bluuebunny/crossref_metadata_2025 huggingface dataset:
Seed Storage Proteins of Triticum turgidum ssp. dicoccoides and Their Effect on the Technological Quality in Durum Wheat
Authors: Ciaffi M. , Benedettelli S. , Giorgi B. , Porceddu E. , Lafiandra D.
Published: April 2006

F4 progenies of a cross between durum wheat cultivar ‘Creso’ and an accession of Triticum turgidum ssp. dicoccoides with high protein content were analysed by two different electrophoretic procedures (A‐PAGE and SDS‐PAGE). Variation of storage proteins at the Glu‐A1, Glu‐B1, Glu‐B3 and Gli‐B1 loci was studied. Electrophoretic analyses have shown that parents contain different alleles at each of the four loci considered and that protein components of T. dicoccoides are uncommon among cultivated wheats. Recombination between the Glu‐B3 and Gli‐B1 loci was observed. To determine the effects of the allelic variants on gluten properties, F5 grains from every F4 line were analysed for protein content and SDS‐sedimentation value. Gluten quality was strongly associated with the allelic type of proteins coded by the Glu‐B3 locus and, to a lesser extent, to those coded by Glu‐A1. Mean sedimentation value of progenies possessing the ‘Creso’Glu‐B3 allele was significantly greater than that showing the T. dicoccoides allele. High molecular weight glutenin sub‐units coded by the T. dicoccoides Glu‐A1 locus were also associated with larger sedimentation values than null form of ‘Creso’. Results of SDS‐test, obtained for recombinants between Glu‐B3 and Gli‐B1, confirmd that specific omega‐ and gamma‐gliadins are only genetic markers of quality, whereas variation for LMW glutenin subunits coded at Glu‐B3 is responsible for differences in gluten properties.
Early Embryo‐Sac Development in Faba Beans (Vicia faba L.)
Authors: Lazaridou T. B. , Roupakias D. G.
Published: April 2006

Early embryo‐sac development in two faba bean (Vicia faba L.) cultivars (A‐108 and A‐151) was studied under a 23/16°C day/night temperature regime. Endosperm nuclei divided synchronously during the first 8 divisions and produced normal nuclei. Aberrant endosperm nuclei were first observed after the 7th division and their number increased rapidly after the 10th division. Endosperm nuclei continued to divide until the 18th day after pollination. During the following days the endosperm nuclei decreased in number and finally disintegrated. Neither cellularization nor starch deposition was observed in the endosperm. It was concluded that early embryo‐sac development in Vicia faba was different from V. narbonensis only in that the mean endosperm cell cycle time in V. faba was longer than in V. narbonensis.
Characteristics of the Incomplete Resistance of Hordeum chilense to the Root‐Knot Nematode Meloidogyne naasi Franklin — Description of a Newly Conceived Test to Detect the Resistance
Authors: Balhadere P. , Person‐Dedryver F.
Published: April 2006

We are able to describe, due to some assays conducted under field conditions, the different ways the root‐knot nematode of cereals was affected in some amphiploid plants carrying the resistance of a wild Hordeum sp. This resistance arises in one of three ways: (i) a reduction in the establishment of the infective juvenile stages in the root, (ii) a delay and/or a cessation of development of the parasite occurring at the J2 or swelling‐J2 stage, (iii) an altered fecundity of the females. These three actions efficiently control the multiplication of the nematode, resulting in few females at the end of growing period of the crop. A new test was developed for early screening of the resistance under controlled conditions. Based on the analysis of the gall rating and the contents of five young galls from each plant, the response of a line can be seen within 16 days, while preserving the viability of the plants to continue their growth.
Evaluation of Potato Hybrids Obtained from Tetraploid‐Diploid Crosses II. Progeny Analysis
Authors: Tai G. C. C. , De Jong H.
Published: April 2006

A total of 45 tetraploid‐diploid (4x—2x) hybrid progenies were obtained by crossing each of ten diploid parents as males to each of five tetraploid parents. Means of six traits of the 45 progenies obtained from a two‐year experiment were used in progeny analysis. A new mathematical model is developed for analyzing the incomplete two‐way table. It is modified from the conventional model for factorial mating design. The aim of the model is to evaluate the potential of 2x parents in terms of their mean effects (μi) and sensitivity measures (Bi) to the 4x parents. The 4x parents were treated as testers in the model. They were compared by the estimates of the magnitude of tester effects (gi). The mean effects of 2x parents showed a dominant influence on variation of tuber number and mean tuber weight of the hybrid progenies. They also demonstrated a substantial influence on the variation of total and marketable yield, chipping score and specific gravity. The linear response of 2x parents to 4x parents, however, also showed a substantial influence on the variation of the latter traits. The information on μi and Bi are useful in terms of choosing superior 2x parents and, together with gj of 4x parents, 4x—2x progenies for specific traits. The μi and Bi estimates of the six traits showed a complicated interrelationship to each other.
Gene Localization of Aspartate Aminotransferase and Endopeptidase Isozymes in Wheat and Rye Using Developmental and Organ‐Specific Patterns
Authors: Drefahl Sonja , Buschbeck R.
Published: April 2006

Wheat, rye and wheat‐rye addition lines have been investigated regarding their developmental and organ‐specific isozyme patterns of aspartate amino‐transferase (AAT) and endopeptidase (EP). Evidence is given, that development‐specific isozymes of AAT are encoded by chromosomes 3R and 4R of ‘Imperial’ rye which can be used as biochemical markers up to leaf age of 14 days. Organ‐specific increase of intensity of bands for AAT in stems could be assigned to genes or alleles of chromosome 3A of ‘Chinese Spring’ wheat. For EP new markers were localized on chromosomes 4R and 6R of ‘Imperial’ rye showing variability. Utilization of these markers is possible at all developmental stages of the leaves. Mechanisms of gene regulation are discussed.
Heredity of Resistance to Botrytis cinerea in Sunflower (Helianthus annuus) Measured by Artificial Infections
Authors: Ladsous O. , Vear F. , De Labrouhe D. Tourvieille
Published: April 2006

This study was made to determine the reactions of sunflower genotypes to artificial infections of Botrytis cinerea under netting tunnels with irrigation. The genotypes were the parents and F1 hybrids of a factorial cross between 5 female (male sterile) and 5 restorer lines. Their resistance levels were measured by the mean delay between infection and symptom appearance on the capitulum. Significant genotypic differences in reaction to B. cinerea were shown. The ratio of general combining ability to specific combining ability was 2.9, indicating that additive effects are important. However, there were some significant interactions between male and female parents. The mean parent‐hybrid and parent‐progeny regressions were both significant with correlation coefficients of r = 0.57 and r = 0.66 respectively. It is concluded that breeding programmes with tests for B. cinerea resistance in early generations should be effective in the development of sunflower hybrids with improved B. cinerea resistance.
A Field Disease Evaluation Method for Selecting Wheats Resistant to Mycosphaerella graminicola
Authors: Jubene Mohammed , Gustafson J. P. , Rajaram S.
Published: April 2006

Reliable and efficient methods of selection are important for improving disease resistance. Three methods of field assessment of the Septoria tritici blotch disease, caused by Mycosphaerella graminicola (Fückel) Schroeter, were compared to identify the most reliable for selecting resistant wheats, Triticum aestivttm L. Nine cultivars which differed in disease reaction to plant height and maturity, and their progenies from several generations were used. The methods consisted of scoring chlorotic and necrotic leaf area covered with pycnidia on the flag leaf and the leaf below the flag leaf (flag leaf‐1) as percent of the total leaf area, on a plant‐basis, and the percent necrosis visually estimated on a plot‐basis. Plot data were greatly influenced by environmental changes leading to inconsistent genetic results. The flag leaf and flag leaf‐1 methods provided the most precise consistent results. The use of the flag leaf‐1 method is suggested for selection.
Identification of Powdery Mildew Resistance Genes in Common Wheat (Triticum aestivum L.)
Authors: Lutz J. , Limpert E. , Bartoš P. , Zeller F. J.
Published: April 2006

Major genes for resistance to powdery mildew were analysed in 24 Czechoslovakian wheat cultivars and, in part, in their parents. For this purpose individual isolates of the pathogen, able to differentiate host lines with known resistance genes, were selected. Eight of nineteen winter wheat cultivars do not possess any major resistance gene. Three cultivars have one and seven have two genes. One cultivar carries a combination of three genes (Pm2, Pm4b, Pm8). The most common resistance genes are Pm4b, Pm5 and Pm8. Pm2 is once combined with Pm6. Only one of five spring cultivars lacked a major resistance gene. Mlk is once present alone and twice combined with Pm5. There is one spring cultivar with a novel combination of three genes: Pm1, Pm5 and another gene needing further characterization. The observations are discussed with additional results of parent lines and further information on pedigrees.
Multigene Families of Powdery Mildew Resistance Genes in Locus Mla on Barley Chromosome 5
Authors: Jørgensen J. H.
Published: April 2006

A review of data on powdery mildew resistance genes in the Mla locus of barley reveals that there are at least 12 clusters of genes present, each comprising one Mla gene and one or more closely linked, additional resistance genes. Tentative designations are listed for 16 additional resistance genes. Many sources of powdery mildew resistance in barley appear to harbour multigene families in the Mla region, not single ‘superior’genes.
Glucosinolates and Resistance to Leptosphaeria maculans in Wild and Cultivated Brassica Species
Authors: Mithen R. F. , Magrath R.
Published: April 2006

Synthetic lines of Brassica napus were derived by combining the genomes of B. atlantica and B. oleracea var. alboglabra, which were respectively resistant and susceptible to foliar infection by Leptosphaeria maculans, with a susceptible line of B. rapa. Resistance was expressed in the synthetic lines containing the genome of B. atlantica. The high levels of alkenyl glucosinolates which occur in leaves of B. atlantica, and which have been implicated in disease resistance, were also expressed within the synthetic lines, although the dominant glucosinolate had changed from sinigrin to glucobrassicanapin. Disease resistance and glucosinolate profiles did not co‐segregate in F2 progeny from crosses between the synthetic lines.
Estimating Linkage Relationship of Isozyme Markers and Morphological Markers in Sugar Beet (Beta vulgaris L.) Including Families with Distorted Segregations
Authors: Wagner Hadwig , Weber W. E. , Wricke G.
Published: April 2006

The linkage relationship between eighteen isozyme loci and the morphological markers hypocotyl colour (R‐r), monogerm character (M‐m), pollen fertility (X) and stem fasciation (Verb.) are tested. Three linkage groups could be set up, involving all morphological marker loci and eight of the isozyme loci. Est‐2, R‐r, Fdp‐2, Got2 and Icd‐1 belong to linkage group I, linkage group II includes the loci Fas‐fas M‐m, Est‐3 and Aco‐1, linkage group III contains the loci X, Mdh‐1 and Est‐5.

When analysing the inheritance of isozymes and RFLPs, deviations are usually found in some lines from the expected frequencies of a 3 : 1 or 1 : 2 : 1 segregation at single marker loci. In many cases these data can still be used for the estimation of recombination values with linked loci under the control of selection. Procedures to estimate linkage in such cases are given and applied to experimental data in Beta vulgaris.
In Vitro Culture of Hybrid Indica Rice Combined with Mutagenesis
Authors: Gao M. W. , Cai Q. H. , Liang Z. Q.
Published: April 2006

The mutagenic effects of gamma radiation and sodium azide (SA) immersion of explants on culturability and frequency of somaclonal variation in indica rice were investigated. The results showed that young inflorescence and mature embryo were satisfactory explants both for in vitro culture and for mutagenesis. 1 kR gamma rays applied to immature embryos and exposure of calli derived from mature seeds at the dose range of 250—500 R led to a higher rate of callusing and plantlet regeneration, 0.5—1 kR would be the appropriate exposure for young inflorescence to produce a better culture response and higher variability, and 2.5—5.0 kR the optimal dose range for mature embryos. Immersion of mature seed in 2—4 mM sodium azide solution is a concentration level to induce these effects in indica rice. Application of optimal gamma exposure and chemical mutagen to rice explants enhanced the somaclonal variation frequency and provided a large number of variants useful for rice breeding.
Polyploidy and Aneuploidy in the Tamarillo, Cyphomandra betacea (Cav.) Sendt. (Solanaceae).
Authors: Pringle G. J. , Murray B. G.
Published: April 2006

The occurrence of spontaneous polyploidy was quantified in the tamarillo (Cyphomandra betacea [Cav.] Sendt.), a diploid (2n = 2x = 24) solanaceous fruit crop cultivated in New Zealand. Polyploids of this species were recognized by their small, almost seedless fruit, these types occurring at a frequency of 0.24 % in seedling orchards. Parallel spindles were seen on rare occasions during meiotic anaphase II in diploid tamarillos and were the probable cause of spontaneous polyploidy in this crop. Pollen volume and viability, seed number per fruit, seed weight, fruit size, stomatal length and guard cell chloroplast number were measured in diploids and polyploids. The polyploids typically showed the manifestation of the gigas effect, with thicker leaves and larger flowers. Pollen volume, stomatal length and guard cell chloroplast number also increased with higher ploidy. Pollen viability was markedly lower in the polyploids compared to the diploids and in combination with post‐zygotic abnormalities caused a reduction in seed set and hence fruit size. Improvements in fertility and thus fruit size would be needed if the polyploids were to have commercial potential.
Evaluation of Pedigree and Single Seed Descent Selection Methods for Cultivar Development in Cowpea (Vigna unguiculata L. Walp)
Authors: Obisesan I. O.
Published: April 2006

Three crosses of cowpea (Vigna unguiculata [L.] Walp) were used to assess the effectiveness of two selection procedures in cowpea. The selection procedures were pedigree selection (PD) and single seed descent selection (SSD).

Lines developed through each procedure were yield tested and selected at F6 and F7 for PD and SSD, respectively. The selected lines for both procedures were compared at F8 for grain yield per plant (YLD), number of pods per plant (NPO), and pod development period (PDP), in two locations.

Lines developed through both procedures differed more in their population means than in the performance of their top 10% or highest yielding lines. There was no consistent relationship between magnitude of genetic variability and percentage of superior lines obtained from each procedure. Both procedures have been effective in producing superior genotypes for yield and number of pods. The PD method produced superior transgressive segregants in two out of the three crosses for PDP. SSD allowed a more rapid generation than PD.
Microspore Embryogenesis Induced by Low Gamma Dose Irradiation in Apple
Authors: Zhang Y. X. , Bouvier L. , Lespinassei Y.
Published: April 2006

Flower buds and extracted anthers of two apple genotypes, ‘Golden Delicious’— a previously known non‐androgenic genotype — and ‘Topred’— a known androgenic genotype —, were irradiated by gamma‐rays at doses ranging from 5 to 20 Gy, after 0 to 5 weeks of cold pre‐treatment (3 °C). When the extracted anthers were irradiated, both microspore embryogenesis and callogenesis were limited for the two genotypes. For ‘Golden Delicious’, androgenic embryogenesis was induced from the flower buds irradiated at 10 to 20 Gy and after 3 to 5 weeks of cold pre‐treatment. For ‘Topred’, androgenic embryogenesis was slightly improved after flower bud irradiation at 5 to 10 Gy following cold pre‐treatment from 0 to 3 weeks; it was limited after 5 weeks of cold pre‐treatment.
EMS Induction of Early Flowering Mutants in Spring Rape (Brassica napus)
Authors: Thurling N. , Depittayanan V.
Published: April 2006

Studies were undertaken to induce early flowering mutants by ethyl methanesulphonate (EMS) treatments of Brassica napus seeds. EMS treatments for 12 h of a highly inbred B. napus line TBS had adverse effects on M1 plant development and fertility only when concentrations were greater than 1%. However, an EMS concentration of 1.5% did not reduce M1 plant fertility to an extent which significantly reduced production of M2 seeds.

Genetic changes induced by EMS treatment and affecting flowering time were of three main types: (1) Changes within a polygenic system reflected by increased variation in flowering time among M2 families. As the increase in variation was due primarily to a higher frequency of later flowering plants, these polygenic changes would be of little value in developing better‐adapted cultivars. (2) Induction of a recessive mutation at a major gene locus which caused M3 plants homozygous for the mutant gene to flower at least 20 days earlier than the parental line TB8. (3) Induction of a dominant mutation at a major gene locus which affects flowering time by causing a substantial reduction in vernalization requirement. M2 plants carrying the mutant gene flowered as early as 59 days before the parental line.

These major gene mutations could be rapidly exploited in the development of agronomically superior cultivars for short‐season, lower rainfall environments in Western Australia.
Genetic Variation for Agronomic Characters in a Burley Tobacco Synthetic Following Recurrent Selection for Increased Black Shank Resistance
Authors: Legg P. D. , Nielsen M. T.
Published: April 2006

Black shank, a fuagal disease caused by Phytophthora parasitica var. nicotianae, is a major hazard in the production of burley tobacco (Nicotiutta tubacum L.). Moderate levels of resistance have been bred into cultivars, but little success has been achieved in utilizing high levels of resistance found in the cigar line. Beinhart 1000‐1. Beinhirt 1000‐1 and seven burley cultivars were combined into a synthetic population and three cycles of selection for increased black slunk resistance were conducted. The objectives of this study were (i) t0 estimate genetic variability for agronomic traits in the original base population (Co) and die three selection cycles and (ii) to characterize the effects of selection for black shank resistance on the agronomic traits. Fifty selfed lines From the base population and each of three selection cycles were evaluated in replicated field trials at Lexington and Princeton, KY. Differences among cycle means for six agronomic traits were not statistically significant. Genetic variation for the six traits among lines within cycles was highly significant and did not change during selection. The results indicated that previously assumed associations between black shank resistance in Beinhart 1000‐1 and undesirable agronomic traits were due to chromosomal linkages which were apparently broken by intercrossing. The C3 population would be a useful base population for selection to improve agronomic performance in black shank resistant genotypes.
The Identification of a Gibberellic‐Acid‐Insensitive Gene in Secale cereale*
Authors: Jliécne M. , Gustafson J. P.
Published: April 2006

Among 16 dwarfing genes identified in wheat (Triticum aestiuvm L. em Thell.), four are known to be associated with insensitivity to the externally‐supplied growth hormone gibberellin (GA). Rht1 and Rht2 (Reduced height 1 and 2, respectively) have been the most extensively used, because of their positive effect on yield. To increase the germplasm pool for dwarfism, a spring rye (Secale cereale) population (UC‐90, CI‐174) was selected because it contains high variability and any useful genes would benefit triticale and wheat as well. Seedlings of the CI‐174 rye population were treated with 50 ppm of GA to identify any insensitive types. GA‐insensitive and ‐sensitive seedlings were identified and, after three generations of selfing, GA‐insensitive and ‐sensitive lines were fixed. Rye insensitive was crossed to a sensitive wheat and to rye and, reciprocally, insensitive wheat was crossed to sensitive rye. The results indicated that a GA‐insensitivity dwarfism system similar to that originally found in wheat also operates in rye and appears to be under simple inheritance. Rye GA‐insensitivity was expressed in triticale. Therefore, it is possible to transfer this new source of insensitivity and dwarfism into triticale and wheat.
Performance of S2 Winter Barley Progenies from Original and Improved Populations Developed via Recurrent Selection
Authors: Marocco A. , Cattivell L. , Dtloou G. , Lorenzoni C. , Sianca A. M.
Published: April 2006

The effect of recurrent selection procedure for improving grain yield in autogamous cereals was evaluated in a six‐rowed winter barley population. Gain from selection was estimated by field testing 90 random S2 lines from each of the C0, C1 and C2 populations. Response to selection for grain yield was 0.78 t/ha from C0 to C1 and 1.09 t/ha from C1 to C2. Broad‐sense heritability and genotypic variance for grain yield remained high in all cycles which suggests further gain from additional selection cycles. Yield increase was due to a higher number of seeds/m2. Significant differences among mean values were observed for heading date (189 days in C0 and 182 days in C2), whereas no variation was seen for plant height and 1000‐kernel weight. The proposed recurrent selection procedure appears effective to improve the population and to extract superior genotypes for varietal development.
Plant Regeneration from Callus Cultures of Allium trifoliatum subsp. hirsutum and Assessment of Genetic Stability by Isozyme Polymorphism
Authors: Viterbo A. , Rabinowitch H. D. , Altman A.
Published: April 2006

Plant regeneration from callus cultures of Allium trifoliatum subsp. hirsutum fertile accession F‐370, was studied as a means for clonal multiplication and germplasm storage of Allium spp. Callus was induced on in votro‐cultured basal leaf explants. Best proliferation was obtained on modified BDS medium supplemented with (mg/1): 0.75 picloram, 2.0 benzyl adenine, and 900 casein hydrolysate. Shoot and root organogenesis were obtained in 3 to 5 month old subcultured calli, on BDS or MS medium supplemented with (mg/1): either 0.03 picloram or no auxin, 2 BA or 2‐isopentenyladenine, and 900 casein hydrolysate. Direct bulb formation, without shoot elongation, occurred on BDS medium with 10 mg/1 IBA. Under these conditions, callus formation and organogenesis were not obtained with A. trifoliatum subsp. hirsutum var. sterile, a male‐sterile genotype. Most regenerants were phenotypically normal, but some abnormal shoots were also observed, i.e. shoots with vitrified or extremely broad leaves. Isozyme polymorphism analysis of seven proteins in the latter regenerants, and in several callus cultures, revealed significant deviation from the original pattern in esterase, 6‐phosphogluconate dehydrogenase and superoxide dismutase. No such deviations were detected in normal regenerated plants.
Origin of Sv Genome of Aegilops variabilis and Utilization of the Sv as Analyser of the S Genome of the Aegilops Species in the Sitopsis Section
Authors: Yu M. Q. , Jahier J.
Published: April 2006

Hybrids of Aegilops variabilis (2n = 28, UUSvSv) with the low‐pairing type lines of Ae. longissima, Ae. bicornis, Ae. searsii, Ae. speltoides and Ae. umbellulata were obtained. This is the first report of successful hybridization between Ae. variabilis and Ae. searsii. Meiotic analysis of these hybrids showed that the U genome of Ae. variabilis donated by Ae. umbelltilata remained nearly unchanged and Ae. longissima is the possible donor species of the S genome to Ae. variabilis. But the Sv genome and the S1 genome of Ae. longissima are not completely homologous and are structurally differentiated by at least one interchange. According to their levels of homology with Sv through the means of chromosome associations, the four genomes of Sitopsis section species can be classified as follow: Sv≃ S1 > Sb > Ss > S. The meiotic behaviour of the hybrids between the wheat ‘Chinese Spring’ and the four Sitopsis section species studied has not supported the view that one of the four species is the donor of the B genome of wheat.
Gamma Ray‐Induced Field Tolerance to Phytophthora Blight in Sesame
Authors: Pathirana R.
Published: April 2006

Due to the non‐availability of sources of resistance in Sri Lanka to Phytopbthora blight in sesame (Sesamum indicum) caused by Phytopbthora nicotianae var. parasitica, a mutation breeding programme was initiated. Seeds of three genotypes were subjected to six doses of gamma rays from 100 Gy to 750 Gy from a 60Co source. Seeds of M2 bulks, sampled by variety and treatment from the first five capsules formed on M1 plants, were grown in a field with a history of repeated incidence of the disease. The best 21 lines, having the highest survival and seed production, identified in the screening of M3 and M4 progeny rows of selected M2 single plants were then tested in a replicated field trial with the recommended cultivar ‘MI 3’ as a control. The plant survival in selected lines averaged 43.3 percent as against 7.2 percent in the recommended variety. Eight selections recorded significantly higher seed yield than ‘MI 3’ at P < 0.01 and another three at P < 0.05. Gamma ray treatments of 450 Gy and 600 Gy produced more lines tolerant to the disease than the other doses used.
Effects of Hordeum chilense and Triticum Cytoplasms on Agronomical Traits in Hexaploid Tritordeum
Authors: Millán Teresa , Martin A.
Published: April 2006

The genome of Tritordeum, AABBHchHch, was substituted into the cytoplasms of Triticum aestivum, T. turgidum and Hordeum chilense by repeated back‐crossing to produce alloplasmic lines. This substitution did not greatly affect the characters studied, except yield per plot and fertile ears per plant, which were lower on T. turgidum cytoplasm. Cytoplasm from either H. chilense or T. aestivum could be used for breeding tritordeum.
Genetic Analysis of Resistance to Xanthomonas campestris pv. oryzae (Ishiyama) Dye in a Rice Breeding Line ARC 10464
Authors: Singh R. P. , Gupta A. K. , Saini R. G.
Published: April 2006

The genetics of resistance to three Indian pathotypes of Xanthomonas campestris pv. oryzae, namely, IX01, IX08 and IX09, was studied in a landrace of Indica rice ‘ARC 10464’. Resistance to each of the two pathotypes IX01 and IX09 was governed by two independently‐inherited dominant genes while a single dominant gene was operative against patho‐type 1X08. The joint segregation tests conducted on F2 plant progenies (F3 families) using pathotypes IX01, IX08 and IX09 suggested that the gene/(s) effective against each of the pathotypes are different.
Triticale, Still a Promise?
Authors: Lelley T.
Published: April 2006

Experiments with primary triticale genotypes produced from defined wheat and rye parents provide a strong indication of a preponderance of specific genome combining ability in the phenotypic expression of triticale. Studying line families developed from specific cross combinations by means of the single seed descent method revealed that, in contrast to wheat, the distribution of genotypes in an F2 population of triticale is strongly skewed, with the majority of them being inferior to the mid‐parent value. This is the case even if recombination is restricted to one fourth of one of the parental components of triticale, i.e. wheat or rye. Correlations of yield components were found to deviate substantially from known types of correlations in wheat, an established natural allopolyploid species. These findings give a strong indication for a genomic inbalance in triticale being a major cause for slow advance in varietal improvement. New breeding strategies designed for the specific genetic structure of triticale are necessary to accelerate breeding progress and to help triticale ultimately to live up to its promise.
Further Characterization of rollC Transgenic Tetraploid Potato Clones, and Influence of Daylength and Level of rolC Expression on Yield Parameters
Authors: Fladung M. , Ballvora A.
Published: April 2006

Tetraploid rolC transformants have been analyzed considering the level of rolC expression and yield parameters. In rolC transformants a maximum of five integrated copies of the gene were detected by Southern analysis. A relation between copy number of the rolC gene, phenotypic rolC expression and intensity of morphological alterations was established. Three experiments were performed to assess the differential effect of the rolC gene on yield and its interaction with growth factors. In the first experiment, the influence of day length on plant morphological and physiological characters was studied. The phenotype of the transgenic plants with a low rolC expression was like the control under the two day‐regimes tested, while the intermediate expressing genotype showed a different reaction. In the second and third experiment, tuber yield, tuber number and weight per tuber were recorded under short and long day conditions. When grown in smaller pots of 1.15 1 volume, the control plants had the highest yield of tubers under both day lengths tested. Yield decreased with increasing rolC expression. Tuber number revealed to be genotype dependent: it was higher for low rolC expressing plants and lower for intermediate rolC transformants (Experiment 2). In the third experiment the influence of variable pot size and shape was analyzed for one clone with intermediate and two with low level of rolC expression. Remarkable differences between pots and flat boxes of the same volume were noted for tuber yield and number: Under the two conditions the control clone and the low rolC expressing genotypes gave similar tuber yield and number in both growth containers, whereas the rolC intermediate genotype yielded significantly more in flat boxes. The effect of variable hormonal levels induced in transgenic plants through prokaryotic genes are discussed with the existence of non‐predictable genotype in relation to environmental interactions. It is concluded that at least the agronomic performance of potatoes transformed with these genes cannot be predicted on the basis of simple linear relationships among the expression of the gene and of the traits.
Correlated Responses in Two Traits when Selection is Practised on their Ratio
Authors: Hühn M.
Published: April 2006

In many fields of application in plant breeding and crop science, ratios of two component traits X and Y are of interest (harvest index in cereals, leaf‐to‐stem ratio in forage legumes, height‐to‐diameter ratio in forest trees etc.). When selection is practised on the ratio X/Y of two traits X and Y, the experimenter may be interested in the resulting changes of both trait means.

Based on improved approximations for the covariances between X and X/Y and between Y and X/Y and for the variance of X/Y the changes in the means of X and Y can be predicted by applying the regression approach from conventional selection theory. Explicit expressions for these correlated responses in X and Y when selection is practised on their ratio X/Y are derived and discussed.

The different outcomes (decrease, zero change or increase) for the selection pressures on X and Y are characterized by phenotypic coefficients of variation of X and Y, phenotypic and genotypic correlations between X and Y and heritabilities of X and Y.
18S.26S Ribosomal RNA Genes Are Not in Every Case Located on the B Chromosomes in the Rye Genome
Authors: Niwa K. , Tsujimoto H.
Published: April 2006

To examine whether or not the 18S.26S ribosomal RNA genes are located on the B chromosomes of rye, we applied conventional and molecular cytological techniques to the B chromosomes of six rye strains, including cultivated, weedy and wild species. The results indicated that the B chromosomes in the rye genome do not generally carry repeats of the 18S.26S rRNA genes detectable at the cytological level.
Histological Observations on Interspecific Crosses in the Genus Lupinus
Authors: Busmann‐Loock Almut , Dambroth M. , Menge‐Hartmann U.
Published: April 2006

The hybridization barriers of interspecific lupin crosses were determined by histological investigations. The cross Lupinus hartwegii×L. mutabilis (both of American origin) revealed embryos in the cotyledonary stage as well as cellular endosperm. In the reciprocal combination, L. mutabilis×L. harwegii, embryo development stopped at the end of the globular stage, and simultaneously the coenocytic endosperm did no differentiate into the cellular state. In the combination L. luteus (European origin) ×L. hartwegii, embryo as well as endosperm development were initiated. Embryo development ended at any early globular stage. Twelve days after pollination the coenocytic endosperm had almost degenerated. With L. hartwegii as the female, no pollen germination could be observed.
Expression of Introduced Genes after Tuber Propagation of Transgenic Potato Plants
Authors: Ottaviani Marie‐Paule , Hänisch ten Cate Charlotte H. , van Vloten‐Doting Lous
Published: April 2006

The stability of expression of alien genes was analysed in transgenic plants of the potato cv. ‘Bintje’ during successive tuber generations. Three generations of four shoot lines selected on the presence or absence of expression of genes, originating from the Agrobacterium strain LBA1060KG, were investigated. Six traits (presence of opines, leaf form, plant habit, tuber form, GUS activity and kanamycin resistance) caused by the expression of marker loci from TR‐ and TL‐DNAs of A. rhizogenes strain LBA9402 and TKG‐DNA from pBI121 plasmid were analysed.

The quantitative analysis of the traits was carried out in 272 plants. In all, 1224 observations were made for the six traits. No variation in the expression of introduced genes was observed among the tuber progeny plants. It was remarkable that none of the silent genes (rolA and GUS in 252 and 168 plants, respectively) was activated in the tuber progeny. Moreover, consistent expression of genes that affect plant development (rolA and rolC with 816 observations) as well as plant neutral genes (opine, GUS and NPTII with 408 observations) was observed. The results indicate that there was no difference in stability of expression between transgenes and resident genes during vegetative propagation through tubers.
Genetic Analysis of Resistance to Gall Midge (Orseolia oryzae Wood Mason) in Rice
Authors: Tomar J. B. , Prasad S. C.
Published: April 2006

The inheritance of resistance to rice gall midge (Ranchi biotype) was studied in 12 resistant cultivars by crossing with susceptible cultivars. By the study of F1, F2, F3, B1 and B2 generations, it was found that resistance was governed by a single dominant gene in ‘Surekha’, ‘Phalguna’, ‘Rajendra Dhan 202’, ‘IET 7918’‘IET 6187’, ‘BG 404‐1’; by duplicate dominant genes in ‘W 1263’, ‘RPW 6‐17’ and ‘WGL 48684’ and a monogenic recessive gene in ‘OB 677’ and ‘BKNBR 1008‐21’.

The allelism test of the resistant genes in the test cultivars with already known genes Gm1 and Gm2 was carried out. A single dominant gene that conveyed the resistance in ‘RPW 6–17’, ‘IET 7918’ and ‘IET 6187’ was allelic to Gm1 and segregated independently of Gm2. The resistance in ‘Phalguna’, ‘Rajendra Dhan 202’, ‘W 1263’ and ‘RPW 6–17’, ‘IR 36’ and ‘WGL 48684’ was governed by Gm2 gene which was independent of Gm1. Two additional genes were identified and designated as Gm3 and gm4. Three test cultivars ‘BG 404‐1’, ‘W 1263’ and ‘WGL 48684’ were found to have Gm3 gene for resistance which was non‐allelic and segregated independently of Gm1 and Gm2. Thus the cultivars ‘W 1263’ and ‘WGL 48684’ had two resistance genes Gw2 and Gm3 together. The cultivar ‘RPW 6–17’ also had two resistance genes Gm1 and Gm2 together. The recessive gene gm4 which conditioned the resistance in ‘OB 677’ and ‘BKNBR 1008‐21’ was nonallelic to and segregated independently of Gm1, Gm2 and Gm3 genes.

Linkage studies of the resistance gene with pigment characters were carried out in ‘Purple gora/IR 36’ cross. The resistance gene Gm2 was found to be linked with the genes governing the pigmentation in node, apiculus and stigma with crossover values of 15.78, 31.57 and 35.78 % respectively. By the trisomic analysis, it was found that the Gm2 gene was located on chromosome 3.
Characterization of Environments in Long‐Term Multi‐Site Trials in Asparagus, through Yield of Standard Varieties and Use of Environmental Covariates
Authors: Rameau C. , Denis J. B.
Published: April 2006

In genotype‐environment interaction studies, in long‐term multi‐site trials, two main problems arise: missing values, and assessment of environments which consist of diverse locations and years. In this paper, a factorial regression model on asparagus data has been used to overcome these difficulties. These data consist in yields of seven asparagus standard varieties observed in 35 combinations of 4 locations × 9 years with missing values. Two kinds of covariates were kept in the model: (i) a biological one, ej, which is the main environmental effect estimated with the additive model on a chosen set of genotypes (standard varieties); and (ii) three external environment covariates: the latitude of the location, the type of production (green or white asparagus), and the mean temperature during the five months preceding the beginning of the harvest. These results suggest that a significant part of genotype × environment interaction in asparagus is due to the different effects of low temperature during the dormant period on the physiology of the sub‐ground crown, depending on the genotype.
Transfer of the Glu‐D1 Gene from Chromosome 1D of Breadwheat to Chromosome 1R in Hexaploid Triticale
Authors: Lukaszewski A. J. , Curtis Christine A.
Published: April 2006

The use of hexaploid triticale as a crop for human consumption has been limited by its inferior bread‐making quality. To ameliorate this problem, a segment of chromosome ID of breadwheat with the Glu‐D1d allele encoding for high molecular weight glutenin subunits 5 7plus; 10 was translocated to chromosome 1R of the hexaploid triticale ‘Rhino’ through a combination of a centric break‐fusion translocation followed by 5D(5B)‐induced homoeologous pairing. The resulting recombinant chromosome 1R has a small interstitial segment of ID with the Glu‐D1d allele. The maximum physical length of the translocated segment is estimated at about 16.5 % of 1DL. Frequency of translocations involving the long arms of homoeologous group‐1 chromosomes in the analyzed progeny suggested that homoeologous recombination in triticale was substantially higher than that previously reported in hexaploid wheat.
The Effect of Gelling Agents on Wheat Anther and Immature Embryo Culture
Authors: Simonson Randal L. , Baenziger P. S.
Published: April 2006

This study was conducted to determine whether inexpensive starches and various agars could replace Ficoll, which is very expensive, and Bacto‐agar, which may be inhibitory, in wheat (Triticum aestivum L.) anther and immature embryo culture. Anthers from Pavon 76’ had significantly greater embryoid‐initiation frequencies (number of embryoids per anther) on PI media with corn (0.67) and wheat starch (1.50) than with Ficoll (0.47). Anthers on 85D12 media with Ficoll, corn starch and wheat starch had similar embryoid‐initiation frequencies (0.51, 0.50, and 0.52, respectively). The embryoid‐regeneration frequencies (number of regenerating embryoids per embryoid plated) on 85D12 media containing corn (0.32) and wheat (0.36) starch were significantly higher than on 85D12 with Bacto‐agar (0.14). Embryoids on MS media with Bacto‐agar, corn starch, and wheat starch had similar embryoid‐regenerating frequencies (0.15, 0.20, 0.22, respectively), which were greater than with some of the other agars tested (0.05 to 0.17). When wheat starch replaced Bacto‐agar in immature embryo cultures, the frequency of responding embryos was unchanged, but the frequency of green plants regenerated increased an average of fourfold for two cultivars.
Inheritance of Resistance to Striga in Sorghum Genotype SRN39
Authors: Hess D. E. , Ejeta G.
Published: April 2006

Striga hermonthica (Del.) Benth., a parasitic weed of grasses, causes major yield reductions in the principal cereal crops of semi‐arid Africa. Cultivar resistance is the most economic control measure, since adapted, resistant cultivars can be grown without additional input from the subsistence farmer. Information on the genetics of resistance to S. hermonthica is scant. This is partially attributable to the rarity of germplasms which exhibit stable resistance across geographical regions. The objective of this study was to determine if the stable resistance observed in sorghum [Sorghum bicolor (L.) Moench] cultivar SRN39 is heritable. Crosses were made between SRN39 and a susceptible parent, P954063. Parental, F1, F2 and backcross generations were grown in infested pots and development of both host and parasite was monitored. Significant variation among genotypes was observed for both host traits and effects on parasite populations. The F1 did not differ significantly in Striga resistance from the susceptible parent, suggesting recessive inheritance. However, hybrid vigor was exhibited by the F1 which yielded and developed as well as the resistant parent. Broad sense heritability ranged from 0.23 to 0.55 for host traits and from 0.10 to 0.43 for effect of genotypes on the Striga population. Joint scaling tests showed that observed variation in each host or parasite trait consisted of additive and dominance components, suggesting possible progress could be made with appropriate selection schemes.
Stability and Heritability of Pith in Sugarcane and Its Influence on Yield
Authors: Deren C. W.
Published: April 2006

Selection for reduction or elimination of pith is common in sugarcane breeding programs. Pith is considered to be associated with reduced sugar yield. The purposes of this experiment were to investigate the relationship of pith to juice extraction and evaluate the stability of expression of pith over diverse environments. Twenty‐four sugarcane (Saccharum spp.) clones were grown at three locations in southern Florida, and evaluated for pithiness and the effect of pith on juice yield. Pith was greatest at the best cane‐growing location. Significant genotype × environment interaction was attributed to only six clones. Ranking of clones for pith changed with locations, but pithy clones tended to be pithy in all environments. Broad‐sense heritabilities for pith, Brix, diameter, and stalk weight ranged from 0.88 to 0.92. Pith was not correlated with juice extraction.
Overcoming Self‐Incompatibility of Brassica napus by Salt (NaC1) Spray
Authors: Tlngdong Fu , Ping Si , Xiaoniu Yang , Guangsheng Yang
Published: April 2006

The results of studies from 1982 to 1989 confirm that self‐incompatibility (SI) of B. napus can be effectively overcome by spraying solutions of 2 — 10 % table salt (NaCl) during the flowering period. The optimum salt concentration was found to be 5 %. Spraying onto both stigma and stamen is better than onto only one of them, in particular better than spraying only onto the stamen. When self‐pollination occurred at intervals of 1 to 32 hours after spraying 5 % NaCl solution upon stigma and stamen, the compatibility indexes fall slightly; they decrease considerably after 72 and 120 hours, but still then they stay higher than without spraying. After spraying 5 % NaCl solution at intervals of 4, 5, 8 and 24 hours, respectively, the compatibility indexes after self‐pollination are almost equal to that of bud‐pollination; this treatment is effective even at intervals of 48 or 72 hours after selfing. In practice, spraying 5 % NaCl solution every 3 to 5 days during the flowering period is enough for satisfying seed set of SI lines under field conditions.
Inheritance of Induced Morphological Mutants in Triticutn monococcum L.
Authors: Multani Dilbag S. , Sharma S. K. , Dhaliwal H. S. , Gill Khem S.
Published: April 2006

The mode of inheritance of fifteen induced morphological mutants in diploid wheat Triticum monococcum L. was determined. The results showed that earliness, reduced height, uniculm, liguleless branched spike, compact ear, and free‐threshing habit of each of these mutants is the result of a single recessive mutation. Red awns and xantha traits are controlled by two recessive genes with duplicate and inhibitory gene interactions, respectively. Some of the early and dwarf mutants were non‐allelic. One dwarf GA3‐insensitive mutant with recessive gene action may be a new source. Mutants such as early maturing, dwarf and free threshing habit may be of significance in breeding diploid wheat.
Genetical Studies on the Mode of Inheritance and Localization of the amo1 (High Amylose) Gene in Barley
Authors: Schondelmaier J. , Jacobi A. , Fischbeck G. , Jahoor A.
Published: April 2006

In the high amylose starch mutant ‘Glacier AC38’, a single recessive gene designated amo1 is responsible for an amylose content of up to 45%. A rapid technique was established in order to evaluate the amylose/amylopectin ratio in half kernels. To localize this gene, crosses with multiple marker lines and trisormes were conducted. In addition, RFLP markers were used to determine their mapping distance to amo1. Two markers are located 2 cM and 7 cM, respectively, from amo1 on chromosome 5S (1HS). The relationship between the wx and amo1 genes was also examined and the role of the amo1 gene in starch synthesis is discussed.