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1.
Summary Three sugarbeet breeding lines partially resistant to the root-rotting fungus, Rhizoctonia solani, were converted to the tetraploid condition without selection. These three diploid and tetraploid lines were crossed with three diploid male-sterile lines to produce equivalent diploid and triploid hybrids. The triploid hybrids were significantly more resistant to Rhizoctonia than were the diploid hybrids. However, the tetraploid resistant limes were no different than their diploid equivalent lines. Reciprocal crosses provided no evidence of maternal effect on resistance. Cytoplasm that included the male-sterility factor had no influence on resistance. Triploid hybrids, where the resistant parent is tetraploid, should be advantageous in the breeding of rhizoctonia-resistant hybrid varieties.Joint contribution of the Agricultural Research Service, U.S. Department of Agriculture, the Colorado State University Experiment Station, and the Beet Sugar Development Foundation. Published with the approval of the Director of the Colorado State University Experiment Station as Scientific Paper Series No. 2072. 相似文献
2.
Summary Selection criteria for agronomic characters in a potato breeding program at the diploid (2x) level may differ from selection criteria used when selecting breeding lines at the tetraploid (4x) level. Differences between selection criteria are expected, (1) when expression of the characters is different at both ploidy levels and/or (2) when the effect of diploid breeding lines on agronomic characters of tetraploid progenies is different from the effect of tetraploid breeding lines. In this investigation sets of diploid and tetraploid progenies, each set derived from the same 2x.2x cross, were compared as to the expression of six agronomic characters. Diploid progenies had significantly lower yields (due to smaller tubers) and significantly higher under water weights than tetraploid progenies. Vine maturity and chip colour were similarly expressed at both ploidy levels. Correlations between yield and yield components, and between under water weight and chip colour were similar at both ploidy levels. The lower yields and higher under water weights found in diploids point to the need of different selection criteria for selecting diploid and tetraploid breeding lines. 相似文献
3.
Early blight (Alternatia solani) is a fungal disease in hot and humid environments, which causes leaf, stem and tuber lesions. Early blight resistance should be incorporated into potato cultivars because the fungicide spraying is an expensive solution for developing countries. The diploid cultivated species Solanum tuberosum group Phureja and group Stenotomum are sources of resistance alleles. The elucidation of the inheritance for early blight resistance must help to decide what could be the best breeding procedure to improve this diploid germplasm and transfer the resistance to the tetraploid level. Three experiments were carried out under controlled and field conditions to determine the heritability of this trait using nested and diallel mating designs with haploid, species and haploid-species hybrids. The narrow-sense heritability estimates were relatively high (0.64–0.78). This means that additivity was the most important type of gene action for determining resistance to early blight at the diploid level. The results suggested that diploid parents showing highest levels of resistance, throughout the cycle of disease development, can be used in 4x×2x crosses to obtain resistant tetraploid progenies to this fungal disease. 相似文献
4.
Introduction of an amylose-free (amf) mutant into breeding of cultivated potato,Solanum tuberosum L. 总被引：2，自引：0，他引：2
Summary Using an amylose-free (amf)mutant of diploid potato (Solanum tuberosum), diploid and tetraploid clones with different genotypes at the amf-locus were produced. In order to make use of the diploid material in analytic breeding of amf-potatoes, clones were selected that produced a considerable frequencies of 2n-pollen and 2n-eggs. Successful attempts were made to select normal synaptic as well as desynaptic clones producing 2n-gametes. Based on the phenotype of starch in the microspores, tetraploid clones with nulliplex, simplex and duplex genotypes at the amf-locus were selected. Prospects of using this material in conventional as well as in analytic breeding of potato are discussed. 相似文献
5.
Masako Akutsu Satomi Kitamura Ryo Toda Ichiro Miyajima Keiichi Okazaki 《Euphytica》2007,155(1-2):143-152
Tetraploid varieties of lilies have superior agronomic traits such as large flowers and resistance to physiological disorders.
In the present study, we attempted to induce 2n pollen of Asiatic hybrid lilies by arresting the meiotic process with nitrous oxide (N2O) gas. To determine which meiotic stage is optimal for induction of 2n pollen, plants with attached buds at different meiotic stages were treated with N2O for 24 h in a pressure-tolerant cylinder. A few 2n pollen grains were induced using plants with anthers in prophase I, whereas mixed pollen grains of differing size were produced
using plants undergoing meiotic metaphase predominantly in anthers. Although normal lily pollen grains are elliptical, nitrous
oxide exposure induced giant pollen grains that appeared spherical. Flow cytometry analysis showed that the giant pollen grains
were diploid. When mixed pollen that included normal and giant pollen was crossed to tetraploid cultivars, the resulting seedlings
were tetraploid and aneuploid, indicating that the giant pollen grains were diploids that could generate tetraploid seedlings
through fusion to diploid eggs supplied from a tetraploid female parent. Thus, treatment with N2O is useful for the production of 2n lily pollen and may provide a new approach for tetraploid lily breeding. 相似文献
6.
Summary Forty-one breeding lines of common wheat, derived from crosses between the Israeli cultivars Miriam and Lakhish and high-protein lines of wild tetraploid wheat, Triticum turgidum var. dicoccoides, were tested for various protein and yield parameters in field trials, under typical agronomic conditions. All lines had a higher grain protein percentage (GPP) than the leading Israeli cultivar Deganit, which was grown as a control. Grain yield (GY) ranged in the breeding lines from a low of 2.44 t/ha to as high as that of Deganit (6.95 t/ha). Despite the weak negative correlation between GPP and GY, several lines excelled both in GPP and in GY. The grain protein yield (GPY) of some of these selected breeding lines was higher than that of Deganit; e.g., 1.19 t/ha in the best line vs. 1.02 t/ha in Deganit. The 16.7% increase in GPY in this line reflected a more efficient utilization of nitrogen. 相似文献
7.
Thirty-six lentil varieties were evaluated under organic and conventional environment for three consecutive years in order
to see whether the promising genetic material for an organic plant breeding program are different from those of a conventional
system. The genetic material studied originated from various countries. In the conventional trial plots standard cultural
practices (P mineral fertilization & pest control) were applied throughout the growing season, while in the organic ones no
fertilizers or pest agrochemicals were applied. Significant regression, but of low value, between grain yield ranking and
earliness or harvest index ranking was detected. Combined ANOVA indicated significant differences between genotypes, years,
environments and genotype × environmental interactions (GEI). It was observed that under conventional management most of the
genotypes had a higher yield compared to the organic one. The mean grain yield ranking of the genotypes in each of the environments
revealed that some of the genotypes occupied the same ranking position at both the organic and the conventional environment
(non-crossover GEI), while others exhibited a significant alteration in their ranking (crossover GEI) under the two environments.
Crossover GEI and non-cross over GEI revealed two types of lentil varieties. Varieties with specific adaptation and varieties
with broad adaptation. It was concluded that grain yield was in general higher when lentil varieties were grown under a conventional
environment compared to the grain yield produced under an organic environment. Yet, there are lentil genotypes with a higher
yielding ability under the organic management and therefore should be targeted by the breeder. 相似文献
8.
Summary The nucleolar organizer activity of diploid and tetraploid Lolium perenne L. and diploid Lolium multiflorum
Lam. varieties was analyzed by the silver staining procedure. Both species show six or twelve Ag-NORs (silver stained nucleolar organizer regions) at the diploid and tetraploid levels, respectively. A positive correlation between the size of secondary constrictions and Ag-NORs was observed. 相似文献
9.
Summary From data available in the literature and supplemented by information from private tulip breeders, it appeared that triploid and tetraploid varieties raised in the past, resulted from crosses between diploid tulips and between diploids and tetraploids. This can only be explained by the occurrence of diploid gametes in diploid (2n=24) cultivars. This phenomenon which may affect both female and male gametes, appears to be specific for certain varieties. Consequences for practical breeding are discussed. 相似文献
10.
Summary Verticillium wilt is a serious disease of potato and is caused by the soil-borne fungi Verticillium dahliae and V. albo-atrum. No major cultivar is resistant to this disease. Two diploid interspecific potato clones, C287 and C545, were previously identified with consistently high levels of Verticillium wilt resistance and are thought to have the same genotype for the loci that confer resistance to V. dahliae stem colonization. The purpose of this study was to determine whether resistance to V. dahliae stem colonization could be transferred to the tetraploid level in potato via unilateral sexual polyploidization (USP). Progenies in eight families obtained by crossing C287 and C545 to two tetraploid breeding clones, S438 and S440, and the cultivar ‘Atlantic’ were planted in a V. dahliae-infested field and a field without a significant V. dahliae infestation. Resistance was evaluated relative to C545 and C287. There were differences among families for stem colonization and yield. No differences between the mean stem colonization of C545 and C287 progeny were detected. Family differences due to the tetraploid parents indicate that they contributed resistance to the progeny. Stem colonization data from this experiment were consistent with the proposed complementary two-gene model for Verticillium wilt resistance in the diploid parents. Unilateral sexual polyploidization is an effective method for transferring V. dahliae stem colonization resistance to the tetraploid level. 相似文献
11.
Summary Crosses of wild barley (Hordeum vulgare ssp. spontaneum and Hordeum vulgare ssp. agriocrithon) with Hordeum vulgare ssp. vulgare were used to select high yielding grain types under dryland Mediterranean conditions. No special difficulties were faced in making the crosses, in eliminating the brittle rachis genes from the grain types or in selecting 6-rowed types in crosses between 2-rowed wild barley and 6-rowed ssp. vulgare varieties. Brittle rachis genotypes, present in the segregating populations were used in developing self-reseeding permanent pastures for dry areas. The best selections were tested in seven trials during 1989–92 and some of them outyielded their parents and also the best improved check variety by 13–22%. Indications for transgressive segregation were obtained for grain yield, straw yield, total biological yield, harvest index and volume weight. The crude protein content of some of the selections was significantly higher than that of the checks. For breeding programs aiming at large seeds, special ssp. spontaneum lines should be used as parents. High grain yield was positively correlated with high straw yield, total biological yield, earliness in heading date, high harvest index and negatively with volume weight. It was concluded that unexploited useful genes, even when not directly observed in wild barley, could be transfered easily into high yielding genotypes by breeding. 相似文献
12.
Y. H. Lee 《Euphytica》1991,54(3):251-254
Summary Ten Aranda cultivars commercially grown in Singapore were selected to study their genomic constitutions and flower characteristics. Cytological evidence and breeding records of these cultivars showed that they are of three genomic classes. Four of them are diploid with AV genomes (one Arachnis and one Vanda genome), another four are triploid with AVV genomes and the remaining two are tetraploid with AVVV genomes. Sizes of flowers as well as of sepals and petals generally show significant increases from diploid to tetraploid. This trend reflects the increasing influence of Vanda resulting from additional one and two Vanda genomes in triploid and tetraploid respectively as compared to diploid cultivars. Among the three genomic classes, diploid cultivars generally bear less flowers per spray than those of triploid and tetraploid although exceptions may occur. There is no clear trend in the length of inflorescences although diploid cultivars tend to have less compact spray with flowers more distantly spaced out. 相似文献
13.
Summary Tolerance to high levels of boron in the soil is an important aspect of the adaptation of crop varieties to southern Australian conditions. This paper reports investigations aimed at exploring the extent of genetic variation in Pisum sativum and at defining appropriate selection criteria for selection for boron tolerance in breeding programs.A collection of 617 accessions of Pisum was screened in controlled conditions and visually assessed for symptoms of boron toxicity. A high proportion of accessions were sensitive with only 3.5% being more tolerant than any of the Australian varieties. Relatively high proportions of tolerant and moderately tolerant accessions originated from Asia and South America.In a second experiment the responses of selected tolerant accessions were evaluated with respect to different parameters. The objectives were to confirm the performance of the putative boron tolerant accessions and identify appropriate parameters for selecting boron tolerant genotypes. In addition to the visual assessment of boron toxicity, measurements at the time of harvest included dry matter yield and concentration of boron in tissues. Symptom expression was highly correlated with dry matter yield and concentration of boron in tissues under high boron conditions and so could be used as a non-destructive selection criteria. A low degree of symptom expression by tolerant accessions could usually be attributed to low levels of boron in the vegetative tissues. The results of this study indicate that considerable genetic variation exists among exotic accessions of Pisum sativum and tolerance to boron could be transferred to sensitive varieties. 相似文献
14.
Summary The dry matter yields of four varieties of Lolium perenne with similar flowering dates (Ba 10761, cv. Talbot, cv. S.321 and cv. Tove) were compared during two harvest years in an orthogonal plot trial with two contrasting harvesting frequencies, three levels of applied nitrogen (200, 400 and 600 kg N/ha/yr) and two wear treatments (with and without wear). Frequent harvesting, reduction of applied nitrogen from 600 to 200 kg/ha, and wear reduced mean annual yield by 6.49, 5.13 and 0.65 t/ha respectively. Differences between varieties in mean annual dry matter yields over all treatments were 0.52 t/ha in the first harvest year and 1.49 t/ha in the second harvest year. Over both harvest years, Ba 10761 outyielded Talbot by 15% under frequent harvesting but by only 5% under infrequent harvesting. This variety/harvesting frequency interaction was due to relatively poor growth of Ba 10761 during the reproductive phase of growth, reproductive growth accounting for a larger proportion of total annual yield under infrequent harvesting than under frequent harvesting. Talbot gave relatively low yields at the lowest level of nitrogen. Genotype/harvesting management interactions arising from genetic independence of productivity during vegetative and reproductive growth can be predicted from results of single-management trials but such predictions of genotype/nitrogen level interaction are not yet possible. 相似文献
15.
B. Maris 《Euphytica》1990,46(1):15-33
Summary To determine whether in potatoes the tetraploid level is preferable to the diploid level, especially regarding tuber yield, four diploid (2n=2×=24) Solanum phureja x dihaploid S. tuberosum hybrid parents and their vegetatively doubled, tetraploid (2n=4×=48) counterparts were intermated, which resulted in two F1 hybrid families at both levels of ploidy. The parents and clones of the F1 families and their offspring were used in crosses in such a way that in addition Sib1, Sib2, F1×Sib1, BC1 and Sib1×Sib1 families were produced. Of the first clonal generation of the 12 2 x families and their 12 counterpart 4 x families two tubers per clone were planted in three replications in a field experiment at Sturgeon Bay in 1969; of the parents six tubers were planted in each replication. Data were recorded on 16 characters, including plant height at four different times.The ANOVA's showed significant clone effects within each family for all characters. Computed from all family means as well as from the family means per ploidy level, differences due to family were also significant for all characters except one.As at the 2 x level and at the 4 x level of ploidy the mean phenotypic correlations between characters were of similar magnitude, it is concluded that they are independent of ploidy level.With the exception of eye depth, the mean coefficient of variation was greater at the 2 x than at the 4 x level of ploidy, indicating the greatest response to selection for those characters at the 2 x level. From the differences in family means between the 4 x and the 2 x level of ploidy it was apparent that the 4 x families generally had significantly taller plants, later maturity, fewer tubers, higher mean tuber weight, more tuber yield and more dry matter yield than their counterpart 2 x families. In contrast, the 4 x parents had on the average shorter plants, lower mean tuber weight, much lower tuber yield and lower dry matter yield than their 2 x counterparts.The phenotypic correlation and Spearman's rank correlation between the family means of the 2 x and the 4 x level of ploidy were positive for almost all characters and significant for nearly half of them.From the results it is concluded that 1. in potatoes the 4 x level of ploidy is preferable to the 2 x level, and 2. the performance of 4 x families is predictable from the performance of their counterpart 2 x families.Based on results mentioned in the literature and on the present results, a continued use of S. tuberosum dihaploids in potato breeding needs to be dissuaded. 相似文献
16.
R. C. B. Hutten M. G. M. Schippers J. Eising P. M. van Til J. G. Th. Hermsen E. Jacobsen 《Euphytica》1996,88(3):175-179
Summary The parental effects on progenies from potato 4x.2x(FDR) crosses were analyzed to determine anether and to what extent selection criteria used for selecting tetraploid breeding lines have to be adjusted when selecting diploid breeding lines. For vine maturity and chip colour multiple regression analysis of progeny means on means of diploid and tetraploid parents revealed high coefficients of determination (R2) for both characters, indicating good predicting power of the performance of both diploid and tetraploid parents on the performance of their 4x.2x progenies. For vine maturity the multiple regression slope for the tetraploid perents was significantly larger than for the diploid parents, and progeny means were towards the tetraploid parents. This indicates that selection criteria for vine maturity may be less stringent at the diploid level. However, diploids may be earlier maturing than tetraploids and therefore selection criteria can better be similar at both ploidy levels. For chip colour, multiple regression slopes for diploid and tetraploid parents were similar and progeny means were towards the darkest coloured parent irrespective of its ploidy level. This indicates that selection of breeding lines for chip colour can be conducted similarly at both ploidy levels. 相似文献
17.
Franziska Löschenberger Andreas Fleck Heinrich Grausgruber Herbert Hetzendorfer Gerhard Hof Julia Lafferty Marion Marn Anton Neumayer Georg Pfaffinger Johann Birschitzky 《Euphytica》2008,163(3):469-480
Breeding for organic agriculture (BFOA) is a strategy for a commercial breeding company based on the exploitation of the frequently
observed high correlation for many traits between conventional, low input (LI) and organic agriculture (ORG). Indirect selection
under LI can be useful to roughly divide the germplasm into the genotypes better adapted to high input and those better adapted
to LI or ORG conditions. BFOA is an evolving process, in which two methods are currently applied: early generations are either
selected following the pedigree system under LI, or grown as bulk populations on ORG fields. In the latter case the system
switches to LI after individual ear selection under ORG conditions. In both methods, the first replicated yield trial is grown
parallel under ORG and LI. Subsequently, the genotypes are grouped into conventional or ORG advanced trial series. The BFOA
strategy allows that the larger genetic variability of both the organic and conventional gene pool can be exploited in the
selection for ORG. Hitherto, seven winter wheat varieties were released in Austria after exclusive organic VCU testing. 相似文献
18.
The production of multispecific octoploids from Fragaria species and the cultivated strawberry 总被引：2，自引：0，他引：2
W. D. Evans 《Euphytica》1982,31(3):901-907
Summary A method of incorporating genetic material from five species of Fragaria and the cultivated strawberry into fertile octoploids is described. A synthetic octoploid derived from a hexaploid x diploid hybrid was crossed to octoploid cultivar breeding lines until a BC2 hybrid was produced. A second synthetic octoploid in which two diploid species and a tetraploid species were combined was crossed to a cultivated strawberry to produce a hybrid breeding clone. The two breeding clones were crossed and 222 seedlings were produced. The seedlings were generally vigorous and fruitful, some having commercial potential. 相似文献
19.
Summary Eight varieties of Vicia faba were examined in association with a standard strain of Rhizobium leguminosarum and also with the application of mineral nitrogen. Large differences in dry matter yield, nitrogen percentage and total nitrogen uptake were apparent between varieties and between rhizobium and mineral nitrogen treatments; the interaction was also significant. Genotypic differences in both the effectiveness of the symbiosis with this strain of rhizobium and the efficiency of utilization of nitrogen were thus demonstrated. The implications of this variability on the assessment of varieties and the possiblity of exploiting it by plant breeding techniques are discussed. 相似文献
20.
F. Pank F. Matzk U. Kästner W.D. Blüthner E. Foltys de Garcia A. Meister U. Ryschka G. Schumann 《Euphytica》2003,134(1):77-84
St. John's wort (Hypericum perforatumL.) is a medicinal crop plant that reproduces by apomixis. To study the reproductive diversity within the initial breeding
material, 656 plants from 92 accessions of the species were analysed by flow cytometric seed screening (FCSS) and compared
to 66 plants of cv. ‘Topaz’ as a control. Among plants from the 92 accessions, 16 were obligate sexuals, nine were obligate
apomicts and all remaining ones were facultative apomicts. Among controls, there were six obligate and 60 facultative apomicts.
Tests of reproductive pathways indicated that, in the investigated collection, all apomictic plants were tetraploid and all
sexual plants were diploid. A strategy for a cross breeding program in St. John's wort is illustrated by crossing one diploid
obligately sexual mother plant with six tetraploid facultative apomicts. All 91 F1 progeny obtained were triploid with 58% being obligate sexuals and 42%
facultative apomicts. To quantify the different routes of seed formation within facultatively apomictic individuals, the reproductive
pathways were reconstructed from about 30 single seeds from each of five tetraploid and two triploid plants using FCSS. The
frequency of seed formed by apomixis ranged from 54% to 67% among four tetraploid genotypes. One triploid and two tetraploids
formed 23% to 73% of the so-called BIII hybrids (fertilization of unreduced eggs) and one triploid was obligately sexual. The results show that while the mode of
reproduction in H. perforatum is highly variable, tetraploid obligate apomicts as well as diploid and triploid obligate sexuals can be selected as starting
material for breeding purposes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献