bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Variation in Nitrogen Uptake and Utilization in Spring Rape (Brassica napus L.) and its Exploitation Through Selection
Authors: Yau S. K. , Thurling N.
Published: April 2006

Field and controlled environment studies revealed significant genetic variation in nitrogen uptake and utilization within an F2 population of spring rape. However, narrow‐sense heritabilities of measures of these characters were consistently low, and were less than that of seed yield in the field. Flowering time in the field had a much higher heritability than seed yield and the expected yield response to selection for this character was 34 % greater than the response to direct yield selection. An even greater yield response was expected from selection based on an index combining measurements of flowering time, nitrogen uptake and nitrogen utilization. The expected yield response to selection for an index incorporating these characters and seed yield was SI % greater than that for direct yield selection.
Isozyme Analysis of Some Male Sterile Lines in Sorghum bicolor (L.) Moench
Authors: Phul P. S. , Chhina B. S. , Kumar Raman
Published: April 2006

A comparative study of peroxidase and acid phosphatase of anthers was carried out on sorghum to characterize five male steriles and their maímainers. Differences in presence/absence and intensity of bands were observed for the isozyme patterns of all the male steriles and their corresponding maintainers. The better expression of enzymes in sterile anthers emphasized the role they play in breaking down various metabolites that are otherwise important for formation of fertile anthers.
In Vitro Response to Fusarium Elicitor and Toxic Substances in Crosses between Resistant and Susceptible Carnation Cultivars
Authors: Buiatti M. , Marcheschi G. , Venturo R. , Bettini P. , Bogani P. , Morpurgo R. , Nacmias B. , Pellegrini M. G.
Published: April 2006

To assess the correlation between in vivo resistance to F. oxysporum f. sp. dianthi and in vitro behaviour, calli from several resistant and susceptible Mediterranean carnation cultivars and F1 progenies of crosses were tested both for the ability to grow on a medium containing crude culture filtrate of F. oxysporum and to produce phytoalexins following treatment with cell wall components (elicitor) of the same fungus. The results show no significant correlation between in vivo resistance and in vitro tolerance to culture filtrate of the fungus, while there was a good correlation in die case of phytoalexin production. Moreover, the character phytoalexin production behaved as a dominant in the crosses between a resistant and a susceptible cultivar.
Inheritance of Dry Root Rot (Rhizoctonia bataticola) Resistance in Chickpea (Cicer arietinum)
Authors: Rao P. K. Ananda , Haware M. P.
Published: April 2006

The inheritance of resistance to dry root rot of chickpea caused by Rhizoctonia bataticola was studied. Parental F1 and F2 populations of two resistant and two susceptible parents, along with 49 F1 progenies of one of the resistant × susceptible crosses were rested for their reaction to dry root rot using the blotting‐paper technique. All F, plants of the resistant × susceptible crosses were resistant; the F2 generation fitted a 3 resistant: 1 susceptible ratio indicating monogenic inheritance, with resistance dominant over susceptibility. F3 family segregation data confirmed the results. No segregation occurred among the progeny of resistant × resistant and susceptible × susceptible crosses.
Induced Vine Mutant in Vigna mungo
Authors: Singh R. K. , Raghuvanshi S. S. , Prakash Dhan
Published: April 2006

Pure dry seeds of variety T9 of Vigna mungo were irradiated by 10, 20 and 30 kR of gamma rays at 33 °C followed by post irradiation treatment with 0.25 % EMS in phosphate buffer (pH 7.0) at 30 ± 1 °C. Vine mutants were isolated from segregating families after 20 kR and 10kR ± EMS treatment. The genetic nature of the mutants was tested by crossing with the wild type. The segregation in F2 proved the mutant to be monogenic recessive. The mutant showed slight improvement in protein content and marked improvement in yield of seeds.
An Inheritance Study of Domestication in Foxtail Millet Using an Interspecific Cross
Authors: Darmency H. , Pernes J.
Published: April 2006

In order better to understand domestication processes, the inheritance of eight morphological characters and isozymes was studied in the F2 progeny of an interspecific cross between a wild and 2 cultivated foxtail millet (Setaria viridis and S. italica). Two linkage groups were determined, one involving seed shedding and the phenol colour reaction of the grain. These two characters, as well as the pericarp pigmentation of the seed, appear to he highly specific for the difference between collections of wild and cultivated plants and probably indicate a genotype particularly suitable for plant domestication.
Yield, Grain Weight and Height Relationships in Two Random Samples of Early Semi‐Dwarf Genotypes of Spring Wheat (Triticum aestivum L.)
Authors: Pinthus M. J.
Published: April 2006

The objective of this work is to study the association between the genotypic differences in mean grain weight and grain yield, the relationship of yield and grain weight with culm length, and the differences between the effects of the Rht1 and Rht2 dwarfing alleles on these characters. Yield, grain weight, grains m‐2 and culm length were evaluated in two random samples of 19 semi‐dwarf early lines, selected in F5 and tested in F2, from two different crosses between cultivars differing in the Rht allele controlling their semi‐dwarf ness. The lines of each cross were tested in 4‐replicated field trials at two different sites. Phenotypic, genotypic, partial and multiple correlations as well as hertability estimates were computed. In each cross the lines differed significantly in their mean values of all the characters tested. In both crosses there was no apparent association between grain weight and grain yield. It therefore seems that in wheat of the type investigated in this study, grain yield and grain weight are independent controlled and that high grain yield is not restricted to any particular range of mean grain weight. A rather high positive correlation between culm length and grain weight was found in one cross but not in the other indicating the dependence of this relationship on the genetic background. In both crosses no significant differences were found between the performance of the lines carrying the Rht1 dwarfing allele and those carrying the Rht2 allele.
Plant Regeneration from Callus Cultures of Brassica carinata A. Br. and its Implications to Improvement of Oil Seed Brassicas
Authors: Narasimhulu S. B. , Chopra V. L.
Published: April 2006

Protocols of plant regeneration have been developed for Brassica carinata for creating somaclonal variation for plant type and adaptability, so that this species can fit into cropping systems in Indian agriculture. The response of cotyledonary and stem explants was assessed for callus induction and shoot regeneration on MS and B5 basal media containing different combinations of auxin and cytokinin concentrations. MS medium supplemented with BA and NAA favoured callus induction. Supplementing MS with combinations of BA and IAA, as also with BA alone, regenerated shoots from the ex pi ants with a high frequency. The frequency of shoot regeneration and the mean number of shoots per explant were higher in cotyledons than in stem explants on identical growth regulator combinations. On B5 medium, supplemented with BA (2 mg/l) and IBA (0.4 mg/l), compact callus was produced which regenerated shoots on transfer to medium containing BA (0.8 mg/l). Genotypic differences among carinata accessions for regeneration were also observed.
Genetic Control of Temperature‐Sensitivity of Cytoplasmic Male Sterility (cms) in Chives (Allium schoenoprasum L.)
Authors: Tatlioglu T.
Published: April 2006

In earlier experiments with chives (Allium schoenoprasum L.) temperature‐sensitive and temperature‐insensitive cms plants could be selected.

To obtain information about the site and nature of the genetic factor(s) responsible for the temperature sensitivity of the cms, temperature‐insensitive and temperauire‐sensitive cms plants were crossed with maintainers as well as with one another. In the progenies each genotype was cloned into two clone members, and these were examined concerning their male sterility under normal (20 °C/14 °C, day/night) as well as under constantly high temperatures (24 °C/ 24 °C).

The results indicate that the temperature‐sensitivity of the cms is controlled by a dominant nuclear gene “T”. This acts like a restorer gene at high temperatures and is ineffective at normal temperatures. Accordingly, important conclusions can be drawn with regard to the selection of temperature‐insensitive cms‐lines as well as to the propagation of the cmi‐lines.

The results are discussed in connection with the mitochondrial polypeptides probably responsible for the formation of the cms.
Seed Yield Selection in Medicago sativa L. and Correlated Responses Affecting Dry Matter Yield
Authors: Veronesi F. , Falcinelli M.
Published: April 2006

Open pollinated (OP) progenies from 72 plants, selected for seed yield within a population of the Italian synthetic variety ‘Adriana’, were evaluated in 1983–1986 under dense stand conditions, both for dry matter yield (DMY) of the 1st cut and seed yield (SY) of the 2nd regrowth. Analysis of variance of the results showed the presense of significant differences in SY potential among entries, with average SY over the years of open pollinated (OP) progenies ranging between 32.1 gm‐3. In contrast, the OP progenies were not significantly different in DMY, averaging between 0.61 kg m‐2 and 0.77 kg m‐2. The results show the possibility of selecting for SY without a negative response affecting DMY in lucerne. Furthermore, the most interesting materials appeared to be characterized both by high average SY and SY stability over the year.
Genotypes of Hybrid Necrosis in 25 Spring Varieties of Common Wheat (Triticum aestivum L.)
Authors: Pfeffer Anna , Zeller F. J.
Published: April 2006

Hybrid necrosis in Triticum is known to be caused by the interaction of two complementary dominant genes. Varieties of many tetroploid and hexaploid wheat species have been described according to their genotype for this character. In the present contribution, the genotype for hybrid necrosis of 25 spring wheat varieties is presented.
Progressive Differentiation of Spikelet Types in Relation to Ploidy in the Genus Avena
Authors: Nishiyama I.
Published: April 2006

In the study of interspecific and interploidy hybrids of Avena the order of spikelet types in the recessive < dominance sequence was found to be as follows: N1 (naked type) < C1,2 (cultivated, type) < W1,2 (wild type) < S1,2 (subwild type) < W3 < S3 < C3 < N(1)3, where superscripts 1, 2 and 3 indicate the spikelet type of diploid, tetraploid and hexaploid species, respectively. Nullisomic studies of hexaploid species showed that chromosome MK‐9 of the 3rd genome controlled multiple alleles W3, S3 and C3 types, except N(1)3 type, and synapsis of meiotic chromosomes. Its homoeologous chromosomes of the 1st and 2nd genomes appeared to affect the W type (probably introduction of W1 and W2) as well as meiotic asynapsis. The asynapsis might be induced by deficiency of a synapsis‐gene(s) in a primary hexaploid form or species. The N(1)3 type probably occurred by dominant or epistatic mutation of the W1 type in A. sativa, and the C3 type hidden was present. The maintenance of such a heterozygosity system may be mainly due to diploid‐like pairing of chromosomes on the balance between the synaptic and asynaptic gene functions.
Genotypic Composition and Mildew Resistance in a Natural Population of Wild Barley, Hordeum spontaneum
Authors: Segal A. , Döurr K. H. , Fischbeck G. , Zohary D. , Wahl I.
Published: April 2006

Two sets of accessions were sampled, tram a natural population of Hordeum spontaneum at Shelomi, Israel, viz.: 100 ears along a transect at intervals of 1—1.5 m and 10 ring clusters of 10 ears each, circling each 10th plant of the transect. Single ear progenies were tested for banding patterns of 5 allozyme loci; in addition, hordein sanding; and field reaction against powdery mildew has been determined. 56 allozyme genotypes and 13 hordein patterns were determined. Most of the progenies showed susceptible to moderately susceptible infection types and high frequencies of low infection grade (slow mildewing). For all characters spatial grouping was found in plants derived from neighbouring transect parents. This was even more pronounced in the ring clusters. Reactions to mildew infection appeared to be closely correlated with hordein banding. In addition, accessions showing hypersensitive reactions carried excessive frequencies of a certain allele of the Est‐1 locus.
Chromosome Irregularities in Wheat and Triticale Plants Regenerated from Leaf Base Callus
Authors: Fedak G. , Armstrong K. C. , Handyside R.
Published: April 2006

Basal leaf sections of Triticum aestivum L., cv. ‘Chinese Spring’, and XTriticosecale Wittmack cv.‘Welsh’were cultured on Kao's medium with 2 mg/l of 2,4‐D. Callus was induced on the leaf sections at frequencies of 64 and 63 %, respectively, and plant‐lets regenerated at 18 and 31 %, respectively. Compared to the controls, the regenerated plants showed higher frequencies of univalent chromosomes at meiosis and low frequencies of trivalents, and quadrivalents; indicating that the callus phase had induced low frequencies of chromosome irregularity.
Meiosis in Two New Intergeneric Hybrids between Hordeum and Secale
Authors: Gutta P. K. , Fedak G.
Published: April 2006

The diploid hybrid Hordeum californicum×Secale vavilovii and the tetraploid hybrid H. parodii× S. anatolicum, were obtained through embryo rescue techniques at relative frequencies of 0.70 and 5.3 % of pollinated florets, respectively. Means of 11.741+ 1.1311 per cell at metaphase I of meiosis were obtained in the diploid hybrid and 14.741+ 6.3l11+ 0.22111+ 0.02IV in the tetraploid hybrid with a maximum of 6.01+ 4.011 and 9.011+2.0111+ 1.0IV respectively. In the diploid hybrid there was preponderance of intragenomic pairing (86.7 %). Increased pairing in the tetraploid hybrid was attributed to autosyndesis among Hordeum chromosomes.
In vitro Selection for Fusaric Acid Resistant Barley Plants
Authors: Chawla H. S. , Wenzel G.
Published: April 2006

Calli of two genotypes of barley,‘Dissa’and W 193, were used for selection of resistance against fusaric acid, a pathotoxin of Fusarium. Callus was initiated from 7‐ to 10 days old immature embryos. 1000 calli of the‘Dissa’and 500 of the W 193 genotypes were grown for 4 selection cycles on medium with 0.8 mM fusaric acid. In the first selection cycle, about 80 % of the calli were killed; after the 4 selection cycles, 8 to 11 % resistant calli were obtained and plants were regenerated. Resistant calli maintained on non‐toxic medium showed retention of resistance ability after 3 months of sub‐culturing. Plants could be regenerated from the surviving calli and testing by leaf bioassay revealed that many were resistant to the same toxin concentration employed for callus selection (100 %), while some were only resistant up to a concentration of 75 %.
Influence of Sucrose and Melibiose on Barley Anther Cultures in Starch Media
Authors: Sorvari S. , Schieder O.
Published: April 2006

Anthers from the barley varieties ‘Arra’, ‘Dissa’ and ‘Ingrid’ were cultured in barley starch gelatinized nutrient media. The importance of osmosis in barley starch medium was studied by using sucrose or an inert carbohydrate, melibiose, as an osmoticum. It was found that in the barley starch medium sucrose was not necessary but energy and carbon could be obtained by tissue enzymatically from the starch. Together with the starch medium melibiose had revolutionary effects OB barley anther cultures. This system not only produced extremely high numbers of embryoids and green plantlets but also drastically reduced the number of albinos.
Utilization of Genetic Variability of Resynthesized Rapeseed
Authors: Kräling K.
Published: April 2006

The performance of single cross hybrids between resynthesized (resyn.) genotypes and varieties of rapeseed was tested in microplots. The results revealed strong, genetic differences between the artificially synthesized rapeseed forms for all the characters investigated, as well as for g.c.a. values. In particular, hybrids with resyn rapeseed exhibited a vigorous vegetative growth. It should therefore, be beneficial to use resyn forms directly in fodder rape breeding programmes.

Disturbances in fertility of the resyn material resulted in a low number of seeds per pod and consequently in an inferior seed yield as compared to the varieties, although some high yielding combinations were also identified. Three‐way hybrids with a 25% genome share of the resyn rapessed reached only lower vegetative performance as compared 10 the hybrids with a 50% resyn genome but their performance in generative traits was general superior‐ In respect to seed yield some progenies of three‐way hybrids showed a higher plot performance than even the high yielding varieties. A further comparison between single‐cross combinations of resyn × variety on the one hand and variety × variety on the other hand demonstrated that resyn genotypes, due to a distinct apical dominance, exhibited a pronounced expression of characters measured on the main stem. But in total, ii is evident from the present findings that any hybridization with this resyn material does not promise immediate short‐term varietal improvement.
Combining Ability and Heterosis for Quantitative Powdery Mildew Resistance in Barley
Authors: Heun M.
Published: April 2006

The estimation of combining abilities and heterosis for quantitative resistance against Erysiphe graminis f. sp. hordei of eight spring barley (Hordeum vulgare) cultivars is presented. Fur this purpose a half diallel cross and its parents were arranged in five Latin rectangles, each inoculated with a current mildew isolate. Significant general combining ability was found whereas specific combining ability was non‐significant. A great pan of the general combining ability could be explained by variety effects. Significant variety heterosis was obtained too. Significant average heterosis was obtained but us effect was small. Among those selected for this study, ‘Grit’ and ‘Hora’ were the best parents for further crosses.
Sources of Resistance to Powdery Mildew in Barley Lines Derived from Hordeum spontaneum Collected in Israel
Authors: Jahoor A. , Fischbeck G.
Published: April 2006

Fourty two barley lines direved from the F7 of crosses between barley cultivars and different accessions of Hordeum spontaneum collected in Israel and 30 lines or varieties with known genes for resistance to powdery mildew were included m this study. Eleven European and three Israeli powdery mildew cultures, possessing virulence genes corresponding to known resistance genes, were used to make comparisons between the varieties with known resistance genes and H. spontaneum derived lines. The reaction pattern of 39 H. spontaneum derived lines was clearly different from the reaction pattern o; any of the known genes for mildew resistance included in this study. Only two cases were observed in which the reaction pattern of H. spontaneum derived lines agreed with reaction patterns of known genes for mildew resistance viz. Ml‐a9 and Ml‐p. Trie Mildew resistance of one line apparently traces back to uncontrolled outcrossing with a Ml‐a.6+Ml‐g resistant cultivar. Since the majority of the 42 host genotypes tested showed distinctive variation in resistant reaction types against different mildew cultures, this study docs not support the assumption that differences in resistant infection types against distinct mildew cultures are sufficient to indicate the presence of supplementary genes for resistance in a given genotype of the host. The results justify the conclusion that the natural population of H. spontaneum in Israel forms a large gene pool for mildew resistance which is not yet used m cultivated barley.
Genes for Powdery Mildew Resistance in Cultivars of Spring Wheat
Authors: Heun M , Fischbeck G.
Published: April 2006

Twenty‐three cultivars of spring wheat were inoculated with nineteen different powdery mildew isolates; their ruction patterns hive been compared with those of twenty‐two cultivars/lines carrying identified powdery mildew resistance genes. Applying the gene‐for‐gene hypothesis, it is evident that three cultivars have none of the resistance genes used, seven others (including ‘Solo’) may carry Pm4b, only. The resistance pattern of ‘Selpek’ is identical to A/‐1 resistant cultivars of winter wheat and may be explained by the presence of Pm5. The resistance pattern of Pm5 (Mt‐i) cultivars is very different from a number of ‘Kolibri’‐related cultivars of spring wheat. Since either all or nothing of that specific pattern has been transferred to all cross progenies of ‘Kolibri’, a single gene is assumed to oe responsible for it, preliminarily designated as Ml‐k. The cultivar ‘Mephisto’ carries the ‘Normandie’ resistance (Pwl 2, 9). In five cultivars to spring wheat the combined effects of at least two of the above‐mentioned sources have been found. Despite the fact that ‘Normandie’ and ‘Sappo’ are not closely related. ‘Sappo’ shows the complete ‘Normandie’ resistance pattern plus that of Pm4b. The same is true for ‘Planet’ and ‘Walter’.
Cytology, Fertility and Morphology of Amphiploids Hordeum chilense × Tetraploid Wheats (Tritordeum)
Authors: Padilla J. A. , Martin A.
Published: April 2006

With the aim of widening the genetic variability of hexaploid tritorceum through the wheat parents, amphiploids between Hordeum chilense and Triticum turgidum ssp. dicoccoides, ssp. georgicum, and Cody, polonicum have been synthesized. The meiotic behaviour and the fertility were examined in these amphiploids. The morphology of the amphiploids in comparison to their wheat parents was described.
Research on the Genetic Resources of Inulin‐Containing Chicory (Cichorium intybus)
Authors: Frese L. , Dambroth M.
Published: April 2006

Chicory has potential as a new industrial crop. However, root chicory seems to have a limited generic basis which might hamper breeding progress. The objective of the investigation was (i) TO assess the yield potential of chicory and (ii) to ascertain whether leaf chicory might be suitable to broaden the genetic basis of root chicory breeding. Forty‐nine accessions of leaf and root chicory were cultivated in field trials. Root yield/plot varied between 15.0 kg and 22.6 kg (experiment 1) and 14.8 kg and 27.0 kg (experiment 2). Total sugar content ranged between 15.2–21.8 % and 14.5–22.9 %. The corresponding values for total sugar yield are 2.32–4.12 kg and 2.38–5.45 kg. Fructose/glucose ratios ranged from 6.59 to 9.76 and 4.20 to g.22 depending on experiment and accession. Estimated on a plot oasis the highest total sugar and fructose yield was achieved by ‘Fredonia’ (10.6 t/ha and 9.5 t/ha, respectively). In addition, correlation coefficients between yield components were estimated. The correlation coefficients between total sugar content and total sugar yield ranged from, r = 0.62–0.78. The results suggest that leaf chicory may not contribute to a rapid breeding progress in root chicory within a short period.
Selection for High Tropane Alkaloid Content in Hyoscyamus muticus Plants
Authors: Oksman‐Caldentey K.‐M. , Vuorela H. , Isenegger M. , Strauss A. , Hiltunen R.
Published: April 2006

Egyptian henbane, Hyoscyamus muticus L. (Sol‐anaceae) is an important source of pharmaceutically valuable compounds, the tropane alkaloids. Even today these alkaloids, scopolamine and hyoscyamine, are extracted on an industrial scale from plants. We have studied the possibilities of increasing the scopolamine content in H. muticus plants by selection during several generations. The quantitative scopolamine and hyoscyamine determinations were performed on the dry leaf material by radio and enzymeimmunoassay.

The increased production of these alkaloids by the progenies was an inherited attribute resulting from systematic selection for high‐alkaloid‐containing plants (inbred). The scopolamine content in the F1 generation was increased by a factor of 3 and in the F4 generation by a factor of 20 compared to the P generation, respectively. The year‐to‐year fluctuation among the mean scopolamine contents of the control groups was small. The maximal scopolamine content in H. muticus strain Cairo exceeded 4%, which is the highest content so far reported in the literature.

When crossing the high and low scopolamine‐producing plants, the scopolamine content of the progenies was found to be intermediate between that of the two parents, thus indicating that scopolamine synthesis is inherited by the progenies from both parents. The alkaloid production of the plants grown in the greenhouse was significantly higher than those grown in the field.
The Amphiploid Hordeum chilense× Triticum aestivum ssp. sphacrocoecum. Variability in Octoploid Tritordeum
Authors: Martin A. , Padjlla J. A. , Fernandez‐Escobar J.
Published: April 2006

In order to increase variability in the octopioid tritordeum a new octoploid tritordeum has been synthesized after colchicine doubling of the chromosomes of the Hordeum chilense × Triticum aestivum ssp. sphaerococcum hybrid. The amphiploid showed full pairing in 30 % of the pollen mother cells, The fertility was higher than in previous tritordeums (1.65 grains per spikelet and 43.00 grains per spike). Hybrids between the octoploid tritorceums were sterile. However, hexaploid × octopiold trhordeum hybrids were fertile and secondary tritordeums were extracted with increased fertility.
Studies of the Genetic Relationship between Anther Culture and Somatic Tissue Culture Abilities in Wheat
Authors: Agache S. , De Buyser J. , Henry Y. , Snape J. W.
Published: April 2006

A population of thirty‐eight doubled haploid lines, developed from the F1 between two wheat parents differing in anther culture and somatic tissue culture responses, ‘was used to examine the genetical control of responses to these in vitro systems.

During anther culture genetic variation between lines was exhibited for frequencies of callus induction., embryo production and embryo regeneration rates. In addition the relative frequencies of green and albino plants was shown to be genotype dependent. However, there was no correlation, between the frequencies of embryo production and the regeneration rate of those embryos suggesting an independent genetic control of these two components. Transgressive segregation for performance was observed for all components indicating that at least two genes are involved in the response of each, and lines for improved performance, combining high ernoryo production rates and good regeneration capacity were identified.

No genetic variation for frequencies of callus induction from immature embryos was observed in this cross. However, genetic variation for the regeneration frequencies of plants was observed. Lines with an improved tissue culture response over the two parents were identified.

There was no correlation between the performance of lines in anther culture and somatic tissue culture, indicating separate genetical control, and lines with alternative levels of response to the two systems were identified.
Nematode Resistance and Meiotic Abnormality in Diploid Sugar Beet Selected from Interspecific Beta vulgaris×B. procumbens Hybrids*
Authors: Nakamura C. , Tsuchiya T.
Published: April 2006

Two nematode‐resistant trisomic lines which were derived from interspecific Beta, vulgaris × B. procumbens hybrids were intercrossed or backcrossed with susceptible diploid sugar beer and their progenies were screened for nematode resistance. The transmission rate of resistance varied from 1.5 % to 47.6 % with an average of 20.4 % in the progenies of individual insomics derived from the two trisomic lines. Eleven resistant diploads were selected with a frequency of 0.2 %. These resistant diploids were classified into two groups, i.e., one group showed relatively high transmission rates of resistance with an average of 25.4 % and the other extremely low with an average of 1.2 % in their backcrossed and s el fed progenies., Meiotic chromosome behavior in a resistant diploid group with high transmission rates was considerably normal as compared to that in a resistant diploid group with low transmission rates. Chromatid bridges and acertric fragments were detected in 93 % of resistant diploids and in 46 % of susceptible diploids. Two different sized fragments occurred in resistant diploids, while only a smaller fragment was present in susceptible diploids. A frequency of sporocytes with bridges‐fragments was 17.4% at anaphase I and 13.9 % at anaphase II in resistant diploids, while in susceptible diploids a frequency was 2.9 % and 5.3 % at the respective stages. These results suggest that at least two paracentric inversions are present in resistant diploids, one of which is linked to nernatode resistance and may be responsible for the low transmission rate of resistance.
Frequencies of Vertical Resistances and Virulences in the Rye‐Powdery Mildew Pathosystem*
Authors: Geiger H. H. , Schuhmacher Andrea E. , Billenkamp N.
Published: April 2006

Nine populations of rye (Secale cereale L.; the cultivars ‘Kustro’, ‘Danko’ and ‘Carokurz’. a breeding population PA 14/75 and five Iranian primitive ryes) were tested with three or two pathotypes of powder)’ mildew (Erysiphe graminis DC. f. sp. secalis Marchal) to determine the frequencies of vertical resistances. Similarly, three populations of powder)’ mildew isolated from the above eultivars were tested with two rye pathodemes to estimate the frequencies of vertical virulences. Tests were carried out on leaf segments cultivated in vitro.

To explain the pattern of the host‐parasite interaction, a model with at least four resistance and virulence genes was required. In the rye populations the genotypes of most plants could be determined unambiguously whereas in the powdery mildew populations no unique classification of one‐postule isolates was possible due to the limited number of rye differentials.

Both the host and the pathogen populations were polymorphic for resistance and virulence, respectively. In all lye populations except PA 14/75 the resistance frequencies were low. In the mildew populations the virulence frequencies were high and complex races occurred rather frequently. The virulence frequencies were related to the resistance frequencies of the respective host population.

Results were compared with mathematical host‐parasite models accounting for gene‐for‐gene interaction and balancing natural selection. Observations agree well with theory.
Inheritance of Eye Pattern and Seed Coat Colour in Cowpea (Vigna unguiculata [L.] Walp.)
Authors: Drabo I. , Ladeinde T. A. O. , Smithson J. B. , Redden R.
Published: April 2006

The F2 progenies of crosses between several cowpea (V. unguiculata) lines were investigated for variation of eye pattern and seed coat colour. It was found that three (W, H, O) and five (R, P, B, M, N) major genes control eye pattern and seed coat colour, respectively. The recessive gene (GO) for restricted eye pattern enables the underlying basic white or cream seed coat colour to be observed. A similar effect is obtained with the recessive gene (rr) for colour expression. The expression of mottling (V), possibly a seed coat pattern, may for be observed when it is combined with the genes for certain eye patterns. The significance of these findings in breeding for consumer preference for specific seed coat colour is discussed.
Classification of Global Environments and Cultivars of Spring Barley Based on Heading Time Interactions
Authors: Gallagher L. W. , Soliman K. M.
Published: April 2006

Global heading time data collected by the International Center for Maize and Wheat Improvement (CIMMYT) during the International Barley Yield Trials were used to assess similarity of environments, variation among cultivars, and genotype × environment interactions. Data for 29 spring barley cultivars grown in 89 environments over three years were analyzed by cluster analysis. The deviation m days to heading of the mean of 28 photoperiod sensitive cultivars from the cultivar ‘Mona’ and the mean of ‘Mona’, homozygous recessive for the eak gene conferring photoperiod insensitivity and thermal stability, were used as environmental coordinates. In addition, diversity of heading time responses among genotypes was illustrated by differences among overall means and patterns of deviation for days to heading from ‘Mona’ in selected environments.

Three main clusters were identified. Mexican environments were similar to warmer Mediterranean, eastern and southern African, West Asian, and Latin American environments. Heading time responses in Syria were similar to those observed m other cool Mediterranean environments.

Early heading cultivars exhibited greater variation for heading response, especially in extremely warm‐and equaiorial‐ short daylength environments, com‐pared to late heading cultivars, presumably because of larger photothermal × genotype interactions. Photoperiod flux about the winter solstice appeared to be a major environmental cue for heading time in photoperiod sensitive spring barleys.
The Growth in Culture of Detached Ovaries of Wheat (Triticum aestivum L. em. Thell)
Authors: Mathias R. J. , Boyd L. A.
Published: April 2006

Viable embryos have been recovered from fertilized wheat (Triticum aestivum) ovaries detached on the day of, or up to 7 days post‐, anthesis and cultured aseptically fur up to 18 days. The most significant factors in determining the yield of embryos was the plating density, age and complexity of the explants. 26% of ovaries excised on the day of anthesis produced viable embryos if cultured as pairs of florets. The potential use of detached ovary cultures in gametophyte microinjection experiments, rescuing embryos from wide crosses and in chemically manipulating the early stages of embryo development are discussed.
Independent Inheritance of Erucic Acid Content and Flower Colour in the C‐Genome of Brassica napus L.
Authors: Chen B. Y. , Heneen W. K. , Jönsson R.
Published: April 2006

The synthetic Brassica napus L. line No7076 was obtained from a cross between yellow‐flowered and zero‐erucic turnip rape (B. campestris) Sv85‐38301 and white‐flowered and high‐erucic (41.4%) B. oleracea ssp. alboglabra No6510. This synthetic B. napus is pale‐flowered and has an average erucic acid content of 25.8 %. It was crossed with the yellow‐flowered and zero‐erucic B. napus line SvS4‐2S053 and segregation of the erucic acid content and flower colour was studied in F1 and F2 generations. The high erucic acid content was controlled by a single gene in the C‐genome and was additively inherited. Strong evidence was obtained in support of independent segregation of the erucic‐arid content and the flower colour characters controlled by the C‐genome of B. napus.
Effects of Temperature on Pollen Tube Growth and Fruit Set in Reciprocal Crosses Between Cucumis sativus and C. metuliferus
Authors: Franken J. , Custers J. B. M. , Bino R. J.
Published: April 2006

Interspecific hybridization between Cucumis sativus and C. metuliferus may be used to introduce disease resistance into the cultivated cucumber. Hybrid plant development, however, is restricted by strong barriers to crossing. The present study was undertaken to examine temperature effects on pollen tube growth and fruit set in reciprocal crosses between C. sativus and C. metuliferus. When crossing C. sativus×C. metuliferus, at 20°C, pollen tube growth was arrested in the stylar region of the pistil and no fruits containing embryos were found. However, at 23° and 26°C, C. metuliferus pollen tubes penetrated into the C. sativus ovules. The enhanced pollen tube penetration was correlated with improved embryo development. Although pre‐fertilization barriers were overcome, post‐fertilization barriers caused abortion of hybrid embryo development at the globular stage.

No effects of higher temperatures were found in the cross C. metuliferus×C. sativus; Pollen tubes were generally arrested in the stylar region of the pistil.
Karyotype Analysis of Sesbania rostrata Brem.
Authors: Joshua D. C. , Bhatia C. R.
Published: April 2006

The karyotype of Sesbania rostrata, a species endemic to West Africa, which produces nitrogen fixing, nodules on stem and branches, was analysed. The somatic chromosome number was 12 with two pairs of long, submetacentric and four pairs of short, metacentric chromosomes. The chromosome number in another species S. aculeata, which is well adapted as a green manure crop in India but not capable of stem nodulation, was also 2n = 12. The similarity between the chromosome complements of the two species indicates that they may be cross compatible.
Effects of Wheat Chromosome 1D Telosomes on Hybrid Seed Development in Wheat × Rye Crosses
Authors: Marais G. F.
Published: April 2006

Pollination of ‘Chinese Spring,’ monosome 1D plants with rye results in failure of hybrid seed development in a proportion of the F1 seeds corresponding to the transmission rate of the nullisomic 1D egg cells. Development and viability of these hybrid seeds closely resemble that normally observed in T. aurum× rye crosses. Using ‘Chinese Spring’ chromosome ID telosomic plants in crosses with rye, it was possible to illustrate that the observed effect was associated with the long arm of this chromosome.
Identification of the Chromosomes in the ‘Esto’ Set of Rye Trisomics
Authors: Melz G. , Schlegel R. , Sybenga J.
Published: April 2006

The original identification of the chromosomes involved in each of the lines of the act of primary trisomics of winter rye variety ‘Esto’ does not correspond with recent results of gene localization studies. Using known morphological marker genes, N‐banding and test crossing with the standard translocation tester set, a more precise identification was possible. In the nomenclature of the Triticinae, the lines can be designated as follows: A = 7R; B = 5R; C = 2R; D = 3R; E = 4R; F = 6R; G = 1R.
Genetics of Hybrid Necrosis in Rye
Authors: Ren Z. L. , Lelley T.
Published: April 2006

In diploid rye, two genes were detected which cause hybrid necrosis by complementary action if both are present in dominant condition. Moreover, these genes cause hybrid necrosis in triticale complementing with cither one of the two genes, Ne1 and Ne2 which are known to cause hybrid necrosis in wheat. It is suggested, that the two genes in rye are named Ner1 and Ner2 corresponding to the wheat gene with which they complement in triticale. The consequences of the presence of necrosis genes in rye populations for breeding of rye are discussed.
Chromosomal Location of Dimeric Phosphatase Structural Genes in Hexaploid Wheat
Authors: Sánchez M. M. , Elorrieta M. A. , Bemto C.
Published: April 2006

Structural genes for leaf dimeric phosphatases (E.C. 3.1,3.2.) have been located on wheat chromosome arms 7BL and 7DL. No gene was found on 7AL. The results obtained pointed to the existence of two kinds of wheat phosphatases (monomers and dimers j located on different homoeologous groups, which is in agreement with results found in Secale cereale and Agropyron intermedium. These results allow homoeologous relationships to be established through the classification of dimeric phosphatases and also provides another useful genetic marker for the 7BL and 7DL arms., They also provide further support for die concept of the conservation of gene synteny groups within the Triticnae.
A Combined Univariate and Multivariate Approach for Selecting High Performing Genotypes of Vicia faba L.
Authors: de Pace C. , Filippetti A. , Ricciardi L.
Published: April 2006

High performing V. faba genotypes have been successfully selected using an approach that combines the univariate and multivariate biometrical analyses of F|S from two complete 7×7 and 9×9 diallel cross experiments. The method used in the analyses included canonical analysis and cluster analysis of the phenotypic and genetic variance‐covariance matrices. All analyses have been applied, to the yield and yield components. Results of analyses provided information on the unit of selection, the selection criteria, and the selection procedure. The choice of an array of F1S seems to be more efficient than the choice of a single F2. Among the yield components studied, 100‐seed weight is the most important selection criterion which can improve yield most efficiently. The detected importance of the nonadditive genetic effects is that selection after intercrossing random plants from the mixed F1 progenies of the same array is expected to be more effective than selection after Selfing.
Glucosinolates Determined by HPLC in the Seeds of Microspore‐Derived Homozygous Lines of Rapeseed (Brassica napus L.)*
Authors: Lichter R. , de Groot E. , Fiebig D. , Schweiger R. , Gland A.
Published: April 2006

Microspore culture was employed to measure the relative efficiencies of anther culture and isolated microspore culture for the regeneration of embryoids and plants of Brassica napus. The yield of embryoids and plants was at least 10‐fold greater from isolated microspores than from anther cultures. Approximately 1400 microspore‐derived homozygous line's, the parental varieties and the corresponding F2 plants were grown in a field trial.

Important agricultural characteristics, such as morphological homogeneity, growth rate, onset of flowering and seed setting were evaluated subjectively and seed yield and glucosinolate content of individual plants were determined. The relative concentrations of up to S different glucosinolates in these seeds were measured via an automated high performance liquid chromatography (HPLC) system. The alkenyl and indole glucosinolates, the two most important categories of glucosinolates, were found in varying proportions and were independently determined in these line's. Our results do not support the previously suggested connection between low concentrations of glucosinolates and weak growth and/or poor seed yield. Additionally, no evidence was found that the lines derived from isolated microspore culture were subjected to unexpected selection pressures that might adversely affect the diversity of the lines obtained. These results demonstrate that microspore culture is a powerful tool not only for genetic analysis bur also for practical plant breeding.
The Influence of Plant Developmental Stage on Expression of Resistance to leaf Rust (Puccinia recondita) in Two Near Isogenic Lines of Wheat
Authors: Kumar Rajindra , Sawhney R. N. , Sharma J. B. , Chopra V. L.
Published: April 2006

Cultivar ‘Thatcher’, and ‘Thatcher’ lines with Lr 21 and Lr 22 were studied against a number of races of Puccinia recondita for seedling and adult plant reaction. The study has established that Lr 21 and Lr 22 are genes effective against P. recondita at adult plant stage. It has also shown that these genes confer resistance against all races when plants are inoculated at boot leaf stage.
Presence of Gene Del in Wild Species of the Genus Lycopersicon Mill.
Authors: Chalukova M. , Stoeva P.
Published: April 2006

The carotene composition of the fruits of F1 hybrids between Lycopersicon esculentum Mill. — cv. 1/D (genotype Del+Dd+) and wild species of genus Lycopersicon with various fruit pigmentation — red, orange, and green — has been investigated. The results reveal that the red and orange‐fruited species carry the recessive allele Del+, while the green‐fruited species carry a δ‐carotene gene which is identical or similar in action to the dominant gene Del. The test of allelism that has been carried out proves that the δ‐carotene gene from Lycopersicon pennellii Corr. is allelic to gene Del.
Correlation and Path Analysis in Jasmine
Authors: Srivastava H. C. , Devaiah K. A.
Published: April 2006

Correlations among 11 morpho‐economic characters and their path analysis were studied using 16 genotype of jasmine. The weight of 100 flowers was significantly associated with the Dower diameter, petal width, petal length, anther length, floral bud length and width, and 100 bud weight in positive direction. Path coefficient analysis revealed 100 flower bud weight and flower diameter to have high direct effect in positive direction. All the other characters affected the yield indirectly through these two characters, indicating that 100 floral bud weight and flower diameter could be taken as selection index.
Comparative Analysis of High‐Molecular‐Weight Glutenin Subunit Composition in Various Triticum Species
Authors: Vallega V.
Published: April 2006

Variation in high‐molecular‐weight glutenin subunit composition amongst Triticum durum cvs. of different origins was investigated by SDS‐PAGE and compared with that reported for T. dicoccum and T. aestivum. Tetraploid wheat collections (408 cvs.) were found to carry nearly twice as many Glu‐A1 and Glu‐B1 alleles as a hexaploid wheat sample of comparable size. In each of the taxa considered, allelic variation at the Glu‐B1 locus was markedly greater than that observed for Glu‐A1. However, because all the Glu‐B1 subunits so far discovered exhibit a restricted and distinctive mobility range during. SDS‐PAGE, it is suggested that they are derived from a single source, possibly from Aegilops searsii. Most durum cvs. carried a ‘null’Glu‐A1 allele and therefore fewer subunits than dicoccums and common wheats. It is argued that differences in the frequency of occurrence of ‘null’Glu‐1 alleles between taxa probably resulted from random samplings made by early agriculturalists and breeders, rather than from an inherent tendency of polyploid wheats to suppress the activity of “redundant” genes.
A New Method to Produce 4× Triticales and their Application in Studying the Development of a New Polyploid Plant
Authors: Baum M. , Lelley T.
Published: April 2006

F1 hybrids of triticale × rye derived from commercial varieties were backcrossed to the respective triticale parent. Selfing of the backcross generation yielded a large number of 4× triticales containing a genetically balanced wheat genome. This indicates that the 28‐chromosome F1 plants with the genomic constitution of ABRR produced functional 14‐chromosome gametes in high frequency each with a complete wheat and rye genome. The cytological mechanism leading to the formation of tetraploid triticales is described. The chromosomal constitution of the wheat genome in the progenies of 30 back cross plants was analysed by the C‐banding technique. One offspring possessed a complete B genome of wheat. The production of tetraploid triticale through backcrossing in comparison to selfing the ABRR hybrid is largely independent of the genotype; it leads to new tetraploids in just three generations and it reduces the chance of translocations between the homoeologous wheat chromosomes. The possibility of studying the effect of different mixtures of chromosomes of the A and B genomes of wheat on the phenotype of the tetraploid triticale is discussed.
Chromosome Constitution of Hexaploid Triticale Lines in the Recent International Yield Trials*
Authors: Lukaszewski A. J.
Published: April 2006

Lines of hexaploid triticale included in the 11th and 12th Eucarpia Triticale Yield Nurseries and the 18th and 19th International Triticale Yield Nurseries were karyotyped using C‐banding. A new chromosome substitution, 6D(6A), was identified in both spring and winter triticales. It is likely that the substitution first appeared in the progenies of octoploid × hexaploid triticale hybrids at CIMMYT and within a few years spread to about one‐fourth of spring materials. The 2D(2R) substitution appeared in winter triticales, probably by introgression from spring lines from CIMMYT.