BA) were comparable to regeneration frequencies obtained for scutella-derived calluses of the same genotypes. Incubation of excised mature embryos and LB/AM on media containing the plant growth regulator, thidiazuron (TDZ), resulted in an increased shoot production. However, TDZ treatment did not stimulate plant regeneration from calluses derived from scutella or LB/AM. Shoots formed from TDZ-treated mature embryos and LB/AM were induced without a callus interphase and the in vitro culture system gave a three- to eight-fold higher regeneration frequency than recorded for scutella-derived calluses on BA medium. The simplicity and rapid development of shoots using the mature embryo system could potentially be used for the regeneration and genetic transformation of barley over alternative regeneration systems. 相似文献
2.
Haakon Hop Christopher J. Mundy Michel Gosselin Andrea L. Rossnagel David G. Barber 《Polar Biology》2011,34(12):1947-1958
Early summer in the Arctic with extensive ice melt and break-up represents a dramatic change for sympagic–pelagic fauna below
seasonal sea ice. As part of the International Polar Year-Circumpolar Flaw Lead system study (IPY-CFL), this investigation
quantified zooplankton in the meltwater layer below landfast ice and remaining ice fauna below melting ice during June (2008)
in Franklin Bay and Darnley Bay, Amundsen Gulf, Canada. The ice was in a state of advanced melt, with fully developed melt
ponds. Intense melting resulted in a 0.3- to 0.5-m-thick meltwater layer below the ice, with a strong halocline to the Arctic
water below. Zooplankton under the ice, in and below the meltwater layer, was sampled by SCUBA divers. Dense concentrations
(max. 1,400 ind. m−3) of Calanus glacialis were associated with the meltwater layer, with dominant copepodid stages CIV and CV and high abundance of nauplii. Less abundant
species included Pseudocalanus spp., Oithona similis and C. hyperboreus. The copepods were likely feeding on phytoplankton (0.5–2.3 mg Chl-a m−3) in the meltwater layer. Ice amphipods were present at low abundance (<10 ind. m−2) and wet biomass (<0.2 g m−2). Onisimus glacialis and Apherusa glacialis made up 64 and 51% of the total ice faunal abundance in Darnley Bay and Franklin Bay, respectively. During early summer,
the autochthonous ice fauna becomes gradually replaced by allochthonous zooplankton, with an abundance boom near the meltwater
layer. The ice amphipod bust occurs during late stages of melting and break-up, when their sympagic habitat is diminished
then lost. 相似文献
3.
Vicky Roslinsky Peter E. Eckstein Victor Raboy Brian G. Rossnagel Graham J. Scoles 《Molecular breeding : new strategies in plant improvement》2007,20(4):323-330
Phytate is the primary form of phosphorus found in mature cereal grain. This form of phosphorus is not available to monogastric
animals due to a lack of the enzyme phytase in their digestive tract. Several barley low
phytic
acid (lpa) mutants have been identified that contain substantial decreases in seed phytate accompanied by concomitant increases in
inorganic phosphorus. Seed homozygous for low phytic acid
1-1 (lpa1-1) or low phytic acid
2-1 (lpa2-1) has a 50% and 70% decrease in seed phytate respectively. These mutations were previously mapped to chromosomes 2HL and 7HL
respectively. The RFLP marker ABC153 located in the same region of 2H was converted to a sequence-characterized-amplified-region
(SCAR) marker. Segregation analysis of the CDC McGwire × Lp422 doubled haploid population confirmed linkage between the SCAR
marker and the lpa1-1 locus with 15% recombination. A third low phytic acid mutant, M635, has a 75% decrease in phytate. This mutation was located
to chromosome 1HL by linkage with an inter-simple sequence repeat (ISSR) based marker (LP75) identified through bulked-segregant
analysis, and has been designated lpa3-1. Based on analysis of recombination between marker LP75 and low phytic acid in an additional mutant line M955 (95% phytate
decrease), lpa3-1 and the mutation in M955 are in the same region on chromosome 1HL, and may be allelic. 相似文献
4.
In vitro regeneration of cereals based on multiple shoot induction from mature embryos in response to thidiazuron 总被引:1,自引:0,他引:1
Seedhabadee Ganeshan Sanjay V. Chodaparambil Monica B?ga D. Brian Fowler Pierre Hucl Brian G. Rossnagel Ravindra N. Chibbar 《Plant Cell, Tissue and Organ Culture》2006,85(1):63-73
The in vitro competency of mature cereal embryos (winter, spring and durum wheats, oat, barley and triticale) was assessed for direct
multiple shoot production on culture media containing the plant growth regulators, thidiazuron (TDZ) and/or 6–benzylaminopurine
(BAP). Mature embryos of CDC Dancer oat showed the best response, with 69 shoots per explant on culture medium containing
a combination of 4.5 μM TDZ and 4.4 μM BAP. TDZ alone induced about 16 shoots per explant from the oat. Among the wheat genotypes,
durum wheat showed the most number of shoots (35) per explant on culture medium containing 4.5 μM of TDZ and 4.4 μM of BAP.
With TDZ alone, shoot regeneration for durum wheat ranged from 27–32 shoots per explant. The regeneration frequency from the
three winter wheat genotypes ranged from 11–25 shoots per explant and was highest on culture medium containing 9.1 μM TDZ
and 4.4 μM BAP. The latter culture medium was also effective for a triticale genotype, inducing 34 shoots per explant. The
regeneration from mature embryos of barley genotypes ranged from 5–9 shoots per explant. The mature embryos of all the cereals
tested could be used for in vitro regeneration with TDZ and TDZ+BAP combinations. 相似文献
5.
L. A. Marquez-Cedillo P. M. Hayes A. Kleinhofs W. G. Legge B. G. Rossnagel K. Sato S. E. Ullrich D. M. Wesenberg 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(4):625-637
A better understanding of the genetics of complex traits, such as yield, may be achieved by using molecular tools. This study
was conducted to estimate the number, genome location, effect and allele phase of QTLs determining agronomic traits in the
two North American malting barley (Hordeum vulgare L.) quality variety standards. Using a doubled haploid population of 140 lines from the cross of two-rowed Harrington×six-rowed
Morex, agronomic phenotypic data sets from nine environments, and a 107-marker linkage map, we performed QTL analyses using
simple interval mapping and simplified composite interval mapping procedures. Thirty-five QTLs were associated, either across
environments or in individual environments, with five grain and agronomic traits (yield, kernel plumpness, test weight, heading
date, and plant height). Significant QTL×environment interaction was detected for all traits. These interactions resulted
from both changes in the magnitude of response and changes in the sign of the allelic effect. QTLs for multiple traits were
coincident. The vrs1 locus on chromosome 2 (2H), which determines inflorescence row type, was coincident with the largest-effect QTL determining
four traits (yield, kernel plumpness, test weight, and plant height). QTL analyses were also conducted separately for each
sub-population (six-rowed and two-rowed). Seven new QTLs were detected in the sub-populations. Positive transgressive segregants
were found for all traits, but they were more prevalent in the six-rowed sub-population.QTL analysis should be useful for
identifying candidate genes and introgressing favorable alleles between germplasm groups.
Received: 18 August 2000 / Accepted: 15 December 2000 相似文献
6.
L. A. Marquez-Cedillo P. M. Hayes B. L. Jones A. Kleinhofs W. G. Legge B. G. Rossnagel K. Sato S. E. Ullrich D. M. Wesenberg North American Barley Genome Mapping Project 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(1-2):173-184
Characterization of the determinants of economically important phenotypes showing complex inheritance should lead to the more
effective use of genetic resources. This study was conducted to determine the number, genome location and effects of QTLs
determining malting quality in the two North American barley quality standards. Using a doubled-haploid population of 140
lines from the cross of Harrington×Morex, malting quality phenotype data sets from eight environments, and a 107-marker linkage
map, QTL analyses were performed using simple interval mapping and simplified composite interval mapping procedures. Seventeen
QTLs were associated with seven grain and malting quality traits (percentage of plump kernels, test weight, grain protein
percentage, soluble/total protein ratio, α-amylase activity, diastatic power and malt-extract percentage). QTLs for multiple
traits were coincident. The loci controlling inflorescence type [vrs1 on chromosome 2(2H) and int-c on chromosome 4(4H)] were coincident with QTLs affecting all traits except malt-extract percentage. The largest effect QTLs,
for the percentage of plump kernels, test weight protein percentage, S/T ratio and diastatic power, were coincident with the
vrs1 locus. QTL analyses were conducted separately for each sub-population (six-rowed and two-rowed). Eleven new QTLs were detected
in the subpopulations. There were significant interactions between the vrs1 and int-c loci for grain-protein percentage and S/T protein ratio. Results suggest that this mating of two different germplasm groups
caused a disruption of the balance of traits. Information on the number, position and effects of QTLs determining components
of malting quality may be useful for maintaining specific allele configurations that determine target quality profiles.
Received: 28 May 1999 / Accepted: 9 November 1999 相似文献
7.
De Koeyer DL Tinker NA Wight CP Deyl J Burrows VD O'Donoughue LS Lybaert A Molnar SJ Armstrong KC Fedak G Wesenberg DM Rossnagel BG McElroy AR 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(7):1285-1298
In spring-type oat (Avena sativa L.), quantitative trait loci (QTLs) detected in adapted populations may have the greatest potential for improving germplasm via marker-assisted selection. An F6 recombinant inbred (RI) population was developed from a cross between two Canadian spring oat varieties: Terra, a hulless line, and Marion, an elite covered-seeded line. A molecular linkage map was generated using 430 AFLP, RFLP, RAPD, SCAR, and phenotypic markers scored on 101 RI lines. This map was refined by selecting a robust set of 124 framework markers that mapped to 35 linkage groups and contained 35 unlinked loci. One hundred one lines grown in up to 13 field environments in Canada and the United States between 1992 and 1997 were evaluated for 16 agronomic, kernel, and chemical composition traits. QTLs were localized using three detection methods with an experiment-wide error rate of approximately 0.05 for each trait. In total, 34 main-effect QTLs affecting the following traits were identified: heading date, plant height, lodging, visual score, grain yield, kernel weight, milling yield, test weight, thin and plump kernels, groat -glucan concentration, oil concentration, and protein. Several of these correspond to QTLs in homologous or homoeologous regions reported in other oat QTL studies. Twenty-four QTL-by-environment interactions and three epistatic interactions were also detected. The locus controlling the covered/hulless character (N1) affected most of the traits measured in this study. Additive QTL models with N1 as a covariate were superior to models based on separate covered and hulless sub-populations. This approach is recommended for other populations segregating for major genes. Marker-trait associations identified in this study have considerable potential for use in marker-assisted selection strategies to improve traits within spring oat breeding programs.Communicated by P. Langridge 相似文献
8.
Tajinder S. Grewal Brian G. Rossnagel Graham J. Scoles 《Molecular breeding : new strategies in plant improvement》2012,30(1):267-279
Spot blotch and net blotch are important foliar barley (Hordeum vulgare L.) diseases in Canada and elsewhere. These diseases result in significant yield reduction and, more importantly, loss of grain quality, downgrading barley from malt to feed. Combining resistance to these diseases is a breeding priority but is a significant challenge using conventional breeding methodology. In the present investigation, an evaluation of the inheritance of resistance to spot and net blotch was conducted in a doubled-haploid barley population from the cross CDC Bold (susceptible)?×?TR251 (resistant). The population was screened at the seedling stage in the Phytotron and at the adult-plant stage in the field for several years. Chi-squared analysis indicated one- to four-gene segregation depending on disease, isolate, plant development stage, location and year. A major seedling and adult-plant resistance quantitative trait locus (QTL), designated QRpt6, was re-confirmed for net-form net blotch resistance, explaining 32?C61% of phenotypic variation in different experiments. Additional QTL for seedling and adult-plant resistance to net blotch were identified. For spot blotch resistance, a major seedling resistance QTL (QRcss1) was detected on chromosome 1H for isolate WRS1909, explaining 79% of the phenotypic variation. A highly significant QTL on 3H (QRcs3) was identified for seedling resistance to isolate WRS1908 and adult-plant resistance at Brandon, MB, Canada in 2008. The identification of QTL at only one location or from 1?year suggests spot blotch resistance is complex and highly influenced by the environment. Efforts are being made to combine spot and net blotch resistance in elite barley lines using molecular marker-assisted selection. 相似文献
9.
Li Cheng-Dao Zhang Xiao-Qi Eckstein Pete Rossnagel Brian G. Scoles Graham J. 《Molecular breeding : new strategies in plant improvement》1999,5(6):569-577
A DNA fragment containing the exons 16, 17 and intron 16 of the limit dextrinase gene was cloned using a 654 bp cDNA as probe. Intron 16 contained a simple sequence repeat (microsatellite). PCR primers were designed to amplify that microsatellite. Using these primers, the limit dextrinase gene was mapped to the short arm of chromosome 1 (7H) using 150 DH lines from the Steptoe × Morex mapping population. This gene co-segregated with the RFLP marker ABC154A. QTLs for malt extract, -amylase activity, diastatic power and fine-coarse difference previously mapped in the North American Barley Genome Mapping Project have been located in this chromosome region. Five limit dextrinase alleles were detected in 31 barley cultivars with a PIC of 0.75. Ten different alleles/genes were identified in 23 uncultivated Hordeum species or subspecies using these microsatellite primers. The primers also amplified one fragment from wheat and two from oat. This microsatellite should be useful for marker-assisted selection for malting quality. 相似文献
10.
A. M. R. Ferrie K. I. Irmen A. D. Beattie B. G. Rossnagel 《Plant Cell, Tissue and Organ Culture》2014,116(1):89-96
The production of doubled haploid (DH) plants from microspores is an important technique used in plant breeding programs and basic research. Although doubled haploidy efficiencies in wheat and barley are sufficient for breeding purposes, oat (Avena sativa L.) is considered recalcitrant. The objective of this project was to develop a protocol for the production of microspore-derived embryos of oat and further develop these embryos into fertile DH plants. A number of experiments were conducted evaluating the factors influencing microspore embryogenesis, i.e. donor plant conditions, pretreatments, media composition, and culture conditions. The initial studies yielded little response, and it was not until high microspore densities (106 microspores/mL and greater) were used that embryogenesis was achieved. Depending on the treatment, yields of over 5,000 embryos/106 microspores were obtained for breeding line 2000QiON43. The doubled haploidy protocol includes: a 0.3 M mannitol pretreatment of the tillers for 7 days, culture in W14 basal medium with a pH of 6.5–7.5, a microspore density of 106 microspores/mL, and continuous incubation at 28 °C incubation. The resulting embryos observed after 28 days were plated onto solidified W14 medium with 0.8 or 1.0 g/L activated charcoal. A colchicine treatment of 0.2 % colchicine for 4 h resulted in conversion of 80 % of the plants from haploid to DH. This protocol was successful for the production of oat microspore-derived embryos and DH green plants with minimal albinism. DH seed was produced and planted for evaluation in a field nursery. 相似文献