bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic Analysis of Production Characters in Lolium
Authors: Devey F. D. , Hayward M. D. , Kearsey M. J. , McAdam N. J. , Eggleston M. P. 
Published: April 2006

AbstractA Triple Test Cross and basic generations (i.e. inbred parents, F1′s, F2′s and backcrosses) have been used to investigate the genetics of dry matter yield in a population of Lolium perenne. Two trial designs, short, individual plant drills and larger sown plots were used at each of two sites in the U.K., at Aberystwyth and Birmingham. The families studied correspond to those raised as spaced plants and reported in the first paper in this series. In contrast to the spaced plants trial, the drill trial resulted in considerable epistasis as well as additivity and dominance variation whilst the plot trial failed to identify any significant genetic variation. There was considerable G × E interaction over sites and harvests, particularly in the amount of dominance. The latter showed a clear linear relationship with mean performance at both sites, the dominance ratio being higher in the poorest environments. This is largely due to the additive variance decreasing in the poor environments rather than the dominance being higher. The implications of these results to grass breeding are discussed.
Die Nutzung der Antherenkulturmethode im Zuchtprozeß von Winterweizen
Authors: Müller G. , Vahl U. , Wiberg A. 
Published: April 2006

AbstractThe use of anther culture in breeding winter wheat.II. Production of new doubled haploid lines of winter wheat with 1AL—1RS‐translocationA total of 4472 anhers was cultured from 8 F1 populations of winter wheat with the 1AL—1RS wheat‐rye translocation cultivar ‘Amigo’ as one of the crossing arents. When averaged over all populations a frequency of embruoid formation of 10% and of regeneration efficiency of green plants of 1% were observed. In addition to the 45 green regenerated plants, 93 albinos were obtained. 44% of the green plantlets had 21 chromosome in root tips and 29% were spontaneous diploids. Multiple peroxidases were used a biochemical markers in the subsequent characterization of the homogeneous breeding material. The electrophoretic patterns showed that 16 doubled haploids without rye chromosome segments were produced. In addition the features of dh0‐ plants showed, that several of the new 1AL—1RS‐translocation lines were awnless.
Inheritance of Resistance to Pseudomonas solanacearum E. F. Smith in Tetraploid Potato
Authors: Tung P. X. , Th. Hermsen J. G. , Vander Zaag P. , Schmiediche P. E. 
Published: April 2006

AbstractInheritance of bacterial wilt resistance in tetraploid potato was investigated in segregating progenies of parent clones with resistance derived from different specific sources and different types of adaptation. A race 1 and a race 3 isolate of Pseudomonas solanacearum were used to test the resistance under warm temperatures. Results obtained indicated partial dominance of resistance. Significant general and specific combining abilities showed that both additive and non‐additive gene actions are important in conditioning resistance expression. There was evidence that epistasis is an important component of the non‐additive gene action in the inheritance of resistance. Other aspects of the resistance and implications for breeding are discussed.
Efficiency of Recurrent Selection Methods to Improve the Line Value of a Population
Authors: Gallais A. 
Published: April 2006

AbstractFive breedings methods have been studied for their efficiency in improving the line value of a population, i.e. the value of all lines that can be derived from the population. These methods are: half‐sib family recurrent selection (HSF‐RS), full‐sib family recurrent selection (FSF‐RS), half‐sib progeny recurrent selection (HSP‐RS), recurrent selection (S1‐RS) and the single‐doubled‐haploid descent recurrent selection (SDH‐RS). All breeding methods are compared on the basis of the genetic advance per unit of time, with the constraint of the same effective size after the first cycle of selection. Two modalities of SDH‐RS are considered for an annual plant without an off‐season generation: one with a cycle in four years (SDH1‐RS) and the other with a cycle in five years (SDH2‐RS). For all methods the possibility of one off‐season generation for intercrossing is considered. Fields of efficiency of the best methods are determined considering five main parameters, the heritability, the importance of additive variance, the correlation QL between the additive effect for line value and the additive effect for the per se value, the length of the cycle for SDH‐RS and the selection intensities. SDH‐RS is the best method when the heritability is low, with a low proportion of additive variance and with a relatively low correlation QL between additive effects for per se and line values. Without off‐season generation, S1‐RS is the best method among the remaining realistic situations; with one off‐season generation for intercrossing it is FSF‐RS. The use of an off‐season generation reduces the domain of efficiency of SDH‐RS while an increase in the selection intensity increases this domain. With a selection intensity for SDH‐RS equal to that for S1‐RS, SDH‐RS is the best in a large range of realistic situations except for SDH2 with one offseason generation and medium to high correlation QL.
Prolamin Analysis of Progenies from Androgenetic Plants of Triticale
Authors: González J. M. , López L. A. , Bernard S. , Jouve N. 
Published: April 2006

AbstractThe present work reports results of the analysis of variability of prolamins in five breeding lines of triticale and 61 androgenetic progenies obtained from them by in vitro culture of the anthers. The phenotypic analysis of the prolamins showed heterogeneity even between seeds harvested from the same plant regenerated by in vitro culture. The variability of prolamins in this material could be, perhaps, explained under different hypotheses: unreduced microspores, embryo fusion. The percentage of androgenetic plants which generated uniform progenies for the prolamins was 14.7. The plants obtained by in vitro culture showed a significant increase of the phenotypic variability for both specific bands and patterns of prolamins as compared with the parental materials. Some plants showed missing groups of prolamins in their electrophoretic profiles, which completely affected specific regions of the proteinogram. This could be explained by gametoclonal variation based on either structural rearrangements, or aneuploidy affecting chromosomes carrying genes involved in the expression of prolamins.
Natural Genes and Mechanisms for Resistance to Viruses in Cultivated and Wild Potato Species (Solanum spp.)
Authors: Vaikonen Jari P. T. 
Published: April 2006

AbstractThe types of resistance to viruses in potato are immunity, extreme resistance coded for by the R genes and hypersensitivity coded for by the N genes. Immunity prevents the establishment of virus infection, whereas extreme resistance is expressed as an extremely low virus titre resulting from restricted virus multiplication or localization of virus infection in the plant without obvious necrotic reactions. Expression of the N genes can also lead to localization of the virus infection followed by necrosis at the infection site. Tolerance to virus infection and resistance to inoculation and virus vectors are useful components of field resistance. Virus or virus strain specific resistance genes have been identified in cultivated and wild potato species and transferred to cultivated potato. However, combining resistance to the three globally most important viruses PLRV, PVY and PVX has proved difficult, and new sources of broad spectrum resistance to viruses are required for potato breeding. New molecular techniques will enhance the isolation of the natural resistance genes and studies of gene regulation.
Falling Number and Alpha‐Amylase Activity in Developing Grain of Alloplasmic Hexaploid Wheat
Authors: Oettler Gitta , Mares D. J. 
Published: April 2006

AbstractTwelve fertile alloplasmic wheat lines, produced by substituting four nuclear genomes of Triticum aestivum into the cytoplasms of T. timococcum Kostoff, T. timopheevi Zhuk., and Aegilops ventricosa Tausch, were examined for cytoplasmic effects on falling number and α‐amylase activity during grain development in different environments. Nuclear genome, cytoplasm and environment were important sources of variation for falling number. In one environment, where the plants were exposed to very hot, dry conditions, the levels and patterns of change in α‐amylase activity were also significantly affected by the cytoplasm. The data indicated that alien wheat cytoplasms might result in useful additional variation in specific environments where sprouting is a problem.
Effect of Sugars in Wheat Anther Culture Media
Authors: Navarro‐Alvarez W. , Baenziger P. S. , Eskridge K. M. , Shelton D. R. , Gustafson V. D. , Hugo M. 
Published: April 2006

AbstractSugars are critical components in bread wheat (Triticum aestivum L.) anther culture media for successful somatic embryo initiation and plant regeneration. In this experiment, anthers from three wheat genotypes were cultured on a modified Liang's 85D12 initiation medium with seven sugar combinations (I‐sugars: galactose, mannose, maltose, fructose, sucrose, glucose, maltose + glucose) at 0.26 M, and 2,4‐dichlorophenoxyacetic acid (2 mg/L), 1‐naphthalene acetic acid (1 mg/L), and glutamine (254 mg/L). Wheat starch (5 % W/V), a potential source of sugars, was used as the medium gelling agent. No previous research has studied the effect of different sugars with wheat starch. A split‐plot experimental design with 42 replications was used with genotypes as whole plots and sugar combinations as subplots. Galactose and mannose did not support embryoid initiation and were dropped from the analysis. Averaged over the three genotypes, maltose was the best sugar (105 embryoids/100 anthers), followed by glucose (47 embryoids/100 anthers) and maltose + glucose (37 embryoids/100 anthers). These three sugar combinations were superior to the standard medium sugar, sucrose (24 embryoids/100 anthers), and to fructose (12 embryoids/100 anthers). The embryoids were divided into two groups for plant regeneration. The first group was transferred to regeneration medium (Liang 85D12 salts, sugars at 0.06 M, and wheat starch at 7 % w/v as gelling agent) with the same sugar (R‐sugar) used as in initiation. The second group was transferred to regeneration media with sucrose. I+R‐maltose (0.55)
Resistance to Karnal Bunt (Tilletia indica Mitra) in Synthetic Hexaploid Wheats Derived from Triticum turgidum×T. tauschii
Authors: Villareal R. L. , Mujeeb‐Kazi A. , Fuentes‐Davila G. , Rajaram S. , Del Toro E. 
Published: April 2006

AbstractSynthetic hexaploids (SH) developed at the International Maize and Wheat Improvement Center (CIMMYT), involving four Triticum turgidum and nine T. tauschii parents, were evaluated for resistance to Karnal bunt (KB) (Tilletia indica Mitra) during three crop seasons over three years at Ciudad Obregon, Sonora, Mexico. Ten tillers of each SH at boot stage, taken at random, were injected with a suspension of sporidia in water (10,000 spores/ml of water). At maturity the inoculated spikes were threshed individually and evaluated for the percentage KB‐infected grains. Based on the mean KB score of each entry for three seasons, 49 % of the SH were immune (0 % infection) to KB. Highly resistant expressions characterized the SH which appeared to be influenced by the resistance of their T. turgidum and/or T. tauschii parents. The overall mean infection of the SH wheats was 0.24 % compared to 56.14 % in the susceptible bread wheat check cultivat ‘WL711’. Transfer of KB resistance genes from SH wheats into bread wheat is currently underway at CIMMYT.
Main Factors Affecting Cucumber (Cucumis sativus L.) Haploid Embryo Development and Haploid Plant Characteristics
Authors: Przyborowski J. , Nlemirowicz‐Szgzytt K. 
Published: April 2006

AbstractThis report gives the first detailed analysis of cucumber haploid plants and the first evaluation of genotype and season effects on haploid embryo development. Female flowers of four F1 varieties and two inbred lines were pollinated with 300 Gy‐treated pollen and three‐week old embryos were cultured in vitro on E20A medium. The variety ‘Polan’ produced the greatest number of embryos (1.34 per 100 seeds), 51 % of which were capable of further development. The number of embryos able to develop was four times higher in summer than in spring. All the plants obtained, except one, were haploids or aneuhaploids. Haploid plants grew slowly and were sterile, although they occasionally set seedless fruits. The length of the stems, leaves and guard cells was smaller than those of diploids.
Heritability, and Intra‐ and Inter‐Generation Associations Between Tuber Yield and its Components in Potato (Solanum tuberosum L.)
Authors: Gopal Jai , Gaur P. C. , Rana M. S. 
Published: April 2006

AbstractThe relative importance of the components of tuber yield in selection in early generations of a potato‐breeding programme was studied. In seedling generation the number of tubers were more important than average tuber weight, whereas in clonal generations the average tuber weight was more important. Correlation coefficients between number of tubers and tuber yield varied from generation to generation whereas those of average tuber weight and tuber yield were more or less constant. Unlike the number of tubers, the average tuber weight of a genotype in a generation influenced its tuber yield in subsequent generations. The average tuber weight had higher heritability than the number of tubers and tuber yield.
Regeneration of dihaploid chicory (Cichorium intybus L. var. foliosum Hegi) via microspore culture
Authors: Theiler‐Hedtrich R. , Hunter C. S. 
Published: April 2006

AbstractIn order to develop fully inbred chicory plants, dihaploid plants were raised from callus derived from microspores of three selected Witloof, Robin and Treviso types. Microspores were isolated from florets containing pollen at the uninuclear state and cultured in a modified MS medium plus 0.5mg/l 2,4‐D, 0.5mg/l IAA and 2.0mg/l zeatin. During culture periods of up to 6 months, gametoplasts emerged from pollen grains, divided and started to form colonies and calli. These were subcultured on the same basal medium supplemented with 0.5mg/l BA and 0.5mg/l IAA. Shoot growth was enhanced on a low salt‐containing medium supplemented with 0.4mg/l kinetin and 0.2mg/l IAA. Shoots were rooted on a half‐strength Lepoivre medium plus 0.2mg/l IBA and finally transferred to soil. Florets were excised from 34 capitula, but only microspores from four of them developed into plants via callus. More than 450 plants were raised in the greenhouse and the field. Leaves from these plants were subjected to DNA fluorescence analysis via flow cytometry: a range of ploidy levels was detected. The cell composition of 44 of these plants was predominantly haploid, with a diploid background. Regenerant plant phenotypes were compared with the parent genotypes. The value of such haploids in commercial chicory breeding is discussed.
Endopeptidase polymorphism and linkage of the Ep‐D1c null allele with the Lrl9 leaf‐rust‐resistance gene in hexaploid wheat
Authors: Winzeler M. , Winzeler H. , Keller B. 
Published: April 2006

AbstractThe aim of this study was to test whether the null allele Ep‐D1c of the endopeptidase Ep‐D1 can be used as a marker for the Lrl9 leaf rust resistance gene. The frequency of Ep‐D1c was determined in 1134 winter wheat, spring wheat and spelt breeding lines and varieties. Only eight lines were found to carry Ep‐D1c. Six of these lines originated from crosses with RL6040, the gene donor for Lrl9. The other two lines were leaf‐rust susceptible in the seedling stage and therefore did not carry Lr19. The genetic distance between Ep‐D1c and Lr19 was determined in a reciprocal cross between the lines FAP75184 (Ep‐D1c, Lr19) and FAP75106 (Ep‐D1a, leaf‐rust susceptible in the seedling stage). Out of 840 F2 seedlings screened, 162 were homozygous for Ep‐D1c. From 150 of these F2 plants, F3 seedlings were screened for segregation for leaf‐rust resistance with isolates avirulent on Lr19. Only one F2 plant produced susceptible F3 progeny indicating a recombination event between Ep‐D1c and Lr19. From these data, a genetic distance of 0.33 ± 0.33cM between Ep‐D1c and Lr19 was calculated. The results show that Ep‐D1c is a useful marker for a practical breeding programme allowing the rapid identification of plants homozygous for Lrl9.
Comparison of doubled haploid lines and F2 bulks for the improvement of barley in the dry areas of North Syria
Authors: Mayer M. , Gland A. , Ceccarelli S. , Geiger H. H. 
Published: April 2006

AbstractDrought stress is the main factor limiting barley yields in West Asia and North Africa. This study compares the utility of doubled haploid lines (DHLs) and conventional F2 plant‐derived bulks (F2Bs) in improving barley in stress environments. Double crosses were made, DHLs were developed by anther culture from double‐cross F1 plants, and F2Bs were produced by bulking the offspring of F2 plants. Field tests were conducted in three drought‐stressed environments. No major differences were observed in the mean performance of DHLs and F2Bs. For most traits, both the genotypic and the genotype × location interaction variances were higher in the DHL group, whereas heritabilities were similar. Higher gains from selection were predicted for the DHL group. Regression analysis of yield stability indicated a lower predictability of the DHL performance. The haploid technique can improve breeding populations from which varieties with stable yields can be developed. The costs involved are determined by the DHL production rate, which needs to be improved in many developing countries.
Effects of plot type on detection of quantitative‐trait‐locus effects in barley (Hordeum vulgare L.)
Authors: Iyamabo O. E. , Hayes P. M. 
Published: April 2006

AbstractHill plots offer advantages in testing large germplasm arrays with limited area and seed. However, the relationship of trait expression between hill vs. row plots remains in question. The development of quantitative‐trait‐locus (QTL) analysis offers alternative methods of testing hypotheses regarding levels of coincident gene effects in divergent plots. The objective of this study was to compare hill and row plots in terms of QTL detection, number of common QTLs and plot‐type‐specific QTLs for various characters in barley. Assessments were based on sets of 100 F1‐derived doubled haploid progeny from two environments of hill‐plot data and two sets of multiple‐environment row‐plot data. Common large‐effect QTLs for height, heading date, and 1000‐kernel weight were detected in both plot types. Fewer QTLs were detected in the hill‐plot data, with only one QTL detected for grain yield. There were no hill‐plot‐specific QTL effects. Hill plots appear to be best suited to highly heritable characters such as height, heading date, and 1000‐kernel weight. Evaluation of grain yield is best deferred until larger experimental units can be employed.
Studies of the intraspecific competition and performance of chance‐hybrids in Lotium multiflorum Lam.1
Authors: Stelling U. 
Published: April 2006

AbstractIn order to study the effects of competition on the genotypic composition of chance‐hybrids in Loliuni multiflorum, eight chance‐hybrids were produced according to Burton (1948). Inbred lines and cultivars were used as parents. The proportions of parental and hybrid components in the seeds and growing‐field stands of the chance‐hybrids were determined over three cuts using gel electrophoresis. The realized hybrid proportions in the seeds, at a maximum of 38.3%, were considerably lower than the theoretically expected 50%. In the field stands, the hybrid proportions of the chance‐hybrids derived from inbred lines increased considerably and continously over cuts, whereas those of the chance‐hybrids produced from cultivars increased only slightly. A maximum hybrid tiller proportion of 76.8% was found at the third cut. Correspondingly, the total yield of the chance‐hybrids produced from cultivars was only slightly higher than that of the parents. The production of chance‐hybrids, therefore, proved to be sensible only if inbred lines had been used as parents.
Tapetal behaviour, gene action and breeding value in male‐sterile peas
Authors: Nirmala C. , Kaul M. L. H. 
Published: April 2006

AbstractEight non‐allelic male‐sterile mutants controlled by a single recessive gene were induced in garden pea (Pisum sativum) after EMS, DES and gamma‐ray‐mutagen treatments singly and in combination. These mutants differ in the time and type of tapetal development due to differential action of male‐sterile (ms) genes over the sporogenous and non‐sporogenous anther tissue. In the msg1 mutant, the sporogenous tissue breaks down during premeiosis, followed by tapetal degeneration. In msg2, sporogenous tissue and tapetal tissue exhibit anomalies at early and late prophase 1, respectively. Although in msg3 and msg5 the ms gene action over sporogenous tissue initiates during early and late prophase, respectively, the tapetal tissue breaks down during post‐meiosis. In msg6, anomalies in the sporogenous tissue appear during prophase II, but the tapetum degenerates during the mononucleate stage. Although both the tapetal and sporogenous tissue anomalies appear simultaneously at pachytene in msg4, the tapetal breakdown is delayed until the microspore stage. In msg7 and msg8, anomalies in both these tissues occur simultaneously during the tetrad and post‐meiotic stages, respectively. Despite differences in the timing of tapetal and sporogenous tissue breakdown, tapetal development is normal in msg1, msg5, msg6, msg7 and nisg8 but abnormal in msg2, msg3 and msg4. The ms gene action is dual in msg2, msg3 and msg4 but single in msg1, msg5, msg6, msg7 and msg8. In all these mutants, the time of tapetal anomaly exhibits no correlation with the time of ms gene action. The gene for open flower found in one male‐sterile mutant needs to be introduced into fertile peas for commercial hybrid‐pea breeding.
Chromosomal location of genes affecting tissue‐culture response in wheat
Authors: Amer I. M. Ben , Worland A. J. , Börner A. 
Published: April 2006

AbstractSix ‘Chinese Spring/Triticum spelta’ substitution lines for chromosomes 1A, 1D (duplicates), 3D (duplicates), 6D, and one ‘Chinese Spring/ Marquis’ substitution line for chromosome 2B were studied for tissue‐culture response (TCR). The results reported here indicate that chromosomes 2B and 6D are critical for TCR, whereas chromosome ID affects callus weight only. Chromosomes 1A and 3D were not found to be critical, however, these chromosomes may carry genes with minor effects.
Identification and cytological analysis of 2n‐pollen producers in Lotus tennis Wald. et Kit.
Authors: Negri V. , Lorenzetti S. , Lemmi G. 
Published: April 2006

AbstractTwo meiotic mutants of L. tennis (2n = 2x = 12) producing unreduced pollen are described. When crossed to male sterile L. corniculatus (2n = 4x = 24) plants, all progeny plants were morphologically similar to L. corniculatus, had 2n = 24 chromosomes, and in the cross, were fully compatible with L. corniculatus, indicating that the male parent plants were 2n‐pollen producers. One of them also had ‘giant’ pollen grains. In metaphase II of both genotypes, there were parallel and tripolar spindles leading to dyad and triad formation, the latter being found most frequently. Since both the above‐mentioned mechanisms result in first‐division restitution‐type microspores, the genotypes examined could be useful in breeding Lotus.