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1.
The expression of the “glanded-plant and glandless-seed” trait was assessed using High Performance Liquid Chromatography (HPLC) analysis methods in different Gossypium hybrids obtained by crossing Australian diploid cottons and various diploid and tetraploid species. Significant variation in the gossypol content in the seed was observed among the analyzed genotypes. HPLC data demonstrated that the gossypol synthesis repression mechanism in the Australian diploid species belonging to C and G genomes was dominant but did not confirm its preferential functioning against A genome species bearing GL2 locus. About 10% of the produced seeds had total gossypol content lower than the limit imposed by the World Health Organisation (600 ppm) for the use of cotton flour in food and feed. HPLC analysis of the terpenoids aldehyde (TA) contents in the aerial parts of the hybrids showed important qualitative and quantitative variability. This result could indicate a certain separation between pigment gland morphogenesis and terpenoid synthesis mechanisms in cotton.  相似文献   

2.
Effects of Brassica napus (N) and B. juncea (J) cytoplasm on seed characteristics of B. carinata (C) were examined. Alloplasmic lines of B. carinata were produced from N × C and J × C hybrids by recurrent backcrossing to the BC8 generation. Fourteen sets of reciprocal crosses were used. Compared with their euplasmic sibs, alloplasmic B. carinata line seeds with B. napus cytoplasm showed reduced dormancy, higher seed weight, lower germination rate at high temperatures, higher germination rate at low temperatures, and had lower erucic acid and higher linoleic acid contents. Alloplasmic B. carinata line seeds with B. juncea cytoplasm had higher seed weight but lower germination rate than their corresponding euplasmic sibs. These results showed a cytoplasmic effect on seed development, and an influence on seed weight, dormancy, and fatty acid composition. B. carinata was more deleteriously affected by cytoplasm from B. napus than by cytoplasm of B. juncea.  相似文献   

3.
Based on the requirements of the space range informatization, the paper discusses the necessity of digital range environment construction; analyzes the function and the main characteristics of digital space range environment, and suggests the constitution and system architecture of digital range environment. The key techniques of digital range environment creation applying visualization interactive simulation are also analyzed and discussed, which include the techniques of 3D-terrain generation, a fast algorithm for 3D-modeling based on complexity, the design of distributed simulation environment and the human computer interaction, etc.  相似文献   

4.
Lilium are Fritillaria-type plants. Triploid lilies, regardless of their male sterility, can be used as female parents to cross with appropriate males, in contrast to other triploid Polygonum-type plants, which are usually seedless. Up to now, however, little attention has been paid to the reason. Here we made allotriploid × diploid/tetraploid crosses in Lilium. Endosperm and progenies of LAA × AA/AAAA crosses were analyzed for ploidy level and genome composition. The endosperm of some LAA × AA/AAAA ovules developed well but there was little or no development of LAA × LL/OO endosperm. The endosperm genome composition of LAA × AA, LAA × AAAA, LAA × LL, LAA × OO are theoretically derived as 5A + 2L, 6A + 2L, 4A + 3L, 4A + 2L + O, respectively. Genomic in situ hybridization showed that the progenies of LAA × AA/AAAA were aneuploid. Based on the experimental results and analyses, our hypothesis is that five same genomes of endosperms are essential for its development in triploid × diploid/tetraploid crosses of Lilium. The hypothesis can explain the success or failure of 3x × 2x/4x crosses in Lilium and is of importance for lily breeders who need to know the likelihood of success when producing new cultivars of this economically important horticultural crop.  相似文献   

5.
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6.
Frego (fg) bract is an important agronomic trait in tetraploid cotton, which has been widely introduced into several cotton varities or lines in the past several years. In order to help us further understand the underlying molecular mechanism of frego bract development, a map-base cloning strategy was used to localize the fg locus. An F2 population which comprised of 290 fg individuals derived from a cross of the multiple-marker line T582 (G. hirsutum, carrying the fg gene) with Hai7124 (G. barbadense) was constructed. Genetic linkage analysis was carried out to map of the fg locus with SSR and EST-SSR markers in tetraploid cotton. Genetic linkage analysis showed that the fg locus was flanked by the marker NAU3016 and NAU3172 on the long arm of chromosome 3, with the genetic distance of 0.3 cM and 4.7 cM, respectively. The information of fg locus provided the basic information for the final isolation of this important gene in tetraploid cotton, these marker information could be used in marker-assisted selection in cotton.  相似文献   

7.
The knowledge of agro-morphological diversity and the distribution pattern of variation among conserved accessions could be an invaluable aid in germplasm management and crop improvement strategies. In this study, the geographical pattern of morphological variation of 880 landrace rice (Oryza sativa (L.)) accessions in Côte d’Ivoire was evaluated for 13 agro-morphological characters. Shannon –weaver diversity index indicated an overall mean of 0.47 ± 0.07 in the collection, with the greatest diversity from derived Savanna and north-west (H′ = 0.52 and 0.50) while the west-central had the lowest diversity (H′ = 0.41). Canonical discriminant analysis showed that traits such as panicle length, grain size (weight and length), tillering ability, number of days to heading and maturity were the main discriminatory characteristics. Result of the phenotypic frequency shows that, the landraces from the north and north-western zones were mostly tall, early heading and maturity, compared to those from the west and west-central which were mainly dwarf to medium height, late heading and maturing. This differential distribution of landraces with height, heading and maturity period reflected the distribution pattern of different Oryza sativa landraces in Côte d’Ivoire, which could be useful in germplasm management and breeding programs.  相似文献   

8.
Reciprocal differences, mostly caused by cytoplasmic effects, are frequently observed in interspecific hybrids. Previously, we found that crosses onto Solanum demissum were much successful with the pollen of interspecific hybrids between S. tuberosum as female and S. demissum as male (TD hybrids) than the reciprocal ones (DT hybrids). To elucidate this reciprocally different crossability, we analyzed the pollen DNA of TD and DT using methylation-sensitive amplified polymorphism (MSAP) analysis. Using 126 primer combinations, MSAP analysis revealed 57 different bands between bulked pollen DNA samples of TD and DT. Individual examination of 16 TD and 9 DT plants disclosed eight bands uniformly different between TD and DT. Their sequencing results revealed two pairs of bands to be identical to each other, resulting in six distinct sequences. As expected, one band shared high homology with chloroplast DNA, and another one with mitochondrial DNA. However, one band that was apparently different at DNA sequence level and maternally transmitted from S. demissum, showed no homology with any known sequence. The remaining three bands were of DNA methylation level differences with no or uncertain homology to known sequences. To our knowledge, this is the first report detecting reciprocal differences in DNA sequence or DNA methylation other than those in cytoplasmic DNA.  相似文献   

9.
A tomato cultivar with high quality fruit and a long shelf life is a main goal in tomato breeding and it would be achieved using wild germplasm. The objective of this work was to explore the inheritance for fruit quality traits, especially fruit shelf life, in three tomato crosses using a standard Argentinean cultivar (Ca, cv ‘Caimanta’), a ripening mutant (nor, homozygous for the nor gene) of Solanum lycopersicum, and a wild cherry type (Ce, LA1385 of S. lycopersicum var. cerasiforme). The wild parent had a shorter fruit shelf life than the mutant genotype but higher than Ca. When the Ce genotype was analyzed in hybrid combination, the F1 (Ca×Ce) was similar to the wild genotype for shelf life whereas the F1 (nor × Ce) had a longer shelf life. Both F1 crosses and backcrosses to the cherry type genotype had significantly lower fruit weight than the cultivated genotypes but higher than the cherry type parent. In the F2 analysis, it was found that the inheritance underlying quality traits is complex since non allelic interactions were detected. A significant additive genetic variance was found for fruit shelf life as well as for other fruit quality traits in each cross. The genetic parameters analyzed by mean values and variances in parental, F1 and F2 and backcross generations indicated that the cross between the normal ripening cultivar and LA1385 of S. lycopersicum var. cerasiforme offers the best possibility to obtain long shelf life tomato genotypes with good fruit quality.  相似文献   

10.
T. Dennis Thomas 《Euphytica》2008,164(2):317-323
Bitter melon (Momordica Charantia L.) is an important vegetable crop with nutritional and medicinal qualities. As a member of cucurbitaceae it is monoecious with varying proportions of staminate and pistillate flowers. This study was undertaken to determine the effects of various applications of ethrel and gibberellic acid (GA3) on sex modification in M. charantia. In the first set of experiments, various concentrations of hormones were added to the seed germination medium, in the second, adult plants growing in the field were sprayed with aqueous solutions of ethrel or GA3 three times at three-day intervals. The number and sex of open flowers was recorded daily for 60 days after the first flower opened and total number of staminate and pistillate flowers was calculated at the end of the experiment. The highest frequency (29.5%) of pistillate flowers was observed in plants treated with 500 ppm ethrel at germination. Similarly, spraying of adult plants with 100 ppm GA3 increased the proportion of pistillate flowers to 26% relative to 15% in untreated controls. Both ethrel and GA3 induced significantly higher number of pistillate flowers than control. In vitro hormone application during seed germination was much more successful than spraying of field grown plants.  相似文献   

11.
Spontaneous chromosome doubling via union of unreduced (2n) gametes has been thought to be the way that common wheat (Triticum aestivum L.) was originated from the hybridization of T. turgidum L. with Ae. tauschii Cosson. Previous works have observed unreduced gametes in F1 hybrids of Ae. tauschii with six of the eight T. turgidum subspecies. It is not clear, however, whether the formation of these unreduced gametes is a norm in the F1 hybrids. In the present study, we tried to answer this question by assessing the occurrence frequency of unreduced gametes in 115 T. turgidum–Ae. tauschii hybrid combinations, involving 76 genotypes of seven T. turgdium subspecies and 24 Ae. tauschii accessions. Our data show that these hybrid combinations differed significantly (P ≤ 0.01, F = 11.40) in selfed seedset, an indicator for production of unreduced gametes. This study clearly showed that meiotic restitution genes are widely distributed within T. turgidum. However, significant differences were found between as well as within T. turgidum subspecies and in the interaction of the T. turgidum genotypes with those of Ae. taushii. The possible application of the meiotic restitution genes from T. turgidum in production of double haploids is also discussed.  相似文献   

12.
Pineapple is one of the most important tropical fruits and therefore intensive genetic improvement programs are being carried out in many countries, including Cuba. Our research team has previously introduced the bar gene, along with chitinase and AP24 genes, into the pineapple genome. Herein, we report on the biochemical side effects of the herbicide FINALE® on these transgenic plantlets during hardening. Levels of aldehydes and chlorophylls, and peroxidase activity were recorded. The transformed clone studied here, not sprayed with FINALE®, showed the following side effects because of transgenesis only. Levels of malondialdehyde, other aldehydes, chlorophyll b, and total chlorophyll pigments decreased. The most remarkable biochemical differences between transgenic and non-transgenic plantlets after application of FINALE® follow. Levels of malondialdehyde and other aldehydes in transgenic material were not decreased by FINALE®, perhaps because these levels were already low as a result of transformation. FINALE® increased peroxidase activity in transgenic plantlets but such increase was higher in non-transgenic material. The herbicide increased contents of chlorophyll pigments (a, b, total) in transformed plantlets. However, as expected, non-transgenic plantlets decreased levels of chlorophylls (a, b, total) after application of FINALE®. The genetic transformation of pineapple with the bar gene not only conferred resistance to the herbicide FINALE®, but also promoted other biochemical changes.  相似文献   

13.
The possibility to induce embryo development after pollination of F1 interspecific cotton hybrids (Gossypium barbadense × Gossypium. hirsutum) with pollen from Abelmoschus esculentus was investigated to determine if wide-cross hybrid, haploid or other types of progeny might result. Small numbers of progeny (Pa) were indeed recovered after numerous alien pollinations and in-planta development or in-vitro culture. The Pa plants were characterized phenotypically and studied cytogenetically and microscopically to help establish their origin documenting their reproductive basis. Root-tip chromosome counts and meiotic Metaphase-I analyses revealed that chromosome numbers among cells of the Pa plants ranged from 33 to 44 and that the differences in chromosome number among cells of the same plant ranged from 1 to 3, indicating somatic instability. Flow cytometric analysis also indicated the aneuploid nature of Pa plants. Although the reproductive mechanisms need to be characterized more extensively by cytological and molecular means, the observations suggest that alien pollinations may have resulted in parthenogenetic (Pa) egg cell development, or some other unusual reproductive events. The production of wide-crosses and high degrees of aneuploidy could be of use for several types of genomic studies, e.g., functional genomic characterization of genome shock, deletion mapping, and germplasm introgression.  相似文献   

14.
For a better understanding of the physiological background of microspore embryogenesis (ME), the protein profile was analyzed in four winter triticale DH lines, which show extremely different embryogenic potential. The analysis were conducted with anthers at the phase of development optimal for ME induction and then after low temperature (LT, 3 weeks at 4 °C) ME-inducing tillers treatment. The sub-proteome of anthers was mapped by two-dimensional gel electrophoresis (2-DE). The protein species significantly more abundant (at least 2-fold) in responsive DH lines after LT treatment were chosen for identification by MALDI-TOF/TOF analysis. In total, 31 protein species were successfully identified as involved in the determination of microspore competence, stress response and in the regulation of ME induction. Microspore competence required sufficient energy supply and efficient system of cell protection that determine survival under prolonged LT stress treatment. LT stress was associated with increased accumulation of proteins typical for cell defence against oxidative stress (e.g., l-ascorbate peroxidase), chaperons (e.g., HSP70) and other enzymes/factors ensuring protein biosynthesis, stability and active cell divisions. Also here, effective cell defence required undisturbed energy supply. Among proteins that accumulated differentially in accordance with microspore embryogenic potential again the most important role seems to be played by the enzymes ensuring energy production and determining ability of plant stress adaptation. Two protein species (enolase, 12S storage protein), proposed earlier as candidates for markers of embryogenesis in other in vitro plant culture systems confirmed their utility for triticale anther cultures.  相似文献   

15.
Grapefruit growers in the tropics require information about existing and new citrus cultivars with high productivity potential. The objective of this study was to determine the growth, yield, and fruit quality performance of seven pigmented and four white grapefruit cultivars under the dry tropic conditions of Colima, Mexico. The trees were budded on sour orange (Citrus aurantium L.) rootstock and planted at a distance of 8 × 4 m. ‘Oroblanco’ and ‘Marsh Gardner’ white-fleshed grapefruit cultivars and ‘Chandler’, a pink-fleshed pummelo, were the largest trees with the greatest height (5.0–5.6 m), canopy diameter (6.2–6.3 m), trunk diameter (21.9–23.3 cm), and canopy volume (109–123 m3). Lower height (4.3–4.8 m) and canopy volume (73–96 m3), but with similar canopy diameter to the previously mentioned cultivars, were recorded for the remaining pigmented cultivars. ‘Chandler’ pummelo and four pigmented grapefruit cultivars (‘Shambar’, ‘Río Red’, ‘Ray Ruby’, and ‘Redblush #3’) had yearly productions of 34.8, 34.9, 34.1, 32.7, and 30.6 ton ha−1, respectively. The most productive white grapefruit cultivar was ‘Marsh Gardner’ (30.5 ton ha−1). Grapefruit cultivars having the largest fruit size showed a higher inverse relationship between fruit weight and yield than those with small fruit. Most genotypes had higher values of fruit weight, juice content, and maturity index than those required by the local market. The most promising grapefruit cultivars based on their acceptable growth, yield superior to 30 ton ha−1, and acceptable fruit color were ‘Río Red’, ‘Shambar’, ‘Ray Ruby’, and ‘Redblush #3’.  相似文献   

16.
An additive-dominance, additive × additive (ADAA) and genotype × environment interaction mix model was used to study the genetic control of β-carotene and l-ascorbic acid in six basic generations (P1, P2, F1, F2, BC1P1 and BC1P2) of tomato derived from the cross CDP8779 accession (Solanum lycopersicum L.) × CDP4777 accession (S. lycopersicum var. cerasiforme). The study was performed in two environments: (1) open field; (2) protected environment, consisting of hydroponic cultivation in a glasshouse. The results indicate that β-carotene accumulation was mainly additive (32.2% of the genetic component), with a small dominant component (4.2%) and an important additive × environment interaction contribution (63.6%). In target environments with moderate to high temperatures and no limiting radiation, this the expression additive × environment interaction could substantially enhance the β-carotene content. This trait showed also a high narrow-sense heritability (h 2 = 0.62). Ascorbic acid accumulation was also mainly additive (61.7% of the genetic component), with a minor additive epistatic component (21.5%). This epistatic effect caused a negative heterosis that reduced the positive main additive effect. Nevertheless, in the described target environments, the additive × environment interaction contribution (16.8%) may enhance the ascorbic acid content and compensate for the negative heterosis effect. The total narrow-sense heritability of this trait can be considered useful (h 2 = 0.52). In conclusion, the CDP4777 accession is a very interesting donor parent for the joint improvement of β-carotene (without diminishing lycopene content) and ascorbic acid content in commercial nutraceutical tomato breeding programmes; the F1 hybrids derived from this accession showed nearly 450% of the commonly reported average β-carotene content and close to 130% of the ascorbic acid content of the female parent.  相似文献   

17.
The individual segregations of 14 seed protein loci named, SpA to SpM and Pha (phaseolin), were analyzed in a RIL population developed from the cross Xana × Cornell 49242. These seed protein loci were included in a genetic map previously developed in the same population. Protein loci, SpA, SpB, SpE, SpI, SpJ, and Pha, are organized in two different clusters, both located in linkage group (LG) 7; SpF, SpG, SpK, SpL, and SpM, form a single cluster in LG 4; SpC, is located in LG 3; and SpD, in LG 1. A close linkage was identified between the SpD seed protein locus, and the fin gene, controlling determinate growth habit. The usefulness of the SpD locus as a marker for the indirect selection of determinate growth habit and photoperiod insensitivity was checked in a F2 population derived from the cross G12587 (an indeterminate and photoperiod sensitive nuña bean) × Sanilac (determinate and photoperiod insensitive) and in a set of Mesoamerican and Andean genotypes. Results indicate that SpD protein locus was useful to detect individuals having determinate growth habit and photoperiod insensitivity in the cross G12587 × Salinac although some recombinants were found. However, the linkage between the SpD locus and the genes controlling growth habit and photoperiod sensitivity should be checked before using the SpD locus for the indirect selection of these traits in different backgrounds.  相似文献   

18.
About 19 cultivars, which had originated from backcrosses between F1 LA (Longiflorum × Asiatic) hybrids (2n = 2x = 24) as female parents and Asiatic cultivars as male parents (2n = 2x = 24), were analyzed with genomic in situ hybridization. 17 of them were triploid (2n = 3x = 36), and two aneuploid (2n = 3x + 1 = 37). The triploid cultivars had resulted from the functional 2n eggs produced by the female parents (F1 hybrids) because first division restitution (FDR) occurred in their meiosis during megasporogenesis. Similarly, the aneuploid cultivars had originated from viable 2n + 1 eggs. The extra chromosome in cultivar 041555 or 041572 resulted from one univalent or one half-bivalent which might have lagged behind when the sister chromatids of the other univalents and half-bivalents were segregating during the FDR process in their LA hybrid parents, respectively. That the majority of cultivars possessed recombinant chromosomes showed that intergenomic recombination might play an important role during the selection of the cultivars directly from BC1 progenies. That five cultivars of the 15 recombinant cultivars only had reciprocal recombinant chromosomes and 10 cultivars had non-reciprocal recombinant chromosomes indicates that the latter are more important. Because 9 of the 10 non-reciprocal recombinant cultivars possessed substitutions for recombinant segments, it also indicated that such substitutions could be an important source for the genetic variation in the sexual triploid BC1 progenies. In such cases there was a potential for the expression of the recessive genes of the backcross parent in a nulliplex (aaa) condition in the substituted segments. Genetic variation resulting from such nulliplex loci might have played a role in the selection of some of the cultivars.  相似文献   

19.
Abstract: This paper compares the evolution of the dominant politico‐economic paradigm over the past 80 years in two ‘resource periphery’ nation states that have become ‘models’ of economic reform, New Zealand and Chile. Analysing the forces that have driven change, it traces the shared transition from a neoclassical model, through structuralist/Keynesian principles, and on to neoliberalism. The paper discusses whether the contemporary convergence around neostructural policy represents a paradigm shift or an adaptation of the neoliberal model designed to sustain free‐market principles in a form that is acceptable to electorates. The paper concludes that the broad commonalities in the transitions are remarkable and come about as a result of shared external shocks as well as similar historical insertions into the global political economy. Notwithstanding the parallels, the comparative approach reminds us of the contingent unfolding of economic paradigms across space, a point that counters arguments that assert that neoliberalism, and the globalisation to which it gives rise, create a homogenous global political economy. This comparative study is timely, as the two countries have recently signed a bilateral strategic trade partnership. This agreement indicates continued pursuit of neoliberal agendas in both countries rather than, as respective governments have heralded it, a move to foster South–South cooperation.  相似文献   

20.
Witches’ broom is a severe disease of Theobroma cacao L. (cacao), caused by the basidiomycete Moniliophthora perniciosa. The use of resistant cultivars is the ultimate method of control, but there are limited sources of resistance. Further, resistance from the most widely used source (‘Scavina 6’) has been overcome after a few years of deployment. New sources of resistance have been intensively searched for in the Amazon basin. Here, we evaluated for witches’ broom resistance, cacao accessions from various natural cacao populations originally collected in the Brazilian Amazon. Resistance of 43 families was evaluated under nursery and/or field conditions by artificial or natural infection, respectively, based on disease incidence. Screening for resistance by artificial inoculation under nursery conditions appeared to be efficient in identifying these novel resistance sources, confirmed by natural field evaluation over a nine-year period. The increase in natural field infection of ‘Scavina 6’ was clearly demonstrated. Among the evaluated families with the least witches’ broom incidence, there were accessions originally collected from distinct river basins, including the Jamari river (‘CAB 0371’; ‘CAB 0388’; ‘CAB 0392’; and ‘CAB 0410’); Acre (‘CAB 0169’); Javari (‘CAB 0352’); Solimões (‘CAB 0270’); and from the Purus river basin, the two most outstanding resistant accessions, ‘CAB 0208’ and ‘CAB 0214’. The large genetic diversity found in cacao populations occurring at river basins from Acre and Amazonas states, Brazil, increased the chance that the selected resistant accessions would be genetically more dissimilar, and represent distinct sources of resistance to M. perniciosa from ‘Scavina 6’.  相似文献   

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