Wyniki wyszukiwania - Biblioteka Nauki

1

Xenia effect on seed and embryo size in cotton (Gossypium hirsutum L.)

100%

Pahlavani M. H. , Abolhasani K.

Journal of Applied Genetics

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2006

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tom 47

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nr 4

331-335

EN

The term xenia was coined to describe the effect of foreign pollen on the development and characters of the seed. To study its importance and consequences for various seed traits in cotton (Gossypium hirsutum L.), the effect of pollen genotype on seed and embryo weight was studied with seeds from 15 F1 hybrids. Cross-fertilization changed seed weight by up to 7.0% in relation to self-fertilization. Xenia effect significantly increased embryo weight of cross-fertilized seeds, by up to 14.4% in comparison to self-fertilized seeds. Seeds of some crosses had a lower hull content than corresponding selfed seeds. On average, the xenia effect was greater for embryo weight than for seed weight. However, in some crosses there was no difference between cross- and self-fertilized seeds for seed weight, embryo weight, moisture content and hull content. Positive xenia effects for seed weight and embryo weight may help us to establish uniform stands of vigorous hybrid seedlings, especially under unfavourable conditions. Also, larger seed and embryo weight, along with lower hull content, could result in higher oil yield. Therefore, careful choosing of genotypes as parents and of cross direction in the production of hybrid seed is very important in cotton.

2

The course of meiosis, pollen fertility and seed setting in barley lines with duplications in chromosomes 6 and 7

86%

Sodkiewicz T. , Sodkiewicz W.

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tom 35

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nr 4

231-240

EN

The aim of the present study was to find the reasons a low fertility of plants with duplicated segments of the short arms of satellited chromosomes.An attempt was made to determine the influence of duplicated segments of different size on the course of meiotic division, pollen stainability and viability as well as to evaluate the influence of these traits on seed setting in barley lines carrying duplications.Material for the study were spring barley (Hordeum vulgaris) lines, derived from the cv.Bonus with structural changes in chromosomes 6 and 7.It was found that percentage of bivalents formed in the course of meiotic division is correlated with the size of a duplicated sector.The formation of quadrivalent chromosome linkages in the course of meiosis was observed in the lines with duplications, and the number of quadrivalents per cell increased with an enlarged size of a duplicated chromosome sector.Seed setting in the lines carrying duplications may be negatively affected by a small amount of pollen grains in the anthers.Per cent of fertile flowers in the group of lines with duplications was not directly correlated either with per cent of viable pollen grains or with the size of a duplicated sector.

3

Fertility improvement in pea (Pisum sativum L.) autotetraploids - mutation breeding

86%

Kumar H. , Mercykuty V. C. , Srivastava C. P.

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nr 1

43-48

EN

C2 seeds of autotetraploids (colchicine-induced) of two diverse genotypes, T 163 and 5064-S, of pea (Pisum sativum L.) and their corresponding diploids were irradiated with 10 kR gamma-ray.Autotetraploids showed high seed-sterility as compared to diploids.Seed fertility increased in M2 as compared to M1.Both quadrivalent and bivalent frequancies desreased in the M1 generation of autotetraploids in relation to their respective controls.However, a positive shift in the mean bivalent formation was noted at the cost of other configurations in C3-M2 with respect to C2-M1 and varied with the genotype.In the M2 generation of autotetraploic, the variability was relatively higher for the number of pods per plnt and seed yield per plant.Although the mean values for pods per plant, number of seeds per plant and seed yield per plant remained more or less parallel in autotetraloids in M1 and M2 generations, there was an increase in the upper range limit probably due to micromutation for these characters in M2.

4

Inheritance of seed dormancy in Tibetan semi-wild wheat accession Q1028

86%

Lan X.-J. , Wei J.-M. , Liu D.-C. , Yan Z.-H. , Zheng Y.-L.

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nr 2

133-138

EN

Tibetan semi-wild wheat (Triticum aestivum ssp. tibetanum Shao) is one of the Chinese endemic hexaploid wheat genetic resources, distributed only in the Qinghai-Xizang Plateau of China. It has special characters, such as a hulled glume and spike disarticulation. However, seed dormancy, another important character for wheat resistance to pre-harvest sprouting, was rarely reported. Seed dormancy of more than 10 Tibetan semi-wild wheat accessions was evaluated, and their germinations were 0% or near 0% with both treatments of threshed seeds and intact spikes at hard dough stage. Tibetan semi-wild wheat accession Q1028 was investigated for its seed dormant characters by testing the seed germination percentages of intact spikes, seeds with bract powder, normal seeds, seeds with pierced coat, and sectioned embryos. It was observed that embryo dormancy of Q1028 accounted for its seed dormancy. Using threshed seeds and intact spikes at hard dough stage, the inheritance of seed dormancy was carried out using the F1, F2, F3 and F2BC1 populations of the cross between Q1028 and a wheat line 88?1643, susceptible to preharvest sprouting. The germinations of seeds and intact spikes in F1 plants were 1.0% and 0.9%, respectively. It indicated that seed dormancy of Q1028 was inherited as a dominant trait. From the genetic analysis of the F2, F3 and F2BC1 populations it was found that the strong seed dormancy of Q1028 was controlled by two dominant genes.

5

Interval mapping of QTLs controlling yield-related traits and seed protein content in Pisum sativum

86%

Irzykowska L. , Wolko B.

Journal of Applied Genetics

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2004

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tom 45

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nr 3

297- 306

EN

A linkage map of garden pea was constructed on the basis of 114 plants (F2 generation) derived from a cross combination Wt10245 ? Wt11238. The map, consisting of 204 morphological, isozyme, AFLP, ISSR, STS, CAPS and RAPD markers, was used for interval mapping of quantitative trait loci (QTLs) controlling seed number, pod number, 1000-seed weight, 1000-yield, and seed protein content. Characterization of each QTL included identification of QTL position with reference to the flanking markers, estimation of the part of variance explained by this QTL, and determination of its gene action. The yield-related traits were measured in F2 plants and in F4 recombinant inbred lines (RILs). The interval mapping revealed two to six QTLs per trait, demonstrating linkage to seven pea chromosomes. A total of 37 detected QTLs accounted for 9.1-55.9% of the trait's phenotypic variation and showed different types of gene action. As many as eight and ten QTLs influencing the analysed traits were mapped in linkage groups III and V, respectively, indicating an important role of these regions of the pea genome in the control of yield and seed protein content.

6

Free Electron Laser in Poland

36%

Romaniuk R. S.

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tom Vol. 55, No 4

669-682

EN

The idea of building a new IVth generation of light sources of high luminosity, which use accelerators, arose in the 80ties of XXth century. Now, in a numerable synchrotron and laser laboratories in Europe, an intense applied research on free electron lasers has been carried out for a couple of years (FEL) [17,18]. Similarly, in this country, free electron laser in Poland - POLFEL [9] is in a design, a coherent light source of the IVth generation, characterized by very short pulses in the range of 10-100fs, of big power 0,2GW and UV wavelength of 27nm, of average power 1W, with effective high power third harmonic of 9nm. The laser consists of a linear superconducting accelerator 100m in length, undulator and experimental lines. It generates a monochromatic and coherent radiation and can be tuned from THz range via IR, visible to UV, and potentially to X-rays. The linac works in quasi-CW or real-CW mode. It is planned by IPJ [9,10] and XFEL-Poland Consortium [16] as a part of the ESFRI [1] priority Euro FEL infrastructure collaboration network [6], part of the European Research Area - ERA [2]. The paper discusses: FEL background in Poland as a part of EuroFEL infrastructure, FEL parameters and performance, FEL research and technical program and FEL networking in Europe and worldwide. Emphasis is put on the usage of superconducting RF TESLA technology and ties linking Polfel and the European X-Ray Free Electron Laser. The Polfel team of researchers is now dissipated worldwide among such projects as Flash and E-xfel in Desy, Cebaf in JLab, Alba in Barcelona, Elettra in Trieste, ILC in Fermilb, LCLS in SLAC. Polfel creates an unique, but quite transient chance to gather and solidly accumulate for a long time this expertise in this country again.