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Praca prezentuje dane literaturowe na temat źródeł odporności na biotyczne i abiotyczne stresy w plemieniu Triticeae. Omawia możliwości poszerzenia bio-różnorodności pszenicy i pszenżyta przez przeniesienie genów z dzikich i uprawnych form plemienia Triticeae.
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Fuzarioza klosow pszenicy

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This reviev of Fusarium head blight (FHB, scab) of small grain cereals describes as Fusarium a large and complex disease. Species causing FHB are adapted to a wide range of habitats all over the world. Fusarium species may infect the host plants at seedling, heading and flowering stages. Fusarium head blight is one of the most severe diseases of small grain cereals. It is caused by several pathogenic species of this genus, mainly F. culmorum, (W.G.SM.) SACC., F. graminearum and F. avenaceum. Recently, FHB has re-emerged as a major disease of wheat in the USA, Canada and other countries. Scab can lead to yield losses, poor grain quality and accumulation of several mycotoxins in infected kemels, husks and rachises. Changes in traditional agricultural practices during last decade - minimum or no-tillage, elimination of proper crop rotation with increased monocrop farming as well as a low resistance level among popular cultivars-are considered tobe reasons of FHB. Resistance to FHB is horizontal, polygenic. Effects of dominant genes probably influence the FHB resistance, but additional effects appear to be important, and resistance genes can be accumulated. Quantitative trait loci (QTLs) of resistance to FHB have been preliminarily mapped on following chromosomes: 1B, 2AL., 3BS, 3A, 5A and 6B. Growing of wheat cultivars resistant to above-mentioned pathogens is the most economic, environment-friendly and effective method of disease control.
The paper is the second part of the studies on spontaneous tetraploids of Festuca pratensis, morphological characters of which were given in the previous article (WIŚNIEWSKA 1994). This paper deals with meiosis in PMCs of spontaneous tetraploids of Festuca pratensis and their F₁ progeny (2n=28) and describes the fertility of these plants in comparison to that of the colchitetraploid cv. Westa and diploid cv. Skrzeszowicka. Different chromosome parings were found in three spontaneous tetraploids. In tetraploid 4/2, most frequently quidrivalents (5.72 IV per 1 PMC) were observed, whereas in tetraploids 465/2 and 534/2, bivalents were prevailing (5.36 and 5.65 II per cell, respectively). The rest of chromosomes remained as univalents, formed trivalcnts and uncountable chromosome associations. Spontaneous tetraploid plants had dehiscent anthers and a high pollen grain fertility (from 78.0 to 94.5%). The degree of seed setting at self-pollination in these plants was low. However, at open pollination, they set a little less seeds than the diploid cv. Skrzeszowicka and the cv. Westa. The plant Si obtained from selfed of spontaneus tetraploids were all tetraploids (2n=28). Seeds obtained from open pollination of spontaneous tetraploids, gave rise to 160 plants of F₁ and all were also tetraploid. No large differences in chromosome pairing.were observed in plants of F₁. At metaphase I a predominant number of bivalents (from 4.72 to 6.05 II) and a smaller number of quadrivalents (from 3.96 to 4.63 IV), were observed. All the plants of F₁ and S₁ generations had dehiscent anthers. Pollen grain viability of Fi plants was high (88.0-90.0%) and similar to that of the parental forms (78.0-89.5%) in the same year of the studies. The average seed setting of all studied F₁ plants at self-pollination ranged from 0.15 to 0.22%, being lower than that of the parental forms. At open pollination it ranged from 34.2 to 36.0%, which was higher than or similar to that of the parental forms in the same year.
Salicylic acid (SA) applied at concentrations from 1–10 µg·ml⁻¹ to germinating seeds of 8 barley cultivars reduced the disease rating of seedlings. Seedlings of barley not treated with SA and inoculated with Fusarium culmorum exhibited disease rating of root on avarage 76 %. Seedlings treated before inoculation with solution of SA 1, 2, 5 and 10 µg/ml exhibited significantly lower disease rating: on average 66, 58, 44 and 38 %. Disease score of leaf decreased in similar extent: from 30 % to 20, 11, 7 and 0 %.
Twelve Polish spring wheat cultivars and 18 spring wheat accessions from CIMMYT, Mexico, were examined for resistance to a highly pathogenic Fusarium culmorum strain KF846 and powdery mildew in 5-year field experiments. Resistant wheat cultivars (Sumai 3 and Frontana) served as controls. The mean percentage of Fusarium-damaged kernels (% FDK) for 5 years was lower in CIMMYT accessions (16.7%) than in Polish spring cultivars (28.3%). In all Polish spring cultivars, % FDK was higher than in the control cultivars Sumai 3 and Frontana (12-20%). The mean disease score (on a scale of 1-9) for powdery mildew (natural infection) for all examined cultivars and lines ranged from 0 to 7 and in the Polish spring cultivars was significantly lower (0-5). Cultivars Eta, Henika, Ismena, Jasna and Olimpia were found to be the least susceptible to powdery mildew in field experiments. The laboratory host-pathogen tests with Blumeria graminis f. sp. tritici isolates showed that only two cultivars were characterized by identical resistance patterns as the standard differential lines with documented resistance genes. Cultivar Alkora had the gene Pm3d, and Henika had Pm5. The gene Pm3d was identified in cultivars Jasna and Eta in combination with another unknown gene/genes. Cultivars Santa and Torka had the gene Pm5 in combination with another unknown gene/genes. Four cultivars: Banti, Ismena, Olimpia and Sigma, showed resistance to all mildew isolates employed in a laboratory test. The accession IPG-SW-14 was the least susceptible to both pathogens (F. culmorum and powdery mildew) in all 5 years of experiments. This line is the best candidate for deriving new cultivars with improved resistance to fungal diseases.
The valuable genes of Aegilops biuncialis, Ae. ovala, Ae. kotschyi, and Ae. variabilis were transferred to rye, by crossing Aegilops-rye amphiploids with tetraploid and diploid substitution rye. The C-banded karyotype of the BC₁ and BC₂ generations of amphiploids with 4x substitution rye and BC₁ with 2x substitution rye showed great variation in chromosome number and composition. In the BC₁ generation of amphiploids with 4x and 2x substitution rye, seed set success rate and germination rate varied depending on origin. However, plant sterility in all cross combinations of amphiploids with 4x and 2x substitution rye resulted in their elimination from further experiments in the BC₃ and BC₂ generations, respectively. In backcrosses of 4x substitution rye with amphiploids Ae. variabilis x rye 4x, fertile 4x rye plants containing Aegilops chromatin were produced in the BC₂ generation.
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