bluuebunny/crossref_metadata_2025_split huggingface dataset:
Screening of Tomato Somaclones for Resistance to Bacterial Canker (Clavibacter michiganensis subsp. michiganensis)
Authors: van den Bulk R. W. , Jansen J. , Lindhout W. H. , Löffler H. J. M. 
Published: April 2006

AbstractTo facilitate testing large numbers of tomato soma‐clones for resistance to bacterial canker, a fast screening procedure was developed. Two inoculation methods were investigated, i.e. excision with an infected scalpel of I) one cotyledon of 2‐week‐old seedlings, and II) the first true leaf of 3‐week‐old seedlings, followed by applying a drop of inoculum on the wound. Inoculation by method II discriminated well between populations of partially resistant and susceptible tomato genotypes. A criterion for the selection of single, putatively resistant plants, based on rating scores of the severity of wilting symptoms, was proposed and tested with plants of a Lycopersicon peruvianum accession with a relatively high level of resistance to bacterial canker. Progenies of 279 somaclones, derived from tissue explants of the susceptible tomato cultivar ‘Moneymaker’, were evaluated for resistance. The presence of somaclonal variation for morphological characters in these populations was previously shown. However, no differences were detected between the somaclone population and controls in either mean susceptibility or distribution of plants over disease severity categories. Moreover, plants with major increases in resistance were not detected. These results suggest that the potential of somaclonal variation as a source of resistance to bacterial canker may be limited.
Genetic Diversity in Tall Fescue Ecotypes from Alabama I. Maturity, Morphological Traits, and Disease Reaction
Authors: van Santen E. , Collins D. J. 
Published: April 2006

AbstractThere is a large hectarage of tall fescue in Alabama. Recognition of the deleterious effects of the endophytic fungus Acremonium coenophialum has resulted in substantial acceptance of new endophyte‐free cultivars. Destruction of old pastures and the concomitant loss of potentially valuable adapted germplasm could be a valid cause for concern. The objectives of this study were to evaluate genetic variation for maturity and plant morphological traits, both among and within tall fescue cv. ‘Kentucky 31’ populations from 18 to 38 year‐old pastures in Alabama. Ten populations of approximately 50 plants each were collected from old Alabama tall fescue pastures. Two pastures were sampled in each of five counties, representing the five major land use areas of the state. In 1990, spaced plants of all populations were evaluated at heading time for maturity, morphological, and disease traits at two locations in central Alabama. Endophyte infection level of the populations ranged from 2 to 100 %. Maturity was highly correlated with tiller length and flag leaf width and was used as a covariate for these traits in the analysis of variance. Leaf rust and net blotch ratings were negatively correlated. Significant variation among populations was observed for maturity and flag leaf dimensions, most variation being due to differences among source counties. Significant variation was observed within all populations for maturity and morphological traits, but only in seven populations for leaf rust. No within‐population variation was detected for net blotch. The average precipitation for the month of May explained 81 % of the variation among populations for maturity. Age of the pasture sampled had a significant effect on tiller diameter (r2= 0.55), and latitude of the pasture sampled was the best individual predictor of leaf width (r2= 0.42). This study reveals that considerable genetic diversity, largely influenced by climatic conditions, exists among ‘Kentucky 31’ tall fescue ecotypes from Alabama.
Effect of Drechslera (Helminthosporium) sacchari Toxin upon the Permeability of Sugarcane Leaf and Callus Tissues
Authors: Leal M. Ramos , Maribona R. H. 
Published: April 2006

AbstractSugarcane leaves and calli from highly susceptible and resistant varieties to eyespot disease were used to evaluate the Drechslera sacchari toxin effect at different concentrations and incubation times by measuring electrolyte leakage. This expression of disease resistance was observed not only in the leaf but also in the callus. Furthermore, the growth of resistant calli MS medium supplemented with DS toxin, was higher when compared to the susceptible ones. The possibility of obtaining resistant somaclones is confirmed.
Analysis of Competitive Ability among Clones of the Palisade Grass, Brachiaria brizantha (Hochst. Ex. A. Rich.) Stapf.
Authors: Senanayake S. G. J. N. , Petersen H. L. 
Published: April 2006

AbstractFour clones of palisade grass, Brachiaria brizantha (Hochst. Ex. A. Rich.) Stapf., were studied in a diallel competition trial to investigate their competitive relationship in clonal mixtures. Clone X associate interactions were observed for plant height, number of tillers per plant and dry matter yield per plant. Both general and specific competitive abilities were observed for tiller number and dry matter yield. Clone X associate interaction for plant height was mainly due to the specific competitive ability of individual combinations. The most competitive clone observed was CIAT 6387. Competitive abilities of local clones were low compared to the imported clones. Local clones (RU 127 and RU 139) yielded more than imported clones (CIAT 6387 and PI 292185) under low competitive stresses. General and specific competitive abilities should be taken into consideration when mixing clones of palisade grass.
Factors Affecting the Differentiation of Resistant Faba Bean Plants after Inoculation with Sclerotinia trifoliorum
Authors: Lithourgidis A. S. , Roupakias D. G. , Tzavella‐Klonari K. 
Published: April 2006

AbstractFaba bean (Vicia faba L.) plants 3, 4, 5 and 6 weeks old were inoculated at different internodes by carrot root pieces colonized by the fungus Sclerotinia trifoliorum Eriks. The plants were left in the growth chamber for 72 h. In addition, eight faba bean cultivars, 4 weeks old, were inoculated by the same inoculum which was left on the stems for various lengths of time. When the inoculum was removed, the plants were scored for disease severity. The highest disease seventy was on the youngest tissues inoculated. Susceptible and partially‐resistant cul‐tivars could be differentiated effectively when the inoculum was removed 48 to 72 hours after the inoculation.
Breeding Progress in Small Grain Cereals — A Comparison of Old and Modern Cultivars
Authors: Feil B. 
Published: April 2006

AbstractThe present paper reviews the results of comparative studies on old and modern small grain cereal cultivars. The contribution of genetic improvement to the increase in grain yield and the influence of environmental factors on the performance of old and modern cultivars are discussed. The evolution of grain yield components and the effects of breeding on numerous physiological, morphological and biochemical characteristics such as formation of above‐ground biomass, havest index, total N uptake, N harvest index, N concentration in the grains, canopy structure, carbon dioxide exchange, tiller survival, root growth, course of development and enzyme activities are considered.
The Influence of Silver Thiosulfate on Potato Protoplast Cultures
Authors: Möllers C. , Zhangm S. , Wenzel G. 
Published: April 2006

AbstractThe influence of silver thiosulfate (STS) on the in vitro shoot propagation of twenty dihaploid potato clons and their protoplast regeneration to plants was investigated. The addition of 1.5 mg/1 STS to the propagation medium led to an incrase of leaf material harvested per culture vessel. Depending on genotype, the increase ranged from 1.2 up to 2.3 times the yield obtained from medium without caused toxic symptoms in the plants to most of the genotypes tested, and it was not possible to isolate viable protoplasts. The addition of STS to the shoot regeneration medium considerably promoted the shoot regeneration from protoplast‐derived calli. This effect again was strongly genotype‐dependent.
Genetic Variation for Anther Callus Inducibility in Crosses of Highly Culturable Winter Wheats
Authors: Becraft P. W. , Taylor G. A. 
Published: April 2006

AbstractHeritability studies suggest that variation among genotypes for callus inducibility should respond to selection. The objective of this study was to determine if crosses among parents with high callus initiation frequencies would produce segregation from which genotypes with improved callus inducibility could be selected. The winter wheat (Triticum aestivum L.) cultivars‘Centurk 78’, ‘Norstar’ and ‘Norwin’ were chosen as parents, based on their high callus initiation frequencies and diverse parentage. F2 populations from crosses between each of these parents were evaluated for callus initiation frequencies and callus vigor as determined by growth rate and healthy appearance. Heterosis was detected for callus initiation in the‘Norwin’×‘Norstar’ cross and for callus vigor in all crosses. Broad sense heritability estimates of 0.25 and 0.37 for callus initiation in the ‘Centurk 78’×‘Norstar’ and ‘Norwin’×‘Norstar’ crosses, respectively, suggest this trait can be improved by selection. Heritability estimates for callus vigor were less promising, ranging from 0.11 to 0.24.
Race‐Specific Resistance Genes Against Erysiphe graminis f. sp. hordei in Old and Recent French Barley Accessions
Authors: Andrivon D. , de Vallavieill‐Pope C. 
Published: April 2006

AbstractLeaf segments from seedlings of 68 old barley varieties and 38 more recent cultivars of past or current importance in France were infected with 6—9 powdery mildew isolates in order to identify race‐specific resistance genes. No resistance gene was apparent in the 21 old winter varieties, 43 of 47 old spring varieties, 10 recent winter and 3 recent spring cultivars. Two old spring varieties (‘Colmar S 142’ and ‘Johanna’) were postulated to have Mlg and Ml(CP), and two others (‘Pontrieux’ and ‘Finistère 62‐5’) had an unidentified, weakly effective gene. Mlg, Ml(CP), Mlb, Mla6 and Mlal3 were the only genes detected in recent winter cultivars. Recent spring cultivars presented the greatest diversity; the presence of one or several genes among Mlal, Mla6, Mla9, Mla12, Mlg, Ml(CP), Ml(La), Mlk and mlo was postulated in several lines.
Chromosomal Location of Genes for Gibberellic Acid Insensitivity in ‘Chinese Spring’ Wheat by Tetrasomic Analysis
Authors: Börner A. , Worland A. J. , Law C. N. 
Published: April 2006

AbstractThe tetrasomics of the homoeologous groups 2, 5 and 7 of‘Chinese Spring’wheat were, together with the euploid standard, screened at the seedling stage for sensitivity to exogenously applied gibberellic acid (GA3). Whilst the seedling length of lines tetrasomic for group 2 chromosomes were taller and those for chromosomes 5A, 5D and 7D shorter in both treatments (with and without GA3) compared to the euploid control, the remaining tetrasomics — 5B, 7A and 7B — were significantly shorter than the euploids in the GA variant only. These results suggest the presence of additional genetic factors for GA insensitivity on chromosomes of the groups 5 and 7 of hexaploid wheat. This corresponds with the localization of GA insensitive dwarfing genes on the homoeologous chromosomes 5R and 7R in diploid rye.
Barley Yellow Dwarf Virus Resistance in Triticum aestivum×Leymus angustus Hybrids
Authors: Plourde Ariane , Comeau A. , St‐Pierrf C. A. 
Published: April 2006

AbstractThe enzyme‐linked immunosorbent assay (ELISA) was used to determine the concentration of barley yellow dwarf virus (BYDV) in leaves of spring wheat Triticum aestivum L. cv. ‘Fukuhokomugi’, Leymus angustus (Trin.) Pilger (Altai wild rye) and their F1 hybrids inoculated at the 2‐ to 3‐leaf stage. The BYDV isolate “Cloutier” (serotype PAV) was used. The results showed that L. angustus confers immunity or strong resistance to the virus. Significant multiplication of the virus occurred in ‘Fukuhokomugi’ which expressed an intermediate level of tolerance to the disease under field conditions. The F1 haploid hybrids of ‘Fukuhokomugi’×L. angustus expressed a level of resistance almost equal to that of their wild parent, with a low concentration of virus appearing 16 days after inoculation and no more afterwards. The discovery of BYDV resistance in L. angustus and the expression of this character in the F1 hybrids provide new opportunities for the enlargement of the gene pool for BYDV resistance in wheat.
Diallel Analysis of the Inheritance of Partial Resistance to Downy Mildew in Peas
Authors: Stegmark R. 
Published: April 2006

AbstractThe aim of the investigation was to see if the partial resistance of three sister‐lines is determined by identical genes. The sister‐lines were selected from a cross between a susceptible line and a partially resistant line. These lines and the susceptible parent line were crossed in all directions. The downy‐mildew resistance of the different combinations was investigated in the F1, F3 and F4 generations. The resistance of the sister‐lines is not determined by the same genes. The moderate resistance of line X309 is recessive and might be determined by a single gene. The more resistant line X282 carry at least one resistance gene that shows dominance in crosses with X309. Line X311 carries, in addition to the resistance in X309, some resistance gene or genes with an intermediate effect.
Genetic Relationships Among Four Pepper Genotypes Resistant toPhytophthora capsici
Authors: Ortega R. Gil , PalazónEspañol C. , Zueco J. Cuartero 
Published: April 2006

AbstractAccording to our previous investigations, resistance toPhytophthora capsidinCapsicum annuum genotypes, ‘Line 29’, ‘PI201232’, ‘PI201234’ and Serrano Criollo de Morelos 334 (‘SCM334’), seems to be controlled by three genes. In order to determine the genie relationships between these four sources of resistance, three experiments were conducted which included the four genotypes, their F1s, F2s, F3s and BC1generations together with the susceptible pepper genotype ‘Morron INI A 224’. Inoculations were made, when plants had 4—6 leaves, by irrigating the culture substrate with a zoospore suspension ofP. capsiciisolate ‘Bl’. Though the four genotypes showed percentages of resistance close to a 100%, none of them actually reached this level in the three experiments. ‘SCM334’ was the most resistant genotype, transmitting a high level of resistance to its F1, F2and BQ generations. ‘Line 29’ was more resistant than ‘PI201232’ and ‘PI201234’. However, the F1F2and BQ generations of these three lines showed similar degrees of resistance. The four genotypes seem to have one of the three genes postulated for their resistance in common. All genes displayed a similar level of resistance, except the specific genes of ‘SCM334’, the effect of which was slightly higher. Several working procedures are suggested for breeding programmes.
Polyploidy and Aneuploidy in the Tamarillo, Cyphomandra betacea (Cav.) Sendt. (Solanaceae)
Authors: Pringle G. J. , Murray B. 
Published: April 2006

AbstractThe successful induction of tetraploids in the tamarillo (Cyphomandra, betacea [Cav.] Sendt.) by the application of colchicine to the germinating seed is described. Chimeric and solid tetraploids were produced although the proportion of the chimeric types could be minimized by optimizing the treatment time. There were reciprocal differences in all interploidy crosses, with triploids being ineffective in crosses when used as the paternal parent. The analysis of aniline blue stained gynoecia showed that incompatibilities in interploidy crosses occurred largely at the post‐zygotic stage of the reproductive process. Triploids and aneuploids were produced from interploidy crosses. The features of some aneuploids were described. Most aneuploids produced were primary trisomics (2n = 2x + 1 = 25) but some had 26 chromosomes and two others were hyperpolyploids. Pollen fertility in these plants varied from 10% to 90%. Morphological traits did not differ between the aneuploids or between the aneuploids and diploids. Fruit and seed size in the aneuploids were comparable to those of the diploids and were thus suitable for potential commercial exploitation.
Correlated Response to Selection for Protein Yield in Oats After Three Cycles of Recurrent Selection
Authors: McFerson J. K. , Frey K. J. 
Published: April 2006

AbstractThree oat (Avena saliva L.) populations (i.e., lines of descent), high grain yield (HG), high protein content (HP), and high protein yield per se (HGP), each developed by three cycles of S, recurrent selection, were evaluated for the effect of selection for groat‐protein yield upon other agronomic traits. Selections making up the HG line of descent had high protein yield primarily due to high grain yield, and those selected for HP had high protein yield due to both high protein content and high grain yield. Selection in HGP was on the basis of protein yield per se. Selection caused increases in bundle weight, harvest index, vegetative growth rate, and seed number in all lines of descent. Heading date, plant height, and seed weight were unaffected, whereas groat percentage and test weight were decreased in HP and HGP. Heritabilities were high for heading date, plant height, test weight, and seed weight, moderate for harvest index and bundle weight, and low for groat percentage. Genetic variability generally declined from CO to C3 for all traits.Groat‐protein yield and amount of protein per groat increased in all lines of descent. In HG, the increase in groat weight was due primarily to increases in the nonprotein fraction, with groat‐protein content actually decreasing. In HGP, groat weight increased due to increases in protein and nonprotein fractions, and groat protein content remained constant. In HP, groat weight and amount of nonprotein per groat decreased, thus increasing groat‐protein content.Three cycles of recurrent selection resulted in oat lines with groat‐protein yields significantly higher than the highest lines from CO. Utilization of index selection may be desirable to obtain populations of greater breeding value.
Amino‐Acid Resources in the Wild Progenitor of Wheats, Triticum dicoccoides, in Israel — Polymorphisms and Predictability by Ecology and Isozymes
Authors: Nevo E. , Beiles A. 
Published: April 2006

AbstractAmino acid contents were measured in 109 genotypes from 22 populations of wild emmer wheat, Triticum dicoccoides, across its ecological range in Israel. Plants were grown outdoors on mesic Mr. Carmel, in a standardized environment, without irrigation and fertilization. T. dicoccoides was high in lysine and isoleucine contents as compared to six other species of wild wheats, but low in threonine and proline. Significant correlations were found among lysine and the other essential amino acids. Significant differences between Israeli populations of T. dicoccoides were found for isoleucine, methionine, leucine and threonine, but not for lysine, arginine, proline and glutamic acid. Significant differences between regions were only found in methionine. Ecological factors and allozyme markers appear to be good guidelines for predicting the ecogeographical location and allozymic constitution of specific elite amino acid genotypes, either singly or in combination. T. dicoccoides may be used in the future as a promising genetic resource for genetically improving the nutritional value of cultivated wheats.
Powdery Mildew Resistance Genes in 127 Northwest European Spring Barley Varieties
Authors: Jensen H. P. , Christensen E. , Jørgensen J. Helms 
Published: April 2006

AbstractOne hundred and twenty‐seven spring barley varieties grown in Denmark since 1979 were characterized for resistance genes using 30 powdery mildew isolates. The resistance genes are traced in the pedigrees to verify the results. Eleven named genes, 12 tentatively named genes/resistances and six unknown resistances were found. Resistance in many varieties was based on combinations of either known genes or of known and new factors. The following five new or relatively new resistance genes more or less effective against the present powdery mildew populations were detected: the ‘Mlo’ resistance conferred by the recessive mlo gene with the characteristic infection type 0/(4), ‘Ricardo’ and ‘Turkish’ sources having gene Mla3 in common and ‘Turkish’ with Ml(Tu2) in addition. In three varieties the new resistance Ml(IM9) was found in combination with different Mia alleles. Variety ‘Jarek’ has two new unidentified resistances.
Agronomic and Bioenergetic Consequences of Selection for High Groat‐Oil Content and High Protein Yield in Oat*
Authors: Schipper H. , Prey K. J. 
Published: April 2006

AbstractFew studies have examined the effects of selection for high oil or protein content on the chemical composition of cereal seeds. This study was conducted to examine agronomic and bioenergetic consequences that result with changes in the chemical composition of groats of oat (Avena sativa L.). Oat lines with low and high groat‐oil content (GO) and with low and high groat‐protein content (GP) were chosen from each of five cycles of a recurrent selection program for increasing GO and from each of four cycles of a recurrent selection program for increasing protein yield via elevating GP, respectively. These lines were evaluated at three Iowa locations in 1988. The results indicated that GP was not significantly affected by selection for high GO and that GO significantly increased during selection for high protein yield via elevating GP. Both selection procedures resulted in oat lines with higher groat‐energy contents. A bioenergetic cost analysis showed that for GO in the oil population and GP in the protein population to be increased, additional photosynthate needed to be available.
Inheritance and Agronomic Performance of the Waxless Character in Brassica napus L.
Authors: Jianguo Mo , Wanqu Li , Jisheng Wang 
Published: April 2006

AbstractA mutant of oilseed rape (B. napus L.) with waxless leaves was discovered in 1988. Three pairs of reciprocal crosses were made between the mutant (Wl) and 3 normal wax layered lines (Nwl). By the summer planting in Kunming and Wenjiang and the autumn planting in Wenjiang, it was confirmed that the Wl character is completely dominant to the normal opposite Nwl. Chi‐square tests revealed that the segregation ratios of Wl to Nwl among B1 and F2 plants fit to 1:1 and 3:1, respectively, i.e. the assumption of one gene pair. The yield of 12 hybrids, which were derived fom Wl and some Nwl lines, exceeded the check control ‘Zhong You 821’, a best cultivar in Chinese production by 19.31 % on the average. When the seedling had 3–4 leaves, both phenotypes can be accurately determined visually on the field. This material possesses potential value for studies of the genetics and breeding, as a prominent genetic marker in B. napus.
A Line with Four‐Seeded Pods Derived from an Interspecific Hybrid in Soybean
Authors: Gour V. K. , Mehta A. K. , Mehta S. K. 
Published: April 2006

AbstractThe cultivated soybean, Glycine max (L.) Merr., was crossed with its proposed wild progenitor, Glycine sofa (Seib. & Zucc.), to create useful genetic variability. A few plants with increased frequency of four‐seeded pods were identified in a segregating generation derived from this interspecific cross. One of them had about 45 percent four‐seeded pods per plant, whereas Glycine max and Glycine soja accessions used as parents in this study had only 8.0 and 5.1 per cent four‐seeded pods per plant, respectively. The established line finally had 32.5 per cent four‐seeded pods per plant, which is substantially higher as compared to either of the parents. Obviously, the genes which are responsible for this character are not expressed in the parental population.