bluuebunny/crossref_metadata_2025_split huggingface dataset:
Androgenesis in Hexaploid Spring Wheat F2 Populations and Their Parents Using a Multiple‐Step Regeneration System
Authors: Pauk J. , Manninen O. , Mattila I. , Salo Y. , Pulli S. 
Published: April 2006

AbstractThe main goals of the wheat androgenesis experiment were to study the main phenomena of in vitro androgenesis in anther culture of F2 populations (10) and their parents (6), to compare the usage of P‐4 and C‐17 media for the formation of embryo/callus and to demonstrate a new plant regeneration system.The P‐4 induction medium was found to be significantly better than the C‐17 in the number of responsive anthers (RA) and calli induced (CI) at the 1 % and 0.1 % level, respectively. Genotypic effect was evident in both RA and CI. The yields of F2 populations in RA and CI were significantly higher than those of their parents regarding both media. The data confirmed the existence of heterosis for RA and CI in F2 populations.The ratio of green/albino plant regeneration was more favourable in the C‐17 derived embryo/calli than in the P‐4 derived ones.The frequency of plantlet regeneration was enhanced in the group of unresponsive calli by the application of the multiple‐step regeneration system. In this system the calli lacking well developed morphogenic structure were transferred to a new regeneration medium, containing a higher concentration of the same cytokinin, other cytokinin or basic medium, before the occurrence of irreversible changes in their physiology.
Resistance to Phytophthora infestans in Potato Genotypes Originating from Wild Species
Authors: Swiezynski K. M. , Sieczka M. T. , Sujkowski L. S. , Zarzycka H. , Zimnoch‐Guzowska E. 
Published: April 2006

AbstractThe reaction to P. infestans in the foliage and tubers of potato was evaluated in resistant genotypes and in their progeny. The genotypes originated from wild species known to carry genes for specific resistance.Evidence was obtained that three types of resistance to P. infestans were presented in the genotypes: (1) Resistance due to major, dominant genes was predominant. The presence of these genes was expressed in both foliage and tubers and did not influence maturity. Some of the genes were R genes, providing specific resistance, but for others this could not be determined as they were effective against the fungus inoculum with the highest virulence available: 1.2.3.4.5.7.10.11. (2) Resistance was present, associated with late maturity. (3) Tuber resistance was present, expressed after inoculation of whole tubers but not after inoculation of tuber slices.Testing of the progeny was essential for the determination of the type of resistance present in the genotypes evaluated.
Genotype × Environment Interaction for Nitrate Concentration in Lettuce
Authors: Reinink K. 
Published: April 2006

AbstractHigh nitrate concentration is a problem when lettuce (Lactuca sativa L.) is grown under low light intensities. Genotypes with low nitrate concentrations have been identified and are being used in breeding programmes. Previous results indicated the occurrence of genotype × environment (GE) interactions. Because of the important influence of light intensity on nitrate accumulation, two types of interactions may be expected: interactions related to daily variation, and those related to annual variation. In the present investigation both types were investigated using eight butterhead genotypes of lettuce which were repeatedly harvested. No daily variation in nitrate concentration and no corresponding GE‐interactions were found, irrespective of the level of global radiation. In contrast, a large annual variation and important corresponding GE‐interactions were found. Joint regression analysis on environmental means and on physical factors related to light intensity showed a differential response of genotypes to changing environmental conditions. Multiple joint regression on daylength and change in daylength accounted for two‐thirds of the interaction variance. However, deviations from regression were still significant indicating non‐linearity of the relationship, or, the existence of other environmental factors contributing to GE‐interaction.
Genetics of Resistance to Phytophthora capsici in the Pepper Line ‘SCM‐334’
Authors: Ortega R. Gil , Español C. Palazóon , Zueco J. Cuartero 
Published: April 2006

AbstractIn order to establish a genetic model of the resistance to Phytophthora capsici in Capsicum annuum genotype ‘SCM‐334’, two experiments were conducted which included ‘SCM‐334’, as well as, the susceptible line ‘Morrón INIA 224’ and their Fl, F2, F3 and BC1 generations. We also tried to introgress a recessive gene, hypothetically responsible for resistance to P. capsici, from ‘SCM‐334’ into ‘Morrón INIA 224’. Inoculations were made, when plants had 4—6 leaves, by irrigating the culture substrate with a zoospore suspension of P. capsici isolate ‘Bl’. The χ2 test was applied to segregating generations to determine how many genes were involved in resistance. The hypothesis which explained the obtained segregations best, although not completely, was one that assumes 3 genes in ‘SCM‐334’;, with at least 3 alleles in the heterozygous condition or 4 at any position, present in any genotype in order to be resistant. The influence of the isolate's aggressiveness and the inoculation method on the results are discussed.
Reproductive Behavior of Hexaploid/Diploid Wheat Hybrids 1
Authors: Cox T. S. , Harrell L. G. , Chen P. , Gill B. S. 
Published: April 2006

AbstractThe bottleneck restricting introgression of useful genes directly from diploid into hexaploid wheats is the low number of BC1F1 seeds obtained. In crosses between hexaploid wheat (Triticum aestivum L.; AABBDD) and Aegilops squarrosa L. (DD) or T. urartu Thum. (AA), this bottleneck may be overcome simply by pollinating a sufficient number of F1 spikes. However, hybrids between hexaploid wheat cultivars (T. aestivum) and T. monococcum L. (AA) generally are highly female‐sterile, often having no pistils. One T. monococcum accession, PI 355520, when crossed with T. aestivum, produced hybrids with female fertility in the same range as that of T. aestivum/A. squarrosa or T. aestivum/T. urartu hybrids, ca. 0.5 to 1.0 backcross seed per spike. We found that female fertility was controlled by two duplicate genes in PI 355520, and that this accession can be used as a bridging parent to introgress genes from other T. monococcum accessions into hexaploid wheat. Pairing of homologous chromosomes was less frequent and weaker in such crosses than in T. aestivum/A. squarrosa crosses, but homoeologous bivalents occurred at a rate of almost 0.5 II per cell. Restitution division was detected in crosses involving all three diploid species and was confirmed cytologically in crosses with PI 355520. Chromosome numbers of BC1F1 plants ranged from 35 to 67; plants with 49 or more chromosomes occurred at frequencies of 0.09 to 0.21 among progeny of A. squarrosa and T. urartu and 0.29 in progeny of T. aestivum/T. monococcum crosses involving PI 355520. These results are consistent with those of previous studies, demonstrating the potential of direct Hexaploid/diploid crosses for rapidly introgressing useful genes into Hexaploid wheat with minimum disturbance of the background genotype.
Genetic Control of Five Isozyme Systems in Sugar Beet (Beta vulgaris L.)
Authors: Wagner H. , Wricke G. 
Published: April 2006

AbstractGenetic markers are most useful in plant breeding but so far only a few morphological and isozyme markers are known in Beta vulgaris. In this paper, the isozyme systems aconitase (AGO), NADH‐:dihydrolipoamiddehydrogenase (DIA), esterase (EST), fructose‐1,6‐bisphosphatase (FDP), and hexokinase (HK) were genetically analysed. Isoelectric focussing (IEF), vertical polyacrylamide gel electrophoresis (PAGE) and starch gel electrophoresis (SGE) were used to separate the isozymes. A total of eight loci could be identified. The allelic forms of Aco‐1, Dia‐1, Est‐1, Est‐5 and Hk‐1 are active monomers. The gene products of Est‐3 and Fdp‐2 are active as dimers. Est‐2 also showed allelic forms without activity; null‐alleles.
Methods for Selection of Low‐Temperature Tolerant Mutants of Chrysanthemum morifolium Ramat. Using Irradiated Cell Suspension Cultures III. Comparison of Mutants Selected with or without Preselection in vitro at Low‐Temperature
Authors: Huitema J. B. M. , Preil W. , De Jong J. 
Published: April 2006

AbstractOne hundred variants of Chrysanthemum morifolium cv. ‘Parliament’, selected on a single plant basis for early flowering at low temperature, were tested on a clonal basis. These variants originated from irradiated or non‐irradiated microcalli subjected to a one‐step greenhouse selection procedure, or, a two‐step selection procedure (preselection in vitro at 6°C followed by selection in the greenhouse). Clones originating from irradiated calli flowered significantly earlier than the controls. Most of the low‐temperature tolerant (LTT) mutants were found among plants obtained by the one‐step selection procedure. Variants originating from slowly regenerating calli yielded more LTT mutants as compared to those of fast(er) regenerating calli. We therefore conclude that, irradiation and subsequent selection of plants from slowly regenerating calli considerably increases the efficiency of selecting LTT mutants. The expected advantage of a preselection in vitro at low‐temperature could not be confirmed.
Genotype × Environment Interaction in the Andean Grain Crop Quinoa (Chenopodium quinoa) in Temperate Environments
Authors: Risi J. , Galwey N. W. 
Published: April 2006

AbstractTen varieties of quinoa with origins ranging from latitude 39° S to 12° S and from sea level to an altitude of 3,800 m were grown on two soil types in two years in Cambridgeshire, England, in order to assess the extent and nature of genotype × environment (G × E) interactions and identify genotypes suited for cultivation at temperate latitudes. There was evidence that varieties differed in their susceptibility to water logging during germination. Plant height was strongly influenced by competition with weeds, and varieties differed in their susceptibility to this. The number of days to anthesis and to maturity were strongly dependent on the variety, but these periods were generally longer following an earlier sowing. The grain yield was also strongly dependent on the variety, but weed competition, a micronutrient deficiency and bird damage affected the varieties differently. Varieties originating at high latitudes gave the highest yields, about 5,000 kg/ha. Earliness and yield were strongly associated at the level of variety means, but the pattern of G × E interaction differed among the variables measured.
Expected Response to Selection in Synthetic Populations of Perennial Ryegrass
Authors: Charmet Gilles , Ravel Catherine Grand 
Published: April 2006

AbstractConfidence intervals for heritability and expected genetic advance of seven agronomic traits in two populations of perennial ryegrass have been computed in two ways (a = bootstrap method; b = parametric method) for five different combinations of selection. Two conclusions can be drawn from our results:

Superiority of individual selection over family or every combination of selection.
Usefulness of methods based on resampling to estimate confidence intervals for genetic parameters without particular statistical hypotheses.
The Rate of Outcrossing in Grain Amaranths
Authors: Agong S. G. , Ayiecho P. O. 
Published: April 2006

AbstractStudies of intra specific and inter specific out crossing rates were carried out for grain amaranths using two populations of A. hypochondriacus (populations 1008 and 1024) and two populations of A. cruentus (populations 1034 and 434). The studies were conducted at Kabete Campus, University of Nairobi and National Horticultural Research Station, Thika, during the months April to August 1988 and October 1988 to February 1989. The mean intra specific out crossing rate estimates for A. hypochondriacus and A. cruentus were 10.4 % and 10.9 % respectively. The mean inter specific out crossing rate involving population 1024 as the dominant marker parent and 1034 as the recessive marker was 1.2 percent. The study involving population 434 as the dominant marker parent gave the mean inter specific out crossing rate as 6.5 percent. The intra specific and inter specific out crossing rate estimates showed substantial variation. Significant differences in out crossing rate estimates were noted due to locational and seasonal variations. The factors probably contributing to the variations were believed to be locational and seasonal differences in pollinator density and differences among the populations.
Inheritance of the Powdery Mildew Resistance Gene Pm9 in Relation to Pm1 and Pm2 of Wheat
Authors: Schneider Dorothee M. , Heun M. , Fischbeck G. 
Published: April 2006

AbstractThe inheritance of the powdery mildew resistance gene Pm9 originating from the hexaploid spring wheat cultivar ‘Normandie’ was analyzed in relation to Pm1 and Pm2.Two leaf segments of individual P1−, P2−, F1− and F2‐plants of the cross ‘Normandie’ (Pm1, 2, 9) ×‘Federation’ (no known Pm gene) were inoculated separately with two powdery mildew isolates. Using powdery mildew isolate No. 6 virulent for Pm1 and Pm2 but avirulent for Pm9, a 1 resistant (r): 3 susceptible (s) F2‐segregation was found for the Pm9 gene. Using powdery mildew isolate No. 3 virulent for Pm1 and Pm9 but avirulent for Pm2, a 3 (r): 1 (s) F2‐segregation was found for the Pm2 gene. Combining the data of both experiments (leaf segments of identical plants had been used), a 9 (sr): 3 (ss): 3 (rr): 1 (rs) segregation resulted for the F2 of this cross: therefore, independent inheritance of the genes Pm2 and Pm9 can be concluded.Similarly, the cross ‘Mephisto’ (Pm1, 2, 9) ×‘Amor’ (no known Pm gene) was analyzed. The Pm9 gene again showed a monogenically recessive inheritance, whereas Pm1 showed a monogenically intermediate segregation upon inoculation with powdery mildew isolate No. 9a virulent for Pm2 and Pm9 but avirulent for Pm1. Combining the single gene segregations, linkage between both genes was found among the progenies. A distance of 8.5 cM was calculated.Analyzing a set of spring wheat cultivars with seven defined powdery mildew isolates, the presence of Pm1, Pm2 and Pm9 in these lines was verified; in most cases, Pm1 occurred together with Pm9.
Improved Culture System for Microspores of Barley to Become a Target for DNA Uptake
Authors: Kuhlmann Ursula , Foroughi‐Wehr Bärbel , Graner A. , Wenzel G. 
Published: April 2006

AbstractFor the winter barley cultivar ‘Igri’, a microspore isolation and regeneration procedure is described which allows the production of such vigorous micro‐spore fractions that this single‐cell system can be used as a target for DNA uptake. Up to 60 % of the vigorous microspores isolated from the anther, and cultured in liquid modified MS medium, formed embryoids and/or calli. Such preparations were used for trials in DNA uptake with the plasmid pBI 221. Transformation trials were performed with polyethylene glycol as the inducing agent. With this treatment, a relative increase of fluorescence could be shown under UV light indicative of transient expression of the uidA gene.
Selection of Semidwarf, Early Maturing and Blast Resistant Mutants after Mutagenic Seed Treatment in Two Locally Adapted Indian Rice Cultivars
Authors: Bansal V. K. , Katoch P. C. 
Published: April 2006

AbstractThe objective of this study was to induce semidwarf, early maturing and blast resistant mutants in two adapted Indian rice cultivars. Seeds of the rice cultivars ‘Madhu Malti’ and ‘Phul Patas 72’ were treated with gamma rays and ethyl methane sulfonate (EMS) as well as a combination of gamma rays and EMS. A total of 96 dwarf (< 75 cm) and semidwarf (< 100 cm) and 104 early flowering/maturing M2 plants were identified among the 18,060 M2 plants observed. Sixty‐eight blast resistant M2 plants were also identified. The true mutant status of these plants has yet to be determined in progeny tests. The induction of desired mutant types in locally adapted cultivars could prove to be superior over their introduction from non‐adapted foreign materials via backcrossing in that the important agronomic characteristics of adaptation to the local environment are retained in the mutants.
Three‐Way and Four‐Way Recurrent Selection in Plant Breeding
Authors: Gallais A. 
Published: April 2006

AbstractThree or four‐way recurrent selection is proposed for the development of three or four‐way crosses. In term of genetic effects, it could be justified if there are interactions between more than three genes, whether alleles or not, if autopolyploids are also considered. For autotetraploids, in particular with tetragenic interaction, four‐way recurrent selection could be more effective than reciprocal recurrent selection (two‐way selection). According to the types of progenies used to develop the tests, different selection procedures are considered, the two extremes being called method 1 and method 3. With method 1 (selection for three or four‐way general combining ability) a plant from a population is used to produce three‐way or four‐way progenies with the other populations used as testers. With method 3 (selection for three or four‐way specific combining ability) three‐way or four‐way crosses are developed with one plant from each population. To study the genetic advance, the theory is developed to consider either diploidy or autotetraploidy. It is shown that method 3 will allow a greater genetic advance than method 1 for low heritability and low selection intensity. The way towards hybrid development with three and four‐way pedigree selection is discussed: again selection can be for general or specific three or four‐way combining ability. It is emphasized that an advantage of recurrent selection for three or four‐way specific combining ability is that it allows direct varietal development with pedigree selection on three or four‐way specific combining ability. Some other practical aspects are also considered.
A DNA Probe for Rapid Screening of Sugar Beet (Beta vulgaris L.) Carrying Extra Chromosomes from Wild Beets of the Procumbentes Section
Authors: Jung C. , Herrmann R. G. 
Published: April 2006

AbstractGenes from wild species of the Procumbentes section can be transferred to sugar beet chromosomes via translocations. Since large translocations, including for example a gene for nematode resistance, generally result in meiotic disturbances, there is a need to select new diploid resistant beets from progenies of monosomic wild beet addition lines. A dispersed repetitive DNA probe, which is closely correlated with the resistance gene and hybridizes exclusively with wild beet DNA, appears to be highly superior to selection based on isozyme markers. Characteristic ‘fingerprints’ on the available monosomic addition lines reveal the existence of at last 5 different chromosomes in the wild species each housing a gene for nematode resistance. This probe can be used advantageously to identify individuals carrying the intact or fragmented wild beet chromosomes, or even various amounts of translocated chromatin. Strategies are discussed for the identification of new translocation types using straightforward squash dot or Southern hybridization techniques in combination with the wild beet DNA probe.
Crosses Involving W. Rimpau's Triticale
Authors: Franke R. 
Published: April 2006

AbstractOne hundred years after the creation of the first true triticale crosses of Rimpau, several recent cultivars of triticale and rye have been crossed with two of them. Recombinants of the awned type of Rimpau's triticale (10) with ‘Grado’, ‘Lasko’ and ‘Otello’ exhibited a prolonged vegetative period, a shorter straw, an improved lodging resistance, good yielding capacity and higher disease resistance as compared to ‘Lasko’.
Cross‐Compatibility of Cultivated Adzuki Bean (Vigna angularis) and Rice Bean (V. umbellata) with Their Wild Relatives
Authors: Siriwardhane D. , Egawa Y. , Tomooka N. 
Published: April 2006

AbstractThe wild Ceratotropis species which occur in Japan consist of Vigna angularis var. nipponensis, V. nakashimae, V. riukiuensis and V. reflexo‐pilosa. The main aim of the present study is to detect cross‐compatibility of adzuki bean and rice bean with these wild relatives.The cross of V. nakasbimae with adzuki bean was successful in both directions and viable seeds were produced, while the cross with rice bean was not successful. V. riukiuensis is cross‐compatible with adzuki bean and rice bean only when V. riukiuensis is used as male parent and the hybrid seeds showed normal germination. The cross between V. reflexopilosa and the two cultigens adzuki bean and rice bean did not succeed in either direction.The present results suggest that V. nakashimae and V. riukiuensis could be used as gene sources for the adzuki bean breeding programme through interspecific hybridization. Successful hybrids between adzuki bean and rice bean cannot easily be produced. However, since V. riukiuensis is cross‐compatible with both adzuki bean and rice bean, V. riukiuensis could be useful as a bridge species between adzuki bean and rice bean.
Male Sterility in Barley
Authors: Singh R. B. , Kaul M. L. H. 
Published: April 2006

AbstractThe anther form and development of eight two‐rowed genie male sterile barley mutants are abnormal. The male sterility in each mutant is conditioned by single non‐allelic recessive genes. These mutant genes cause reductions in anther size and lumen diameter. Though in seven mutants, the male meiosis is normal until microspore liberation, the micro‐spores abort in all cases after release from the PMCs. In one mutant, the microspores degenerate at the tetrad stage before release from the PMCs. In four mutants, the tapetal development and disintegration are normal, in four others they are abnormal. Despite these variations, the male sterility in all the eight mutants is complete.
Determination of the Ploidy Level of Pure and Mixed Plant Populations of Sugar Beet (Beta vulgaris L.) by Flow Cytometry
Authors: Akinerdem F. 
Published: April 2006

AbstractTo improve estimates of the true ploidy level of pure diploid triploid, and tetraploid sugar beet (Beta vulgaris L.) plants, and of populations of mixed ploidy, the effect of leaf age/size was evaluated on ploidy determination by flow cytometry. There were significant differences between old and young leaves, with young leaves giving the best estimate of the true ploidy level of the plants. The old leaves seemed to express a high degree of endopolyploidy.
Evaluation of Potato Hybrids Obtained from Tetraploid‐Diploid Crosses I. Parent‐Offspring Relationships
Authors: De Jong H. , Tai G. C. C. 
Published: April 2006

AbstractA total of 45 tetraploid‐diploid (4x—2x) hybrid progenies were obtained by crossing each of ten diploid parents as males to each of five tetraploid parents. A relatively low degree of determination (R2) of both 4x and 2x parents on the performance of their 4x—2x hybrid progenies was found for all six traits studied. This implies that test crossing and subsequent progeny analysis is necessary before such parents can be used in a breeding program. Since marketable yield was found to have a higher predictability than total yield, it is the preferred yield trait to be measured. Diploids which produce 2n gametes via FDR usually give rise to 4x progenies with a greater amount of heterosis than similar progenies derived from diploids which produce 2n gametes via SDR, although such heterosis is not necessarily expressed in terms of marketable yield.