摘要:

AbstractThe possibility of gene transfer betweenBrassica rapaand the two weedy speciesB. nigraandSinapis arvensiswas evaluated with the special concern on transgene escape fromB. rapato these two weedy species.B. rapacultivar Tobin was reciprocally crossed to five and four strains ofB. nigraandS. arvensis, respectively, using controlled cross. A single interspecific hybrid was obtained from the crossB. rapa×B. nigra, but no other cross was successful. The fertility of this hybrid on open pollination, selfing and backcrosses was investigated. The data of the present study and the information available to date indicate that gene transfer betweenB. rapaandB. nigrais possible. The chance of transgene escape fromB. rapatoB. nigradepends essentially on whether natural cross can occur between these two species. Gene transfer betweenB. rapaandS. arvensisis at the most difficult, whereas trans‐gene escape directly fromB. rapa to S. arvensisappears very unlike

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00861.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractResistance responses of resynthesizedBrassica napuslines to infection withPlasmodiophora brassicaewere investigated. Lines that were derived from interspecific crosses between clubroot‐resistantB. rapaand resistantB. oleraceaexhibited very broad and effective resistance in both greenhouse and field tests. When clubroot resistance was introduced into resynthesized lines from theB. oleraceaparent only, the plants were mainly susceptible. Interspecific hybrids from the most resistant parental genotypes, i.e.B. campestrisECD‐04 and theB. oleraceacultivars ECD‐15 or ‘Bohmerwaldkohf’, were used to initiate aB. napusresistance‐breeding programme. These artificial rapeseed lines were resistant to isolates that were virulent on allB. napusdifferential lines and/or parental lines. Preliminary segregation analysis suggests that their resistance is due to at least two dominant and unlinked genes. In some cases progenies from selfed resynthesized plants exhibited resistance reactions that differed from those of the parental hybrid plant; this may have been the result of cytological

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00862.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractIn order to enhance the economic value of edible rapeseed oil, an improvement of quality is necessary. Mutagenesis of rapeseed resulted in a low linolenic acid content and a low ‘linolenic acid (CIS: 3) level to linoleic acid (CIS: 2) level’ ratio, that is, the linoleic desaturation ratio (LDR), in the seeds of the Canadian variety ‘Stellar’. As an early breeding marker for low linolenic acid content, the pollen fatty acid composition was determined on 80 doubled haploid plants derived from a single F1hybrid obtained from a cross between ‘Stellar’ and a high CIS: 3 variety ‘Drakkar’. Fatty acid analysis on seed and pollen showed that the low CIS: 3 and the low LDR traits from the ‘Stellar’ variety were expressed in pollen and in seeds, and that a very close correlation (r = 0.88) existed between seed and pollen for these two traits. The inheritance of these traits is controlled by two major genes with additive effects, both in seed and pollen. However, minor genes also appeared to be expressed in pollen and seed. These genes may allow the production of plants with lower CIS: 3 levels than that of the low linolenic acid content parent. The efficiency of this new tool for early screening in breeding prog

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00863.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractPatterns of morphological diversity were examined inLupinus pilosusin relation to geographical origins or selection history of accessions. There was significant variation among accessions for most architectural and reproductive characters in a field experiment in Perth, Western Australia. Late flowering was associated with resetted early growth, profuse branching and collection in higher rainfall sites. High yield and profuse podding on the main stem was associated with large pods and leaves, many seeds per pod, greater height to the first main‐stem pod, and collection in higher altitude sites.Ten groups of accessions, identified by hierarchical cluster analysis, accounted for 79% of genotype and 69% of genotype x character sums of squares. One group, possibly taxonomically distinct from the others, consisted exclusively of wild types from northern Israel with poor pod set and low seed yield, poor nodulation, pale foliage, and small leaves. Wild types from Turkey and Crete had rosetted early growth and were late flowering, and the Turkish group had extremely rapid mid‐season growth. Ornamental types from Europe or Australia with pink, purple or white flowers clustered together in an early flowering group with vigorous early growth. A smooth‐seeded type ofL. pilosuswas discovered in a group of short, late flowering and rough‐seeded types fro

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00864.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThis paper reports a procedure for isolating triploid and tetraploid olive plants, which have not been produced before either artificially or in nature. These polyploids were isolated from two mixoploid somatic mutants obtained earlier by treating Trantoio' and ‘Leccino’ plantlets with gamma radiation. The mixoploid mutants exhibit increased thickness of leaf, stem and root tissues, short internodes, a modified leaf lamina shape and a strong resistance toSpilocaea oleagina(Cast.) Hugh. In addition, they produce a mixture of normal drupes and some abnormally large ones, almost twice normal size. The variation in the nuclear DNA content of the mixoploid mutants is closely correlated with variation in their pollen size, crop capacity and the production of large fruit. Triploid genotypes with 69 chromosomes were isolated by germinating the seeds of these large fruits, collected from both the mixoploid mutants. Tetraploid plantlets, with 92 chromosomes, were obtained from cv. ‘Frantoio’ by selectingin vitro, during several proliferation phases, the shoots with obvate leaf shape which occurred among the shoots with normal lanceolate or intermediate lea

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00865.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThis report documents the difficulty breeders have experienced in combining resistance to Cercospora leaf spot (causal agentCercospora beticolaSacc.) with high yield in sugarbeet (Beta vulgarisL.). Forty commercial hybrids, all recommended for Cercospora‐threat areas, were grown in a Cercospora‐free and a diseased (inoculated) environment in 1991 and 1992. A 2.9 Mg/ha decrease in root yield associated with each increment increase in susceptibility confirmed that under a severe epiphytotic (1991) Cercospora resistance provided substantial protection. Under less‐severe disease conditions (1992) there was no apparent relationship between yield and resistance, suggesting that the benefits of resistance were similar to the yield potential sacrificed to obtain the resistance. In the absence of the disease, root yields increased 2.7 Mg/ha for each increment of increased susceptibility. There was no evidence of association between sucrose concentration and resistance in the Cercospora‐free environment. Despite the limited efforts and/or success in developing resistant commercial hybrids, the demonstrated ability of Cercospora to produce fungicide‐resistant strains and the possibility that effective fungicides will not be available provide incentives to seek genetic resistance through breedin

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00866.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThe variability of seed tocopherol content in wild sunflower species, the expressivity oftph1 andtph2 mutations in different lines and the oxidative stability of sunflower oil with altered tocopherol and fatty acid composition were objectives of this research.Near‐isogenic lines for three genes, i.e.Tph1,Tph2, andOl, were developed and investigated. Tocopherol content was determined with TLC and HPLC, as well as fatty acid composition with GC of methyl esters. Rancimat tests were used to estimate the oxidative stability of the oil.The seed tocopherol composition of wild sunflower species was shown to be uniform with a prevailing content of the α‐homologue (90‐99%). The genetic background of different near‐isogenic lines was found to influence expressivity of mutations for tocopherol composition. High content of strong antioxidants, such as β‐, γ‐, and δ‐tocopherols increased oil oxidative stability of linoleic and oleic types of oil by 1.2–3.0 times.The breeding model of sunflower hybrids should include antioxidant and vitamin parameters balanced for oils of dif

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00867.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractAfter 10 years of evaluation in different locations with high levels of incidence of disease, a group of sugarcane somaclones derived from callus tissues was selected for eyespot resistance. Resistance evaluations of four somaclones were performed under field and laboratory conditions. The results confirmed the superiority of two somaclones, one resistant and one tolerant to eyespot disease. Restriction analysis of mitochondrial DN A revealed that the two somaclones had a different DNA organization which distinguished them both from each other and from the donor plant; the restriction profile was similar however to that of the resistant control done. Restriction patterns of a third somaclone, also resistant, were similar to those of the donor plant. Differences among the somaclones were also evident when using a maize ribosomal DNA probe.

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00868.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractMalting quality and winter‐hardiness in barley are ‘ultimate’ phenotypes composed of constituent quantitatively inherited traits. A synthesis of molecular‐marker linkage data and field phenotyping to reveal the location of quantitative trait loci (QTL) may assist in the development of winter‐habit malting barley varieties. One‐hundred doubled haploid progeny from a winter x spring cross were evaluated under fall and spring‐planted conditions. Malting quality phenotypes and a 76‐point map were used to identify QTL and to assess the effect of spring‐and autumn‐sowing on QTL expression. Many QTL effects were common to both environments and corresponded to QTL detected in other barley germplasm. While there were significant differences in the magnitude of effects across environments, there were no changes in the favourable allele phase. QTL effects for grain protein and diastatic power level coincided with the locations of known function genes. Coincident QTL for a number of mailing‐quality traits on chromosome 7 suggests either the presence of a multi‐locus cluster of genes controlling components of malting quality or a regulatory gene or genes controlling the cascade of enzymatic processes that function during the malting process. Based on these results, simultaneous selection for malting quality and cold tolerance should be possible in

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00869.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractRAPD markers were developed for octoploid XTritordeum(amphiploidHordeum chilense × Triticum aestivum) and its parents. Two bread wheats, twoH. chilenseaccessions and the two tritordeums synthesized with them were used. A total of 41 arbitrary decamer primers were tested, yielding 190 products that could be assigned to wheat, 185 toH. chilenseand 108 that were nonspecific (present in wheat and barley). A total of 44 products were specific to oneH. chilenseline and 33 to the other 16 of the former were located on the chromosomes using a set ofH. chilenseinT. aestivumaddition lines. The potential of RAPDs for developing addition lines or the detection of introgressions ofH. chilensein bread wheat is discussed

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1996.tb00870.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY