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1.
Summary Genotypic stability of grain yield and yield related traits was estimated for the 8 wheat-Agropyron derivatives, 441, 442, Vostock, PPG 56, PPG 56SS, 449, 450 and 441SS, together with two spring wheat controls, Drabant and Sv 01382, grown under varying watering regimes for two years. Differences among environments, genotypes and their interactions were highly significant for all traits. The genotypes X environments linear response were significant for number of spikelets per main spike, grain number per main spike and single grain weight. No significant linear responses were detected for grain yield or the rest of yield related traits. Deviations from linear responses were highly significant for all traits under study. Grain yield stability was not associated with the stability of yield components. PPG 56SS was identified as the stable variety with the highest mean grain yield per plant under the severe stress environment. Mean grain yields in the severe stress environment were correlated with the genotypic stability parameter . The severe stress environment was recognized as the optimum test environment. The study revealed a shift in the association between grain yield per plant and its components under the varying environments.  相似文献   

2.
Summary Thirteen maize (Zea mays L.) populations including five adapted, five adapted x exotic, two composites of adapted and exotic, and one exotic selected for adaptability were crossed in a diallel mating system. The parents and 78 crosses and nine check hybrids were evaluated for grain yield and plant height in five environments. The Gardner-Eberhart model Analysis II indicated that additive and nonadditive gene effects accounted for 60 and 40% of the total variation among populations, respectively, for grain yield and 86% and 14% of the total variation, respectively, for plant height. Components of heterosis were significant in the combined analysis for both traits. Adapted Corn Belt populations tended to have higher performance in crosses and greater values of variety heterosis than 50% adapted populations. Nebraska Elite Composite, Corn Belt x Mexican, and Corn Belt x Brazilian showed high mean yields in crosses, however, they were not among those with high estimates of variety heterosis. One exotic population (Tuxpeno x Antigua Grupo 2) and three adapted populations [307 Composite, NB(S1)C-3, and NK(S1)C-3] might be combined together to form a high-yielding population. It may be possible to synthesize two useful populations for reciprocal recurrent selection by grouping Tuxpeno x Antiqua Grupo 2, NB(S1)C-3, and NS(FS)LFW-8 into one population and NK(S1)C-3, KrugxTabloncillo, and 307 Composite in the other one.Contribution from the Department of Agronomy, University of Nebraska, Lincoln, NE 68583. Published as Paper No. 8011. Journal Series, Nebr. Agric. Exp. Station. Research was conducted under Project 12-049  相似文献   

3.
Summary Crude protein extracts from single seeds of nondomesticated Mexican bean accessions were analysed by SDS polyacrylamide gel electrophoresis for variability in phaseolin protein. Six new phaseolin types; M1, M2, M3, M4, M5, M6, which contained polypeptides within the same range of molecular weights (51,000 to 45,000 daltons) as occur in the S, T and C phaseolin types of cultivated beans were identified. No T and C types were found among the non-domesticated Mexican accessions, and the S type occurred in less than 7% of the seeds screened. Genetic analyses of F2 progenies from crosses between Sanilac (S), and five of the M types showed that each M phaseolin phenotype was allelic to the S type and expressed codominantly.  相似文献   

4.
Summary The present study offers the picture of crystal formation in cultures of dermatophytes photographed in white light. Isometric and anisometric crystal forms are profusely depicted. Pranks and mimics of crystal forms are pointed out. Photomicrographic data are given.
Zusammenfassung In der vorliegenden Untersuchung wird das Bild der Krystallbildung in Dermatophytenkulturen in weissem Licht dargestellt. Isometrische und anisometrische Krystallformen werden reichlich illustriert. Auf Streiche und Nachahmungen der Krystallformen wird hingewiesen. Photomikrographische Daten sind gegeben.

Résumé La présente étude offre le tableau des formations des crystaux des dermatophytes photographiées en lumière blanche. Des formes isométriques et anisométriques des crystaux ont été illustrées abondamment. Des coups et des mimiques des crystaux sont présentés. Les données photomicrographiques ont été élucidées.
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5.
The carbohydrate-binding specificity ofPseudomonas aeruginosa lectin I (PA-I) in iodinated or biotinylated form was studied. A large number of glycosphingolipids, as well as some glycoproteins and neoglycoproteins were used as ligands. Also, inhibition by free saccharides of PA-I binding to glycosphingolipids was tested. It was found that the lectin binds most strongly to terminal and nonsubstituted Gal3Gal- or Gal4Gal-structures.Abbreviations PA-I Pseudomonas aeruginosa lectin I - Cer ceramide - lactosylceramide Gal4GlcCer - iso globotriaosylcerami Gal3Gal4GlcCer - globotriaosylceramide Gal4Gal4GlcCer - globoside or globotetraosylceramide GalNAc3Gal4Gal4GlcCer - Forssman glycolipid GalNAc3GalNAc3Gal4Gal4GlcCer - P1 glycolipid Gal4Gal4GlcNAc3Gal4GlcCer - lactoneotetraosylceramide Gal4GlcNAc3Gal4GlcCer - B5 glycolipid Gal3Gal4GlcNAc3Gal4GlcCer - gangliotetraosylceramide Gal3GalNAc4Gal4GlcCer - GM1 Gal3GalNAc4(NeuAc3)Gal4GlcCer - RBC red blood cells - BSA bovine serum albumin - PBS phosphate-buffered saline - SDS sodium dodecyl sulfate - TLC thin-layer chromatography - HPLC high pressure liquid chromatography - MS mass spectrometry - FAB fast-atom bombardment - EI electron impact  相似文献   

6.
In a previous study, cDNA microsatellite markers were described in apricot (Prunus armeniaca L.). Specific PCR primers were designed to amplify the microsatellite-containing regions from genomic DNA in different Prunus species. In the present work, cDNA microsatellite markers were developed in the hexaploid Prunus domestica L. species and polymorphism was ascertained in a segregating plum population. Co-dominant mendelian segregation of alleles was demonstrated and microsatellite polymorphism displayed up to 6 alleles per SSR locus per individual. Parentage lineage of three full-sib European plum cultivars (cv. Cacanska najbolja, Cacanska rana and Cacanska lepotica) was reconstructed by the analysis of the above nuclear SSR markers, completed by four chloroplastic microsatellite loci. The six most informative nuclear loci enabled discrimination between the three Cacak cultivars and unrelated individuals as well as the previously proposed parents, Wangenheim and Pozegaca. Data obtained support previous evidence that these cultivars originated from the Stanley cultivar. However, SSR analysis finally excluded Wangenheim as the other possible parent. Based on the results obtained with nuclear and chloroplast SSR loci, we propose the origin of those three Cacak cultivars in a cross between Stanley as the mother plant and Ruth gerstetter as the pollinator. Furthermore, we demonstrate the utility of these apricot SSR markers for genotype fingerprinting of the hexaploid plum cultivars.  相似文献   

7.
Summary Meiotic pairing in Triticum turgidum cv. Ma (4x) with a mean chiasmata frequency of 27.16 per cell was compared with chiasmata frequencies in its hybrids with several triticale strains, Chinese Spring wheat and its addition lines for Imperial rye chromosomes 4R and 6R. In hybrids between Ma and x Triticosecale cv. Rosner the chiasmata frequency was marginally reduced by an average of 1.25%, by 8.8% in hybrids with x Triticosecale cv. DRIRA HH and by 6.7% with DRIRA EE (lacking 90% telomeric heterochromatin from chromosome arm 7RL). In pentaploid hybrids between Ma and T. aestivum cv. Chinese Spring the reduction was an average of 10.30%, while addition lines with rye chromosome 6R reduced chiasmata frequencies by an average of 7.4% and rye addition line for 4R showed the greatest depression in chiasmata frequency in hybrids by a 25.04% reduction. An interchange difference involving long chromosome segments was observed between Ma and Rosner.Contribution No. 819 Ottawa Research Station  相似文献   

8.
Summary Expression of -crystallin, a lens-specific protein, in 6-day-old chick embryonic brain cells was examined in situ and in vitro. The presence of minute amounts of -crystallin and its mRNA (-mRNA) in brain cells in situ was demonstrated by immunoblot and Northern blot analysis. In spreading cultures of the brain cells, -crystallin and -mRNA showed a significant increase from their in situ level. Immunohistological staining (peroxidase antiperoxidase) with monospecific anti-serum against -crystallin revealed that -producers were both epithelial cells and dendritic cells. Neither lentoidogenesis nor -crystallin expression was observed. Stimulation of -crystallin synthesis in cultured brain cells differed when compared with transdifferentiating cultures of neural retina cells. In the latter, -crystallin synthesis occurred concomitantly with differentiation of morphologically distinct lens cells containing -crystallin.  相似文献   

9.
Summary The genetics of tiller number at different development stages in rice was studied in a 6 x 6 diallel cross set involving six indica rice varieties in which a large difference of phenotypes existed. Estimates of genetic parameters following Hayman's method showed significant additive and nonadditive gene action, and the latter appeared to be solely due to dominance. High tillering ability was inherited as a partial dominant character conditioned by two or more blocks of genes, and var H1459 had more dominant genes, whereas Zhu-Yun-Luo had more recessive ones. Combining ability analysis by Griffing's method also indicated significance of both additive and nonadditive effects, but the former was more important than the latter. H1459 and Bi-Yu-Zao-Luo were good general combiners, and their hybrids H1459 x Le-Yi and Zhu-Yun-Luo x Bi-Yu-Zao-Luo were better crosses for combining an optimum tiller number with high percentage of productive tiller. An identical polygenic system appeared to be responsible for the genetic control of both tiller number at the different growth stages and the terminal character, productive tiller number. However, with growth of the plant, relative contributions of nonadditive gene action and environmental factors to the variation decreased, while those of additive gene action increased. Selection for high tillering ability, therefore, should be exercised at peak tillering or later stages.  相似文献   

10.
Expression sites of genes encoding (13,14)--glucan 4-glucanohydrolase (EC 3.2.1.73) have been mapped in germinated barley grains (Hordeum vulgare L.) by hybridization histochemistry. A32P-labelled cDNA (copy DNA) probe was hybridized to cryosections of intact barley grains to localize complementary mRNAs. No mRNA encoding (13,14)--glucanase is detected in ungerminated grain. Expression of (13,14)--glucanase genes is first detected in the scutellum after 1 d and is confined to the epithelial layer. At this stage, no expression is apparent in the aleurone. After 2 d, levels of (13,14)--glucanase mRNA decrease in the scutellar epithelium but increase in the aleurone. In the aleurone layer, induction of (13,14)--glucanase gene expression, as measured by mRNA accumulation, progresses from the proximal to distal end of the grain as a front moving away from, and parallel to, the face of the scutellum.Abbreviations cDNA copy DNA - RNase ribonuclease  相似文献   

11.
Summary The nature and extent of heterosis for grain yield and its component characters was estimated in a seven-parent F1-diallel cross in rice under the cold stress conditions of Palampur, representing sub-temperate climate of the mid hills of Himachal Pradesh. The highest heterotic effects for grain yield were observed in Himalaya 1/Phul Patas 72 and China 988/Himdhan hybrids, which gave 60.36 and 32.48% heterosis, respectively, over mid parent, 38.76 and 26.86% heterosis, respectively, over high parent and 32.30 and 26.86% heterosis, respectively, over the best variety, Himdhan. Heterosis for grain yield in these crosses was due to an increase in tiller number, panicle length, spikelets/panicle and 1,000-grain weight. Large number of crosses exhibited significant heterosis for high spikelet sterility and the majority of them had significant heterosis for late flowering, taking more than 120 days to flower, which resulted in lack of heterosis for grain yield in such crosses due to cold stress at the reproductive stage.Part of the thesis submitted by the senior author to Himachal Pradesh Agricultural University, Palampur (H.P.) India, in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Agriculture  相似文献   

12.
Summary Dry seeds of rice varieties T(N)1, IR 8 and Sona, with stabilised moisture content and presoaked in distilled water, were treated with chemical mutagens MMS, dMS, dEMS and dES with the purpose of evaluating chlorophyll mutation frequency and spectrum. In the M2 generation, mutants occurred in 24 lines of 'T(N)1; 94 lines of IR 8 but only in six of Sona. They include albino, viridis, xantha and other categories of which viridis was predominant. dES was found to be most effective of all mutagens used in all the three varieties and varietal differences were observed.  相似文献   

13.
The effects of soil water stress imposed at different growth stages of three cowpea varieties, namely, Adzuki (an erect type), Ife Brown (semi erect) and New Era (a spreading type) on growth, floral abscission and yield were investigated in the greenhouse. Stomatal density, aperture and behaviour as influenced by soil water potential was also evaluated. Root system development, grain yield, soil water content and potentials were determined in a field experiment. Soil moisture stress significantly reduced the growth and yield (34–46%) of the three cowpea cultivars. Although grain yield reduction was highest (36.8%) when stress was imposed at flowering/podding stage for Ife Brown, the variety New Era showed no reduction in yield. Floral abortion which increased with a decrease in matric potential may also be linked with imperfect aeration conditions. The choice of these cultivars for intercropping purposes should take cognisance of depth of rooting, lateral root spread, and root density, which affect water extraction at different soil depths, leaf area index, stomatal density, aperture and behaviour to decreased soil water potential all of which differed widely amongst the cultivars.  相似文献   

14.
Summary Detailed restriction enzyme analysis of the DNA from a Chinese female showed that one of her chromosomes had a >17.5 kb deletion of DNA, including the , 2, and 1 globin genes, which is present in many Southeast Asians with an -thalassemia-1 chromosome. Her normal chromosome had the expected cluster of -like globin genes (5----2-1-3), but the segment of DNA between the two globin genes was elongated by some 0.5–0.7 kb. Analyses of various restriction sites suggested that this normal variant of the human globin gene complex is due to a crossover between a normal chromosome with () and a chromosome with an -thalassemia-2 (–3.7) and an -21-hybrid gene.  相似文献   

15.
Summary Lectins and carbohydrate-specific monoclonal antibodies were used as cytochemical probes to investigate the possible influence of lactation products on the expression of intestinal membrane and secretory glycoconjugates in suckling piglets. Two different lactational regimes were compared; the first involved normal rearing of piglets for 8 weeks on a single dam and the second involved repeated cross-fostering of littermates onto recently farrowed sows, thereby restricting them to early milk. Five histo-blood group phenotypes were recognized within the piglet population: two immature phenotypes, O immature or Oi and A immature or Ai, and three mature forms, O, A and -. Under the normal suckling regime the transition from immature to mature OA phenotypes was evident at the fifth weekpost partum. However, in the repeatedly cross-fostered piglets this transition was evident much earlier at 3 weekspost partum. It is suggested that qualitative or quantitative variations in milk composition during the sow's lactation may significantly influence the expression of intestinal histo-blood group antigens in her suckling young.Abbreviations GalNac N-acetylgalactosamine - Gal Galactose - GlcNac N-acetylglucosamine  相似文献   

16.
Summary Ultraviolet-B light (UV-B) and ultraviolet-A light (UV-A) at higher doses exert a strong inhibitory (toxic) effect on axis growth in Scots pine (Pinus sylvestris L.) seedlings. This effect is unrelated to control of growth rate by phytochrome. Rather, after a toxic UV dose growth of the pine seedling no longer responded to phytochrome. Both, the effect of UV-B as well as the inhibiting effect of UV-A could be photoreactivated by blue light (B). The action of UV-A was 2 fold: (i) it exerted a toxic effect which could be photoreactivated by B, and (ii) applied after UV-B it photoreactivated to some extent the toxic UV-B effect. Obviously, the UV-A range causes a toxic effect, and at the same time is capable of photoreactivating the toxic UV effect. At higher doses the toxic effect prevails.  相似文献   

17.
Wheat plants, 22d. old, were exposed to wide range of soil water osmotic potential (s = 0 to –1.2 MPa) induced by NaCl and CaCl2 treatments in combination with roots maintained under aerobic (drained at field capacity) or nonaerobic (flooded) conditions in the soil, and sprayed with 10 mg L–1 kinetin solution. In drained plants, not receiving kinetin, increased soil salinity resulted in appreciable inhibition of shoot growth and reduction in chlorophyll (Ch1.), soluble sugars (SS) contents and grain yield. Shoot growth, Ch1. content, soluble sugars and grain yield were significantly lower for flooded plants than unflooded analogues over the entire s range. Both salinity and waterlogging synergize to increase Na+, Ca+ and Cl– accumulation in shoot tissues and to decrease the stability of leaf membranes to either dehydration (40% polyethylene glycol 6000) or heat (51 °C) stress. The ratio of K+/Na+ transported to shoots under aerobic and anaerobic conditions decreased progressively on salinization. The association between the internal mineral element concentrations was largely affected by kinetin treatment. Kinetin application ameliorated the deleterious effects of salinity and oxygen deficiency. It reduced Na+, Ca2+ and Cl– accumulation and improved K+ uptake under salinity and waterlogging stresses. Increased K+/Na+ ratio helped the plants to avoid Na+ toxicity and enhanced shoot growth and grain yield. Kinetin also reduced membrane injury by dehydration and heat stresses and improved the water status of plants under both aerobic and anaerobic conditions. The effects of single factors (Soil salinity s, soil waterlogging WL and Kinetin Kin) and their interactions (s × WL, s × Kin, WL × Kin and s × WL × Kin) were shown by analysis of variance to be statistically significant for most parameters tested. Calculation of the coefficient of determination (+) led to three important findings. (1) Salinity (s) was dominant in affecting leaf relative water content (RWC), shoot dry mass, grain yield, stability of leaf membranes to dehydration stress and the contents of Na+, Ca2+, Mg2+ and Cl–. (2) Kinetin (Kin) had a dominant effect on the stability of leaf membranes to heat stress as well as on chlorophyll and soluble sugars contents. (3) The share of waterlogging (WL) was dominant for K+ content. It can be concluded that kinetin application helped wheat plants to grow successfully in the areas subjected to combined effects of salinity and oxygen deficiency, such as in salt marshes.  相似文献   

18.
In microbiology the terms viability and culturability are often equated. However, in recent years the apparently self-contradictory expression viable-but-nonculturable (VBNC) has been applied to cells with various and often poorly defined physiological attributes but which, nonetheless, could not be cultured by methods normally appropriate to the organism concerned. These attributes include apparent cell integrity, the possession of some form of measurable cellular activity and the apparent capacity to regain culturability. We review the evidence relating to putative VBNC cells and stress our view that most of the reports claiming a return to culturability have failed to exclude the regrowth of a limited number of cells which had never lost culturability. We argue that failure to differentiate clearly between use of the terms viability and culturability in an operational versus a conceptual sense is fuelling the current debate, and conclude with a number of proposals that are designed to help clarify the major issues involved. In particular, we suggest an alternative operational terminology that replaces VBNC with expressions that are internally consistent.  相似文献   

19.
Summary We show that Alaskan woody plants respond to browsing in two ways that might destabilize a plantherbivore interaction and account for snowshoe hare population cycles. (1) Browse production of preferred, earliersuccessional woody plants increases in response to moderate levels of browsing. Such yield increases are potentially destabilizing. Later successional woody plants show decreases in yield after moderate browsing, which is consistent with the persistence of snowshoe hares in late successional refuge habitats (Keith 1966, Wolff 1980). (2) Many woody plants are destructively overbrowsed or girdled at the peak of the snowshoe hare cycle. The more palatable and plastic, early to mid successional plants respond by sprouting accompanied by juvenile reversion. Sprouts are markedly less palatable than mature shoots. We show here that sprout palatability and twig biomass are restored in 2–3 years for earlier successional plants, but palatability may not recover for 4–10 years in sprouts of some mid to late successional plants. The decrease in palatability helps to account for the snowshoe hare crash (assuming that damage to more palatable plants is widespread during the peak), and the 2–3 year time lag for recovery of more palatable species could account for (May 1974) the observed 8–11 year period of the hare cycles. Browse yield increases acting during the snowshoe hare population nadir and increase, and sprouting with juvenile reversion acting during the hare peak and decline can in principle account for the oscillatory nature and the observed 8–11 year periodicity of the snowshoe hare cycle.  相似文献   

20.
Type II thyroxine 5-deiodinase (5-D) activity in both pineal and Harderian glands of the Swiss mouse was studied. Pineal 5-D activity exhibited a nyctohemeral profile with a maximal peak value at 05.00 h, which coincides with that for pineal melatonin production. However, no rhythm of 5-D activity in the Harderian gland could be found. In pineal gland, light at night inhibited the nocturnal increase in 5-D activity, while isoproterenol, a -adrenergic agonist, could not stimulate the enzyme. In the Harderian gland, neither darkness, nor light at night, or isoproterenol were capable of modifying basal values of 5-D activity.  相似文献   

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