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1.
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   

2.
Leprosis, caused by citrus leprosis virus (CiLV) and transmitted by the tenuipalpid mite Brevipalpus phoenicis, is one of the most important viruses of citrus in the Americas. Sweet oranges (Citrus sinensis L. Osb.) are highly susceptible to CiLV, while mandarins (C. reticulata Blanco) and some of their hybrids have higher tolerance or resistance to this disease. The mechanisms involved in the resistance and its inheritance are still largely unknown. To study the quantitative trait loci (QTL; quantitative trait loci) associated with the resistance to CiLV, progeny analyses were established with 143 hybrid individuals of ‘Pêra’ sweet orange (C. sinensis L. Osb.) and ‘Murcott’ tangor (C. reticulata Blanco × C. sinensis L. Osb.) from controlled crossings. Disease assessment of the hybrid individuals was conducted by infesting the plants with viruliferous mites in the field. The experiment consisted of a randomized completely block design with ten replicates. The evaluated phenotypic traits were incidence and severity of the disease on leaves and branches, for a period of 3 years. The MapQTL™ v.4.0 software was used for the identification and location of possible QTL associated with resistance to CiLV on a genetic map obtained from 260 AFLP and 5 RAPD markers. Only consistent QTLs from different phenotypic traits and years of evaluation, with the critical LOD scores to determine the presence or absence of each QTL calculated through the random permutation test, were considered. A QTL was observed and had a significant effect on the phenotypic variation, ranging from 79.4 to 84% depending on which trait (incidence or severity) was assessed. This suggests that few genes are involved in the genetic resistance of citrus to CiLV.  相似文献   

3.
Dual-passage excitation control method based on dynamical synchronous reference frame is analysed according to the base theory of A.C. excited generator. Using the dual-CPU project basing on the high speed DSP, excitation control system of A.C. excited generator is realized. Considering the characteristic of this control system, taking full advantage of the high speed and the convenient peripherals of DSP, the hardware and software of the control system are designed appropriately. Dual-passage excitation control system is realized using the dual-CPU method. Dual-passage excitation control strategy based on dynamic synchronous reference frame is proved with the experiment.  相似文献   

4.
Genetic resistance is an efficient and environmentally acceptable way of limiting the damaging effects of plant pathogens on yield and quality of crops. Tests of winter barley variety Venezia revealed an unknown resistance to all tested Blumeria graminis f. sp. hordei isolates. Response type arrays (RTAs) obtained here were created using common avirulent (RT 0) isolates and virulent (RT 4) isolates that first appeared in 2011. RTA of Venezia was identical to RTAs of six other varieties, but differed from RTAs of all other previously tested varieties. Venezia was the first variety to be registered with this resistance, and it is recommended that the resistance be designated Ve. Among 905 isolates randomly collected from the Czech aerial pathogen populations from 2009 to 2015, 13 contained Ve virulence. Each of the isolates differed from the others and thus belonged to different pathotypes. Seven of these 13 pathotypes were collected in the western region of the Czech Republic in an area close to Germany, where Venezia was grown. This finding could support the hypothesis that pathotypes virulent to Venezia have migrated from Germany into the Czech Republic.  相似文献   

5.
The structure and shape of a cotton shrub aredetermined in result of combining theirelements:length and amount internodes of amain stem and fruit brunches,amount and shapeof leaf blades.Some lines of genetic collectionhave been crossed between each other for many  相似文献   

6.
7.
In this paper, the moving laws at any point of meshing discharge are stuied about internal gears E. D. M. grinding. It is the first time that the meshing theory of gears is combined with electric discharge machining, and the discharge principles of infernal gears of E. D. M. are described.  相似文献   

8.
Usually, mapping studies in potato are performed with segregating populations from crosses between highly heterozygous diploid or tetraploid parents. These studies are hampered by a high level of genetic background noise due to the numerous segregating alleles, with a maximum of eight per locus. In the present study, we aimed to increase the mapping efficiency by using progenies from diploid inbred populations in which at most two alleles segregate. Selfed progenies were generated from a cross between S. tuberosum (D2; a highly heterozygous diploid) and S. chacoense (DS; a homozygous diploid clone) containing the self-incompatibility overcoming S locus inhibitor (Sli-gene). The Sli-gene enables self-pollination and the generation of selfed progenies. One F2 population was used to map several quality traits, such as tuber shape, flesh and skin color. Quantitative trait loci were identified for almost all traits under investigation. The identified loci partially coincided with known mapped loci and partially identified new loci. Nine F3 populations were used to validate the QTLs and monitor the overall increase in the homozygosity level.  相似文献   

9.
Populus adenopoda Maxim. and P. alba L. [section Populus (aspen), genus Populus] are two tree species of ecological and economic value. To date, no high-density genetic maps are available for these two species. In this study, 1100 interspecific hybrids were obtained by controlled crossing and embryo culture. Simple sequence repeat (SSR) and sequence-related amplified polymorphisms (SRAP) were used to genotype 189 F1 individuals. The genetic linkage map of P. adenopoda × P. alba generated from this study includes 212 markers (192 SSRs and 50 SRAPs) and consists of 26 linkage groups spanning 2178.5 cM, with an average distance of 11.7 cM between markers. This is the first SSR- and SRAP-containing genetic linkage map for aspen. The SSRs on the map will serve both as bridges for comparison with the poplar maps published to date and as a direct link to the Populus genomic sequence. Future studies focusing on the data presented here should enhance the density and precision of the map for identifying and localizing quantitative trait loci and promote genomic research on the genus.  相似文献   

10.
In order to verify influence of Potash on yield and quality of stem tumorous mustard,set up the six different amount treatment of applying potash.By fields trials and lab analyses.The result indicates that:The more the amount of applying potash is,the more the amount of creature on the ground of stem tumorous mustard is,the ratio of stem/leaf is raised,the yield of tumorous stem is raised,the maximum amount can be raised by 80.4%.At the same time,applying potash can reduce content of skin of vegetable(4.6%) to a certain extent,improve index of vegetable shapes of tumorous stem(1.09),raise processing quality and commodity.Content of soluble carbohydrate and content of crude protein between the amount of applying potash exists obvious harmonization.Content of VC and the amount of applying potash exists obvious relation.The maximum content of soluble carbohydrate can be raised by 47.7%,and content of crude protein by more than 10%,and content of VC by 3.9%.The amount of applying Potash(K2O)in production is within 13 kg/667m2,can obtain higher yield and better quality.  相似文献   

11.
The degree of centralization indicates the concentration of production management in a particular industry and is an important indicator to reflect industry and market structures. We use the concentration rate ( ) to analyze the concentration of the construction industry from 2000 to 2005 in P. R. China and compare that industry with others in the country. We also use a Lorenz curve to analyze the industrial structure of P. R. China based on data from P. R. China and developed countries. We conclude that the concentration of the Chinese construction industry definitely has developed; there still exist, however, considerable gaps when it is compared with counterparts in developed countries. We therefore discuss ways to improve the degree of centralization of the Chinese construction industry, based on the laws and regulatory system, market order, and industrial and enterprise structures.  相似文献   

12.
13.
Wilt caused by Fusarium oxysporum f. sp. pisi is a serious production constraint for peas worldwide. An attempt was made to isolate wilt-resistant mutants in two susceptible pea genotypes, Arkel and Azad P-1, employing induced mutagenesis and in vitro selection techniques. Two thousand seeds of each genotype were mutagenized either with ethyl methane sulfonate (EMS, 0.2% and 0.3%) or gamma rays (5-22.5 kR) in 60Co gamma cell for three consecutive years. Screening of different mutagenized populations under wilt-sick plots resulted in the isolation of 25 mutants exhibiting complete or enhanced wilt resistance compared to parental genotypes. Five of these wilt-resistant mutants also outperformed the susceptible background genotypes in terms of yield and other horticultural traits. Efforts were also made to isolate wilt-resistant regenerants from callus cultures exhibiting insensitivity to culture filtrate (CF) of F. oxysporum f. sp. pisi. A total of 250 regenerants (R 0) were obtained from CF-insensitive calli selected from medium supplemented with 20% culture filtrate. When evaluated in artificially inoculated sick plots, only five R 2 lines obtained from the regenerants exhibited enhanced wilt resistance compared to parental cultivars. However, the selected lines did not exhibit resistance levels equivalent to those shown by wilt-resistant lines isolated through in vivo mutagenesis. To conclude, induced mutagenesis through irradiation and EMS treatments exhibited superiority over in vitro selection for inducing wilt resistance in peas.  相似文献   

14.
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   

15.
Sugarcane is one of the most important crops in the tropical and sub-tropical regions worldwide because it supplies over half of the world’s sugar. The main goal of sugarcane breeding programs is releasing new cultivars with improved sugar content, disease resistance and agronomic traits. Molecular markers linked to the sugar yield would greatly facilitate the development of sugarcane cultivars with higher sugar content. In this study, quantitative trait loci (QTL) associated with sugar and yield related traits were identified using a segregating F1 population derived from two Saccharum spp. hybrids. Specifically, BRIX, POL, recoverable sugar content (SC), fiber content (FC), moisture content (MC), juice purity, stalk diameter (SD), and stalk weight (SW) data were collected from a replicated field trial of a bi-parental population. A total of 36 and nine QTL for sugar and yield related traits, respectively were identified using a high density genetic map with markers developed by genotyping-by-sequencing. Of the 45 detected QTL, seven QTL were associated with each of the three sugar related traits BRIX, POL, and SC; six QTL with FC and MC; three QTL with juice purity; four QTL with SD; and five QTL with SW. The QTL explained a total of phenotypic variations of 70.90, 61.80, 61.68, 68.67, 91.62, 33.00, 49.91, and 64.49% for BRIX, POL, SC, FC, MC, purity, SD, and SW, respectively. Upon validation, markers from the identified QTL would be useful in marker-assisted selection for selecting superior cultivars with these traits.  相似文献   

16.
[Objectives]To study and compare the processing methods of Ziziphus jujuba Mill.[Methods]Z.jujuba was processed by seven methods:cleaning,yellowish frying,burnt frying,carbonized frying,moistening by hot sand,steaming,and boiling.Ultraviolet-visible spectrophotometry was used to determine the content of total flavonoids in each processed Z.jujuba.[Results]The content of total flavonoids measured by various processing methods was different.The content of total flavonoids in the processed Z.jujuba by moistening by hot sand was relatively high and the absorption peak spectrum was almost the same as that of the cleaned processed Z.jujuba and the rutin reference substance.[Conclusions]The moistening by hot sand is the optimal method for processing of Z.jujuba.  相似文献   

17.
Summary Homozygous and heterozygous Phaseolus vulgaris and P. acutifolius parental genotypes were hybridized to determine if genotypic diversity would aid gene transfer between these species. Certain P. vulgaris female parents resulting from diverse intraspecific crosses increased the frequency of species hybrids obtained. From a total of 19 self-sterile hybrids, 20 backcross-1 (BC1) lines (P. vulgaris recurrent parent) were produced from 4 partially female-fertile hybrids, each of which had a heterozygous P. vulgaris female parent. Heterozygous P. acutifolius male parents did not influence the frequency at which interspecific hybrids could be produced but apparently improved female-fertility. Fertility of the F1BC1 generation was highly variable. The frequency of fertile individuals increased in each subsequent backcross generation (F1BC2 and F1BC3).Purdue University Agricultural Experiment Station Publication 9946.  相似文献   

18.
Summary Interspecific hybrids were generated from crosses between 4 Zinnia angustifolia clones (maternal parents) and an inbred line of Z. elegans Orange King (paternal parent) to investigate the influence of Z. angustifolia genotype on morphology and flowering of hybrids. Leaf length, leaf width, flower diameter, number of ray petals, and days to flowering of interspecific hybrids were significantly influenced by Z. angustifolia clonal genotype. Genetic analysis of hybrid morphology and development was performed using 2 parental Z. angustifolia clones and 18 F1 (9 seedlings from each of 2 populations generated from reciprocal crosses between parental clones) as maternal parents in crosses with Z. elegans Orange King. Genotype of Z. angustifolia significantly affected plant height, fresh weight, number of nodes, and days to flowering of interspecific hybrids. Control of these traits was through the Z. angustifolia nuclear genome. Improvement in interspecific hybrid morphology or development, i.e., shorter stature, earlier flowering, or larger flowers, may be possible by selection of superior-performing Z. angustifolia clones as parents.  相似文献   

19.
The authors determine the index system and the index weight of capability of real estate by applying Delphi method and AHP method, and found the fuzzy comprehensive evaluation model of capability of real estate. They creates the model of capability Vs. price based on value engineering theory. The authors analysis detailedly deciding method of capability Vs. price of real estate combined with a practice example and application. The method adapts to a house as well as the type of the house. The method resolves the problem which capability Vs. price of real estate was only described by qualitatively for ages, which supplies theory basis to developer and consumer.  相似文献   

20.
On the patterns of geographically remote G.hirsutum L.cotton hybrids produced byintraspecies hybridization of local and importedbreeds we have investigated particularities inheredity and variability of the most importanteconomical and physiological features,display ofreproductive and adaptive heterosis in different  相似文献   

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