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1.
Rafael Fernández-Muñoz María Salinas Eva Domínguez Marta Álvarez Jesús Cuartero 《Acta Physiologiae Plantarum》2000,22(3):358-359
The two-spotted spider mite (Tetranychus urticae Koch) is an important pest of tomato (Lycopersicon esculentum Mill.) crops in temperate regions as this spider mite has a very large capacity for population increase and causes severe
tomato yield losses. There is no described tomato cultivar fully resistant to this pest, although resistant accessions have
been reported within the green-fruited tomato wild species L. pennellii (Corr.) D’Arcy and L. hirsutum Humb. & Bonpl. We observed a L. pimpinellifolium (Jusl.) Mill. accession, ‘TO-937’, which seemed to be completely resistant to mite attacks and we crossed it with the susceptible
L. esculentum cultivar. ‘Moneymaker’ to obtain a family of generations consisting of the two parents, the F1, the F2, the BC1 to L. esculentum, and the BC1 to L. pimpinellifolium. This family was evaluated for mite resistance in a polyethylene greenhouse using an experimental design in 60 small complete
blocks distributed along 12 double rows. Each block consisted of five F2 plants in one row and one plant of each of the two parents, the F1, the BC1 to L. esculentum, and the BC1 to L. pimpinellifolium in the adjacent row. Plants at the 10–15 leaf stage were artificially infested by putting on them two pieces of French bean
leaf heavily infested with T. urticae. After two months, evaluations of infestation were made by visual observation of mite nets and leaf damage. Plants that were
free of signs of mite reproduction on the top half were considered as resistant, plants with silky nets only on their basal
leaves, intermediate, and plants with mite reproduction on both basal and top canopies were scored as susceptible. Dominance
for resistance appeared because all the ‘To-937’, BC1 to L. pimpinellifolium, and F1 plants were resistant. Not all ‘Moneymaker’ plants behaved as susceptible because 35% of plants were intermediate. In the
BC1 to L. pimpinellifolium and the F2, most plants were scored as resistant, only 7 % BC1 and 3 % F2 plants were intermediate, and a single F2 plant (0.3 %) was susceptible. With these figures, resistance seemed to be controlled by either four or two genes according
to whether segregation in the BC1 or in the F2, respectively, were considered. These results could in part be explained because of appearance of negative interplot interference
due to the high frequency of resistant genotypes within most of the generations. Therefore, the family was evaluated again
but using a different experimental design. In the new experiment, 16 ‘TO-937’, 17 ‘Moneymaker’, 17 F1, 37 BC1 to L. pimpinellifolium, 38 BC1 to L. esculentum, and 125 F2 plants were included. Each of these test plants was grown besides a susceptible ‘Moneymaker’ auxilliary plant that served
to keep mite population high and homogeneous in the greenhouse. Negative interplot interference was avoided with this design
and all the ‘TO-937’, F1, and BC1 to L. pimpinellifolium plants were resistant, all ‘Moneymaker’ test plants were susceptible, and 52 % BC1 to L. esculentum and 25 % F2 plants were susceptible, which fitted very well with the expected for resistance governed by a single dominant gene. The
simple inheritance mode found will favour sucessful introgression of mite resistance into commercial tomatoes from the very
close relative L. pimpinellifolium. 相似文献
2.
M. H. Quazi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1988,75(2):309-318
Summary Interspecific hybrids between Brassica napus and B. oleracea are difficult to produce, and previous attempts to transfer economic characters from one species to the other have largely been unsuccessful. In these studies, oilseed rape cv. Tower (2n38) (B. napus) was crossed with broccoli and kale (2n18) (B. oleracea), and hybrid plants were developed from embryos in culture by either organogenesis or somatic embryogenesis. In rape × broccoli, F1 plants were regenerated from hybrid embryos and the plants produced viable selfed seeds. F5 plants (2n38) homozygous for white flower colour were selected for high oil content (47%) and Line 15; a selection from these plants produced fertile hybrids with rape, broccoli and kale without embryo culture. In reciprocal crosses between oilseed rape cv. Tower and an aphid resistant diploid kale, 28 and 56 chromosome F1 hybrid plants were regenerated from somatic embryos. The 56 chromosome plants were self-fertile and it was concluded from F2 segregation ratios that a single dominant gene controls resistance to cabbage aphid in kale. The 28 chromosome F1's were self-sterile, but these and the 56 chromosome F1's could be backcrossed to rape and kale. A cross between the F1 (2n56) and a forage rape resulted in the selection of a cabbage aphid (Brevicoryne brassicae L.) resistant line (Line 3). Both Line 15 and Line 3 can serve as bridges for gene interchange between B. campestris, B. napus and B. oleracea, which has not been possible hitherto. Hybridisations between rape and tetraploid kale produced F1 plants with 37 chromosomes. One F2 plant possessed coronal scales and the inheritance was shown to be controlled by a single recessive gene unlinked to petal colour.This paper is dedicated to Mr. T. P. Palmer, a colleague and close friend who retired from the DSIR as Assistant Director of the Crop Research Division in September 1984 相似文献
3.
T. J. McCoy L. Y. Smith 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,71(6):772-783
Summary New interspecific hybrids between alfalfa (Medicago sativa L.) and several perennial Medicago species were obtained by embryo rescue techniques. The methodology, designated ovule-embryo culture, involved preculturing the fertilized ovule (10 to 20 days post-pollination) for a period of six to 12 days followed by excision and direct culture of the embryo. Placement of the hybrid embryo directly onto culture medium without the interim ovule culture was unsuccessful. Ovule culture to germination without removing the embryo also was unsuccessful. Ovule-embryo culture was essential for recovering interspecific hybrids between diploid alfalfa (2n=2x=16) and the following diploid (2n=2x=16) species: M. hybrida Traut., M. marina L., M. papillosa Boiss., M. rhodopea Velen. and M. rupestris M.B. In addition, trispecies hybrids between M. sativa x M. dzhawakhetica Bordz. F1 hybrids (2n=3x=24) and either M. cancellata M.B. (2n=6x=48) or M. saxatilis M.B. (2n=6x=48) were obtained from ovuleembryo culture. Media manipulations using M. sativa x M. rupestris F1 and first backcross generation embryos demonstrated the optimum concentration of 12.5 mM NH4
+ for successful embryo rescue; ammonium salt formulation (whether chloride, nitrate or sulfate) was not critical. From a few thousand crosses, hybrids between M. sativa and either M. rhodopea or M. rupestris were recovered relatively efficiently with 157 and 66 hybrids, respectively. However, only 13 hybrids between M. sativa and M. papillosa were obtained from more than 2,000 crosses, and just two hybrids each have been recovered from the combinations M. sativa x M. hybrida and M. sativa x M. marina from 2,000 to 3,000 crosses. The predominant chromosome number between diploid alfalfa and the other diploid perennial species was 2n=2x=16. Morphology of the hybrids was generally intermediate. Electrophoretic analysis of the F1 hybrids and parental clones on uniform or gradient polyacrylamide gels demonstrated that peroxidase phenotypes could be used to confirm hybridity. For all interspecific combinations there was at least one peroxidase isozyme unique to the wild species that was present in the F1 interspecific hybrid. 相似文献
4.
T. Gangadevi P. N. Rao K. V. Satyanarayana 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1982,63(2):177-181
Summary Interspecific F1 hybrids of Nicotiana debneyi Domin (2n=48) and N. umbratica Burbidge (2n=46), both belonging to the section Suaveolentes, showed a high degree of meiotic chromosome pairing. Two of the five F2 plants obtained exhibited chromosome mosaicism. The first colchiploid generation (C1) had the expected chromosome number of 2n=94 while C2 showed 2n=88, a loss of three pairs of chromosomes. This same chromosome number continued in further colchiploid generations, followed up to C5, except for a few plants in C3 which showed chromosome mosaicism. The F1 phenotype was stable through C1 to C5 and fertility was normal in colchiploids through all generations in spite of the loss of three pairs of chromosomes and chromosome mosaicism. This stability and fertility apparently reflect the tolerance of the genomes to the genetic adjustment of chromosome complements which is believed to be associated with the originally polyploid nature of the parental species and the chromosome doubling brought about in the amphidiploids. 相似文献
5.
W. P. Williams G. L. Windham 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1990,80(6):810-812
Summary A diallel cross of eight maize, Zea mays L., inbred lines was analyzed for reaction to two species of root-knot nematodes, Meloidogyne arenaria (Neal) Chitwood and M. javanica (Treub) Chitwood. Egg production following inoculation of F1 hybrid seedlings with nematode eggs was determined in a greenhouse experiment. Data were analyzed using Griffing's Method 4, Model I. General combining ability was a significant source of variation in egg production of both M. arenaria and M. javanica; specific combining ability was not a significant source of variation for either. The correlation between egg production of the two nematode species on the 28 F1 hybrids was highly significant. Hybrids with Mp313 or SC213 as one parent were the most resistant to both species. This indicates that germ plasm is available for developing inbred lines and hybrids with resistance to both M. arenaria race 2 and M. javanica.This article is a contribution of the Crop Science Research Laboratory, U.S. Department of Agriculture, Agricultural Research Service, in cooperation with the Mississippi Agricultural and Forestry Experiment Station, Journal No. J-7481. 相似文献
6.
Hiroshi Okada 《Plant Systematics and Evolution》1989,167(3-4):129-136
Cytogenetical studies were carried out on the successive generations of offsprings from the induced tetraploid hybrid (2n = 32) betweenRanunculus silerifolius (2n = 16) andR. chinensis (2n = 16). Aneuploids, 2n = 30 to 35, frequently occurred. In latter subsequent generations the deviation of aneuploids increased, but the proportion of euploids decreased, accompanied by the reduction of fertility of pollen grains and seed sets. F2 and F4 PMCs constantly exhibited meiotic abnormality, i.e. formation of quadrivalents and univalents. The speciation process ofR. cantoniensis (2n = 32), which was presumed to arise from tetraploid hybrids between the above two species, is discussed on the basis of the above evidences.Former contributions of this series areOkada & Tamura (1977) andOkada (1984). 相似文献
7.
A. Amante-Bordeos L. A. Sitch R. Nelson R. D. Dalmacio N. P. Oliva H. Aswidinnoor H. Leung 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1992,84(3-4):345-354
Summary
Oryza minuta J. S. Presl ex C. B. Presl is a tetraploid wild rice with resistance to several insects and diseases, including blast (caused by Pyricularia grisea) and bacterial blight (caused by Xanthomonas oryzae pv. oryzae). To transfer resistance from the wild species into the genome of cultivated rice (Oryza sativa L.), backcross progeny (BC1, BC2, and BC3) were produced from interspecific hybrids of O. sativa cv IR31917-45-3-2 (2n=24, AA genome) and O. minuta Acc. 101141 (2n=48, BBCC genomes) by backcrossing to the O. sativa parent followed by embryo rescue. The chromosome numbers ranged from 44 to 47 in the BC1 progeny and from 24 to 37 in the BC2 progeny. All F1 hybrids were resistant to both blast and bacterial blight. One BC1 plant was moderately susceptible to blast while the rest were resistant. Thirteen of the 16 BC2 progeny tested were resistant to blast; 1 blast-resistant BC2, plant 75-1, had 24 chromosomes. A 3 resistant: 1 susceptible segregation ratio, consistent with the action of a major, dominant gene, was observed in the BC2F2 and BC2F3 generations. Five of the BC1 plants tested were resistant to bacterial blight. Ten of the 21 BC2 progeny tested were resistant to Philippine races 2, 3, and 6 of the bacterial blight pathogen. One resistant BC2, plant 78-1, had 24 chromosomes. The segregation of reactions of the BC2F2, BC2F3, and BC2F4 progenies of plant 78-1 suggested that the same or closely linked gene(s) conferred resistance to races 2, 3, 5, and 6 of the bacterial blight pathogen from the Philippines. 相似文献
8.
Fertile progeny of a hybridization between soybean [Glycine max (L.) Merr.] and G. tomentella Hayata
R. C. Shoemaker M. S. Heath H. Skorupksa X. Delannay M. Edge C. A. Newell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1990,80(1):17-23
Summary A colchicine-doubled F1 hybrid (2n=118) of a cross between PI 360841 (Glycine max) (2n=40) x PI 378708 (G. tomentella) (2n=78), propagated by shoot cuttings since January 1984, produced approximately 100 F2 seed during October 1988. One-fourth of the F2 plants or their F3 progeny have been analyzed for chromosome number, pollen viability, pubescence tip morphology, seed coat color, and isoenzyme variation. Without exception, all plants evaluated possessed the chromosome number of the G. max parent (2n=40). Most F2 plants demonstrated a high level of fertility, although 2 of 24 plants had low pollen viability and had large numbers of fleshy pods. One F2 plant possessed sharp pubescence tip morphology, whereas all others were blunt-tipped. All evaluated F2 and F3 plants expressed the malate dehydrogenase and diaphorase isoenzyme patterns of the G. max parent and the endopeptidase isoenzyme pattern of the G. tomentella parent. Mobility variants were observed among progeny for the isoenzymes phosphoglucomutase, aconitase, and phosphoglucoisomerase. This study suggests that the G. Tomentella chromosome complement has been eliminated after genetic exchange and/or modification has taken place between the genomes.Journal Paper No. J-13776 of the Iowa Agriculture and Home Economics Experiment Station, Ames, IA, USA, Project 2763 相似文献
9.
Morphological and cytological investigations as well as crossing experiments were carried out with the 5 species of theRanunculus alpestris group (R. alpestris L.,R. traunfellneri
Hoppe,R. bilobus
Bertol.,R. crenatus
Waldst. etKit.,R. magellensis
Ten.). A key to the species is presented; localities and distribution are given in addition to extensive diagnoses. Crossing experiments between the 5 taxa were successful (F1-F3 individuals, backcross types, tripeland quadrupelbastards); the morphology of the experimentally obtained F1-hybrids was mostly intermediate. All 5 species as well as all hybrids have a chromosome number of 2n = 16; there is no statistically significant difference between the karyotypes of the 5 taxa. According to the results of the morphological investigations and the crossing experiments we can distinguish 2 subunits of very closely related species: a)R. alpestris, R. traunfellneri, R. bilobus; b)R. crenatus, R. magellensis. The speciation within the group ofRanunculus alpestris is discussed. 相似文献
10.
F. Matzk 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1981,60(2):119-122
Summary Five F1 plants have been obtained after extensive crossing between different ecotypes or varieties of Festuca arundinacea Schreb. and Dactylis glomerata L. The success did not appear to depend on specific treatments (spraying with -aminocaproic acid or gibberellic acid or pre-pollination with killed pollen from the seed parent), but the crossability is limited to exceptional plants.F1 hybrids showed characteristics of both the parents. In four hybrids various developmental disturbances were observed (low viability, aneusomaty, absence of development of inflorescences). Only one hybrid consistently showed 2n=35 chromosomes, good viability and growth, however, it was sterile. After clonal propagation, attempts for polyploidization were started. 相似文献
11.
Highly fertile F1 hybrids were made between Triticum turgidum L. ssp. turgidum (2n = 28, AABB) and Aegilops tauschii Coss. (2n = 14, DD) without embryo rescue and hormone treatment. The F1 plants had an average seed set of 25%. Approximately 96% of the F2 seeds were able to germinate normally and about 67% of the F2 plants were spontaneous amphidiploid (2n = 42, AABBDD). Cytological analysis of male gametogenesis of the F1 plants showed that meiotic restitution is responsible for the high fertility. A mitosis-like meiosis led to meiotic restitution
at either of the two meiotic divisions resulting in unreduced gametes. Test crosses of the T. t. turgidum–Ae. tauschii amphidiploid with Ae. variabilis and rye suggested that the mitosis-like meiosis is controlled by one or more nuclear genes that continue to function in derived
lines. This discovery indicates a potential application of such genes in producing double haploids. 相似文献
12.
Genetic analysis of RFLPs, GATA microsatellites and RAPDs in a cross between L. esculentum and L. pimpinellifolium 总被引:1,自引:0,他引:1
S. Grandillo S. D. Tanksley 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(8):957-965
A population of 257 BC1 plants was developed from a cross between an elite processing line of tomato (Lycopersicon esculentum cvM82-1-7) and the closely related wild species L. pimpinellifolium (LA1589). The population was used to construct a genetic linkage map suitable for quantitative trait locus (QTL) analysis to be conducted in different backcross generations. The map comprises 115 RFLP, 3 RAPD and 2 morphological markers that span 1279 cM of the tomato genome with an average distance between markers of 10.7 cM. This map is comparable in length to that of the highdensity RFLP map derived from a L. esculentum x L. pennellii F2 population. The order of the markers in the two maps is also in good agreement, however there are considerable differences in the distribution of recombination along the chromosomes. The segregation of six GATA-containing loci and 47 RAPD markers was also analyzed in subsets of the population. All of the microsatellite loci and 35 (75%) of the RAPDs mapped to clusters associated with centromeric regions. 相似文献
13.
The genetic diversity and population structure of eighteenPotentilla fragariodes var.major (Rosaceae) populations in Korea were determined using genetic variations at 22 allozyme loci. The percent of polymorphic loci within
the enzymes was 66.7%. Genetic diversity at the species level and at the population level was high (Hes = 0.203; Hep = 0.185,
respectively), whereas the extent of the population divergence was relatively low (GST = 0.069). FIS, a measure of the deviation from random mating within the 18 populations, was 0.075. An indirect estimate of the number of
migrants per generation (Nm = 3.36) indicated that gene flow was high among Korean populations of the species. In addition, analysis of fixation indices
revealed a slight heterozygote deficiency in some populations and at some loci. Wide geographic ranges, perennial herbaceous
nature and the persistence of multiple generations are associated with the high level of genetic variation. AlthoughP. fragariodes var.major usually propagated by asexually-produced ramets, we could not rule out the possibility that sexual reproduction occurred
at a low rate because each ramet may produce terminal flowers. Mean genetic identity between populations was 0.983. It is
highly probable that directional movement toward genetic uniformity in a relatively homogeneous habitat operates among Korean
populations ofP. fragariodes var.major. 相似文献
14.
A new synthetic species of Cucumis (Cucurbitaceae) from interspecific hybridization and chromosome doubling 总被引:2,自引:0,他引:2
A new synthetic species,Cucumis hytivus J.-F. Chen & J. H. Kirkbr. (2n=38), obtained by doubling the number of chromosomes in the sterile interspecific F1 hybrid (2n=19) betweenC. sativus L. (2n=14) andC. hystrix Chakr. (2n=24), is described. 相似文献
15.
Genetic analysis of Verticillium wilt tolerance in cotton using pedigree data from three crosses 总被引:1,自引:0,他引:1
M. E. Devey M. L. Roose 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1987,74(1):162-167
Summary Three crosses and descendant generations were used in a field study of the inheritance of tolerance to Verticillium wilt, caused by Verticillium dahliae Kleb., in upland cotton (Gossypium hirsutum L.). The tolerant cultivar Acala SJC-1 was crossed to more susceptible parents, breeding line S5971 and cultivars Acala 4-42 and Deltapine 70. Seven generations were evaluated for each cross: the two parents (P1 and P2), F1; F2, F3, and reciprocal backcrosses (B1 and B2). The genetic control of tolerance in these crosses appears to involve more than one gene, based on an unsatisfactory fit to expected phenotypic distributions for the generations under a single-locus model. An analysis of generation means indicated that pooled additive and pooled dominance effects over loci were adequate to explain the variation among generations for crosses of SJC-1 X S5971 and SJC-1 X DPL70. Tolerance in these crosses appeared to be controlled by recessive factors. For the SJC-1 X 4-42 cross, an adequate fit to a digenic epistatic model was not possible, and none of the genetic parameters except the F2 mean were significant. Heritabilities for tolerance to Verticillium wilt, determined from regressions of F3 progeny on F2 parents for the crosses of SJC-1 X S5971 and SJC-1 X DPL70, ranged from 0.12 to 0.28. Therefore, individual plant selection for improved tolerance is expected to be inefficient.Contribution from the Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA, to be included in a dissertation by the senior author in partial fulfillment of the Ph. D. degree 相似文献
16.
João Pedro Correia das Neves Luís Filipe Portugal Ferreira Maria Margarida Vaz Luiz Carlos Gazarini 《Acta Physiologiae Plantarum》2008,30(1):91-97
Salt marshes are ecosystems subjected to a variety of environmental stresses like high salinity, water deficit, intense radiation
or high temperatures. Field measurements were conduced in two halophyte species, Atriplex portulacoides L. and Limoniastrum monopetalum L., in the Reserva Natural do Sapal de Castro Marim, to compare their physiological response, i.e., water potential (ψ),
net photosynthetic rate (A), stomatal conductance (gs) under natural conditions. Both species demonstrated marked variations
in ψ throughout the year, with very low values in the summer, the period of higher salinity, drought and temperature. Deficit
water potential (Δψ = ψmidday − ψpredawn) was lower in the summer than in other seasons in A. portulacoides but not in L. monopetalum. The highest values for A and gs in L. monopetalum were observed in autumn and for A. portulacoides in winter, presenting both lowest values in spring and summer. Amax was particularly high for L. monopetalum than for A. portulacoides in summer and autumn, despite gsmax was similar in both species. Diurnal pattern of A and gs were similar in both species, with higher values in the morning,
decreasing throughout the day. 相似文献
17.
In calcareous soils, genotypes of Lupinus albus L. generally grow poorly, resulting in stunted plants that often develop lime-induced chlorosis. In contrast, some genotypes
of L. pilosus Murr. occur naturally in calcareous soils without developing any visible symptoms of stress. Some genotypic variation for
tolerance to calcareous soil does exist in L. albus and the tolerance mechanisms need to be determined. The adaptation through root system morphological plasticity of L. albus and L. pilosus, to heterogeneous limed soil profiles (pH 7.8) containing either patches of acid (non-limed) soil, or vertically split between
acid and limed soil, was investigated. When grown in the presence of patches of acid soil, L. albus had a 52% greater shoot dry weight and visibly greener leaves compared with plants grown in the homogeneous limed soil. Total
root dry matter in the acid-soil patches was greater than in the control limed-soil patches. This was due to a four-fold increase
in the cluster root mass, accounting for 95% of the root dry matter in the acid-soil patch. Although these cluster roots secreted
no more citric acid per unit mass than those in the limed soil did, their greater mass resulted in a higher citrate concentration
in the surrounding soil. L. pilosus responded to the patches of acid soil in a manner comparable with L. albus. When grown in the homogeneous limed soil, L. pilosus had a greater maximum net CO2 assimilation rate (Pmax) than L. albus, however, the Pmax of both species increased after they had accessed a patch of acid soil. Differences were apparent between the L. albus genotypes grown in soil profiles split vertically into limed and acid soil. A genotype by soil interaction occurred in the
partitioning between soils of the cluster roots. The genotype La 674 was comparable with L. pilosus and produced over 11% of its cluster roots in the limed soil, whereas the other genotypes produced only 1–3% of their cluster
roots in the limed soil. These results indicate L. pilosus is better adapted to the limed soil than L. albus, but that both species respond to a heterogeneous soil by producing mainly cluster roots in an acid-soil patch.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
18.
R. M. Gambier D. L. Mulcahy 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(1):140-144
In both Oenothera villaricae Dietrich and O. picensis ssp. picensis, chromosomes are transmitted as two Renner complexes. Reciprocal combinations of the Renner complexes produce eight different F1 hybrids, but only seven are viable. Each species, and each F1 hybrid, produces three sizes of pollen, approximately 50% small sterile grains, 15% medium-sized viable grains and 35% large viable grains. Medium- and large-sized grains were separated manually and subjected to random amplified polymorphic DNAs (RAPDs) analysis. A pattern of RAPD amplifications was obtained which indicates that, for each species and F1 hybrid, one specific Renner complex characterizes the medium- and another the large-sized viable pollen. The results indicate that pollen size is determined in part by the pollen genotype and in part by the genotype of the other pollen grains developing within the same anther. 相似文献
19.
The intertribal sexual hybrids between three Brassica napus (2n = 38) cultivars and Lesquerella fendleri (2n = 12) with the latter as pollen parent were obtained and characterized for their phenotypes and chromosomal and genomic constitutions.
F1 plants and their progenies mainly resembled female B. napus parents, while certain characters of L. fendleri were expressed in some plants, such as longer flowering period, basal clustering stems and particularly the glutinous layer
on seed coats related to drought tolerance. Twenty-seven F1 plants were cytologically classified into five types: type I (16 plants) had 2n = 38, type II (2) had 2n = 38–42, type III (3) had 2n = 31–38, type IV (5) had 2n = 25–31, and type V (1) had 2n = 19–22. Some hybrids and their progenies were mixoploids in nature with only 1–2 chromosomes or some chromosomal fragments
of L. fendleri included in their cells. AFLP (Amplified fragments length polymorphism) analysis revealed that bands absent in B. napus, novel for two parents and specific for L. fendleri appeared in all F1 plants and their progenies. Some progenies had the modified fatty acid profiles with higher levels of linoleic, linolenic,
eicosanoic and erucic acids than those of B. napus parents. The occurrence of these partial hybrids with phenotypes, genomic and fatty acid alterations resulted possibly from
the chromosome elimination and doubling accompanied by the introgression of alien DNA segments and genomic reorganization.
The progenies with some useful traits from L. fendleri should be new and valuable resource for rapeseed breeding. 相似文献
20.
K. C. Armstrong 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1990,79(1):137-142
Summary Hybrids between B. inermis Leyss (2n=8x=56) and B. riparius Rehm. (2n=10x=70) were easily made. The F1 hybrids had a fertility of 20%–50% under open pollination and backcrossing to B. inermis. Chromosome pairing in B. riparius was predominantly as bivalents (29.04–33.85 per cell for plant means). Bivalents also predominated in the F1 hybrid (2n=9x=63) and there was a high level of pairing with no reduction in chiasma frequency. It was impossible to estimate the frequency of auto-versus allosyndetic pairing. Chromosome pairing in a hybrid between B. arvensis (2n=2x=14) and B. riparius confirmed that the B. riparius complement is capable of complete autosyndetic pairing. Chromosome numbers in the F2 progeny ranged from 2n=56 to 72 but they were skewed towards 2n=63 to 70. Backcrosses ranged from 2n=56 to 63, as expected, with the distribution skewed towards 2n=56. Selection towards the 2n=56 level would be difficult in the F2. Empirical observation suggested that cytoplasm had a major influence on morphology in the backcrosses. Additional studies are required to determine the best breeding scheme to introgress germ plasm between B. inermis and B. riparius. 相似文献