摘要:

AbstractGeneral criteria for the assignment of names to enzyme systems, regions of activity, isozyme loci and allozymes have been lacking in crucifer species. This paper proposes a standard nomenclature for seven isozyme systems in the three diploid species of U's triangle:Brassica nigra, B. oleraceaandB. campestris.Gel/electrode buffers, which provided the best resolution for seven isozyme systems, acid phosphatase (APS), aconitase (ACO), leucine aminopeptidase (LAP), 6‐phosphogluconate dehydrogenase (6 PGD), phosphoglucoisomerase (PGI), phosphoglucomutase (PGM), and triosephosphate isomerase (TPI), were proposed as standards. Isozyme genetic analysis was determined forB. oleraceaandB. campestrisfrom previous studies and by segregation of selfed progenies of heterozygousB. nigraplants. Several populations were studied and 148 allozymes at the 18 loci observed were described for the three species. Their relative mobility was studied using a pure line of oilseed rape as reference. The comparison of the different alleles within and between the species is discusse

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00839.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe possibility of gene transfer betweenBrassica napusandSinapis arvensiswas evaluated. Six spring‐type cultivars ofB. napusand four strains ofS. arvensiswere reciprocally crossed through controlled crosses. No hybrid was yielded from any cross. However, one hybrid with 28 chromosomes was obtained fromB. napus×S. arvensisthrough ovule culture. The hybrid plant was highly sterile and set no seed on open pollination. Two F2plants, with 35 and 36 chromosomes respectively, were obtained through self‐pollination by hand. Backcross ofB. napusproduced 23 plants carrying some characteristics ofS. arvensis, but backcross toS. arvensisfailed to produce a plant. The chromosome counts of the BC1F1plants indicated that gametes with more than nine chromosomes were favoured during the meiosis. The data demonstrated that gene transfer fromS. arvensistoB. napuswas very difficult under controlled cross and backcross, while to transfer genes fromB. napustoS. arvensiswould be extremely remote even under the most favorable condit

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00840.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractLong‐term resistance to rust diseases depends on the identification and use of durable resistance sources or on the continuing use of new resistances and combinations of genes for specific resistance. These studies include four Australian wheats with intermediate, but inadequate levels of resistance and a French wheat ‘Hybride‐de‐Bersée’ (‘Bersee’), with reputed durable resistance to stripe rust. Studies of F2and F3populations from crosses with the susceptible ‘Avocet’ indicated that intermediate levels of adult plant stripe rust resistance in cultivars ‘Harrier’, ‘Flinders’ and ‘M2435’ were inherited monogenically, whereas King possessed two genes for resistance. Cultivars Harrier and M2435 possessed the same gene. Similarly, cvs. King and Flinders carried a gene in common. Like ‘Harrier’ and ‘M2435’, ‘King’ and ‘Flinders’ share common parents. The higher level of resistance in ‘Bersee’ was controlled by four genes. This conclusion was based on conventional genetic analysis, tests on F2‐derived

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00841.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractRelatively little is known about host‐plant insect‐resistance genes. Near‐isogenic lines (NILs) can be a useful tool in evaluating such genes and their mechanisms of action. Through backcrossing and single‐seed selection, NILs have been produced in wheat (Triticum aestivumL.) for resistance/susceptibility to biotype‐E greenbug,Schizaphis graminum(Rondani). Crosses among several resistant and susceptible NILs produced segregation patterns in the F2generation that were inconsistent with simple monogenic inheritance. The simplest genetic hypothesis consistent with the data would involve two independently segregating loci, requiring complementary expression of multiple resistance alleles. F3segregation data were also consistent with the proposed genetic hypothesis. Multiple alleles are required to account for the observed variation, although the source of the multiple alleles is unknown. Direct comparison of specific resistant/susceptible pairs of NIL's, as well as bulked segregant analysis, should permit elucidation of resistance mechanisms. Based on the segregation data presented, new designations for the resistance loci studied are

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00842.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractComparisons involving 28 random F2‐derived F6wheat (Triticum aestivumL.) lines from the cross, ‘Nacozari’/‘Seri 82’, suggested that advanced derivatives with the 1BL/1RS chromosome translocation possess superior agronomic performance in both full and reduced irrigation conditions when compared with 1B derivatives. This performance advantage was attributed to high grain yield, above‐ground biomass at maturity, grains/spike, 1000‐grain weight and test weight. The 1BL/1RS lines were shorter with delayed flowering and maturity. The superiority of the 1BL/1RS translocation group on grains/m2was expressed only under the full irrigation environment. Higher harvest index, longer spike‐length and grain‐filling period were detected only under reduced irrigation conditions. A significant grain yield relationship with test weight was detected only among the 1BL/1RS genotypes, indicating that they possess heavier and plumper grains than

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00843.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractA synthetic hexaploid,Triticum timofeevii×T. tauschii, was used to transfer disease resistance genes to the commercial cultivar Saratovskaya 29 (S29) by backcrossing. After five backcrosses the resulting derivatives still showed some traits of the synthetic, namely brown spike glumes and several gliadin components. Genetic analysis showed that the derived forms had inherited theGli‐D1 allele of the synthetic, which was found to be tightly linked to a gene for glume colour. Recombination percentages between these genes was estimated to be 2.5 ± 1.7%. The development of the derivatives was also accompanied by a rearrangement within theGli‐B1 locus, resulting in the formation of a new variant of the allele i

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00844.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractCharacterization of large numbers of breeding lines for vernalization and photoperiod response in wheat is needed to enhance adaptation. A total of 20 wheat lines were evaluated for response to vernalization and photoperiod under two controlled environments and high ambient air temperatures under field conditions. Vernalized and non‐vernalized seedlings were transplanted into pots and placed in three photoperiod (8, 12 and 16 h of light) cabinets, in the greenhouse or in growth chambers. Days to anthesis decreased with increasing photoperiod. Vernalized plants flowered earlier than non‐vernalized. There was a significant correlation between days to anthesis in the greenhouse and the growth chamber (r = 0.88, P<0.001). Basal vegetative period, effect of vernalization and photoperiod from the two screening techniques were positively correlated with each other. Growth habit, vernalization requirement and heading date in the field were highly correlated with the main effect of vernalization in the two controlled environments. The results indicate that selection for vernalization response in a large number of genotypes can be achieved under high ambient air temperatures in the field and the selected material can subsequently be screened for photoperiod response under greenhouse conditi

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00845.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractHordeum chilense(Roem. et Schult), a native grass of South America, is a source of antixenotic and antibiotic resistance to the greenbugSchizaphis graminumRondani. The genetic and environmental components of the variability in antibiotic resistance shown byH. chilensewere determined by measuring the developmental time, the length of adult life, fecundity and intrinsic rate of population increase of green‐bugs reared on this host. The aphids belonged to a clone of biotype C. Plants were cloned to reduce the incidence of environmental variability.Different plant characters appeared to prolong aphid developmental time and reduce the length of adult life and total fecundity. The broad sense heritability and the genetic variability of these plant characters were different. The plant character that affected aphid development appears to differ from that affecting fecundit

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00846.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractColchicine uptake into ovules of sugar beet after 7 days of culture and its chromosome‐doubling effect on ovule‐derived plants were studied with high colchicine concentrations (0.4–6.0%) and short treatment duration (0–5 h). The best result of 4.2 diploid plants per 100 ovules was produced by treatment with 0.4% colchicine for 2.5 h. Both colchicine concentration and treatment time of ovules showed toxic effects on embryo formation, but it was stabilized at a low level with short exposure. The chromosome‐doubling effect, by contrast, was unchanged with the colchicine concentrations used, but highly affected by the duration of exposure studied. A maximum percentage of 60% diploid plants was obtained after 3–5 h of uptake, which corresponds to only 31–39% of the total capacity for colchicine uptake in the ovules. Further uptake of the drug produced mainly toxic effects. Flow‐cytometric measurements of the ploidy level in plantletsin vitroand of the same plants before flowering in soil were similar in about 80% of cases. Thus, flow‐cytometric selection of diploid plants in vitro may be

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00847.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractA study of regenerants obtained from long‐term callus cultures of different pea (Pisum sativumL.) genotypes revealed specificity ofin vitromutagenesis. The specificity was displayed in the preferential generation of the somaclonal variations affecting quantitative and developmental characters. About 60% of regenerated lines obtained from the cultivar Ranny Zeleny carried mutations in theLfandSnloci, which control initiation of flowering. Anin vitrostudy of isogenic lines differing at theLfandSnloci illustrates the growth advantages of mutant genotypes in tissue culture. These experiments suggest that mutations affecting developmental characters (e.g. mutations in loci which control flowering behaviour) may be expressed in tissue culture and may cause increased adaptation in mutant cells to thein vitroconditions. Rapid propagation of mutant cells duringin vitroculture may lead to a higher proportion of quantitative mutations among the regenerated plant

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00848.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY