bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural Cross‐Pollination in Sesame (Sesamum indicum L.)
Authors: Pathirana R. 
Published: April 2006

AbstractThree sesame genotypes with contrasting characters were grown in alternate rows to estimate the degree of natural cross‐pollination (NCP) at two locations. Capsules from the lower (first‐formed five capsules), upper (last five fully‐developed capsules) and middle portions were harvested separately and the frequency of appearance of progenies with dominant markers was used as the criterion for NCP. The degree of inter‐genotypic NCP was similar in the three genotypes and at the two locations (4.02—5.10 % NCP) when the total number of hybrid seeds per plant was considered. The lower portion of the early (1.03—1.31 % NCP) and medium (1.51—2.08%) flowering genotypes and the upper portion of the late‐flowering genotype (2.27—2.49 % NCP) recorded less NCP than the total plant. The NCP in the lower portion of the early‐flowering genotype due to pollen from the late‐flowering genotype was negligible (0—0.7 %). The results indicate the need for controlled self‐pollination for purity maintenance in sesame. However, contamination due to NCP can be reduced by sampling seeds from the lower capsules of early and medium‐flowering genotypes and from the upper capsules of late‐maturing genotypes when pollination control is not practised.
Development of a New Cytoplasmic Male‐Sterility System in Brassica juncea through Wide Hybridization
Authors: Rao G. U. , Batra‐Sarup Vinita , Prakash S. , Shivanna K. R. 
Published: April 2006

AbstractA new cytoplasmic male‐sterility system was developed in an oilseed Brassica, viz. B. juncea var. ‘Pusa Bold’ with the cytoplasmic background of a wild species, Diplotaxis siifolia, obtained through wide hybridization. The synthetic alloploid (D. siifolia×B. juncea: 2n = 56, D3D3AABB) was repeatedly backcrossed to B. juncea to achieve cytoplasmic substitution. The CMS plants resembled the cultivar in growth and morphology. The flowers had narrow sepals and petals and short, shrivelled anthers which failed to dehisce. The meiotic process appeared to be normal. The microspores degenerated at an early stage after tetrad formation. Female fertility in the CMS plants was as good as in the cultivar. Female transmission of sterility confirmed it to be cytoplasmically encoded.
A Greenhouse Method to Assess Sunflower Resistance to Sclerotinia Root and Basal Stem Infections
Authors: Grezes‐Besset B. , Tournade G. , Arnauld O. , Urs R. , George P. , Castellanet P. , Toppan A. 
Published: April 2006

AbstractA method was developed to assess sunflower resistance to sclerotinia root infections in greenhouses. Some of the genotypes were also tested in the field to validate the greenhouse testing method. Efficiency of this method was also tested in a diallel cross. The susceptibility could be assessed by the final percentage of dead plants or by the time required to reach a given threshold of attack (threshold latency parameter). The correlation coefficients between susceptibility assessed in the field and with the greenhouse method were significant. The diallel cross analysis indicated that only additive effects are important. Correlation for susceptibility to sclerotinia wilt, between parental lines and the mean of their hybrids, was significant. It is concluded that breeding programmes for increase of resistance to sclerotinia root and basal stem attacks, using the described testing method, should be effective.
Evaluation of the U.S. Cucumber Germplasm Collection for Early Flowering
Authors: Walters S. A. , Wehner T. C. 
Published: April 2006

AbstractA greenhouse study was conducted to evaluate 866 cultigens (718 accessions, 38 breeding lines, and 110 new and obsolete cultivars) of cucumber (Cucumis sativus L.) for early staminate flower production. Complete data were obtained for 866 cultigens. The study was conducted on plants that were part of a root‐knot nematode experiment. Plants were grown from seeds in greenhouses in each of 3 seasons with 2 replications per season. There were significant differences for mean time of flowering over all cultigens among the 3 seasons. Days from planting to first staminate flower ranged from 26 to 45, with a mean of 35 for all cultigens. Root‐knot nematode infestation may be related to flowering, since early‐flowering cultigens had more root galling. The earliest flowering cultigen was PI 249561 (26 days to flowering); the latest was PI 470254 (45 days to flowering).
Karnal Bunt Resistance in Wheat‐Barley Addition Lines
Authors: Chauhan R. S. , Singh B. M. 
Published: April 2006

AbstractWheat‐barley addition lines 7H, 2H, 3H, 4H, 6H and 5H having barley chromosomes 1, 2, 3, 4, 6 and 7, respectively, were evaluated for resistance to karnal bunt (Neovossia indica) using syringe inoculation of sporidial suspensions of N. indica under glasshouse conditions. Addition lines 4H and 7H were rated as highly resistant and resistant, respectively, with zero and 3.22 coefficients of infection compared to ‘Chinese Spring’ which had a 23.5 coefficient of infection. All the six addition lines were found to be susceptible to specific virulences of Puccinia recondita tritici and P. striiformis.
The Effect of A Genome Substitution on the Resistance of Brassica napus to Infection by Leptosphaeria maculans
Authors: Crouch J. H. , Lewis B. G. , Mithen R. F. 
Published: April 2006

AbstractSix accessions belonging to four subspecies of Brassica rapa, including three accessions of B. rapa subsp. sylvestris, were crossed with B. oleracea subsp. alboglabra in order to develop a series of synthetic B. napus lines with a common C genome but contrasting A genomes. Different A genomes had significant effects on the efficiency of B. napus resynthesis and the sexual compatibility of the synthetic lines with oilseed rape cultivars. The synthetic lines were used to investigate the effect of A genome substitution on the resistance of B. napus to infection by Leptosphaeria maculans, and to explore the potential for the use of wild forms of B. rapa in oilseed rape breeding programmes. Synthetic lines derived from two wild accessions of B. rapa, and their F1 hybrids with oilseed rape cultivars, expressed high levels of resistance to L. maculans in glasshouse experiments. One of these lines also expressed high levels of resistance in field experiments in England and Australia when exposed to a genetically diverse pathogen population. All other synthetic lines and cultivars were highly susceptible in both glasshouse and field experiments. F1 hybrids between oilseed rape cultivars and synthetic lines derived from B. rapa subsp. chinensis were significantly more susceptible than either parent.
Hardening of Some Winter Wheat (Triticum aestivum L.), Rye (Secale cereals L.), Triticale (×Triticosecale Wittmack) and Winter Barley (Hordeum vulgare L.) Cultivars During Autumn and the Final Winter Survival in Finland
Authors: Hömmö Leena Maarit 
Published: April 2006

AbstractProfound hardening is the prerequisite for survival of a cultivar over winter. In the present study, hardening abilities of 13 winter wheat, 10 rye, 3 triticale and 6 winter barley cultivars were determined in field samples collected during the autumns of 1990 and 1991 by measuring the amount of ion leakage from frost‐treated leaf segments. The cultivars tested were selected from the Inter‐Nordic Winterhardiness Project, in which Field Survival Indices were determined for a total of 23 winter wheat, 13 rye, 5 triticale and 11 winter barley cultivars in order to estimate winter survival potentials under Finnish conditions. The winter survival of the materials studied correlated well with their hardening ability assessed by using the electrolyte leakage method.
Adjustment for Competition Between Genotypes in Single‐Row‐Plot Trials of Winter Wheat (Triticum aestivum)
Authors: Goldringer I. , Brabant P. , Kempton R. A. 
Published: April 2006

AbstractSeveral statistical methods were investigated for improving yield estimation for 72 genotypes of winter wheat tested in a single‐row‐plot (SRP) trial. The different analytical models were compared using several criteria: the residual mean square fit; the standard error of differences of genotype means; the correlations of genotype means with means from six‐row‐plot (6RP) reference trial; the expected genetic gains relative to 6RP trial from selecting the 10 top yielding genotypes.There was no significant correlation between the unadjusted genotype means for SRP and 6RP. Genotype yields were positively correlated with height in SRP, but this correlation was reversed in 6RP. Using the mean height difference of a plot with its two neighbours as a covariate to adjust for competition in SRP reduced the standard error of difference of genotype means and substantially increased their correlation with the 6RP means. The predicted selection efficiency in SRP trial increased from zero, before adjustment, to 83 % of 6RP trial. Including the difference in heading date and the effect of guards at borders as covariates in the SRP analysis improved the residual mean square fit but had no effect on correlation with 6RP means or selection efficiency. A producer‐competitor model in which individual competitor effects were estimated for each genotype gave a substantial improvement in fit over the covariate models but a much lower correlation with 6RP means and selection efficiency.Yield selection in early generation wheat trials based on single‐row plots could be considerably strengthened by use of a plot covariate derived from height difference between neighbours.
Inheritance of Resistance to Mycosphaerella graminicola in Hexaploid Wheat
Authors: Jlibene M. , Gustafson J. P. , Rajaram S. 
Published: April 2006

AbstractSeptoria tritici blotch constitutes a major disease problem of wheat world‐wide. To efficiently breed wheat for resistance to this disease, an understanding is required of the inheritance of resistance. Our objective was to study the quantitative inheritance of resistance under field conditions. A nine‐parent diallel and a generation mean experiments were conducted at Toluca, México in 1986 and 1987, respectively, to investigate gene effects. General combining ability effects accounted for most of the variation although specific combining ability effects were detected in some crosses. Ias20*5/H567.71, Thornbird, and RPB709.71/Coc contributed the most to reduced disease severity. Reciprocal effects were detected in two of 36 crosses, where RPB709.71/Coc contributed additional reduced disease severity when used as female. The analysis of generation means confirmed results obtained from the diallel. Additive effects were also most important. Dominance effects and epistasis, mostly of the additive × additive type, were found in some crosses. Hence, substantial genetic progress for resistance can be expected among progeny from crosses with resistant parents. However, selection would be most effective if delayed to later generations because of dominance, and choice of the specific female parent may produce a higher level of resistance.
Triploid and Hexaploid Regenerants from Hexaploid Timothy (Phleum pratense L.) via Anther Culture
Authors: Abdullah A. A. , Pedersen S. , Andersen S. B. 
Published: April 2006

AbstractPollen embryos were obtained from eight genotypes and viable green plants were regenerated from four genotypes in an anther‐culture experiment with 165 genotypes of Phleum pratense L. Formation of proembryos inside the cultured anthers during the first 10—12 days was significantly influenced by genotypes and by the type of nutrient media. Primary embryos developed into multiple secondary embryos before regeneration of plants. Among a total of 62 plants regenerated, only 13 were albinos. Of the green regenerants, 11 were triploid while 35 were hexaploid when DNA‐content was measured by flow cytometry. Eight plants with a triploid DNA‐content did possess the triploid chromosome number of 21. Triploid and hexaploid regenerants from two different parents showed simplified isozyme (GPI and PGD) banding patterns relative to that of their parents.
Inheritance of ‘Hullability’ in Sunflowers (Helianthus annuus L.)
Authors: Denis L. , Dominguez J. , Vear F. 
Published: April 2006

AbstractImprovement of the feed value of sunflower seedmeal by hulling achenes before crushing is of economic importance and varieties with good ‘hullability’ (ease of hulling) would be economically significant. Knowledge of the genetics of this characteristic is therefore necessary. Studies of heritability were made on a factorial cross of six female and six restorer lines. Hullability was measured as the ratio of hull removed by a laboratory huller against the total quantity of hull in the achene. The genotypes studied showed a wide range of hullabilities. There were considerable environmental effects but only small interactions; correlations between results in different locations were significant. Additive genetic effects predominated, although there were some interactions between parental lines. Narrow‐sense heritabilities were 0.73–0.85 for genotype means, 0.52 when calculated from individual plants, and 0.36–0.76 from parent‐progeny regressions. Early selection based on progeny means or a combination of individual and progeny values would appear to be the best method of breeding for improved hullability of sunflower achenes.
Wheat Breeding in a Water‐stressed Environment. I. Delineation of Drought Tolerance and Susceptibility
Authors: Sadiq I.I.S. , Siddiqui K. A. , Arain C. R. , Azmi A. R. 
Published: April 2006

AbstractTo elucidate genotypic differences expressed through the grain yield of drought‐stressed wheat, 21 commercial varieties and advanced lines were evaluated in the field under a range of soil water levels to induce varying degrees of drought stress. This paper presents data on grain yield and yield‐based indices to indicate drought tolerance and drought susceptibility. AZS‐4 was identified as drought tolerant and AZS‐17 and ‘Pavon’ as drought susceptible. High gram yield under stress can be explained in terms of high yield potential, thus grain yield proved to be the best indicator of drought tolerance.
The Transfer of Thinopyrum‐Derived Leaf‐rust Resistance from Common Wheat to Durum Wheat.
Authors: Littlejohn G. M. , Pienaar R. DeV. 
Published: April 2006

AbstractThe leaf rust resistance gene on chromosome 7AL of ‘Chinese Spring’ transfer no. 12 derived from Thinopyrum ponticum, was transferred to durum wheat by standard backcrossing. In ‘Agatha’ and ‘Indis’ a leaf rust resistance gene from Thinopyrum ponticum and Thinopyrum ponticum respectively, is found on a translocated segment on chromosome arm 7DL. The use of the ‘Langdon’ disomic D‐chromosome substitution lines for 7A and 7B resulted in the recovery of tetraploid leaf‐rust resistant lines from the crosses with ‘Agatha’ in the B2F1 generation. Tetraploid lines carrying the ‘Indis’ translocation segment were recovered in the B2F2 generation. The F2 segregation ratios for rust resistance after selfing or back‐crossing generally fitted a 1: 1 ratio indicating non‐transmission of the translocation segments in the male gametes. Homozygous resistant plants were not obtained. Meiotic instability was observed in 28 chromosome B2 F2 derivatives of the crosses between ‘Chinese Spring’ transfer no. 12 and durum wheat.
Nuclear Mutations Affecting Chloroplastic Pigments of Photoperiod‐insensitive Barley
Authors: Gallagher L. W. , Hafez A. A. , Goyal S. S. , Rains D. W. 
Published: April 2006

AbstractThree photoperiod‐sensitive spring barley cultivars (Hordeum vulgare L.) and three independently derived, single‐gene, nuclear mutants expressing photoperiod insensitivity and extremely early heading time under short daylengths were investigated for chloroplastic pigment variation in three environments using reverse‐phase high‐performance liquid chromatography (HPLC) to account for differences in laminae colour. In a greenhouse, non‐stress environment and in a full sunlight, high‐temperature stress environment, no systematic differences were observed among pigments of the mutant‐parent pairs. However, under 12 h of daily light (600 μE m 2sec−1) and stress temperatures (20/10°C, night/day) in a growth chamber, the three mutants appeared similar to each other in chlorotic appearance and laminae pigment contents, but differed from the three non ‐chlorotic parents, which were similar to each other. The mutants had less chlorophyll a and b, β‐carotene, lutein, taraxanthin, violaxanthin, and neoxanthin but more zeaxanthin than their parents. When shaded, the mutants became less chlorotic. How phenotypic differences for heading time and perception of day‐length might be related to altered chloroplast contents remains unclear. The single‐gene mutants conferring photopenod insensitivity were more sensitive to photothermal stress than their photoperiod‐sensitive counterparts and as a result, their zeaxanthin content increased but the level of other pigments decreased.
Components of Seed and Straw Yield in Common Vetch (Vicia sativa L.)
Authors: ÇAkmakci S. , Aclikgöz E. 
Published: April 2006

Abstract178 common vetch (Vicia sativa L.) strains were tested for 2 years under dryland conditions in Bursa, Turkey. Broad‐sense heritability of the traits was calculated for each trait. Phenotypic and genotypic correlation coefficients between seed and straw yield, with several morphological and reproductive traits, were obtained. Broad‐sense heritability estimates were high for 1000‐seed weight and number of seeds per pod. Heritability values for both seed and straw yield were small and insignificant. Harvest index, 1000‐seed weight and spring vigour showed significant positive correlations with seed yield, but days to flower correlated negatively with seed yield. Spring vigour, plant height and number of leaflets per leaf correlated positively, while harvest index, seeds per pod and seeds per plant correlated negatively with straw yield. Correlations between seed and straw yield were both positive and significant.
Relationship between the Origin of European Landraces and the Level of Partial Resistance to Wheat Leaf Rust
Authors: Broers L. H. M. , De Haan A. A. 
Published: April 2006

AbstractThe reaction to leaf rust of 33 European spring‐wheat landrace selections was assessed in the field and in the greenhouse to study the relationship between levels of partial resistance and levels of leaf rust at the origin of the landrace selections. The selections were classified into three groups according to the mean annual damage observed at the collection site. For each group of selections with high‐infection types the mean disease‐severity, area under disease progress curve and latency period were assessed. The data suggest that there is a greater likelihood of finding partial resistance in selections that come from locations with a high or intermediate mean annual damage as they displayed lower disease severity, lower area according to a disease‐progress curve and a longer latency period than the selections from locations with low mean annual damage.
Orychophragmus violaceus, a Potential Edible‐oil Crop
Authors: Luo Peng , Lan Z. Q. , Li Z. Y. 
Published: April 2006

Abstract Orychophragmus violaceus, a member of the Cruciferae family, has been found to have a high oil quality with high contents of palmitic (14.3 %) and oleic (20.3 %) acids, and lower contents of linolenic (4.8 %) and erucic (0.9 %) acids. Plants of O. violaceus exhibit a high number of branches, pods per plant, and seeds per pod, which contributes to the high yield potential of this plant. Individual selection was made in the original population of O. violaceus, and a few early, disease‐tolerant and high‐yielding lines were obtained. Intergeneric hybridization was performed between B. napus and O. violaceus and several hybrid plants (F1) were obtained. After treatment with colchicine, amphidiploid plants developed. O. violaceus shows great potential for becoming an edible oil crop or being used as genetic material in a rapeseed breeding programme.
Prediction of Yield for Specific Locations in German Winter‐wheat Trials
Authors: Weber W. E. , Westermann T. 
Published: April 2006

AbstractThe interaction between varieties and environment can make the prediction of crop performance difficult. The farmer is obviously interested in achieving optimum production within the particular growing environment of his farm, thus, this paper investigates if crop performance predictions can be improved by making information from other locations into account. The investigation is based on yield data from winter wheat resulting from official German variety‐performance tests. The predictors are based on the single location (control), unweighted means, principal components, and weighted means, produced using regression coefficients as weights. These predictors were tested on an independent data set from another year. For the given yield data in winter wheat, the overall mean proved to be the best, which suggests that prediction for all locations should be the same, and predictors for specific locations cannot, therefore, be recommended. The main reason for this is the relatively small interaction between genotype and location, in comparison to the second‐order interaction between genotypes, locations and years.
Utilization of Asymmetric Somatic Hybridization for the Transfer of Disease Resistance from Brassica nigra to Brassica napus
Authors: Gerdemann‐Kncörck M. , Sacristan M. D. , Braatz C. , Schieder O. 
Published: April 2006

AbstractAsymmetric somatic hybrid calli were produced between Brassica napus and a transgenic (Hyg R) line of B. nigra using a donor recipient fusion method for the production of cybrids. The transgenic line of B. nigra used as a donor also possessed genetic resistance to the pathogenic fungi Phoma lingam and Plasmodiophora brassicae. Using hygromycin for selection, 332 hybrid calli were obtained from which 30 produced shoots (1—‐20 per callus) which were rooted on a hormone‐free culture medium. The rooted shoots were transferred into soil and cultivated in a growth chamber where the plants were tested for resistance against the two pathogens. Out of 129 hybrid plants tested for resistance against P. brassicae, 30 (23.3 %) plants proved to be resistant and from 78 plants tested for resistance against P. lingam, 41 (52.6 %) plants remained disease‐free after infection.
Introgression of Phaseolus acutifolius A. Gray Genes into the Phaseolus vulgaris L. Genome
Authors: Pratt R. C. , Gordon S. G. 
Published: April 2006

AbstractThe tepary bean (Phaseolus acutifolius A. Gray) is a desirable genetic resource for incorporation of improved disease, pest, and stress resistance into common bean (P. vulgaris L.). Reproductive barriers separate the two species and the degree to which tepary genes may be introgressed into the common bean genome has not been well described. Greenhouse studies of gene introgression through recurrent back‐crossing to common bean were performed using two first backcross (BC1) and nine second backcross (BC2) populations. The truncate primary leaf characteristic of tepary bean was readily observed but the short primary leaf petiole and narrow bract tepary traits were infrequently observed in both BC1 and BC2 populations. In one BC, population high frequencies of adaxial stomata (characteristic of P. acutifolius) and the presence of a 30 kD cotyledon polypeptide from P. acutifolius were also observed; however, a diapho‐rase isozyme from P. acutifolius appeared to be eliminated from BC1 progeny at a high rate whereas 6‐phosphogluconate dehydrogenase alleles appeared to be transmitted normally. The expression of tepary primary leaf truncate morphology and bract width were correlated with decreased fertility in one of the two BC1 populations. Given suitable parental genotypes and population sizes it should be possible to transfer genes from P. acutifolius to P. vulgaris, especially in regions of the genome which are not associated with inviability or sterility. It will be difficult to transfer factors from certain regions of the tepary genome which are preferentially eliminated during introgression.