bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Analysis of Resistance to Brown Planthopper in Rice (Oryza sativa L.)
Authors: Kabis Anwarul , Khush G. S.
Published: April 2006

Seventeen rice cultivate resistant to brown planthoppers were genetically analyzed using the Bangladesh insect population. Seven cultivars were found to have a single dominant gene for resistance. These genes segregated independently of the recessive resistance gene bph‐5. Tae dominant resistance gene of ‘Swarnalata’ was designated Bph‐6. In ten cultivars, resistance is conferred by single recessive genes. In eight cultivars, the resistance genes are allelic to bph‐5. However, the recessive genes o: two cultivars are non‐allelic to bph‐5. The recessive gene of T12 is designated bph‐7.
Cytological Evidence for Fertilization in Hexaploid Wheat × Sorghum Crosses
Authors: Laurie D. A. , Bennett M. D.
Published: April 2006

Crosses were made between the hexaploid wheat ‘Chinese Spring’ (2n = 42) and the diploid grain sorghum ‘S9B’ (2n = 20). Sixty‐nine out of 100 florets fixed 48 h after pollination contained an embryo, an endosperm, or both, a remarkably high frequency in view of the taxonomic distance spanned by the cross. Percentages of single or double fertilization ranged from 50 % to 91 % for individual spikes. The hybrid origin of the embryos was confirmed by examining zygotes from spikes fixed 25 to 27 h after pollination. Seven of the 8 zygotes in which chromosomes were sufficiently contracted to be counted contained 21 large wheat chromosomes and 10 much smaller sorghum chromosomes. The eighth contained 21 chromosomes from wheat and 20 from sorghum. Sorghum chromosomes did not appear to be attached to the spindle in zygote nietaphases and showed no evidence of movement towards the spindle poles in the single zygote anaphase found. Embryos with two or more cells invariably contained one or more micronuclei and metaphases in embryos with three or more cells contained only 21 wheat chromosomes showing that sorghum chromosomes were rapidly eliminated. Endosperm, when present, was always highly abnormal.
Leaf Rust Infection in Homogeneous and Heterogeneous Populations of Bread Wheat
Authors: Malik B. S. , Rao M. V. , Yadav S. P.
Published: April 2006

Three commercial Indian wheat varieties —‘Sonalika’, ‘Kalyansona’ and ‘Janak’ were used to develop homogeneous and heterogeneous lines for leaf rust resistance, utilizing diverse sources of resistance from fourteen donors. Four kinds of multilines were developed to study coefficients o: infection, areas under disease progress curves (AUDPC), rates of spread and grain yields over their component means.

Heterogeneous populations showed minimum coefficients of infection at initial as well as final stages, which were less than or equal to the resistant component even in dirty multilines carrying up to 50 % susceptible populations. Large reductions in coefficients of infection and in AUDPC were also observed. Rate of spread was independent of coefficient of infection and AUDPC.

Grain yield advantage over both component means and recurrent parents was higher in clean multilines. The significance of the use of multilines in limiting losses due to disease is discussed.
Repeatability of Some Statistical Measures of Phenotypic Stability —
Authors: Léon J. , Becker H. C.
Published: April 2006

The objective of this study‐ was to evaluate whether different statistical measures of phenotypic stability vary in their repeatability. Eight multi year and multi location variety tests of wheat, barley and oat were analysed separately for each year. Single year data of yield, of response parameters: environmental variance (S23 and coefficient of regression (b), and of stability parameters: deviation mean squares (S23), coefficient of determination (r2), ecovalence (W), and the nor, parametric measure variance of ranks (Si4), were correlated with multi year, multi location results.

Repeatability of single year results was highest for yield, where rank correlation coefficients amounted to about 0.80. s2x and b showed medium values of nearly 0.55 The stability parameters s2d, r2, W and Si4 did not differ in their repeatability. Respective correlation coefficients possessed values of approximately 0.40 and were very variable from experiment to experiment. Reliability of single year results was especially low for experiments with high varieties × years interactions. Single year results of the examined variety tests could not serve as a basis to quantify phenotypic stability even if more than ten locations were involved.
Heterosis in Primary Hexaploid Triticale with Heterozygous Wheat or Rye Genome*)
Authors: Oettler G. , Geiger H. H. , Utz H. F.
Published: April 2006

Twelve primary hexaploid triticale (X Triticosecale Wittmack), synthesized from, three lines of tetraploid wheat (Triticum durum L., T. turgidum L.) and four inbred lines of rye (Secale cereale L.), were used to produce 18 crosses with homozygous wheat and heterozygous rye genome and 12 crosses with heterozygous wheat and homozygous rye genome. Parents and crosses of triticale, wheat, and rye were tested for two years (rye for one year only) in two‐replicate block designs with 1 m2‐plots. Data were assessed for plant height, grain yield and for yield‐related traits.

Performance of triticale crosses was considerably lower than that of the wheat and rye crosses. The amount of heterosis varied greatly between years. Positive and mainly significant heterosis was revealed in triticale generations F1 and F2. The average values were closer to those in wheat than to those in rye. For most characters a high level of heterosis was retained in tnucalt1 generation F2. Heterozygosity of the wheat and rye genome both contributed to heterosis in triticale. However, gene action of the rye genome strongly depended on the homozygous wheat background: one wheat line almost completely suppressed and another greatly stimulated the heterotic effect of the rye genome. In the later case, the amount of heterosis was related to that in rye per se. Information from hybrid rye breeding may therefore be used when establishing gene pools for hybrid breeding in triticale.
Genetic Analysis of Chromosome 2D of Wheat
Authors: Worland A. J. , Petrovic S. , Law C. N.
Published: April 2006

The Yugoslavian varieties ‘Novosadska Rana 1’ and ‘Sava’ are shown by monosomic comparisons to carry weak height promoters on chromosome 2D characteristic of the ‘Akakomugi’ gene for reduced height, Rht8. Reciprocal monosomic crosses between ‘Bersee’ and ‘Sava’ demonstrate ‘Sava’ chromosome 2D reduces height by about 16 cms, accelerates ear emergence by about 9 days and increases yield through increased grain number and grain size.

Recombinant lines developed for chromosome 2D suggest that this chromosome in Mediterranean wheats carries three genes, Rht8, Ppd1 and Yr16, important to their adaptation. Rht8 and Ppd1, a gene for day length insensitivity together reduce height. Ppd1 and, to a minor degree, either yr16, the susceptible allele of a gene for adult plant resistance to yellow rust or a closely linked gene, accelerate time to flowering and thereby avoid desiccating Yugoslavian summer conditions. The same genes reduce spikelets numbers but this is offset by increased floret fertility producing an overall increase in the number of grains per ear. Ppd1 also by avoiding desiccating conditions increases gram size and together with either yr16 or the closely linked fertility gene increases ear and plant yields.
Resynthesis of Brassies napus L. through Interspecific Hybridization between B. alboglabra Bailey and B. campestris L. with Special Emphasis on Seed Colour
Authors: Chen B. Y. , Heneen W. K. , Jönsson R.
Published: April 2006

Brassica napus L. was resynthesized through interspecific hybridization between B. alboglabra Bailey and B campestris L. with the objective or developing yellow‐seeded forms of this species. For hybridization, one black‐seeded form and one light brown‐seeded form of B. alboglabra (a subordinate of B. oleracea) and one brown and ten yellow‐seeded forms of B. campestris were chosen as parents. Crosses with B. alboglabra as the female parent were more successful than crushes with B. campestris as female. The use of the embryo rescue culture technique greatly increased the number of surviving hybrid embryos. Colchicine treatment was required for doubling the chromosome number of the amphihaploid hybrid plants. In the newly‐resynthesized rape forms, the white petal of B. alboglabra was partially epistatic over the yellow petal of B. campestris. The self compatibility of B. alboglabra was hypostatic to the self incompatibility of B. campestris. The black‐seeded character of B. alboglabra and the brown‐seeded character of B. campestris were completely eptstatic over the yellow‐seeded character of B. campestris and the light brown‐seeded character of B. alboglabra. Implications of the results from this study in breeding yellow‐seeded B. napus are discussed.
Somatic Embryogenesis in Maize and Comparison of Genetic Variability Induced by Gamma Radiation and Tissue Culture Techniques
Authors: Novak F. J. , Daskalov S. , Brunner H. , Nesticky M. , Afza R. , Dolezelova M. , Lucretti S. , Herichova A. , Hermelin T.
Published: April 2006

Sixteen inbred lines and one hybrid of manse were tested for their capability of somatic embryogenesis, and fully developed plants could be regenerated, from ten inbred, lines. The highest frequency of plant regeneration was expressed in the inbred line CHI 31, and when this line was crossed with a recalcitrant, non‐regenerating line, the F1 and BC hybrids were regenerable. The results of reciprocal crosses demonstrated that dominant nuclear genes and cytoplasmic factors are primarily responsible for the heritable determination of embryogenic callus proliferation and in vitro regeneration of maize plants.

Somaclonal and radiation‐induced variability was studied in maize to assess their nature and potential contribution to plant breeding., The inbred line CHI 31 possessing a high in vitro capacity of somatic embryo formation was used as experiments.] material. CHI 31 plants were selfed and twelve‐day old zygotic embryos irradiated with 60Co gamma radiation in situ. Mature caryopses were harvested and assigned as M1 material. In another series, immature zygotic embryos (size 1.2—1.5 mm) were cultured in vitro on N‐6 medium supplemented with 2,4‐D (2.5 μM), and somatic embryos regenerated into plants; these were transplanted into soil and self‐pollinated. Regenerants from non‐irradiated cultures were grown as R1 generation, while regenerants from irradiated explants were considered as M1R1 generation.

The genetic variability was evaluated in the M2, R2 and M2R2 generations, respectively, and compared with a non‐treated seed control. Irradiation induced a variety of chlorophyll and morphological variants segregating in the M; generation; however, the frequency of deviant types obtained in the R: generation (somaclonal variation) was significantly exceeding the one derived from the M2 populations. The combination of expert irradiation and in vitro regeneration was most effective for the manifestation of chlorophyll and morphological o if types in the M2R2 generation, and increased drastically the frequency of early flowering variants. Differences in the segregation patterns of mutant phenotypes amonsister somaclones in the R3 and M3R3 generations indicate a different genetic basis, of plants originating from the same explant. This phenomenon suggests a mutational sectoring of the callus during culture. Radiation induced and somaclonal variation exerted a similar spectrum of chlorophyll and morphological deviants.
The Genetic Basis of Variation for Salt Tolerance in Sorghum bicolor (L.) Moench Seedlings
Authors: Azhar F. M. , McNeilly T.
Published: April 2006

The genetic basis of salt (NaCll tolerance at the seedling stage was examined in eight accessions of Sorghum bicolor (L.) Moench which differed in relative NaCl tolerance. The eight accessions were crossed in all possible combinations. The Nad tolerances of the resulting 56 F: hybrids and their eight parents were assessed after two weeks growth in solution cultures containing 0, 103, and 150mM NaCl. Indices of salt tolerance (relative tolerance) were used for analysis using the diallel method.

Both additive and dominance effects appeared to be important for the expression of variation under low and high salinity levels, but the effect of genes with dominance properties was more pronounced. Estimates of narrow sense hentabilities for sail tolerance were appreciable, suggesting that rapid improvement in salinity tolerance is possible in this species using high selection pressures in the F2 population.
Genetics of Seed Yield and its Components in Common Bean (Phaseolus vulgaris L.) of Middle‐American Origin
Authors: Nienhuis J. , Singh S. P.
Published: April 2006

Increase in yield potential of dry common bean (Phaseolus vulgaris L.) cultivars has been either imperceptible or small and gradual, in spite of large variation of most traits, including seed yield. Therefore, general combining ability (GCA) of 80 cultivars and lines of mostly Middle‐American origin was investigated. Eight sets of 10 entries each were used, with five parents each as females and males in a Design II mating system. The resulting 200 F, populations, excluding parents, were evaluated in a replicates‐in‐sets design for yield and its, components at two locations in Colombia. GCA was, calculated by Griffing's Method 4, Model I.

Sixty‐two parents, including high yielding and widely grown small‐seeded Latin American cultivars (‘Aete 3’, ‘Carioca’, ‘Catu’, ‘ICA Pijao’, ‘IPA 74‐19’, ‘Jamapa’, ‘Moruna 80’, ‘Porrillo Sintetico’. ‘Rio Tibagi’), new releases, and many sources of diseases, insect pests, and drought resistance, had zero or negative GCA for yield and its components at both locations. Seventeen out of the 18 parents that had positive GCA for yield at one or both locations were bred lines. At least nine of these resulted from a cross between a small‐seeded cultivar with zero or negative GCA for yield, on one hind, and a landrace from the highlands of Mexico, on the other. Two such landraces, ‘Guanajuato 31’ and ‘Ojo deLiebre’, contributed positive GCA for seed yield and seed weight to all their lines studied, suggesting a major gene control.
Introgression of Resistance to Shattering in Brassica napus from Brassica juncea through Non‐Homologous Recombination
Authors: Prakash Shyam , Chopra V. L.
Published: April 2006

Genetic information conffering non‐ shattering of siliques has been introgressed in rapeseed (Brassica napus) following; interspecific hybridization between Brassica juncea and B. napus. A reconstituted B. napus plant with complete non‐dehiscence of its fruits was isolated in the BC‐, generation. This plant had normal meiosis and formed 19 bivalents. Its seed fertility, however, was low (23 percent). It is suggested that the gene(s) for shattering‐resistance were incorporated into a B. oleracea chromosome following allosyndetic; chromosome pairing and. segmental exchange between B. nigra and B. oleracea chromosomes in the initial interspecific AABC hybrid.
The Size of the Root System of Lucerne Varieties Grown for Forage and Seed, and its Relation to Yield
Authors: Chloupek O.
Published: April 2006

The size of the root system as determined by its electrical capacity was evaluated in lucerne plants of two varieties and three new synthetic populations in field experiments during four years (1981–1987). The average size of the root system of plants which were harvested three times, per year for forage was about 11 % smaller than that of plants grown for forage in the primary growth and for seed in the secondary growth of each year. The smallest root system was determined in the variety ‘Bobrava’ and the synthetic population ZE‐S‐VH (relatively 100 and 100.9 %), followed by the variety ‘Palava’ and the synthetic population ZE‐S‐IV (1 05.1 anc 106.7 %). The largest root system was Sound in the synthetic population ZE‐S‐V (111.7%). One of the five parental Tories in ZE‐S‐IV and ZE‐S‐V exhibited significant effects of general combining ability for root system size. The large root system could also be due to higher resistance to vascular wilt. The larger root system is related to higher persistence, stability for more: cuts, higher level and stability of forage and seed yield in comparison to the control variety. The results present evidence for succesfully breeding, lucerne for larger root systems.
Heterosis and Genetic Variances and their Implications for Breeding Improved Varieties of Spring Beans (Vicia faba L.)*
Authors: Ebmeyer E.
Published: April 2006

Handcrosses were made in a factorial manner with 24 Vicia faba inbred lines m three sets, each between four male and four female parents. The resulting 48 hybrids, their parental inbreds and three commercial varieties were grown in performance trials during the years 1985—87 with three replications at one location. Yield and yield components were recorded on single plant basis.

The average superiority of the hybrids above the control varieties was 26 % in plant yield. The best crosses outyielded the controls by more than 50 %. However, a few inbred lines also reached, the yield level of the controls.

The average heterosis was significant for all characters except for maturity date. In plant yield the average heterosis was 75%, ranging between 34% and 148% in the various cross combinations. The highest average heterosis of 110 % was observed in yield at the lateral stems. In all characters the best inbreds were superior to the lower hybrids and in some characters even equal to the average of the hybrids.

A strong positive relationship was found for all characters between hybrid performance and mid‐parent value and between the per se performance of the inbreds and their general combining ability.

Genotypic differences between the hybrids as well as between the inbreds were highly significant. Most of the variability between the hybrids in all characters were attributed to general combining, ability with only little evidence for specific combining ability.

In the discussion the results are evaluated according to the choice of the breeding category of the partial allogamous faba bean species.
Variation in Reaction of Faba Bean Lines to Different Accessions of Orobanche crenata Forsk.
Authors: Radwan M. S. , Abdalla M. M. F. , Fischbeck G. , Metwally A. A. , Darwish D. S.
Published: April 2006

Three pot experiments were earned our to investigate the variation among geographic accessions of Orobanche crenata Forsk. in their ability to attack different stocks of Vicia faba L. Orobanche accessions were quite different in their influence on the performance of genetic lines of the host. However, host parasite relationships appeared to be dependent upon environmental conditions. The usefulness or host genotypes for differentiating between parasite accessions was rather limited. The number of Orobanche shoots per host plant does not appear 10 be a precise indicator of host tolerance although it has been frequently used for this purpose.
Peroxidase Isozyme Pattern in Pearl Millet Lines Resistant and Susceptible to Downy Mildew
Authors: Chahal S. S. , Kumar R. , Sidhu J. S. , Minocha J. L.
Published: April 2006

Peroxidase isozyme patterns of five downy mildew (DM) resistant inbred lines (PIB‐57‐1, PIB‐1248, PIB‐1356, PIB‐1364 and PIB‐1440), five susceptible lines (PIB‐1335‐1‐1, PIB‐1314‐2‐2, PIB‐2231‐1, 7042 and PIB‐1530‐1‐1) and DM free plants from the susceptible lines of pearl millet were studied. The results suggested a possible involvement of an isoperoxidase (C9) in imparting the resistance. The involvement of two other isozymes (C5 and C6) was also indicated in the1 resistance mechanism. The specific differentiation m particular isozyme pattern can be a useful criterion for characterization of resistance to downy mildew.
Response of Sericea Lespedeza Genotypes Low in Tannins to Different Environments
Authors: Mosjidis J. A.
Published: April 2006

Transfer of the low‐tannin trait to otherwise desirable sericea lespedeza high‐tannin lines produced genotypes with considerably lowered forage yield. It is not known if low‐tannin sericeas are proportionally less productive than high‐tannin sericeas in high‐yielding environments. If so, low‐tannin sericeas would be less desirable to grow in more productive environments. Regression analysis was used to partition GE interactions between regressions and the residuals after regression, and to measure the response to changing environments, Shukla's stability‐variance parameters were used to measure genotype stability. Variance and coefficient of variation were calculated across environments for each genotype and rank correlated to the aforementioned parameters of stability to determine their usefulness in the early stages of cultivar testing. Stability analysis was carried out on the dry forage yield of 10 genotypes grown in 10 environments in Alabama. The only low‐tannin genotype that consistently responded to environmental fluctuations like ‘Serala’ was 74‐100‐5. Low‐tannin sericeas were found to be proportionally less productive than high‐tannin sericeas in high‐yielding environments. However, it is possible to select low‐tannin lines with an environmental response similar to high‐tannin sericeas. Rank correlations among stability parameters indicated that EV is a stability parameter which is easy to calculate and could be used in the early stages of cultivar testing.
Zur Genetik der Bisaboloide bei der Kamille
Authors: Horn W. , Franz Ch , Wickell I.
Published: April 2006

Genetics of Bisaboloids in Camomile

To meet international quality standards, genetic studies and breeding programmes concerning secondary plant products in medicinal plants are important. It was the intention of the present study to test existing hypotheses on the inheritance of the bisaboloids using the genetic analysis of segregating progenies from controlled, self and cross pollinations within and between different chemotypes. Such types were analysed by means of TAS‐TLC.

Results from 40 interconnected progenies confirmed the biosynthetic pathway from bisabolol via bisabololoxid A to bisabolonoxid. It could further he shown that three loci act in this pathway; the genotype oo., (bisabolol) is epistatic to P/p, a gene controlling synthesis from bisabolol‐5,6‐epoxid (OO) of either bisabololoxid A(O.P.) or B (O.pp). The dominance of P appears to be incomplete. The genotype pp is epistatic to the locus N/n which governs the step from bisabololoxid A – (O.P.nn) to bisabolonoxid (O.P.N). The most desirable genotype, which contains both bisabolol and matricine, is double recessive.
In vitro Culture of Cucumis sativus
Authors: Malepszy S. , Nadolska‐Orczyk A.
Published: April 2006

The variability of morphological traits in 1800 individuals of R2 generation of Cucumis sativus was studied. R2 generation was obtained from 60 R1 planes which regenerated from leaf explants of a highly inbred Line of cv. Borszczagowski. All the plants of R1 population were phenotypically identical with the initial variety; some (8,3 %) of the R2 progeny, however, exhibited segregations. Variability was manifested in the following traits: 1. type of growth (dwarf and bushy), 2, male sterility, 3, mosaic type leaves, 4, xantha type chlorophyll change. In R3 generation, only one new phenotype (yellow fruit flesh) has been found. The traits mentioned above were frequently accompanied by lower viability and fertility of R2 plants. The latter was connected with disturbances in microsporogenesis and lover pollen germination ability. Genic instability of one trait is described.
Wheat Substitutions in Hexaploid Triticale*
Authors: Gustafson J. P. , Dille J. E. , Skovmand B.
Published: April 2006

Crosses between octoploid and hexaploid triticales have been made m breeding programs for several years, From an analysis of the progeny of such crosses where selections for an octoploid‐like phenotype had been made, it was established that 149 out of 150 lines were hexaploid in chromosome number, C‐banding and in situ hybridization demonstrated that all but five of the 62 lines analyzed in detail contained visible chromosomes or segments from the D genome. Only four lines had D‐genome chromosome replacing rye chromosomes. All of the remaining 53 D‐genome substitutions involved the replacing of wheat chromosomes from either the A or B genomes. This establishes the ease with which D‐genome genes can be placed into triticale without the loss of rye chromosomes.
Genetics of Five Seed Esterase Isozymes in Pearl Millet
Authors: Rao M. V. Subba , Rao Y. Saideswara , Manga V.
Published: April 2006

Inheritance and linkage relationships of pearl millet seed esterase isozymes were studied using; polyacrylamide dise: gel electrophoresis and α‐naphthyl acetate as substrate. The Zone of enzyme activity was resolved into five bands. The presence of a band showed complete dominance over its absence. Each one of the bands (1 to 4) was under the control of a single gene. Band five was found to be controlled by three independent loci with duplicate gent action Loci for Est1, Est3 and Est4 Were found to be linked. Est2 Was independent of this linkage group.
Half‐Seed Analysis: Rapid Chromatographic Determination of the Main Fatty Acids of Sunflower Seed*
Authors: Conte L. S. , Leoni O. , Palmieri S. , Capella P. , Lercker G.
Published: April 2006

The halt‐seed technique, with some recent modifications of traditional analytic methods, is proposed for selecting sunflower with modified fatty acid composition. A rapid method was used for extracting the oil and for methylating the fatty acids (about 3 min per sample). Thin‐layer chromatography (TLC) plates activated with AgNO3, and/or gas chromatography (GLC) with capillary columns were used to analyse the methylated esters. Half‐seed, whole‐seed and meal analysts of sunflower and other oilseed species confirmed the validity of the method with regard to sampling, analytic result and embryo germinability. In addition, GLC using a suitable internal standard can be used to evaluate the percentage oil content of the seed. About ten samples per hour can be analyzed with GLC versus 20—25 with TLC. These times can be further shortened in practice in the laboratory by partially overlapping some steps.
Genetics of Resistance to Fruit Borer, Heliothis armigera Hübner, in Lycopersicon
Authors: Kalloo  , Banerjee M. K. , Kashyap R. K. , Yadav A. K.
Published: April 2006

Inheritance of resistance to the fruit borer, Heliothis armigera Hübner in tomato was studied in TWO interspecific crosses. L. hirsutum f. gLabratum‘B 6013′. a fruit borer‐resistant parent, was crossed with two susceptible L. esculentum varieties ‘HS 101’ and. ‘HS 102′. Six generations of two crosses were evaluated for percentage fruit: infestation (on a number basis) and the estimates of the gene effects were derived from the generation mean using a three parameter model A preponderance of additive gene effects was found for this trait. Heritability in the narrow sense was observed to be high indicating the fixable nature of the character.
Chromosome Locations of Additional Barley Enzyme Loci Identified Using Wheat‐Barley Addition Lines
Authors: Soliman K. M. , Allard R. W.
Published: April 2006

Disomic wheat‐barley addition lines carrying a full hexaploid set of chromosomes of the wheat cultivar Chinese Spring, plus a pair of either chromosome 1, 2, 3, 4, 6, or 7 from the barley cultivar Betzes, were assayed electrophoretically. Comparisons of zymograms of each addition line with the Chinese Spring wheat and Betzes barky parents of the addition lines gave direct (presumptive in the case of chromosome 5) evidence of the chromosomal locations of nine enzyme loci which have been useful genetic markers in studies of the population genetics, ecogeneties and breeding of barley. Previously reported chromosome locations of several loci were confirmed and evidence was presented for the existence and probable chromosome locations for additional enzyme loci.
Inheritance of Waxlessness in Kohlrabi (Brassica oleracea L. var. gongyloides) and its Utilization in Hybrid Seed Production
Authors: Tatlioglu T.
Published: April 2006

By genetic analysis of selfed progenies and reciprocal F1, F2 and B1: populations of crosses of a waxless mutant and three waxy plants two recessive genes were identified in kohlrabi (Brassica oleracea L. var. gongyloides), causing waxlessness independently from each other. Gene a is responsible for glossy waxless and gene b tor dull waxless plants. To be able to form a wax layer a plant must have both genes in the dominant constitution, i.e. A.B. (“complementary gene effect).

Some segregation results which deviate from expectation could indicate a potential linkage between one of the two wax loci and the incompatibility locus.

Both genes can be used as markers m hybrid breeding of cole crops as well as in basic research.
Agronomic, Isozyme, and Cytogenetic Characteristics of ‘Chris’ Wheat Doubled Haploids1
Authors: Makbuger J. E. , Jauhar P. P.
Published: April 2006

Doubled haploids of wheat (Triticum aestivum L.) cultivar ‘Chris’ were analyzed for presence of variation in agronomic characters, isozyme patterns, and meiotic traits. Twenty‐two doubled haploid lines and the parent cultivar were evaluated for days of heading, plant height, number of tillers per row, number of kernels per spike, 1,000 kernel weight, yield per tiller, and row yield. Leal material of selected doubled haploids and ‘Chris’ was analyzed by disc polyacrylamide gel electrophoresis for esterase, glutamate oxaloacetate transaminase, and superoxide dismutase. Ring and rod configurations were scored at meiotic metaphase 1. The doubled haploids averaged significantly lower 1,000 kernel weight and yield per tiller than ‘Chris’. Although not significantly different, the doubled haploids were 19% lower in yield than ‘Chris’. Variations in isozyme patterns and meiotic abnormalities occurred in plants of selected doubled haploid lines that were significantly different from the parent cultivar in agronomic characters. These variations suggest that chromosomal abnormalities may have been responsible for altered enzyme activity and agronomic performance of the doubled haploids.
The Genomic Relationships Among Glycine soja Sieb. and Zucc., G. max (L.) Merr. and ‘G. gracilis’ Skvortz.
Authors: Singh R. J. , Hymowitz T.
Published: April 2006

The objective of this study was to establish genomic relationships among G. sojii, G. max, and ‘G. gracilis’ based on cytogenetic analyses. All three species hybridized readily, though pod set was low (2.2 %—5.3 %); seeds produced viable, vigorous and totally fertile F, plants which were normal in meiotic pairing. This suggests that all three species‐belong to one gene pool and should be considered as forms of one species.
Seed Yield Stability of Okra as Influenced by Planting Date
Authors: Adetunji I. A. , Chheda H. R.
Published: April 2006

Fifteen selected okra varieties consisting of ten newly‐developed lines and five established varieties were evaluated for stability of seed yields in eight different environments i.e. several monthly plantings for three consecutive years. Seed yield data were analyzed to determine the effectiveness of using different planting dates in seed yield trials of new okra varieties. The wide ranges of environmental indices (‐ 10.8 to 24.4) and seed yield (2.7 to 38.0 g plant ‐1) indicated significant variation between the environments even though the trials were conducted at the same location. A regression method of stability analysis showed that the mean differences between environments, the varieties and their interactions were highly significant. These results suggest that where limited resources prevent the use of several locations, different dates of planting for two or more years could be used to evaluate okra varieties for seed yield without losing much information on their relative ranking.
Race Specific Powdery Mildew Resistance in 31 Northwest European Wheat Cultivars
Authors: Hovmøller M. S.
Published: April 2006

Race specific powdery mildew resistance in 23 winter wheat cultivars, eight spring wheat cultivars, and 14 lines/cultivars possessing known powdery mildew resistance genes, has been studied by analyzing host/pathogen interactions. The cultivars were tested as intact seedlings, and as detached primary leaf segments on water agar; both methods revealed reproducible and concordant results. The 45 cultivars/lines were divided into 24 resistance spectra according to the patterns of reaction to the powdery mildew isolates used. Of the 31 cultivars investigated, eight did not possess any of the resistance genes detected, and the remaining 23 were divided in 16 resistance spectra. The race specific resistance of nine cultivars was conferred by the single resistance genes Pm2, Pm4b, Pm5/Ml‐i: or Pm6, while the race specific resistance of 14 cultivars was conferred by 2, 3, 4 or 5 genes in combination.
Somatic Embryogenesis and Plant Regeneration from Tritordeum
Authors: Barceló P. , Vazquez A. , Martín A.
Published: April 2006

Regeneration of plants by somatic embryogenesis from immature embryos of hexaploid tritordeum (AABBHchHch, amphiploid Hordeum chilense×Triticum turgidum conv. durum) and durum wheat (Triticum tergidum) was induced on MS medium supplemented with different 2.4‐D concentrations. Well‐defined embryoids were formed with a high frequency on the scutellar callus from 1 or 2 weeks onwards and plantlets were developed from them. In the best cases from one single explant more than 100 plants could be obtained. Plants were also regenerated by somatic embryogenesis from inflorescences of Hordeum chilense×Triticum turgiditm conv. durum hybrid and its respective hexa‐amphiploid. With regard to callus induction and regenerative ability, evident differences between hexa‐ and octoploid (H. chilense×T. aestivum) tritordeum were found, the latter showing a very low response.
Components of Response in Barley Anther Culture
Authors: Knudsen S. , Due I. K. , Andersen S. B.
Published: April 2006

Anther culture response with 17 widely‐grown varieties and one model variety of barley was studied with one replication from field‐grown donor plants and one replication from a growth‐chamber. Plants were regenerated from all 18 varieties and green plants were obtained from 16 of them. On average, 1.6 green plants were obtained per 100 cultured anthers from all the material. Estimated variance components for the formation of embryos/callus from the anthers were dominated by the effects of the genotypes and interactions between plant material and environments which together accounted for 60.1 and 17.0 % of the total variation respectively, while environments were nonsignificant for this character. Plant regeneration from embryos/callus were not significantly influenced by either genotype or environments. Components of variance for green plant formation were dominated by the effects of the genotypes, accounting for 73.2 % of the total variation, and a smaller effect from environments accounting for 11.2% of the total variation. Main effects from genotypes on the percentage of green regenerants divided 7 varieties into two distinct groups, indicating that major genetic factors were involved. The genetic basis for green plant regeneration seems different from that governing embryo formation. The results are discussed with respect to the possible prediction of anther culture response for new barley hybrids, as a means for directing the use of barley anther culture towards material that responds well.
Variations in the Proportions of Fertile Colchicine‐Treated Haploid Plants Derived from Winter Barley Hybrids
Authors: Devaux P.
Published: April 2006

In a doubled haploid production programme from many winter barley (Hordeum vulgare L.) hybrids, the number of both fertile and sterile colchicine‐treated haploid plants was recorded for each hybrid. The proportion of fertile plants at maturity varies from 40 % to 98.73 %, depending on the origin of the material, with an average value of 71.30 %. The G‐test applied to the values indicates that the differences are significant. The correlation coefficient between the number of colchicine‐treated haploid plants which flowered and the number of fertile plants is high (r = 0.96). Several reasons are given to explain these variations, among which we discuss the direct effects of colchicine on chromosome doubling and the indirect effects, such as tillering and depression after treatment.
Comparisons of Isozyme Patterns in Resynthesized Amphihaploid Rapeseed (Brassica napus) and Their Parental Species Brassica campestris and Brassica oleracea
Authors: Mündges Hiltrud , Diederichsen Elke , Köhler W.
Published: April 2006

Resynthesized rapeseed plants produced by embryo culture and the progeny of their selfed parents from Brassica oleracea and Brassica campestris were analyzed by starch gel electrophoresis staining of enzymes GPI, LAP and SDH. In at least one unequivocal case it could be proved for each enzyme system studied that the alleles of both parents arc independently expressed in the newly synthesized individuals and that in the pattern of the dimeric enzyme GPI interlocus bands of the homoeologous loci arc visible. Comparisons with enzyme patterns in cultivated B. napus leads to the conclusion that in general active enzyme loci of both parental genomes are present. This is of great significance in estimating slide frequencies, degree of heterozygosity and other genetic parameters of B. nupus populations/cultivars.
Prediction of the Line Value of a Genotype from a Top Cross with a Single Cross Hybrid
Authors: Gallais A.
Published: April 2006

With the assumption of biallelism it is shown that differences in line values of genotypes from a random mating population can be predicted by the differences of values in top cross progenies with a heterozygous tester. This prediction is also valid in the case of multiallelism with a constant degree of dominance for each pair of alleles and if the tester is heterozygous for the more “distant” alleles. With an arbitrary tester, the efficiency of the prediction is affected by the proportion of the loci which are heterozygous for the more distant alleles. However, with the assumptions considered on multiallelism, with partial to complete dominance, the correlation between line value and combining ability with the tester is expected to be high for a large range of the repartition ot the loci. A two tester top cross design using highly complementary lines, could also be used.
Spatial Dependence of Check Plot Yield and Local Control
Authors: Samra J. S. , Anlauf R. , Richter J.
Published: April 2006

For maximizing genetic gains, with given resources, plant breeders generally conduct large but un‐ or inadequately‐replicated field trials especially during early generation evaluations and population improvement programmes. Checks arc often used to improve the precision of test plot comparisons. Adjustments by moving or weighted means etc. arc, however, empirical or based on assumptions too difficult to verify. An alternative stochastically best linear unbiased optimal locally weighted method of spatial prediction of micro‐environmental heterogeneity indices of treatment plots was examined. Two checks used in an unreplicated evaluation of 1560 test lines of winter wheat expressed the micro‐environmental variation in similar ways. About 46, 38 and 16 percent of the total variation in yield was a simple row and column effects, spatially dependent, and random errors, respectively. Optimal weights derived to simulate the micro‐environmental heterogeneity indices were sensitive to the position of the test plot and thus provided a better local control. The model was validated, and prediction standard deviations of simulations computed.
Contribution of Weather Variables to Genotype X Environment Interaction in Grain Sorghum1
Authors: Gorman D. P. , Kang M. S. , Milam M. R.
Published: April 2006

Genotype × environment (GE) interactions are a major problem in plant breeding programs that involve testing in diverse environments. These interactions can reduce progress from selection. Few studies have characterized the effects of weather variables on GE interactions in sorghum (Sorghum bicolor [L.] Moench). The present investigation estimated the contribution of environmental index, (Ȳ, or mean yield of all cultivars in jth environment minus Ȳ. xor overall mean yield for all cultivars and all environments), rainfall, minimum and maximum temperature, and relative humidity, to GE interaction. Yield means of 5 full‐season and 10 medium‐season grain sorghum hybrids grown during 1986—1988 at four locations were used in the study. The GE interaction was significant and partitioned into σ2i, components assignable to each genotype. Weather variables (covariates) were used to remove heterogeneity from the GE interaction. The remainder of the GE interaction variance was partitioned into variance components (s2i) assignable to each genotype. In both maturity groups, the environmental index removed most, although non‐significant, heterogeneity from the GE interaction sums of squares. Of all weather variables, preseason and seasonal rainfall contributed most to the GE interaction sums of squares.
Area Under the Disease Progress Curve: Its Reliability as a Measure of Slow‐Rusting Resistance
Authors: Singh H. , Rao M. V.
Published: April 2006

Differences between the area under the disease progress curve (A‐value) and the rate of disease development (r‐value), the two commonly used measures of slow‐rusting resistance, are discussed with the help of theoretical models. A study on development of leaf rust (Puccinia recondita f. sp. tritici) in two sets of breeding lines of wheat (Triticum aestivum L.) showed that the A‐value and the r‐value (calculated as slope of the regression line of disease progress data) are not necessarily correlated and that the initial inoculum level can have a large effect on the A‐value. These studies suggested that the A‐value and the r‐value measure different aspects of resistance and they should, therefore, be used with greater discrimination.
Multivariate Analysis in Relation to Genetic Improvement in Lavender, Lavandula officinalis Chaix*
Authors: Singh A. K. , Singh J. , Sharma S.
Published: April 2006

Forty‐three genotypes of lavender, Lavandula officinalis Chaix, comprising 20 parental stocks including variety ‘Karlovo’, and 23 promising clones were subjected to genetic divergence analysis by Mahalanobis D2 statistics. All the clones were grouped in 12 clusters. Intracluster D2 was highest for cluster × followed by cluster IX and I. Highest intercluster D2 value was observed between cluster VII and IX. Major emphasis was given to including Sher‐i‐Kashmir, B 10, E 2, A3 and one from each cluster I, II, V, VII, VIII and × for polycross for maximum chance of transgressive segregants of practical utility.
Response of Lettuce Cultivars Carrying the Resistance Gene Dm11 to Isolates of Bremia lactucae from Lactuca serriola
Authors: Lebeda A.
Published: April 2006

Seven Bremia lactucae isolates from Lactuca serriola were tested for pathogenicity on 41 Lactuca sativa cultivars carrying a race specific resistance gene Dm11 which originated from L. serriola. Some of these cultivars also carried other Dm genes.

Sporulation was observed in 34 % of the 287 cultivar/isolate combinations, but it was limited in most cases. A compatible response was recorded in 7.3% of cultivar/isolate. Cultivars with Dm 11 alone, or in combination with Dm 2, exhibited a higher decree of susceptibility then those also carrying Dm 3. There were differences in specific virulence among the isolates under study. Nearly all the isolates studied were virulent on newly described resistance genes Dm 15, Dm 16, and Dm 7 +? which originate from L. serriola.
Evaluation of R1 Alfalfa Somaclones for Herbage Yield and Morphological Characteristics
Authors: Nagarajan P. , Walton P. D.
Published: April 2006

Tissue culture protocols were used to generate somaclonal variation in two synthetic populations of alfalfa. In both cases the somaclone populations give yields of dry matter about 29 % lower than the synthetic populations from which they were derived. Plant height and, for one population (LE‐1), stem length, number of node per stem and internode length was also lower for the somaclones than for the original populations. The implications for plant breeding programs are considered and two hypotheses (one genetic and the other physiological), to account for the changes are presented.
A Compendium on Host Genes in Flax Conferring Resistance to Flax Rust
Authors: Islam M. R. , Mayo G. M. E.
Published: April 2006

A list with information about named host genes controlling resistance to rust in both cultivated and wild flax has been compiled. These will be useful for genetic, physiological and biochemical research as well as breeding for resistance. Information regarding mutation, temperature sensitivity and the effect of inhibitor/avirulence gene interaction on expression of certain host genes is included.
Studies on “Three Line” Polima Cytoplasmic Male Sterility Developed in Brassica napus L.
Authors: Tingdong Fu , Guangsheng Yang , Xiaoniu Yang
Published: April 2006

Polima CMS lines can be divided into three groups according to the sensitivity of male sterility to temperature: 1) high temperature CMS lines (62.9%), 2) low temperature CMS lines (28.6 %) and 3) stable CMS lines (8.5 %). The heterosis of Pol CMS hybrids is evident and common in some of the characters tested, especially in plant seed yield and siliqua number. The cytoplasm has no deleterious effects on the FI characters tested.
The Inheritance of Polima Cytoplasmic Male Sterility in Brassica napus L.
Authors: Guangsheng Yang , Tingdong Fu
Published: April 2006

The restores tested in this study have only one pair of fertility‐restoring genes (Rf) but many temperature‐sensitive genes (Ts). The Rf genes are alleles at the same locus. The cytoplasm of the restorers RC1, RC2, RC3 and ‘Huaie’ is male sterile, but that of RC4, is normal.
Meiotic Regularization, Restoration of Seed Fertility and Alkaloid Content in the Induced Autotetraploids of Hyoscyamus albus L.*
Authors: Srivastava Sangeeta , Lavania U. C.
Published: April 2006

Colchicine‐induced autotetraploids produced in the medicinally important solanaceous plant Hyoscyamus albus (2n = 68) revealed a general increase in pollen, stomata and seed size, but resulted in the reduction of leaf size and plant height. Also, an initial performance trial showed a decline in biomass yield but an increase in alkaloid content of 16.2 %. Thus, in terms of alkaloid yield, the tetraploids demonstrated a slight improvement over diploids for this economic product.

Seed fertility of the raw colchiploids was low but a higher value (> 80 %) could be obtained in advanced generations following rigid selection. High fertility was accompanied by a diploidized meiotic chromosome behaviour in the autotetraploids, with high bivalent pairing and regular anaphase separation. Bivalents were predominantly of open type in the autotetraploids as against a predominance of ring bivalents with distal chiasma localization in the parental diploids. The algebraic estimate of multivalent pairing frequency recorded even in the raw colchiploids was quite low (0.239) compared to that expected on the basis of random pairing (0.667), which further dropped to 0.107 in the C3 generation. Such reduction in multivalent frequency in autotetraploids could be brought about by a combination of reduction in crossover frequency and correction in pachytene pairing.