bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development Traits Affecting Time to Low Ear Moisture in Maize
Authors: Newton S. D. , Eagles H. A. 
Published: April 2006

AbstractA diallel cross of six inbred lines of maize (Zea mays L.) from the Corn Belt of the USA and one inbred line (NZ1A) with characteristics of maize from the highlands of Mexico was grown in a cool, temperate environment. The objective was to investigate interrelationships and combining abilities of plant development traits likely to influence the time required to reach low ear moistures in the field. The traits were days to silking, days to physiological maturity, ear moisture at physiological maturity, grain filling duration and ear drying rate after physiological maturity. Grain yield and grain moisture at harvest were also considered.Differences among the hybrids of this diallel cross for ear and grain moisture at the usual harvest time were largely determined by differences in ear drying rate after physiological maturity, and not by differences in days to silking, days to physiological maturity, or in ear moisture at physiological maturity. General combining ability (GCA) effects were much larger than specific combining ability (SCA) effects for all traits. NZ1A had positive GCA effects for grain filling duration and negative GCA effects for ear moisture at physiological maturity which were outside the range of the Corn Belt lines suggesting that this line, or similar Mexican germplasm, could be useful for developing hybrids with high grain yields and low ear moistures at harvest in cool, temperate environments.
The Effect of Chromosome 1B/1R Translocation on the Yield Potential of Certain Spring Wheats (Triticum aestivum L.)
Authors: Villareal R. L. , Rajaram S. , Mujeeb‐Kazi A. , Del Toro E. 
Published: April 2006

AbstractNearly 50 percent of the 1988 advanced breeding lines of the CIMMYT bread wheat breeding program possess the 1B/1R homozygous translocation. Hence, a trial was conducted to estimate the effect of 1B/1R chromosome translocation on the yield potential of some of our high‐yielding spring wheats, where non‐limiting levels of fertility, moisture, preventive pest and disease programs were used. In conclusing the 1B/1R lines seemed to have increased their above‐ground biomass yield, number of spikes per meter2, 1000‐grain weight and test weight. They also exhibited a slight advantage over the 1B homozygous lines on grain yield. The observed difference, however, was non‐significant, as was the plant height difference observed among the two groups. Varietal comparisons indicated that the 1B/1R group headed later than the 1B group.
Breeding of Polyploid Asparagus (Asparagus officinalis L.)
Authors: Skiebe K. , Stein M. , Gottwald J. , Wolterstorff B. 
Published: April 2006

AbstractAsparagus is especially suitable for polyploidy breeding. The aim is to develop clone‐based hybrid varieties, in particular male 4 × varieties. For this purpose, genetically divergent diploid idiotypes*) are subjected to mitotic or meiotic polyploidization. In developing hybrid partners, special attention is paid to resistance in addition to yield and quality characters. Early diagnoses are applied in selection so as to shorten breeding times. Somaclonal variations may occur relatively often on in vitro propagation; these need to be eliminated. Triplex and quadruplex type males are suitable for paternal hybrid partners. Strong inbreeding depressions need to be avoided in their production.
An Economic Investigation of Early‐Generation Quality Testing in a Wheat Breeding Program
Authors: Brennan J. P. , O'Brien L. 
Published: April 2006

AbstractPublic plant breeders, in seeking the most efficient means of achieving their objectives, face decisions on the appropriate breeding strategy and program structure to use. This paper reports an analysis comparing the changes in costs and benefits from the introduction of recent technology enabling testing for flour and dough properties to be carried out on small samples in the early‐generations of a wheat breeding program in Australia. The average costs of a suite of early‐generation tests are higher than the equivalent (unreplicated) yield testing. The analysis presented confirms that the introduction of early‐generation quality testing leads to a faster rate of expected progress in quality, but a slower rate of progress in yield. The estimated market value of an increase in yield is greater than that for quality, based on current market information. Thus, the result of incorporating early‐generation quality testing is higher costs and lower expected returns, so that there is a loss of community welfare from using early‐generation quality testing if the resultant cultivar is released from each program. However, the probability of the higher‐quality cultivar being released for commercial cultivation is greater, so that recognition of the probability of release means that there may be net gains from the use of early‐generation quality testing.
Identification of a Monogenic Dominant Male Sterility Mutant in Broccoli (Brassica oleracea var. italica Plenck)
Authors: Dunemann F. , Grunewaldt J. 
Published: April 2006

AbstractAfter mutagenic treatment with NMU (nitroso‐methylurea) flower buds and flower‐bud pedicels of broccoli were cultivated in vitro. Among regenerated MJ plants, one male sterile, but female fertile mutant was found, for which a monogenic dominant inheritance of male sterility was demonstrated. A scheme to utilize dominant controlled genie male sterility in Brassica oleracea for hybrid breeding is discussed.
The Use of RFLPs (Restriction Fragment Length Polymorphisms) Detects Germplasm Introgressions from Wild Species into Potato (Solanum tuberosum ssp. tuberosum) Breeding Lines
Authors: Debener T. , Salamini F. , Gebhardt Christiane 
Published: April 2006

AbstractThe germplasm of the potato (S. tuberosum ssp. tuberosum) has been modified since the beginning of this century by breeders who introgressed important agronomic traits, for example disease resistance genes, from several wild and cultivated Solanum species of the Americas. In this paper we show that the Rflp analysis of potato‐breeding material can be used to detect chromosomal regions descended from more‐distantly related Solanum species. The Rflp patterns of individuals of ten Solanum species, ten breeding lines of S. tuberosum ssp. tuberosum and the cultivated variety ‘Bintje’ were analyzed. Rflp data for each of eight single loci of known genomic position were used for the computation of locus‐specific phenograms by distance matrix methods. Several of the potato‐breeding lines deviated clearly from the clustered species S. tuberosum, S. stenotomum and S. canasense for one or more of the loci considered. These deviations indicated the presence of “exotic” germplasm at a particular locus. The possibility of detecting such germplasm has implications for mapping the agronomic traits for which the wild species were introgressed and which may still be linked to “foreign” chromosome fragments.
High Frequencies of Fertilization and Haploid Seedling Production in Crosses Between Commercial Hexaploid Wheat Varieties and Maize
Authors: Laurie D. A. , Reymondie Sylvie 
Published: April 2006

AbstractNineteen commercial hexaploid wheat varieties were crossed with the maize F1 hybrid ‘Seneca 60’. Fertilization frequencies ranged from 32.1 % to 47.5 % of pollinated florets (mean 39.5 %) in the 14 winter wheat varieties and from 40.7 % to 51.4 % (mean 47.8 %) in the five spring wheat varieties. In some cases only an endosperm was formed and the frequencies of embryo formation were therefore slightly lower, being 28.2 % to 45.9 % (mean 36.4 %) for winter wheats and 39.8 % to 48.6 % (mean 45.1 %) for spring wheats. Mean values were significantly higher in the spring wheats but no significant variation was found between varieties within the spring or winter categories. In the five spring wheats the mean yield of embryos, and hence the potential yield of haploid plants, was 3.4‐fold higher than with the tetraploid Hordeum bulbosum clone PB179. For the 14 winter wheats the figure was 10.9‐fold higher. These differences were highly significant (p < 0.001) in all varieties. A single 2,4‐D treatment given to spikes one day after pollination with maize enabled embryos to be recovered from all 19 varieties. A total of 311 embryos were recovered from 950 florets (an average of 7.3 embryos per spike) of which 191 germinated, giving an average yield of one haploid plant for every 5.0 florets pollinated (4.4 haploid plants per spike).
Genome Size Variation in Maize Populations Selected for Cold Tolerance
Authors: McMurphy L. M. , Rayburn A. Lane 
Published: April 2006

AbstractPrevious studies have indicated a relationship between genome size and cold tolerance in plants. Many species adapted to growth in cool environments have large genome sizes. These studies are based on interspecific DNA content variation. In this study, the nuclear DNA content of eight maize populations was determined. These populations were obtained from the University of Nebraska and represent populations selected for cold tolerance and their respective unselected original populations. Intraspecific DNA content variation was observed between the selected and unselected populations. Upon assessing the data based solely on cold tolerance, no clear relationship between genome size and cold tolerance was apparent. When both freeze tolerance and cold tolerance were considered, populations which were cold tolerant and exhibited a certain degree of freeze tolerance were observed to have significantly larger genomes relative to the unselected populations. Thus, it appears that the relationship between intraspecific genome size variation and cold tolerance is similar to the relationship between interspecific genome size variation and growth at cooler temperatures in plants.
Quantitative‐Genetic Basis of Sprouting Resistance in Rye
Authors: Wehmann Frauke , Geiger H. H. , Loock A. 
Published: April 2006

AbstractThe quantitative‐genetic basis of sprouting resistance in winter rye (Secale cereale L.) was investigated in order to facilitate breeding for improved baking quality. Crosses within and between the Petkus and Carsten gene pools were tested along with the parental lines over two locations, two years, and two harvest dates. Heritabilities of approximately 0.6 were found for falling number (FN), a‐amylase activity, dormancy, and amylograph curve characters. FN showed moderate heterosis that reached 35%. High genetic variation for FN was observed in most genetic materials, and error variances were generally small. Considerable genotype × year interactions occurred. Genotypes with high FN showed more instability for FN over environments. General combining ability was the main source of genetic variation for FN (80%) and was correlated with line per se performance in the Carsten gene pool (r = 0.66). FN showed moderate to strong correlations with slowness of development, but only loose ones or none with other agronomic traits. We conclude that improving sprouting resistance by selecting for FN should be highly effective and would not cause unfavourable side effects with regard to yielding performance.
Germplasm Assessment in Trifolium Species
Authors: Fay M. F. , Mytton L. R. , Dale P. J. 
Published: April 2006

AbstractPopulations of 64 taxa of Trifolium were assessed for nitrogen fixation and dry matter production with and without added mineral nitrogen. The number of rhizobia per gram of compost capable of inducing nodulation was tested in 7 species and ranged from 3 to 114, showing interspecific variation for nodulation with indigenous rhizobia. In a sample of 8 species, nitrogen fixation was assessed by acetylene reduction and nodule scoring. There was a good correlation (84 %, P ≤ 0.01) between the two methods, and therefore nodule score was used as a measure of nitrogen fixation in the main assessment. There were large differences between populations in terms of shoot and root dry weight, the shoot: root ratio and nodule score. Added nitrate had a significant effect on all characters, increasing shoot dry weight and the shoot: root ratio and decreasing root dry weight and the nodule score. Results showed the importance of assessing legume germplasm with and without added nitrate in locations where suitable rhizobia for the nodulation of exotic species might not be present.
Variabilité Génétique de Certains Paramètres de la Qualité Brassicole de l'Orge
Authors: Garcera L. , Sarrafi A. , Jestin L. , Ecochard R. 
Published: April 2006

AbstractGenetic Variability for Some Brewing Quality Characters in Barley Malting and brewing quality of six different barley genotypes and their F1 hybrids were investigated in a diallel cross programme. Plants were grown in pots in a randomized block design with four replications. General and specific combining abilities were determined for 1000 grain weight, percentage of proteins of the grain, percentage of water uptake, and, after micromalting, for β‐glucanase and α‐amylase activities. Significant general and specific combining abilities were observed for all the traits studied. 1000 grain weight, percentage of proteins and water uptake have been found to be essentially controlled by genetic additive effects, while enzymatic activities of malt have been found to be mostly controlled by dominance effects. ‘Karl’ has interesting characteristics for all traits and general combining abilities, except for 1000 grain weight, and has been introduced in a three‐way cross programme with ‘Plaisant’ and ‘Clarine’, also showing interesting values for malting quality and productivity.
Analysis of Factors that Influence Kernel Weight of Wheat Infected by Septoria nodorum
Authors: Scharen A. L. , Lund R. E. , Dietz‐Holmes M. E. 
Published: April 2006

AbstractSeveral methods for determining yield reduction resulting from Septoria nodorum blotch have appeared in the literature during the past decade. These methods varied from the measurement of effects of disease on components of yield to calculation of area of symptoms on certain leaves at different growth stages. We analyzed data from a uniform group of wheat entries in the USDA Septoria nursery that had been grown in seven locations in North America and Europe during the years 1982–1987. Symptom severity and height of symptom on the plant were compared to kernel number and kernel weight. Location, year‐within‐location and genotype were also considered. In the context of this study, we concluded that location, and year‐within‐location are the most important factors determining yield reduction (as measured by relative kernel weight). Selection directly for components of yield is quite effective, but selection by means of disease symptoms is often not correlated with yield. We also conclude that specific methods for relating symptoms to yield reduction that are applicable to a particular location are probably useful and appropriate for that location only.
Genetic Variation of the Content of Sinapoyl Esters in Seeds of Rape, B. napus
Authors: Kräling K. , Röbbelen G. , Thies W. 
Published: April 2006

AbstractA broad spectrum of rapeseed (rape) lines as well as resynthesized (resyn) genotypes of B. napus were analyzed for their contents of sinapoyl esters. In the rape material the concentrations varied between 17.8 and 71.9 μol/g defatted seed meal and exhibited a heritability of h2= 0.6. The resyn genotypes showed an even smaller variation but had a similar heritability. Therefore, no additional, immediately usable, genotypes with low sinapoyl ester concentrations could be created by a resynthesis.
A Simple Device to Prepare Single Ears of Spelt (Triticum spelta L.) for Seeding with the “Seedmatic‐System”
Authors: Bleiker Ursula , Winzeler H. 
Published: April 2006

AbstractSpelt is usually planted as spikelets. These cannot be obtained by the threshing machines generally used for bread wheat. With a simple device it is possible to separate single ears of spelt into spikelets ready for sowing. At the same time, it is possible to score the fragility of the rachis and the degree of free thresh‐ability, both important characteristics for the selection of spelt.
Associations between 23 Quantitative Traits and 10 Genetic Markers in a Barley Cross
Authors: Kjaer B. , Haahr V. , Jensen J. 
Published: April 2006

AbstractAssociations of 23 quantitative traits and 10 genetic marker characters were examined in 63 chromosome‐doubled lines (DH‐lines) derived from the F1‐ generation of a cross between an old and a modern spring barley variety. One fourth of the marker × trait combinations showed significant associations. More than two thirds of these associations were to earliness (heading date). Earliness was found to be controlled by two loci: the previously known eak locus and a new locus designated Ea. It is concluded that the associations of quantitative traits with the earliness loci were caused by pleiotropy. Associations were found between two absolutely linked C‐bands on chromosome 3 and QTLs (quantitative trait loci) for lodging, straw diameter, and length of top internode of the straw. The three loci on chromosome 5, eak and the two linked powdery mildew loci, Mla9 and Mlk, were associated with a possible QTL for magnesium concentration in grain. Association to the C‐band on chromosome 6 suggests QTLs for TGW (thousand grain weight), straw diameter and magnesium concentration in grain. Locus Estl on chromosome 3 was not associated with any of the quantitative traits.
A New Intergeneric Hybrid between Triticum aestivum L. and Agropyron fragile (Roth) Candargy: Variation in A. fragile for Suppression of the Wheat Ph‐Locus Activity
Authors: Ahmad F. , Comeau A. 
Published: April 2006

AbstractNew intergeneric hybrids were obtained between Triticum aestivum L. cv. Tukuho’ (2n = 6x = 42, AABBDD) and Agropyron fragile (Roth) Candargy PGR 8097 (2n = 4x = 28, PPPP) at a frequency of 1.06 %, through the use of direct embryo culture and in ovulo embryo culture. Such hybrids could be used to transfer barley yellow dwarf virus (BYDV) resistance and winterhardiness into bread wheat. The somatic chromosome number in all the hybrid plants was 2n = 5x = 35, as expected. Considerable variation in chromosome pairing was observed among the different hybrid plants. Average meiotic chromosome configuration at metaphase I was 17.29 Is + 6.57 rod Us + 1.97 ring Us + 0.18 III + 0.03 IV + 0.002 VI. The high level of chromosome pairing in some F1 hybrids was attributed to Ph‐suppressor gene(s) present in A. fragile. The hybrids could not be backcrossed to wheat, but amphiploid seeds have been obtained by colchicine treatment.
Estimation of the Isozymatic Genetic Variability of a Spanish A vena sativa Germplasm Collection
Authors: Gomez C. , De Miera L. Saenz , De La Vega M. Perez 
Published: April 2006

AbstractAn analysis of Spanish land races of Avena sativa from the Germplasm Bank of the I.N.I.A. was carried out using starch gel electrophoresis. Samples of 15 seedlings per accession were used for estimating the intra‐ and interpopulational genetic variability. Electrophoretic analyses were performed with crude extracts from 15 day‐old seedling leaflets by means of eight isozymatic systems representing a total of ten genetic loci. Two systems were mono‐morphic in all the accessions, while the other six showed polymorphism both within and between populations. Intrapopulational variability was particularly high in this collection, only 16 out of the 137 accessions being uniform for all the isozyme systems. Thus the material was shown to represent a high potential of genetic variability for breeding programmes.
Selection for Increased Seed Nitrogen Accumulation in Common Bean: Implications for Improving Dinitrogen Fixation and Seed Yield
Authors: Miranda B. D. , Bliss F. A. 
Published: April 2006

AbstractEstimates of N2 fixation in segregating populations of bean plants based on 15N‐isotope methods are technically demanding and expensive; therefore, indirect measures based on related traits including total seed N were used to select for improved N2 fixation and yield. In 1985, six populations of F2‐derived F3 families resulting from six parental lines crossed to a common tester were grown in field trials on a low‐N soil. In 1986, 25 selected half‐sib families and two populations of full‐sib F4 families were grown under similar conditions. Parents and a non‐nodulating soybean line were included both years. Narrow sense (HNS) heritability estimates based on parent‐offspring regressions ranged from 0.57 for total seed N to 0.39 for shoot biomass in one population, but were near zero for all measured traits in a second population. Among the criteria used to identify parental lines with superior potential for producing progenies with high total seed N, testcross population means combined with estimates of realized heritability were the most reliable. Selection of the best F3 families for total seed N resulted in F4 families with increased total seed N and higher seed yields, while seed protein percentage was unchanged. When plants are grown on low‐N soils, selection for total seed N offers a useful alternative to selection for increased N2 fixation based on 15N‐isotopic or total‐N‐difference method.
Independent, Alternate, and Simultaneous Selection for Resistance to Anthracnose and Angular Leaf Spot and Effects on Seed Yield in Common Bean (Phaseolus vulgaris L.)
Authors: Singh S. P. , Pastor‐Corrales M. A. , Molina A. , Urrea C. , Cajlao C. 
Published: April 2006

AbstractTwo double‐cross populations were used to evaluate the efficiency of independent, alternate, and simultaneous selection practiced from the F2 to F8 for resistance to anthracnose and angular leaf spot of common bean (Phaseolus vulgaris L.). Seven resistant and high‐yielding lines were selected from each of the four environments used during this study. These lines and the seven parents involved in two populations were evaluated in an 8 × 8 lattice design with three replications in two cropping seasons. Pathogen inoculum was used to create the three test environments: anthracnose alone, angular leaf spot alone, and anthracnose and angular leaf spot together. All entries were also evaluated in a fourth, disease‐free environment. Selection for resistance to anthracnose and angular leaf spot was effective in both populations. Mean disease scores of all selected lines for anthracnose were lower than that of angular leaf spot irrespective of selection environment. Among the three stress environments, yields were higher in the anthracnose environment. However, lines selected alternately for anthracnose and angular leaf spot were usually higher yielding, and the highest yielding line in both populations originated from this selection environment. The mean yield of selected lines was higher and the highest yielding line originated from the population involving a parent (G 1805) belonging to the Mexican highland race ‘Jalisco’. Positive association existed between seed yield of protected and pathogen‐inoculated environments. No association was found between resistance to anthracnose and angular leaf spot.