bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance Studies in F6 Lines of Autotetraploid Fenugreek
Authors: Singh J. , Raghuvanshi S. S. , Singh A. K.
Published: April 2006

Hybridization followed by pedigree selection was carried out between two autotetraploid strains of fenugreek (Trigonella foenum‐graecum L.). Morphological and cytological investigations were carried out in two autotetraploid parents, their F1 hybrids and F6 lines derived from F1 after selfing. Cytomorphological data of F6 lines were compared with those of F1, hybrids and of their parents. The hybrid plants were intermediate with respect to different vegetative traits, however, they showed increased seed set as compared to their autotetraploid parents. The mean pod number per plant in F6 was one and half times as high as one of the high yielding tetraploid parents and approximately twice as high as that of F1 hybrid. Meiosis in F6 was more regular than in F, and the parents. Thus, hybridization followed by pedigree selection is helpful not only in regularizing the meiotic behavior, but vigour and seed fertility have also improved in autotetraploid fenugreek.
Genetics of Seed Yield and Its Components in Common Beans (Phaseolus vulgaris L.) of Andean Origin
Authors: Singh S. P. , Teran H. , Molina A. , Gutierrez J. A.
Published: April 2006

Additive genetic variance in large‐seeded common beans (Phaseolus vulgaris L.), mostly of Andean South American origin, was higher than nonadditive variance for all traits. Heritability was 0.43 ± 0.19 for yield, 0.49 ± 0.20 for pods/m2, 0.63 ± 0.21 for seeds/m2, 0.76 ± 0.23 for 100‐seed weight, and 0.55 ± 0.22 for days to maturity. Expected gain from selection (expressed in percentage of the population mean) was 9.2 for yield, 12.8 for pods/m2, 21.0 for seeds/m2, 17.6 for 100‐seed weight, and 4.6 for days to maturity.
A New Approach for Screening Peas (Pisum sativum L.) for Yield Capacity
Authors: Rydberg Ingrid
Published: April 2006

Efficient nitrogen fixation by legumes has been proved to be important for yield of dry matter. A search was made for easily‐measurable characteristics associated with efficient fixation in young pea plants (Pisum sativum L.) which could be used in a selection programme for high yield. Altogether, 17 characteristics were investigated in 120 breeding lines of pea grown in a liquid solution. Of these characteristics, the protein content of the three upper leaves in a 30‐day‐old plant showed the best correlation with yield capacity. The correlation was also good (r = 0.32—0.94), when samples from the 3 upper leaves were taken in field‐grown material. The protein content of the 3 uppermost leaves can be used to reject genotypes that have low initial nitrogen fixation and thereby low yield capacity. This will increase the possibility of testing lines for other agriculturally important characters.
Selection for Seedling Emergence Using a Glasshouse Test in Pearl Millet*
Authors: Witcombe J. R. , Soman P.
Published: April 2006

Despite a fovourable environment during seed filling, ripening and harvest, and good storage conditions subsequent to harvest, there is variation for the ability of seeds of progeny of pearl millet (Pennisetum glaucum [L.] R. Br.) composites to emerge under favourable conditions in pots, or in the field. Seedling emergence in pots and in the field was found to be a heritable trait in at least two of four composites that had not been specifically constructed for improvement of seedling emergence. The predicted genetic advance from selection for ability to emerge in pots is appreciable. From examination of genotypic correlations, there will be smaller but useful gains over selection cycles in ability to emerge in the field by selection for improved emergence in pots. Direct selection under carefully controlled conditions in the field will produce higher gains, but is more resource consuming than a pot test.

We conclude that screening progenies in a pot test in a glasshouse and discarding progenies with poor emergence before a field progeny trial will reduce missing plots due to poor seedling emergence. Selection for improved emergence in pots should lead to an appreciable improvement in seedling emergence in the field over cycles of selection. The pot test is, therefore, a cost effective selection method for the important trait of high seedling emergence.
The Level of Field Resistance to Bremia lactucae in Lettuce (Lactuca sativa) Cultivars Carrying the Resistance Gene Dm11
Authors: Lebeda A.
Published: April 2006

Forty‐one lettuce cultivars (butterhead type), carrying race‐specific resistance gene Dm11 in combination with some others, were studied for field resistance to Bremia lactucae. Significant differences in the level of field resistance were revealed. Most of the cultivars under study were highly susceptible under field conditions. There are evident relationships between combinations of race‐specific Dm genes and field resistance. The cultivars with gene combinations Dm2, Dm3 and Dm11 are susceptible. A very high level of field resistance was detected in the cultivars with combination of genes Dm5/8, Dm6 and Dm16 (cvs. ‘Celia’, ‘Katanga’ and ‘Musette’). This is in close link with their Lactuca serriola origin and a high level of field resistance in progenitors.
Gene for Resistance to Barley Mild Mosaic Virus in German Winter Barley Located on Chromosome 3L
Authors: Kaiser Renate , Friedt W.
Published: April 2006

In order to identify the chromosome arm carrying a gene for resistance to barley mild mosaic virus (BaMMV) in German winter barley cultivars, a line trisomic for the long arm of chromosome 3 (telo‐trisomic 3L) was crossed to the resistant cvs. ‘Sonate’ and ‘Ogra’. Results of tests for BaMMV reaction in the F2 indicate that the gene for resistance in German cultivars is located on the long arm of chromosome 3.
Measuring the Severity of Eyespot Disease Induced by Pseudocercosporella herpotrichoides (Fron) Deighton in Wheat Cultivars at Different Growth Stages
Authors: Lind V.
Published: April 2006

From the total soluble protein of Pseudocercosporella herpotrichoides (Fron) Deighton, specific proteins were isolated and used as antigens. One antiserum proved to be highly sensitive and was used for quantitative determination of eyespot severity in 16 wheat cultivars. The detection limit in ELISA was calculated as 2.2 μg total fungus protein per ml plant sap. From anthesis, genotypes showed the most characteristic and reliable differentiation for a longer period of time, viz. at growth stages 60 and 75. These quantitative differences could be more successfully demonstrated with ELISA than with eye‐spot scoring. There was, however, a close correlation between both traits. The most resistant genotypes carried the gene Pch‐1 with the resistance originating from ‘Capelle Desprez’. Some genotypes originating from this cultivar showed rather low levels of susceptibility, which might be explained by additional effects of the genotypic background.
The Potential for Exploiting Variation in Salinity Tolerance in Pearl Millet (Pennisetum americanum (L.) Leeke)
Authors: Ashraf M. , McNeilly T. M.
Published: April 2006

Abstrct

Shoot and root growth and plant dry weight were determined for twenty four accessions of pearl millet, Pennisetum americanum (L.) Leeke, after two weeks growth in saline solution culture at EC 20 dS m‐1. The EC was achieved using NaCl + CaCl2 1:1 by weight in solution culture. Although salinity markedly inhibited growth of all accessions, three, 93613, KAT/PM‐2 Kitui, and Kitui local produced significantly greater dry matter, and they and 93612 had longer shoots than the other accessions. Accessions WCA 78 and Bulk 7704 were highly sensitive to salinity in all 3 characters measured. There was considerable variation between the 24 accessions, suggesting that selection for increased tolerance to salinity in pearl millet should be possible. This was examined using normal seed of the cultivar Al/3. A first cycle of selection screened 16,000 seeds after 15 days growth in nutrient solution at EC 26 dS m‐1. 106 individuals were selected to form the S1 selection line. Selected seedlings were grown to maturity and polycrossed.

In a second cycle of selection, 30,000 S1 polycross progeny were screened as previously, but at EC 30 dS m‐1. A selection intensity of 0.08% was achieved. The selected plants were again grown to maturity and again polycrossed.

Efficiency of the selection procedure was assessed from comparison in sand culture of the performance of the selected line with the unselected Al/3 line and Kitui local which from the previous assessment of the 24 accessions was rated as relatively salinity tolerant. The selection line was superior to the other two lines at four salinity levels. The results of this study suggest that further improvement in salinity tolerance in pearl millet may be expected from further selection and breeding, using the methods described here.
Test Systems for Evaluating Quantitative Resistance Against Fusarium Foot Rot in Inbred Lines of Winter Rye
Authors: Höxter Henriette , Sieber Gerlinde , Miedaner T. , Geiger H. H.
Published: April 2006

The first results of three test systems for evaluating the susceptibility of rye inbred lines to foot rot caused by Fusarium culmorum and F. graminearum are presented. The test systems were specifically designed for greenhouse, foliar tent and field experiments. The inbred lines, some of which are being used in commercial hybrids, showed significant variation for resistance. Significant interactions occurred between genotypes and test systems, and within the test systems between genotypes and years or growth stages. A significant correlation existed between susceptibility in the greenhouse and in the field (r = 0.84, P = 0.05), when inoculation in the greenhouse took place at the jointing stage (EC 31). In earlier growth stages, however, this correlation was not significant. In both greenhouse and foliar tent experiments, susceptibility to F. culmorum and F. graminearum was strongly correlated (r = 0.71, 0.87, resp., P = 0.01). In the field, F. culmorum alone was used for artificial inoculation. Genotypic variance and repeatability in the field were highest after inoculation in spring with conidia suspensions. It is concluded that, in inbreeding generations with limited seed quantities, the greenhouse and the foliar‐tent test systems offer good possibilities of indirectly improving foot‐rot resistance in rye.
Genetic Variability for Grain Yield and Protein Content in Barley and Its Modification by Net Blotch
Authors: Arabi M. I. , Sarrafi A. , Barrault G. , Albertini L.
Published: April 2006

Protein content, yield and 1000‐grain weight of healthy and net blotch‐diseased plants were studied in a diallel cross programme concerning nine different varieties of barley (Hordeum vulgare L.). F1 hybrids and their parents were grown in the field in two randomized block design experiments each with three replications (three inoculated and three non‐inoculated plots). General and specific combining abilities were determined for yield, protein percentage, 1000 grain weight, protein yield, and non‐protein yield. A high genetic variability for the traits studied was observed. Non‐protein yield and 1000‐grain weight decreased significantly in inoculated plants where protein yield was not affected. Significant general and specific combining abilities were observed for all traits. Values for general and specific combining abilities were, in some cases, significantly modified by net blotch of barley. This indicates that attention must be paid to the danger of drawing conclusions in quantitative genetics studies dealing with both diseased and healthy plants.
Radiation‐Induced Nullisomy in Hordeum vulgare L.
Authors: Ahmad H. , Khawaja H. I. T.
Published: April 2006

A plant with drastically reduced vigour was observed in a population of diploid barley (Hordeum vulgare) raised from seeds exposed to gamma radiation. Cytological studies revealed that the plant was nullisomic with 2n = 12. At meiosis, regular formation of 6 bivalents was observed. The plant was totally sterile and produced neither stainable pollen nor seed.
Agronomic Traits and Chromosome Behavior of Autotetraploid Sorghums
Authors: Luo Y. W. , Yen X. C. , Zhang G. Y. , Liang G. H.
Published: April 2006

The agronomic performance and chromosome behavior of autotetraploid sorghum [Sorghum bicolor (L.) Moench] inbreds and F1 hybrids were investigated. Autotetraploids have possible commercial use and can serve as bridging species in crosses to natural tetraploids. Autotetraploid sorghum inbreds (2n = 40) had higher kernel weight, seed yield, and protein and amino acid content than their diploid counterparts. Stalk height and panicle length of the autotet‐raploids, however, were not different from those of the diploids, and seed set of autotetraploids was lower in early generations. Seed set of autotetraploid Ft hybrids was related to and higher than that of the autotetraploid parental inbred lines. Frequency of quadrivalents, anaphase I and II laggards, and quartet micronuclei varied among autotetraploids. Frequency of quadrivalents did not appear to be an important factor in seed set nor was it significantly associated with frequency of laggards. Aneuploids (2n = 39, 41) had higher percentages of laggards and micronuclei than did euploids (2n = 40). Methods of pollination significantly affected seed set in autotetraploid S4 lines. Differences in seed set among autotetraploid lines indicated the feasibility of selecting for lines with high seed set and utilizing those lines for hybrid production.
Random Amplified Polymorphic DNA (RAPD) Markers in Sugar Beet (Beta vulgaris L.): Mapping the Genes for Nematode Resistance and Hypocotyl Colour
Authors: Uphoff H. , Wricke G.
Published: April 2006

The random amplified polymorphic DNA (RAPD) technique was adapted for segregation analysis in sugar beet. 83 IO/I individuals were scored with a set of 20 arbitrary decamer primers. 4 preliminary linkage groups could be established, enclosing 9 RAPD markers, 2 isozyme loci, a gene for the hypocotyl colour and a gene for resistance to the root knot nematode (Heterodera schachtii Schm.).
New Sources of Cucumber Mosaic Virus Tolerant Land Races of Cucumber Identified at the Centre of Origin (India)
Authors: Dhillon N.P.S.
Published: April 2006

Three land races of cucumber, ‘Srinagar Local‐I, ‘Srinagar Local‐II’, and ‘Paprola Local’, derived from the lower Himalayas were observed to be tolerant to cucumber mosaic virus. Tolerance was conferred by a single dominant gene in each variety. Tolerant genes present in ‘Srinagar Local‐I’ and ‘Srinagar Local‐II’ were allelic, whereas the tolerant gene present in ‘Paprola Local’ was non‐allelic.
Relationship Between Productivity and Phosphate Requirement as a Parameter of Selection in Medicago rigidula (L.) Allioni
Authors: Lorenzetti Sllvia , Scarponi L. , Perucci P. , Falcinelli M.
Published: April 2006

Among one hundred lines of Medicago rigidula (L.) Allioni, fifteen (5 high‐producing, HP, 5 intermediate‐producing, IP, and 5 low‐producing, LP) were chosen as experimental material because of their different dry‐matter production when grown at 0.5 mg L‐1 of P2O5 in hydroponic solution (critical level). The aim of this work was to evaluate the response to selection with respect to dry‐matter yield (DMY), made at 0.5 mg L‐1 of P2O5 and to check if superior lines could also be isolated when plants were grown at 20 and 200 mg L‐1 of P2O5. Results show that HP lines were also superior with respect to DMY (g/plant) at the higher phosphorus concentrations. Highly‐productive line selection in M. rigidula can also be achieved when plants are grown at a critical level of phosphorus in the nutrient solution. Phosphate content in the dry matter produced and phosphatase activity were also analysed. Plants of the more‐productive lines were characterized by lower phosphate content per unit dry matter and by a higher phosphatase activity.
Genetic Diversity for Adult Plant Resistance to Leaf Rust (Puccinia recondita) in Near‐Isogenic Lines and in Indian Wheats
Authors: Sawhney R. N. , Sharma J. B. , Sharma D. N.
Published: April 2006

Variation for adult plant resistance in near‐isogenic wheat lines carrying Lrl4b, Lrl4ab and Lr30 in a ‘Thatcher’ background indicated the possible presence of novel adult plant resistance genes effective against the Indian leaf rust population.

Sixty‐one wheats released for cultivation in India were grown in isolated nurseries. Each nursery was separately inoculated with one of four leaf rust pathotypes which had been selected to aid identification of resistance effective only in the adult plant stage. Seven distinct response groups were recognised and a minimum of six sources of adult plant resistance were postulated. In a group of 14 wheats, resistance was explained on the basis of the seedling response genes that were identified. Similar results for two years with pathotype 77‐1 gave support to the reliability of field tests. Adult plant resistance (APR) sources were either race‐specific or effective against all pathotypes used. Seedlings of cultivars with APR showed susceptible reactions. The possible presence of Lr34 in Indian wheats and its role in durable leaf rust resistance are discussed.
Aneuploid Analysis of Anther Culture Response in Wheat
Authors: Buyser J. De , Hachemi‐Rachedi S. , Lemee M.‐L. , Sejourne S. , Marcotte J.‐L. , Henry Y.
Published: April 2006

Genetic stocks of Triticum aestivum including the disomic, 8 ditelosomic and 3 nullisomic‐tetrasomic ‘Chinese Spring’ wheat lines were employed to ascertain the chromosomal arm locations of the genes acting on the production of embryos from micro‐spores and on the regeneration capacity (green and albina) of the microspore‐derived embryos. All these aneuploid lines differed significantly from the parental line ‘Chinese Spring’ for embryo production. Our results confirmed or in most cases established that genes affecting embryo production are located on several chromosomal arms: IBS, 1BL, 3AS, 3AL, 5AS, SAL, 5BS, 5BL, 7DS, 7DL. Whereas most of the chromosomal arms stimulate the production of embryos from the microspores, IBS and 1BL reduce it. The results of plant production from microspore‐derived embryos suggest that the genes increasing regeneration ability are located on CS5A chromosome and are likely associated to a gene increasing green plant frequency. On the contrary, the 1BL arm increases the albina frequency.
Changes in Frequency of Plants Resistant to Barley Leaf Rust Caused by Puccinia hordei Otth. in a Barley Composite Cross Population
Authors: Reinhold M. , Bjarko M. E. , Sands D. C. , Bockelman H. E.
Published: April 2006

The response of barley Composite Cross XLI to selection for resistance to leaf rust was evaluated. Representative samples from eight cycles of recurrent selection were inoculated with an isolate of Puccinia bordei Otth. in both the seedling and adult plant stage. Disease symptoms were evaluated 14 days after inoculation. The resistance in CC XLI increased with selection in the seedling stage from 15.1 to 20.5 %, and in the adult plant stage from 20.5 to 37.5 %, respectively. The largest gains in resistance were observed in the earlier cycles of recurrent selection. Significant fluctuations in percent resistant plants occurred between the years.
Reciprocal Crosses in Almond
Authors: Dicenta F. , Garcia J. E.
Published: April 2006

Reciprocal differences were determined in 18 inter‐varietal crosses of almond (9 direct and its 9 reciprocals) obtained from 6 varieties by means of hand pollination. Five traits were analyzed over three years (1989—1991) and seven traits over one year (1989). No reciprocal differences were detected for blossom density, percentage of double kernels and kernel smoothness. For flowering times (start, full and end) the differences were nearly inexistent. They were of varying importance for production density, time of ripening, kernel/in‐shell ratio and integument colour intensity in some crosses. In these cases, the direction of the cross must be kept in mind in order to improve the efficacy of future breeding programmes.
Efficient Production of Uniform Plants from Cotyledon Explants of Sugarbeet (Beta vulgaris L.)
Authors: Jaco B. , Tetu T. , Sangwani R. S. , De Laat A. , Sangwan‐Norreel B. S.
Published: April 2006

In order to improve regenerative potential in Beta vulgaris L. cultural conditions were established for efficient plant regeneration from cotyledon‐derived calli. Organogenic calli were initiated at frequencies of 8–59 % with six sugarbeet lines. N6‐benzyl‐ammopurine (1 mg/1) associated with 2,3,5 triiodobenzoic acid (0.5 mg/1) was found to be the best combination to alter the endogenous phytohormonal balance in 21 ± 1 day‐old seedlings. Flow cytometry was used to determine nuclear DNA Content (ploidy) in cotyledons, calli and regenerated plants, and suggested that 88 % of the regenerants were diploids. The relatively high cytological stability of the regenerants was attributed to the rapid cell differentiation within initiated calli. The problem of vitrification was overcome by using phloridzin and high agar concentration.
Anther Culture in Rye: Improved Plant Regeneration Using Modified MS‐Media
Authors: Daniel G.
Published: April 2006

The use of androgenetic doubled haploids in rye breeding is still limited by low regeneration rates. In this study we tested the influence of two modified MS‐media on the number of reacting anthers and on plant regeneration. Picloram and 2,4‐D were used as auxin components in the induction media. The highest induction rates (reacting anthers per 100 cultivated anthers) and the highest regeneration rates (number of green plants per 100 cultivated anthers) were reached on a modified MS‐medium containing Picloram as auxin source, regardless of the donor plant material. The comparison of the results obtained with the single cross ‘SC 35’ which contains genes of Secale vavilovii and the true Secale cereale donor forms clearly show the genotypic influence of donor plant material on induction and regeneration ability.
The Introgression of Genetic Information from Triticum monococcum L. into Hexaploid Triticale by Hybridization with a T. monococcum×S. cereale Amphiploid
Authors: Kison H.‐U. , Neumann M.
Published: April 2006

From the crosses (6 × triticale ‘Lasko’× AARR) ×‘Lasko’ one plant with 56 chromosomes was obtained. The selfed progenies showed reduction of somatic chromosome number. A reciprocal cross of hyperploid introgressive plants with ‘Lasko’ indicated similar transmission rates of additional chromosomes through female and male gametes. The degree of initial reduction is of great importance for the number of succeeding generations needed to reach the hexaploid level. With regard to the output of introgressive lines of practical breeding importance, it is necessary to continue and to promote the recombination processes between donor and recipient genetic information for as long as possible. An interruption of recombination by beginning selection too early leads to the loss of genetic variability in the progenies.
Resistance to Sunflower Rust and its Inheritance in Wild Sunflower Species
Authors: Quresh Z. , Jan C. C. , Gulya T. J.
Published: April 2006

Resistance to the prevailing races of sunflower rust, Puccinia hehanthi Schw., is lacking in the commercial hybrids (Helianthus annuus L.). The objective of this study was to identify new sources of resistance to the four North American rust races in wild Helianthus species, and to determine their mode of inheritance. Seventy‐eight accessions of H. annuus L., H. argophyllus Torrey and Gray, and H. petiolans Nutt. were evaluated in the greenhouse. Resistance to races 1, 2, 3, and 4 was observed in 25, 28, 15, and 26% of the plants, respectively, and 10% of the plants were resistant to all four races. Seven accessions that had a high percentage of resistant plants to all the four races were selected and one resistant plant from each accession was crossed with susceptible inbred line HA89. Three to four F1 plants resistant to all four races from each cross were backcrossed with HA89. F1 plants from PI‐413118 × HA89 and PI 413175 × HA89 were resistant to all four races. The PI 413023 × HA89 F1 plants were 100 % resistant to races 3 and 4 and segregated in a 3: 1 resistant (R) to susceptible (S) ratio to races 1 and 2. The other four F1 combinations segregated 3R: IS ratios to all four races. Bc1F1 progenies revealed that plants from PI 413048, PI 413037, PI 413038, and PI 413171 used in the crosses possessed two dominant genes in heterozygous condition for resistance to each of the four races, whereas plants from PI 413023 possessed two dominant genes in heterozygous condition for resistance to each of races 1 and 2, and one dominant resistance gene in homozygous condition for each of races 3 and 4. Plants from PI 413118 and PI 413175 carried a single dominant gene in homozygous condition for resistance against each of the four races.
Identification of a Stable Maintainer Line for ‘Polima’ Cytoplasmic Male Sterility in Rapeseed (B. napus L.)
Authors: Sodhi Y. S. , Pradhan A. K. , Mukhopadhyay A. , Pental Deepak
Published: April 2006

‘Polima’ cytoplasmic male sterility (CMS) was transferred to three different genotypes of B. napus i.e. GSL‐1, ISN706 and HNS‐8 by repeated backcrossing and was found to be completely stable in the nuclear background of synthetic B. napus genotype, ISN706, derived from a cross B. campestris ssp. oleifera var. brown sarson ×B. oleracea var. botrytis cv. Tusa Katki'. The BC5 and BC6 generation lines of ISN706, GSL‐1 and HNS‐8 with ‘Polima’ CMS were grown under a range of temperature and photo‐period conditions to test their stability. No breakdown in sterility was observed in ‘Polima’ ISN706 and, therefore, this genotype can be used as a maintainer for hybrid seed production.
Decrease of Waxy (Wx) Protein in Two Common Wheat Cultivars with Low Amylose Content
Authors: Nakamura T. , Yamamori M. , Hirano H. , Hidaka S.
Published: April 2006

Two cultivars with a low amylose content, Kanto107 (K107) and K79, were discovered in Japanese common wheat (Triticum aestivum L.). The amount of Wx protein, identified as a single major starch granule‐bound protein of about 61 kD by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE), was greatly decreased in those two cultivars. Analysis of their Wx protein with a modified SDS‐PAGE and two dimensional‐PAGE showed that two of the three Wx proteins, produced by Wx‐A1 and Wx‐B1 loci, were not detected. It was thus concluded that only one locus, Wx‐D1, was active in the two low amylose cultivars. These mutants were termed “partial waxy mutants” and considered to be very useful material for breeding waxy wheat.
Differential Adaptation of Complete and Substituted Triticale
Authors: Royo C. , Rodriguez A. , Romagosa I.
Published: April 2006

Adaptation of seven complete and twelve substituted triticales to specific soil types has been studied, based on a series of twenty trials carried out in 1989 and 1990 across Spain. The nature of the GE interaction for grain yield was revealed by means of the additive main effects multiplicative interaction (AMMI) model and using the soil pH at the different sites as linear covariate. The percentage of the variability explained by the first principal component axis of the AMMI model was 72 and 65 % for the two years, suggesting a specific pattern of adaptation. Soil pH was the single most important environmental factor to explain the adaptation of complete and substituted types. Complete triticales outyielded substituted genotypes in the majority of sites. Triticale adaptation to acid and alkaline soils seems to be largely controlled by the single wheat/rye chromosome 2D(2R) substitution, for which both types differ. Complete triticales seem better adapted to the acid soils, whereas substituted types are, in general, more suited to alkaline soils.
Variation in Doubled Haploid Plants of Wheat Obtained through Wheat (Triticum aestivum) × Maize (Zea mays) Crosses
Authors: Suenaga K. , Nakajima K.
Published: April 2006

Variation was investigated in 110 doubled haploid (DH) lines of wheat derived from wheat × maize crosses. Field observation revealed visible variations in 15 DH2 lines such as extreme dwarfism, low seed fertility, alteration of spike type and stripes. Six agronomic traits, i.e., heading date, spike number/ plant, culm length, spike length, seed fertility and grain weight were statistically analyzed in the DH2 and DH3 generations. Out of the 88 DH2 lines/DH3 groups, 26 %/64 % showed significant differences from the parental variety in the means of one or more traits. Ranges of the DH3 lines were larger than those of the DH2 lines, except for spike number/plant. Furthermore, analyses of variance within and between DH lines showed the presence of heterogeneity/heterozygosity in the DH2 lines/plants. These results indicated the occurrence of gametoclonal variation in the DH lines. It is considered that most of the variations detected were due to the colchicine treatment rather than to the 2,4‐D treatment or in vitro culture.
Improved Drought Resistance in Introgression Lines Derived from Lolium multiflorum × Festuca arundinacea Hybrids
Authors: Humphreys M. W. , Thomas H.
Published: April 2006

In a back‐crossing programme involving Lolium multiflorum (the recurrent parent) and Festuca arundinacea, the diploid L. multiflorum phenotype was rapidly recovered with the inclusion, in some progeny, of a small number of genes from the fescue parent. In field drought trials derivatives of these backcross populations were on average less drought resistant than the L. multiflorum parental populations, but 3 % of individuals were as drought resistant as F. arundinacea. After only one cycle of selection and polycrossing these drought‐resistant Lolium‐like plants, the mean drought resistance of most progeny lines was significantly improved, in some cases to near that of F. arundinacea. Available evidence strongly indicates that this improved drought resistance was due to the transfer of genetic material from Festuca into Lolium. These populations will contribute to variety improvement and to our understanding of the genetics and physiology of drought resistance.
Genetic Diversity for RFLPs in European Maize Inbreds
Authors: Boppenmaier J. , Melchinger A. E. , Seiltz G. , Geiger H. H. , Herrmann R. G.
Published: April 2006

Restriction fragment length polymorphisms (RFLPs) have been proposed for predicting the yield potential of different types of cross. Their has been evaluated in 15 flint and 12 dent inbreds from the European maize (Zea mays L.) germplasm as well as in 68 F1 crosses (21 flint × flint, 14 dent × dent, and 33 flint × dent) produced between them. The materials were evaluated for F1 performance and midparent heterosis of grain yield, dry matter content (DMC) and plant height in two environments in Germany. Genetic distances (GDs) between parental lines, calculated from RFLP data of 194 clone‐enzyme combinations, showed greater means for flint × dent (0.67) than dent × dent (0.62) and flint × flint (0.55) crosses. Cluster analysis based on GDs resulted in a clear separation of flint and dent lines and agreed well with pedigree information. For the complete set of 64 crosses analyzed (excluding 4 crosses between closely related lines) correlations of GD with F1 performance and heterosis were significant for all traits except F1 performance of DMC. When separate calculations were performed for individual subjets of crosses, correlations of GD with Fl performance and heterosis were significantly positive (0.48 ≤ r ≤ 0.80) for all traits in the flint × flint crosses, but not significant for the subsets of flint × dent and dent × dent crosses. Our results confirm those of previous investigations in that the predictive value of RFLP data is restricted to crosses between lines from the same heterotic group, and cannot be applied to crosses between lines from genetically divergent heterotic groups.
Change of Expected Response to Multitrait Selection in a Synthetic Population of Perennial Ryegrass Through Recurrent Selection
Authors: Charmet G. , Ravel Catherine , Balfourier François
Published: April 2006

The changes in genetic parameters, variances, covariances and heritabilities, caused by the Bulmer effect have been predicted for an artificial breeding population of perennial ryegrass using recursion formulae. This enabled anticipation of the decrease in the expected response to multitrait index selection, using two different sets of economic weights. This theoretical decrease in selection efficiency was found to be quite substantial; it is approximately halved after 4 cycles of individual recurrent selection with a fairly high selection intensity of 5 %.

However the synthetic population is improved for 4 out of 5 agronomic traits and could theoretically reach quite a high level of performance after 5 cyles. The choice of economic weights has relatively little influence on the expected genetic progress of each trait.
Transmission of Biochemical Flavor Constituents from Apricot and Plum to their Interspecific Hybrid
Authors: Gómez E. , Ledbetter C.
Published: April 2006

Intact fruit from five plum × apricot hybrids, two Japanese plums and seven apricots were sampled for their volatile constituents by headspace analysis to study the transmission of biochemical flavor constituents from apricot and plum to hybrids between them. Volatiles were collected in Tenax traps, eluted with ether, and examined by gas chromatography‐mass spectrometry. Forty‐one compounds from seven chemical classes were identified in the fruit samples. Seven of the identified volatiles were unique to plumcot, and not present in either the plum or apricot parent. Aromatic profiles from plumcot accessions more closely resemble apricot profiles rather than plum.
Maternal Effects on the Expression of Individual Aliphatic Glucosinolates in Seeds and Seedlings of Brassica napus
Authors: Magrath Ruth , Mithen R.
Published: April 2006

An investigation into the glucosinolate profile of seed and leaf tissue of F1 hybrids from reciprocal crosses between B. napus‘Cobra’ and a synthetic B. napus line was undertaken to test hypotheses concerning the site of biosynthesis of seed glucosilates. The profile of the seed aliphatic glucosinolates was dentical to the maternal parent suggesting the absence of glucosinolate biosynthesis and glucosinolate interconversion within the embryo and the transfer of fully formed glucosinolates from maternal tissue into the developing seed. In cotyledons, while there was no evidence for de novo glucosinolate biosynthesis, there was evidence for side chain modication and the interconversion of existing glucosinolates. in true leaves, the glucosinolate profile of the reciprocal F1 hybrids were identical, and in accordance with that expected from the F1 genotype.
The Reproductive System of a Lolium rigidum Gaud. Population from Sardinia and its Implications for Breeding*
Authors: Bullitta S. , Floris R. , Hayward M. D. , Veronesi F.
Published: April 2006

In order to establish an appropriate breeding programme, the reproductive system of a population of Lolium rigidum Gaud, from Sardinia was analyzed to determine the mechanisms operational in this species. A dual approach was adopted of genotype assay, exploiting the polymorphism at the Pgi‐2 locus, and an assessment of the effects of inbreeding on agronomic characters.

The statistical analysis showed highly significant differences for the number of plants due to selfing among the 35 progenies obtained by controlled crossing of genotypes homozygous for different alleles at the Pgi‐2 locus. The greatest inbreeding effect was on dry matter yield. Although at a bulk population level the species is outbreeding, highly self‐compatible plants can be found within this naturally‐derived population.
Anther Culture Derived Homozygous Lines in Hordeum bulbosum
Authors: Gudu S. , Procunier J. D. , Ziauddin A. , Kasha K. J.
Published: April 2006

The production of homozygous doubled haploids via anther culture was investigated in the self‐incompatible diploid species Hordeum bulbosum. Anthers from three accessions (GBC77, GBC752 and GBC753) were cultured on FHG media using IAA or three levels (1, 50 and 100 mg/l) of the auxin phenylacetic acid (PAA). Four green plants and 63 albino plants were obtained from a total of 1620 plated anthers (540/accession). The best mean anther response, number of embryogenic calli and regenerated plants were obtained with 50 mg/1 PAA. Three of the four green plants survived to maturity and, based on root‐tip squashes stained with feulgen, all had 14 chromosomes like the anther donor parent. These anther culture‐derived plants contained only some of the parental DNA bands, as observed by PCR analysis, indicating that they are of gametic origin rather than arising from somatic parental tissue. This is the first report of homozygous lines produced from this self‐incompatible species.
Identification of New Genes for Mildew Resistance of Barley at the Mia Locus in Lines Derived from Hordeum spontaneum
Authors: Jahoor A. , Fischbeck G.
Published: April 2006

Genetical studies have been conducted with lines derived from H. spontaneum showing that these lines carry dominant mildew resistance genes located at or near the Mla, locus. The resistance spectra of the lines ‘RS170—10 × Piccolo A’, ‘Diamant × 1B‐20’, ‘RS1—8 × Piccolo E’ and ‘Diamant × 1B‐151’ obtained from 10 European and Israeli isolates differ from previously‐identified Mia alleles. Therefore, it is suggested that these genes should be designated as Mla 25, Mla 26, Mla.27 and Mla 28, respectively. In addition, the RFLP‐patterns of these lines and their crossing parents were studied by hybridization with probes MWG 1H036, MWG 1H060 and MWG 1H068, which are very closely linked to the Mia locus. Two double crossover events have been identified. The use of RFLP markers for the identification of mildew resistance genes is discussed.
Variance Components and Heritability of Nut and Kernel Defects in Hazelnut
Authors: Mehlenbacher S. A. , Smith D. C. , Brenner Loretta K.
Published: April 2006

Nut samples of hazelnut (Corylus avellana L.) cultivars, selections, and seedlings were cracked and scored for frequency of good kernels and 7 types of defects. Blanks, poorly filled nuts, and moldy kernels were the most common defects. Variance components were calculated using defect counts from trees of 17 genotypes which were sampled in each of 4 years. The largest components were for among genotypes, genotype × year interaction, and between samples within trees. Year effects were large only for poorly filled nuts. The genotype × year interaction term was large for black tips, shrivels, and blanks. Variance components indicate limited genetic variability for brown stain, but moderate to large amounts for all other defects. Narrow sense heritability estimates from regression of progeny means on mid‐parent values exceeded 50 % for frequency of blanks (51 %), moldy kernels (61 %), kernels with black tips (60 %), and doubles (84 %), but was low for frequency of shrivelled kernels (22 %), poorly filled nuts (25 %), and brown stain (15 %). The low heritability of poorly filled nuts appears to indicate that the frequency of poor fill in the first crop or two produced by a young seedling does not reliably predict the genotype's susceptibility to this disorder rather than a lack of additive genetic variance. Heritability was intermediate for frequency of good kernels (42 %). Phenotypic correlation coefficients indicate that nut weight, kernel percentage, fiber rating, and pellicle removal rating are, for applied breeding purposes, inherited independently of the frequency of the 7 types of defects.
Heritability Estimate for Resistance to Alternaria dauci in Carrot
Authors: Boiteux L. S. , Della Vecchia P. T. , Reifschneider F. J. B.
Published: April 2006

An estimate of the narrow sense heritability of resistance to Alternaria dauci was obtained for the open‐pollinated carrot cultivar ‘Brasília’. The estimate, based on plot means of 96 half‐sib families was 0.4032 ± 0.1672, which may be considered in the medium‐low range. Considering this result, it is concluded that recurrent selection based on half‐sib progeny tests, will be more effective than simple phenotypic recurrent selection in increasing the resistance level of ‘Brasília’ to A. daucci.
Selection for Non‐Shattering Common Vetch, Vicia sativa L.
Authors: Abd El‐Moneim A. M.
Published: April 2006

Loss of seeds from mature pods is common in Vicia sativa L., an important annual, resown forage legume in West Asia and North Africa. Pod shattering restricts its use as a leguminous forage crop. This paper reports the results of germplasm evaluation for non‐shattering pods and of breeding and selection to improve seed retention.

Wide variation in pod‐shattering exists between common vetch ecotypes collected from different regions. Three wild mutants with almost completely non‐shattering pods were identified and isolated for use as a genetic resource in cross breeding programmes.

Genetic studies revealed that the non‐shattering character in the wild types of common vetch is due to a simple recessive gene, whereas shattering in the cultivated types is due to an allelic dominant pair of genes. Incorporation of the non‐shattering gene into agronomically‐promising lines was achieved by back‐crossing. Lines having an average of 95—97 % non‐shattering pods were obtained, as compared to 40—50 % in the original cultivated lines which represents a major agronomic advance in common vetch breeding. The importance of seed retention to the economics of seed production is discussed.
Development of Yellow Seeded Brassica napus Through Interspecific Crosses
Authors: Rashid A. , Rakow G. , Downey R. K.
Published: April 2006

Yellow seeded Brassica napus was developed through interspecific crosses with the two mustard species, B. juncea and B. carinata. The objective of these two interspecific crosses was the introgression of genes for yellow seed colour from the A genome of B. juncea and C genome of B. carinata into the A and C genomes of B. napus, respectively. The interspecific F1 generations were backcrossed to B. napus in an attempt to eliminate B genome chromosomes and to improve fertility. Backcross F2 plants of the (B. napus×B. juncea) ×B. napus cross were then crossed with backcross F2 plants of the (B. napus×B. carinata) ×B. napus cross. The objective of this intercrossing was to combine the A and C genome yellow seeded characteristics of the two backcross populations into one genotype. The F2 generation of the backcross F2 intercrosses was grown in the field, plants were individually harvested and visually rated for seed colour. Ninety‐one yellow seeded plants were identified among the 4858 plants inspected. This result indicated that the interspecific crossing scheme was successful in developing yellow seeded B. napus.
Combining Ability in Almond
Authors: García J. E. , Dicenta F. , Carbonell E. A.
Published: April 2006

2483 almond seedlings developed from 42 crosses between 12 parents were studied for three years (1989, 1990 and 1991). General and specific combining ability was determined for six traits (all years) and eight traits (1989 only). Additive factors are largely responsible for the genetic control of all traits, non‐additive factors being of importance for the density of flowering and particularly for the density of production, time and duration of maturation and double kernels. The results permit the correct choice of parents and crosses for future breeding programmes and provide a better insight into the genetic control of the traits studied.
Somaclonal Variation in Tissue Culture of Triticum aestivum×Agropyron desertorum F1 Hybrid
Authors: Li L. H. , Dong Y. S.
Published: April 2006

Callus induced from immature inflorescences of the partially self‐fertile hybrids (2 n = 35; ABDPP) between Triticum aestivum (2n = 42; AABBDD) and Agropyron desertorum (2n = 28; PPPP) led to the regeneration of 88 plants on MS medium supplemented with 2 mg/l of 2,4‐D. These regenerants were used to investigate somaclonal variation and to obtain more selfed derivatives. Immature inflorescences at the stage of developing floral primordia gave the best response in terms of callus induction and plant regeneration. The regenerants exhibited great variability for most morphological traits. Although the regenerants did not exhibit variation in chromosome number, they did show a higher degree of meiotic instability than the initial hybrid. In particular, the regenerants gave much higher selfed seed‐set (5.49 %) than the donor hybrid (0.46 %), so that a total of 484 selfed seeds were obtained.
Agroinoculation of Tomato Yellow Leaf Curl Virus (TYLCV) Overcomes the Virus Resistance of Wild Lycopersicon Species
Authors: Kheyr‐Pour A. , Gronenborn B. , Czosner H.
Published: April 2006

Accessions of the wild tomato species Lycopersicon chilense LA 1969 and L. hirsutum LA 1777 which are resistant to tomato yellow leaf curl virus (TYLCV) in field‐ and in whitefly‐mediated transmission tests were agroinoculated with a tandem repeat of the TYLCV genome. Large amounts of viral DNA started to accumulate in the agroinoculated L. chilense and L. hirsutum plants about 10 days after the agroinoculation. Yellowing and narrowing of the upper leaves were observed in the L. chilense plants but no curling as in susceptible L. esculentum cultivars. The agroinoculated L. hirsutum plants showed typical yellowing and curling of young leaves. These findings indicate that TYLCV introduced by means of agroinoculation leads to the breakdown of natural resistance mechanisms which prevent the replication, spread and expression of symptoms in resistant tomato genotypes.
Evaluation of Somaclonal and Mutagen Induced Variation in Fingermillet
Authors: Pius J. , George L. , Eapen S. , Rao P. S.
Published: April 2006

The effects of gamma rays and EMS on plant regeneration and somaclonal variation in fingermillet were studied. While EMS had an inhibitory effect on plant regeneration, gamma irradiation in low doses (5 Gy) was stimulatory. A wide range of variation was observed for almost all the traits and it was similar in both mutagen treated and untreated regenerants and seeds. This indicates that tissue culture itself induces variation and it can be exploited to advantage for crop improvement.
Distorted Segregation for Mildew Resistance in Doubled Haploid Lines of Spring Barley
Authors: Kintzios S. , Islam R. M. , Fischbeck G.
Published: April 2006

The mildew reactions of the second generation of doubled haploid (DH) plants, derived from anther culture of crosses among three spring barley lines carrying different Mla mildew resistance alleles and the cv. ‘Pallas’, were analyzed by using a set of three European and one Israeli mildew isolate. The results indicated, (1) a significant level of distortion segregation in favour of resistant DH genotypes, which was possibly due to linkage of mildew resistance genes on chromosome 5 with genes for plant regeneration and (2) various degrees of dominance for the different resistance genes studied as well as the possible action of modifier genes.
Designing a Wheat Ideotype with Increased Sink Capacity
Authors: Denćić S.
Published: April 2006

In this investigation, genotypes with branched, tetrastichon (two spikelets per node of the rachis), and normal spikes were used in order to induce changes in sink capacity, while high‐yielding domestic and foreign varieties served as donors of other traits. These materials were crossed by the methods of single‐, back‐, and top crossing and the desirable genotypes were selected by the pedigree method. After 10 years of breeding for the desired ideotype, whose main features had been a highly fertile spike of normal structure, short straw, curved leaves, and reduced tillering, 229 lines were tested in comparative yield trials. Among them, four lines were superior in yield and other traits to the highest yielding standards. Regarding the expected changes in sink capacity, considerable progress was made in spike length, number of grains per spike, number of grains per spikelet, and the weight of grains per spike.