bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF APHOLATE ON CHROMOSOMES OF GERM CELLS IN THE GRASSHOPPER TESTES
Authors: Klassen Waldemar , Chang Tsueng Hsing , Eide Paul E.
Published: November 2014

Apholate was injected into Melanoplus differentialis males, and periodically the meiotic chromosomes were microscopically examined during the subsequent 3-week period. The frequency of chromosomal aberrations was found to be highest among meiotic chromosomes that had been treated just prior to prophase I or during early prophase I. As prophase I progressed the resistance of chromosomes to breakage increased. Damage to chromosomes in the spermatogonia persisted and was observed in the spermatocytes.
β-MERCAPTOETHANOL-INDUCED RECOVERY OF X-IRRADIATED YEAST CELLS
Authors: James A. P. , Werner Mary M.
Published: November 2014

Prolongation of the interval between X-irradiation and first postirradiation cell division of diploid yeast cells by treatment with β-mercaptoethanol resulted in an increase in survival and a decrease in lethal sectoring among survivors. With haploids, a statistically significant increase in survival was not detected. A similar artificial prolongation of the interval between first and second postirradiation division of diploids resulted in a significant increase in the frequency of survivors which were free of lethal sectors, an indication that repair occurs in this interval and thus that some types of X-ray-induced lesions can persist through DNA replication. After treatment of X-irradiated cells with β-mercaptoethanol the relative frequencies of the different kinds of death (doublet formation, abortive colony formation, and lethal sectoring) were significantly altered, the frequency of recovery in each category being negatively correlated with the extent of residual cell division. It was concluded that the expressions of death reflect to some extent the number of lesions induced within a cell.
CYTOGENETIC STUDIES OF POECILIA (PISCES). I. CHROMOSOME NUMBERS OF NATURALLY OCCURRING POECILIID SPECIES AND THEIR HYBRIDS FROM EASTERN MEXICO
Authors: Prehn Lillian M. , Rasch Ellen M.
Published: November 2014

Cytological studies of fish from the subgenus Poecilia (Pisces) including members of an all-female species, P. formosa, have clearly shown diploid, somatic chromosome complements and Robertsonian arm numbers of 46. A triploid somatic chromosome complement of 3N = 69 was demonstrated for members of a naturally occurring variant clone of P. formosa, a form whose general body morphology closely resembles that of its sympatric species P. mexicana. Chromosomes of the different poeciliid species studied are remarkably similar in size, shape and structure, being mostly short acrocentrics, 2 μ long or less.The presence of a chromosome bearing a sub-terminal centromere within the complement of the Amazon molly provides the only direct evidence to date of centric shifts within the chromosome complement of the subgenus Poecilia. This finding also provides the first plausible cytogenetic basis for concluding that P. formosa is of relatively recent origin. Comparisons of relative chromosome lengths from both mitotic and meiotic configurations of related species indicate that the heteromorphic chromosome pair of P. formosa probably was derived by hybridization between P. latipinna and P. mexicana. Finally, as suggested by the numbers and forms of chromosomes in atypical, triploid specimens of P. formosa, their complements apparently contain both a maternal diploid set of chromosomes from the all-female species, and a paternal haploid set of chromosomes from P. mexicana.
INHERITANCE OF CHLOROTIC COTYLEDON INBRASSICA CAMPESTRISL.
Authors: Stringam G. R.
Published: November 2014

Inheritance of chlorotic cotyledon in Brassica campestris was studied in the M3generation descending from seed treated with ethyleneimine. Also studied were F1progenies from crosses between plants having the cotyledon character and a normal unrelated line. Data indicated the trait was controlled by a single partially dominant gene designated C with recognizable genotypes, CC (green), Cc (chlorotic), cc (albino). Mature plants of each genotype were indistinguishable except for some loss of vigor in plants with albino cotyledons.
QUANTITATIVE CHANGES IN BREEDING GROUPS OF LEBISTES AFTER IRRADIATION
Authors: Schröder Johannes Horst
Published: November 2014

Neonatal guppies of a wild-coloured inbred strain were X-irradiated with 1000 R, corresponding to early oogonia and spermatogonia. At sexual maturity the irradiated fish and their sham-treated controls were mated to unirradiated guppies of another stock. The proportions of the body shape and the number of vertebrae of the F1 and F2 generations were determined. The quantitative characters controlled by polygenes in both experimental and control groups showed that the number of vertebrae increased in the F1 and decreased in the F2. The changes in body proportions reveal a trend towards a more compact type after ancestral irradiation. The variability coefficient was greater among females of the irradiated series. Shifts in the mean values were combined with alterations of viability revealing an increase in postnatal mortality and a reduction of litter size in the backcross generation. An increase in litter size and a decrease in postnatal mortality appeared in the F1 and F2 generations where radiation-induced detrimental mutations were less likely to become homozygous.
COBALT AS A VITAL STAIN FOR YEAST MITOCHONDRIA IN SQUASH PREPARATIONS
Authors: Lindegren Carl C. , Be Miller Paraskevi M.
Published: November 2014

Squashes of yeast cells grown in nutrient medium containing cobalt were observed by phase- and electron-microscopy. Co++ is a vital stain that is bound to structures inside the inner membrane of the mitochondria.
THE CHROMOSOMES OF THE MASKINONGE (ESOX MASQUINONGY)
Authors: McGregor John F.
Published: November 2014

The air-drying technique and aceto-orcein stain were used on uncultured kidney cells from juvenile maskinonge, Esox masquinongy, to determine the chromosome number and karyotype. A somatic chromosome number of 2n = 50 was found in 88% of 200 well-spread colchicine metaphases. Karyotype analysis showed that all the chromosomes have their centromeres located in the terminal region. Chromosomal polymorphisms reported by others for kidney cells of fish were not observed in this study.
CYTOLOGICAL OBSERVATIONS ON SPERMATOGENESIS IN FOUR SPECIES OF MECOPTERA
Authors: Atchley William R. , Jackson R. C.
Published: November 2014

Spermatogenesis was examined in Panorpa anomala, P. acuta, Bittacus pilicornis and B. stigmaterus. Both species of Panorpa were found to be achiasmate and had a chromosome number of n = 22 + X(O). The behavior of the sex bivalent and frequency of end-to-end association among non-homologous chromosomes is discussed for the Panorpa species Bittacus pilicornis (n = 14 + X[O]) and B. stigmaterus (n = 15 + X [O]) had chiasmate meiosis
GENETIC VARIATION IN TRITICUM AFFECTING THE LEVEL OF CHROMOSOME PAIRING IN INTERGENERIC HYBRIDS
Authors: Driscoll C. J. , Quinn C. J.
Published: November 2014

Genetic differences which affect the extent of homoeologous chromosome pairing in intergeneric hybrids have been demonstrated between varieties of Triticum aestivum. Each of seven varieties of Triticum was crossed with the same strain of Aegilops variabilis. Significant differences in chiasma frequencies between varieties were found. Varieties Eureka, Gamut and Chinese Spring constitute one group with a relatively low chiasma frequency and varieties A. R. Falcon, Federation and Poso constitute a distinct second group with a relatively high chiasma frequency. The variety Bearded Yalta is intermediate to the two groups. Thus, this genetic variation appears to be common among varieties of Triticum. Presumably this variation does not become subject to natural selection as long as chromosome pairing in the parental varieties remains strictly homologous.
LITTER SIZE AND SEGREGATION INMUS MUSCULUSCLASSIFIED FORTRANSFERRIN
Authors: Nagai Jiro , Kristjansson F. K.
Published: November 2014

Two random-bred populations were synthesized from four inbred strains and were maintained for 6 and 12 generations respectively under a standard environment. Size of each population was kept constant. Blood was collected at 8 weeks of age and was used to identify transferrin (Trf) genotypes. Litter sizes at birth, 3 and 8 weeks of age were recorded.While Trfa/Tradams produced somewhat smaller litters than dams of other genotypes, least squares analysis of covariance indicated that litter size was not affected significantly by Trf genotypes of sire and/or dam. Segregation in 5,404 offspring was essentially normal. The Trfafrequency did not change significantly with generations.Under the experimental conditions described the Trf alleles do not appear to affect fitness substantially. It is, therefore, suggested that these alleles may serve as useful markers in experimental populations.
A SECONDARY TRISOMIC IN AVENA STRIGOSA
Authors: Rajhathy Tibor , Fedak George
Published: November 2014

The pairing behaviour of the chromosomes and the morphology of a secondary trisomic plant is briefly described. The plant was male and female sterile caused presumably by a deleterious dosage effect.
A NOTE ON THE INHERITANCE OF POLLEN COLOUR IN SAFFLOWER (CARTHAMUS L.)
Authors: Khidir M. Osman
Published: November 2014

Two pollen colours are found in the genus Carthamus, namely, white and yellow. Pollen colour has been used to differentiate between species belonging to different sections particularly tetraploid and hexaploid species. A hypothetical model is suggested to explain the inheritance of this character in interspecific hybrids. It seems that pollen colour is governed by a single locus with three alleles.
PRIMARY SIMPLE TRISOMICS IN PEARL MILLET
Authors: Gill B. S. , Virmani S. S. , Minocha J. L.
Published: November 2014

To establish a series of trisomics in Pennisetum typhoides (2n = 14), plants with 2n + 1 chromosome numbers were isolated from the progenies of triploid plants and triploid-diploid crosses. These primary simple trisomic plants were distinguishable from the diploids by their relatively poor vigour, short height, narrow leaves and late flowering. They were also distinguishable from one another and were classified into seven morphological groups: 'Tiny', 'Dark Green', 'Lax', 'Slender', 'Spindle', 'Broad' and 'Pseudonormal'. The extra chromosome in the seven trisomic types could be distinguished on the basis of somatic chromosome morphology.
DIALLEL ANALYSIS OF CROSSES BETWEEN FLUE-CURED AND BURLEY TOBACCO CULTIVARS
Authors: Povilaitis Bronius
Published: November 2014

The eight tobacco cultivars Delcrest, Hicks Broadleaf, Yellow Gold and Jamaica Wrapper of the flue-cured type and Burley 1, Burley 21, Virginia B29 and Kentucky 12 of the burley type and their crosses and reciprocals were grown in an 8 × 8 diallel-cross experiment. Diallel analyses were completed according to procedures described by Hayman, Griffing and Robinson.The mean squares for general combining ability and for Hayman's a made up a considerably higher proportion of the total variability than the other subdivisions. The variances for special combining ability were in all instances smaller than those for general combining ability, although there were differences in size and in levels of significance between Griffing's and Robinson's methods. The statistic due to additive effects of genes (Hayman's D) was significant for days to flower, height, and number of leaves, and the statistic due to dominance effects significant for days to flower and height. The greatest effect in decreasing the number of days to flower was exhibited by the cultivar Delcrest, and the greatest effect in increasing the number of days to flower was by Yellow Gold and Kentucky 12. Kentucky 12 showed the greatest effect in increasing height and number of leaves.
CHROMOSOMAL POLYMORPHISM IN NORTH AMERICANPISSODESWEEVILS: STRUCTURAL ISOMERISM
Authors: Smith Stanley G.
Published: November 2014

Pissodes approximatus and P. canadensis, two taxa named by Hopkins, are shown to constitute a hybrid complex that forms a numerical-morphological karyocline between the southeast of North America and the Yukon. The two A metacentrics and the two B submetacentrics in the SE (predominantly 2n = 30) are each sequentially replaced by twin acrocentrics, aa and bb, in the NW (mainly 2n = 34). The two b pairs, of markedly different length, are segmentally interchanged in the SE relative to those in the NW, the distal interchanged segments being equal. The two Bs, derived by fusion of alternative acrocentrics, simulate pericentrically inverted, complementary submetacentrics. Introgression of the four structurally different types, commonest at the centre of the karyocline, results in 10 distinct B: bb karyotypes of which only 6 appear different; the other 4 are mirror images, or isomers.The intermediate karyotypes have been synthesized by crossing different AB and aabb taxa; they implicate two pairs of isomeric species in the origin of the polymorphic complex. Of these, one AB species with 'standard' Bs and two aabb species with relatively interchanged bs are extant. The fourth, a species with inverted Bs, may be extinct, have merely escaped detection, or else is completely introgressed.Chiasma formation is near perfect in natural polyisomorphs and almost equally so in synthetics. In fact, in both bb/bb heterozygotes the maximum number of associations per cell, normally 16 (the XY pair is achiasmate), is increased by the formation of anomalous quadruple configurations resulting from extra unions at the centric ends of the bs. If chiasmate and situated in minute arms, these unions far exceed expectation on a length-frequency basis, for such arms cannot be resolved in colchicined gonial metaphases. Whether the extra unions are truly chiasmate, as believed, or not, they nevertheless greatly influence the first metaphase disjunctional arrangement of the multiples and cause production of about 80% unbalanced gametes vs. the 50% expected of random assortment, thus generating a genetic isolating mechanism. Such acrocentric heterozygotes, though carrying a heavy segregational-sterility load, persist by recurrent SE-NW introgressive hybridization.
CYTOGENETIC STUDIES OF MEIOTIC ABNORMALITIES INCOLLINSIA TINCTORIA. I. CHROMOSOMAL STICKINESS
Authors: Mehra R. C. , Rai K. S.
Published: November 2014

Certain plants of Collinsia tinctoria showing chromosomal stickiness at metaphase I and other stages of microsporogenesis were isolated among second generation progeny of an irradiated plant. Genetic analysis of the F1and F2progenies from crosses involving such plants showed that this meiotic abnormality can be attributed to a single recessive gene. Besides excessive clumping of chromosomes, this mutant also caused other meiotic abnormalities. These were: increased heteropycnosis at pachytene, high chromosomal fragmentation at prophase I, distortion of normal location and orientation of chromosomes at metaphase I, arrested chromosomal movement and abnormal cytokinesis. All these abnormalities resulted in a high degree of male sterility. Possible mechanisms causing the stickiness of chromosomes during meiosis and consequent abnormalities are discussed.
FERTILITY STUDIES AND CYTOLOGICAL ANALYSIS OF THE PROGENY OF A TRIPLOID × DIPLOID CROSS IN HOP,HUMULUS LUPULUSL.
Authors: Haunold Alfred
Published: November 2014

The triploid (2n = 30) female hop genotype 56008, hand pollinated with pollen from 10 different males, produced 0.35 seeds per cone. No striking differences in seed set due to the male parent were observed. Seed set among other open pollinated triploid genotypes averaged about 2.8% by weight. Chromosome numbers in the seedling progeny of a triploid × diploid cross varied from the diploid 2n = 20 to 2n = 55. Tetraploids made up the largest group, followed by double trisomics and primary trisomics in that order. A series of karyotypes with chromosome numbers ranging from 2x + 1 to 2x + 9 was recovered.
A PROTEIN ELECTROPHORETIC STUDY OF THREE AMPHIPLOIDS AND EIGHT SPECIES INAVENA
Authors: Murray Beatrice E. , Craig Iris L. , Rajhathy Tibor
Published: November 2014

Seed proteins of three synthetic amphiploids, one autotetraploid and eight species that include representatives of all ploidy levels and karyotypes of Avena were studied by acrylamide gel electrophoresis. Complete or nearly complete additiveness in banding pattern of the parental protein was obtained in the amphiploids and mechanical mixtures. The pattern of autotetraploid A. pilosa was more similar to the amphiploid derived from its diploid and A. sativa than to its diploid form. This was interpreted as a dosage effect indicating the presence of the same genes in both parental species. No distinct zonation of protein bands was apparent in the basic gels, but in the acidic gels a gap separated the fastest moving bands from the slower bands. About 50% of the bands were common to all species studied, indicating extensive residual homology. The A and C genome diploids were readily separated by band differences, the A genome protein patterns were essentially identical and the C genomes differed primarily in band number. The tetraploid protein patterns differed but the hexaploids had high homology and intraspecific polymorphism was detected in the hexaploid cultivars. Almost complete homology occurred between the A genome spectrum and the tetraploid and hexaploid patterns, as well as between the C genome spectrum and the tetraploid A. magna and the hexaploid protein patterns. Protein homology in Avena indicated close genomic relationships.
A STUDY ON THE RADIOPROTECTIVE PROPERTY OF THIOUREA AGAINST RADIATION-INDUCED CHROMOSOME DAMAGE
Authors: Reddy S. B.
Published: November 2014

The protective ability of thiourea in five different concentrations ranging from 5 × 10−2M to 1 × 10−5M has been demonstrated on chromosome aberrations in root tips of Allium cepa exposed to 350r X-irradiation. It was shown that protection against radiation-induced chromosome fragments and anaphase bridges was attained when the germinating seeds had been treated with thiourea for 1 hour prior to irradiation.
THE GENETICS OF TWO ALLELES FOR LEAF RUST RESISTANCE AT THE LR14 LOCUS IN WHEAT
Authors: Dyck P. L. , Samborski D. J.
Published: November 2014

Two genes conferring a similar mesothetic reaction to different races of leaf rust were backcrossed into the wheat variety Thatcher. One of the genes came from Selkirk and the other from Maria Escobar and Bowie. The two genes are alleles at the Lr14 locus, but have been combined into a single line. The inheritance of pathogenicity on these two alleles was studied by using an F2 population of 150 cultures from a cross between races 9 and 161 of leaf rust. Virulence on Lr14a was conferred by a recessive gene and on Lr14b by a dominant gene. These genes for virulence are independently inherited.
THE QUANTITATIVE INHERITANCE IN SPRING WHEAT OF MORPHOLOGICAL STRUCTURES ABOVE THE FLAG LEAF NODE
Authors: Hsu P. , Walton P. D.
Published: November 2014

A diallel cross between five spring wheat varieties showed that structures above the flag leaf node which contributed to the overall photosynthetic area of this region were highly heritable. For most of the characters studied additive genetic variance was significant while non-additive variance was not. The number of ears per plant and the yield per plant showed full dominance, while for the 1,000-kernel weight overdominance was present. Partial dominance was significant for peduncle length, the extrusion of the head from the leaf sheath and for the ear length.
A CYTOGENETIC ANALYSIS OF THREE ASYNAPTIC MUTANTS INBRASSICA CAMPESTRISL.
Authors: Stringam G. R.
Published: November 2014

Genetic data on three asynaptic mutants showed that all are monogenically controlled by recessive genes. Differences in cytological abnormalities suggested that each mutant was controlled by a separate gene. The symbol, as, is proposed for these characters with the designations, as, as2, and as3.The degree of asynapsis varied from complete failure of pairing in two of the mutants to partial asynapsis in the third. Other aberrations, such as chromosome fragmentation, lagging, attenuated univalents, micronuclei, restitution nuclei, and aberrant sporad formation were observed. The value of these asynaptics in breeding and cytogenetic research is discussed.
MITOTIC CYCLES IN ROOT TIP CELLS OF TWO SPECIES OF TRILLIUM (LILIACEAE)
Authors: Boothroyd E. R. , Mark Nancy MacDonald
Published: November 2014

There is a fourfold difference in the reported lengths of the mitotic cycles in Trillium. One report (29 hours at 23 °C for T. erectum) was based on the colchicine tag method, whereas the other (120 hours at 25 °C for T. grandiflorum) was based on the autoradiographic technique. In the present study both methods were used on both species. Experiments, carried out at 20 °C, gave minimum estimates of 104 hours and 84 hours respectively for T. grandiflorum and T. erectum, as determined by the colchicine method, and 92 hours and 80 hours by autoradiography. Both methods gave evidence of the existence of two or more populations of cells with different mitotic cycle times.
CYTOPHOTOMETRIC DETERMINATION OF DNA CONTENT INNICOTIANAMEGACHROMOSOMES
Authors: Collins G. B. , Legg Paul D. , Anderson M. K.
Published: November 2014

DNA content in normal Nicotiana chromosomes and in unusually long chromosomes called megachromosomes was determined by Feulgen cytophotometric techniques. DNA content estimates expressed as per cent transmittance were made at specific points on a megachromosome and the mean value for these measurements was compared to the mean transmittance values for normal chromosomes in the same pretreated metaphase cell. DNA measurements for interphase cells, unpretreated metaphase cells and the metaphase chromosome which forms the megachromosome were also obtained. Our observations support the conclusion that comparable unit areas of normal chromosomes and megachromosomes contain equivalent amounts of DNA. The finding of DNA amounts in megachromosomes comparable to DNA levels in normal chromosomes is interpreted as evidence for a replicative mechanism of megachromosome origin instead of a simple extension of the DNA in a chromosome of normal length throughout the length of a megachromosome.
5-BROMODEOXYURIDINE-INDUCED CONSTRICTIONS IN HUMAN CHROMOSOMES
Authors: Palmer Catherine G.
Published: November 2014

BUdR treatment during the last 5 to 7 hours of growth of leukocyte cultures significantly increases frequency of all secondary constrictions and produces characteristic morphology in certain chromosomes of the human complement. BUdR-induced morphology of the D group and sex chromosomes is described and specific patterns are related to specific chromosomes by the use of identifiable chromosomal abnormalities.
CENTRIOLE ADJUNCT DEVELOPMENT IN THE COCKROACH, EUBLABERUS POSTICUS
Authors: Lindsey James N. , Biesele John J.
Published: November 2014

With electron microscopy it is possible to recognize and describe the development of the centriole adjunct during spermiogenesis of the cockroach, Eublaberus posticus, an orthopteran insect. The four stages identified may be classified as: (1) presumptive granular stage; (2) endoplasmic reticulum associated stage; (3) ordered granular and vacuolate stage; and (4) mature stage. A description of the four stages of the centriole adjunct development, one in a spermatocyte, two in a spermatid and a fourth in the mature stage, suggests some possible origins of this structure and gives a detailed description of its development.
MULTIPLE SEX CHROMOSOMES AND CONFIGURATION POLYMORPHISM IN THE MONOCHAMUS SCUTELLATUS-OREGONENSIS COMPLEX (COLEOPTERA: CERAMBYCIDAE)
Authors: Lanier G. N. , Raskf A. G.
Published: November 2014

Fission-fusion polymorphism of the X chromosome and multiple sex chromosome configurations were observed in the Monochamus scutellatus-oregonensis complex. Segregation of fission X chromosomes opposite the Y is ensured by nucleolar orientation. However, occasional XY gametes may result when one X becomes disjoined from the nucleolus before the first meiotic division.
RELATIONSHIPS OF THE POLYTENE CHROMOSOMES OFDROSOPHILA MEDIOSTRIATAANDD.GRISEOLINEATA
Authors: Kastritsis Costas D. , Pasteur Georges , Quick Joan
Published: November 2014

Comparisons of the polytene chromosomes of late third instar larvae of Drosophila mediostriata (tripunctata group) and D. griseolineata (guaramunu group) revealed that distinct banding and puffing similarities exist between the species. The most impressive similarities were found to exist between the 3rd mediostriata and the 2nd griseolineata chromosomes; almost the entire length of this element of the former species could be homologized with that of the latter. Two simple inversions could account for the differences in banding sequence for this element if one were to disregard the fact that the griseolineata 2nd chromosome was considerably longer than the mediostriata 3rd.The amount of similarity found between the chromosomes of the species considered here is greater by far than that which can be found when mediostriata is compared to other species of the tripunctata group. It is concluded that the grouping of the species of this section of the phylogenetic tree of Drosophila must be reviewed and possibly revised.
PREWEANING GROWTH OF INBRED, F1HYBRID, AND RANDOM-BRED MICE AS A MEASURE OF MOTHER'S LACTATION
Authors: Nagai J. , Lee A. J. , Hickman C. G.
Published: November 2014

A cross-fostering experiment was performed in which inbred and random-bred mothers suckled three groups of young: inbred (the SWR strain), F1hybrid (SWR × C3H), and random-bred (originally synthesized from SWR, C3H, CBA and C57BL). Two inbred mothers and one random-bred mother were placed in each of 43 cross-fostering sets, and each mother suckled two of her own young and two from each of the other two mothers. Body weights of young were recorded individually at birth and at 12 days.In 12-day weight and gain from birth to 12 days, differences among the three groups of young and differences between inbred and random-bred mothers were significant (P < 0.01). Although the ratios of the between-dam to within-dam mean squares in log scale varied among nine mother-young subgroups, the differences between any pair of these ratios were statistically insignificant. It was therefore concluded that in detecting lactation differences among mothers the value of a given type of young was not different between inbred and random-bred mothers and that as a means of detecting lactation differences among random-bred mothers, inbred and F1hybrid young did not appear to offer any substantial advantage over random-bred young.
GENETIC VARIABILITY OF YIELD IN F2 POPULATIONS OF GRAIN SORGHUM SORGHUM BICOLOR (L.) MOENCH
Authors: Reddy C. R. , Liang George H.
Published: November 2014

Plant-to-plant genetic variability was estimated for F2 grain yield from 10 sorghum populations. The higher-yielding parents tended to produce greater genetic variability in F2, with larger population means, possibly because of the accumulation of desirable genes. The genetic variability in most populations did not seem to be sufficient for effective selection as evidenced by the ratio between estimated genetic and environmental variances. Incorporating diverse exotic materials in the current germplasm is suggested. Using heritability without examining the magnitudes of genetic and environmental variance components may be misleading in certain cases.
TRISOME IDENTIFICATION IN SORGHUM BICOLOR (L.) MOENCH BY OBSERVING PROGENY OF TRIPLOID × TRANSLOCATION STOCKS
Authors: Hanna W. W. , Schertz K. F.
Published: November 2014

Crosses between triploids (3n) × translocation-tester-stocks (2n) in Sorghum bicolor (L.) Moench produced F1 trisomics heterozygous for an interchange. These trisomics were used to associate the trisomes with the translocated chromosomes. This method was used because four of the trisomics of sorghum are not sufficiently fertile to make recovery of trisomic F1 progeny possible from trisomic × translocation-tester-stock crosses.Over 91% of the progeny from the triploid × translocation-tester-stock crosses were F1 plants and 41.6% were F1 primary trisomics. Frequency of the 10 trisomic types varied from 1.9 to 7.1% of the total.The 10 trisomes of sorghum were identified cytologically to be chromosome A-bottle brush, B-sparse branch, E-compact, D-stiff branch, E-large glume, F-asymmetric, G-cone, H-light green, I-small glume and J-spear.
HYBRID VIGOR AND GENE ACTION IN A SIX-PARENT DIALLEL CROSS OF SOFT WINTER WHEAT
Authors: Bitzer M. J. , Patterson F. L. , Nyquist W. E.
Published: November 2014

Six soft winter wheat lines were crossed in a diallel fashion and data were obtained from the parents and F1hybrid generation over two years. The mean squares for year by genotype interaction were significant for most measured characters indicating that the genotypes responded somewhat differently each year. The yield response of the F1generation hybrids ranged from −0.7 to 28.1% with 13 of 15 F1hybrids above the higher parent; however, none was significantly higher.Combining ability analyses were performed on the F1hybrids, and mean squares for general combining ability were significant for earliness, plant height, and kernels per spike. No significant mean squares for specific combining ability were detected. Monon was the best general combiner for both number of spikes and yield, and Gaines was a good general combiner for kernels per spike. The Jinks and Hayman (Vr, Wr) graphic analysis indicated that plant height, kernel weight, and number of spikes were controlled by some partial dominance and yield by apparent overdominance.
A COMPARATIVE STUDY OF SEED PROTEINS OF ALLOPOLYPLOIDS OF GOSSYPIUM BY GEL ELECTROPHORESIS
Authors: Cherry J. P. , Katterman F. R. H. , Endrizzi J. E.
Published: November 2014

Polyacrylamide gel electrophoresis of seed proteins from recently synthesized F1 triploid and colchicine-induced hexaploid plants showed the additive banding patterns of their parents (G. hirsutum × G. sturtianum) when compared to the synthetic mixture of the latter. Gene mutations, diploidization and species specific regulatory systems are discussed as possible evolutionary processes for the protein banding differences in the allopolyploids of the genus Gossypium.
CHARACTERISTICS OF TOBACCO FROM CROSSES BETWEEN BURLEY AND FLUE-CURED CULTIVARS
Authors: Povilaitis Bronius
Published: November 2014

Four burley and four flue-cured tobacco cultivars were selfed and crossed in all possible combinations to produce seed for a complete diallel cross test which was grown in 1965. Burley parents and burley × burley entries were omitted from the test in 1967 and only selected burley × flue crosses and their flue-cured parent were grown in 1968.Mean squares for the general combining ability were significant for yield, lamina weight, filling value, total alkaloids and reducing sugars, and non-significant for total nitrogen content. The mean squares for specific combining ability were significant for all six characters, suggesting that in the inheritance of these characters, additivity and dominance are both important. Heterosis effects for yield, lamina weight and reducing sugars were significant, but non-significant for days to flower and total alkaloids. The burley × flue hybrids gave considerably higher yields than their flue-cured parental cultivars. Lamina weight and the reducing sugar content of the hybrids was lower than the flue-cured tobacco cultivars. The subjective rating of the hybrids for body, color and texture of the cured leaf gave lower values than those assigned to the flue-cured parents.
GENES FOR STEM RUST RESISTANCE IN WHEAT VARIETIES HOPE AND H-44
Authors: Knott D. R.
Published: November 2014

Tests were carried out to identify and locate the genes for resistance to races 15B-1L and 56 in Hope and H-44. The gene Sr1 which conditions resistance to race 56 was found to be either very closely linked or more probably allelic to Sr9. It is proposed that it be redesignated Sr9d. The gene Sr2 which conditions adult plant resistance to race 56 appears to be on chromosome 3B. The recessive gene conditioning resistance to race 15B-1L was identified as sr17 which is on chromosome 7B.
CHROMOSOME ASSOCIATIONS AT DIAKINESIS IN THE CULTIVATED STRAWBERRY
Authors: Mok D. W. S. , Evans W. D.
Published: November 2014

The analysis of chromosome pairing in the cultivated strawberry revealed that multivalent formation occurs in each of the nine cultivars examined. Secondary pairing and a loose association of bivalents were also observed. The cytological evidence suggests that tetrasomic inheritance should be considered in the interpretation of genetic data.
SOME GENETIC AND PHYSIOLOGICAL CHARACTERISTICS OF UREASE-DEFECTIVE STRAINS OFNEUROSPORA CRASSA
Authors: Haysman Philip , Howe Jr. H. Branch
Published: November 2014

Fourteen mutant strains have been isolated which differ from wild type with respect to urease activity: Seven strains lack detectable activity in vivo and in vitro, B1, C21 and allele 601, D1 and allele D3, D2, and W2, and fail to grow with urea as sole nitrogen source; seven have activity in vivo and varying amounts in vitro, A7, E3, E7, R2, S3, and temperature-sensitive strains C5 and K3. Strains D1 and D3 are allelic to Kolmark's ure-1; W2, to Kolmark's ure-2. Strain D2, which is either allelic or closely linked to ure-1, complements none of the strains lacking urease activity nor three of the strains having defective activity, and may be a regulatory mutant. Strains B1, C21 and allele 601 represent two previously unreported loci in linkage group I. Only two of the seven swains having defective urease activity have been mapped, A7 and S3, and have been assigned to linkage group V. These seven strains grow readily on Vogel's medium modified by having urea as sole nitrogen source but not on W-M medium similarly modified; growth is restricted on modified Vogel's medium as well, however, if the initial concentration of nitrogen, as urea, is suitably adjusted to exceed that of phosphorus.
TYPES OF GENE ACTION AT THREE GENE LOCI IN SUBLINES OF A MAIZE INBRED LINE
Authors: Russell W. A.
Published: November 2014

"Isogenic" lines of maize (Zea mays L.) inbred Hy, derived by backcrossing and differing by single marker genes and chromosome segments linked to these gene loci were used to study gene action in the inheritance of nine quantitative plant and ear characters. The 27 genotypes representing all combinations of the homozygous and heterozygous genotypes at the three loci, wx, br2, and rf2, were used. Highly significant differences among genotypes were observed for all characters studied. Frequencies of significant comparisons (P < 0.05) for the types of gene action were: additive, 74%; dominance, 74%; additive × additive. 78%; dominant × dominant, 70%; additive × dominant, 39%; additive × additive × additive, 67%; additive × additive × dominant, 30%; additive × dominant × dominant, 48%; dominant × dominant × dominant, 67%. Greatest effects were observed at the br2segment; effects were greater at the rf1segment than at the wx segment. Overdominance was significant for four characters at the wx segment, one character at the br2segment, and three characters at the rf1segment.
EFFECTS OF MUTATION FOR PHOTOPERIODIC RESPONSE ON TOBACCO PLANT DEVELOPMENT IN ISOGENIC LINES
Authors: Povilaitis Bronius
Published: November 2014

Crosses were made between the flue-cured tobacco cultivar Delcrest and a short-day line, Mammoth Delcrest G.5, developed from a spontaneous mutation in Delcrest. Four sets of crosses were used, each set consisting of six genetic populations, viz. P1 (Delcrest), P2 (Mammoth Delcrest G.5), F1 (P1 × P2), F2 (F1 selfed), B1 (F1 × P1), and B2 (F1 × P2). The data observed on flowering time were in good agreement with the postulated monofactorial segregation of normal (day-neutral) against short-day plants, the latter being homozygous recessive. The mean flowering time of the first filial generation was very close to the Delcrest parent but the difference was still significant. The mutant gene apparently had no differential effect on the dimensions of the bottom and mid-stem leaves, but towards the top of the plant incomplete dominance was indicated for both the width and length of the leaves.
INTERSPECIFIC HYBRIDS INVOLVING ALFALFA. VI. INEFFECTIVENESS OF ALLOPLOIDY IN INDUCTION FERTILITY IN MEDICAGO PIRONAE × M. DAGHESTANICA HYBRIDS
Authors: Lesins K.
Published: November 2014

Colchicine treatment of hybrids from the interspecific cross Medicago pironae Vis. × M. daghestanica Rupr. induced the formation of three tetraploid shoots, one with 2n = 29 and two with 2n = 32, in their somatic nuclei. Their flowers had 21, 44 and 62% plasma-filled pollen, respectively. No seed was obtained from these tetraploids after selfing and intercrossing more than 1,200 flowers, indicating the presence of a built-in fertility barrier between the two species.By applying pollen from the tetraploid hybrids to alfalfa (M. sativn L.) two trispecies hybrids with 2n = 34 and 30 chromosomcs were produced. The first had 32%, the second 22% plasma-filled pollen grains. On backcrossing to M. sativa, a higher seed set was obtained with pollen from the 2n = 34 plant than from the 2n = 30 plant. Meiosis in the 2n = 30 plant was abnormal. At MI multivalents were observed, indicating that chromosomal material may be interchanged between M. pironae-daghestanica and M. sativa. Approximately half the meiocytes at AI possessed lagging chromosomes and only 6% of secondary meiocytes at AII were without disturbances.
EVALUATION OF CELL VIABILITY IN CHROMOSOMALLY HETEROGENEOUS CELL POPULATIONS
Authors: Cox D. M. , Ray M.
Published: November 2014

A method is described for determining cell viability in chromosomally heterogeneous cell populations. Individual cells were plated out to obtain clonal growth and the clones processed for chromosomes in situ. The majority of cell types in each of the parental populations examined were represented amongst the clones arising from that population.
COMPONENTS OF GENETIC VARIATION FOR SOME QUANTITATIVE CHARACTERS IN DIPLOID COTTON (G.HERBACEUML.)
Authors: Patil M. S. , Mensinkai S. W.
Published: November 2014

Genetic analysis of some quantitative traits of cotton through diallel cross technique revealed that both additive and dominant inheritance were important for all the seven characters studied excepting boll weight which showed predominantly nonadditive gene effects. However, the dominance component was higher than the additive component and overdominance was observed for all the seven characters studied. Therefore reciprocal recurrent selection is suggested for the improvement of yield in the present material.Heritability was relatively high for seeds per boll and lint index, medium for yield, and low for the remaining characters. The average frequency of positive and negative genes was asymmetrically distributed in the parents for all the seven characters. There were more dominant than recessive genes for all the characters except boll weight. The direction of dominance was positive for all the characters except yield and seed index. At least one group of dominant genes appeared to be responsible for the control of yield, boll number and seed index, while at least 5, 11 and 12 effective factors appeared to be controlling seeds per boll, lint index and lint per cent, respectively. But a large number of dominant factors was involved in the control of boll weight.
ULTRASTRUCTURE STUDY OF SPORIDIA OF USTILAGO HORDEI
Authors: Kozar F. , Weijer J.
Published: November 2014

The fine structure of germinated and ungerminated sporidia of Ustilago hordei (Pers.) Lagerh. was generally found to be similar to that of other fungi. The cytoplasm exhibited electron-transparent vacuoles, endoplasmic reticulum, fat bodies, vesicles, microtubules, crystals, and dense masses as well as various membraneous structures. Unlike the typical fungal cells, such as the N. crassa cell, sporidia of U. hordei contained elongated as well as branched mitochondria. Mitochondria were observed enveloped in membraneous structures and at times contained mesosome-like bodies. Nuclei with large discontinuities in the nuclear membrane were also observed.
A CROSSOVER SUPPRESSOR-ENHANCER SYSTEM IN THE MOSQUITO AEDES AEGYPTI
Authors: Bhalla Satish C.
Published: November 2014

A small reciprocal translocation T(1;2)1 involving chromosomes 1 and 2 and a paracentric inversion In(1)3 on m chromosome (1) of A. aegypti interact to give peculiar but consistent crossover values. The system is termed COSES and is associated with partial sterility. In females it suppresses crossing over tremendously to the right of bz and enhances crossing over to its left. In the males it enhances crossing over to the right of m (only 3 crossover units away from bz) hut the region to its left remains unaffected. COSES also displays interchromosomal effects by enhancing crossing over in linkage group III. Cytological and genetic evidence for the presence of translocation and inversion are presented. All three pairs of chromosomes are correlated to the three linkage groups.
AN IMPROVED METHOD FOR CHROMOSOME PREPARATION FROM MOUSE LIVER
Authors: Sun N. C. , Chu E. H. Y.
Published: November 2014

A simple method for preparing mitotic chromosomes from adult mouse liver is described. The procedure involves the accumulation of metaphases in regenerating liver resulting from CCI4treatment, followed by Trypsin perfusion, hypotonic pretreatment and fixation of cells, and flame-drying of slides to spread chromosomes. Approximately 2 × 106intact liver cells can be obtained from a single mouse liver – enough to prepare 50 slides. A peak mitotic activity, with more than 1% of cells in mitosis, was observed 72 hr after subcutaneous injection of 0.1 ml of 45% CCI4per animal. The distribution of diploid, tetraploid, and octaploid cells in mitosis was about 86, 11, and 3%, respectively. The abundant number of analyzable metaphases in such preparations makes this method valuable for cytogenetic analyses of normally non-proliferating tissue from adult laboratory mammals.
MEIOTIC CHROMOSOME BEHAVIOR IN TETRAPLOID HYBRIDS BETWEEN SYNTHETIC LOTUS AMPHIDIPLOIDS AND L. CORNICULATUS
Authors: Somaroo B. H. , Grant W. F.
Published: November 2014

Meiotic and fertility studies were carried out on 15 different tetraploid hybrids obtained by crossing 11 synthetic amphidiploids with L. corniculatus. The predominance of bivalents m meiocytes of these hybrids indicated that there was a strong tendency for homogametic pairing and that some preferential pairing was taking place between the chromosomes of L. corniculatus. Evidence for affinity between the chromosomes of the diploid species involved in the amphidiploids and L. corniculatus was provided by the presence of multivalent configurations at MI and inversion bridges at AI and AII. The meiotic chromosome behavior in these tetraploid crosses suggests that the most important species in the evolution of L. corniculatus are L. japonicus and L. alpinus. From pollen fertility data, it is considered possible to introduce desirable germplasm from the diploid taxa to the cultivated species by means of amphidiploids.
CHROMOSOMES OF TABANIDAE (DIPTERA)
Authors: Boyes J. Wallace , Wilkes A.
Published: November 2014

This first report on the chromosomes of Tabanidae provides descriptions of the complements of 13 species. The numbers range from 2n = 8 to 2n = 18 with considerable morphological differences between complements having the same chromosome numbers. The 56 complements analysed averaged 67.3 μ in total length. It is suggested that the primitive number of chromosomes is 2n = 18 and that different processes of reduction have taken place in different genera.
SEX AND SUPERNUMERARY CHROMOSOMES IN THE DIOECIOUS GRASSSOHNSIA FILIFOLIA
Authors: Singh D. N.
Published: November 2014

A dioecious grass Sohnsia filifolia (Fourn.) Airy Shaw (Syn. Calamochloa filifolia Fourn.) from Mexico has been found to have 2n = 20 chromosomes in both male and female plants. The staminate plants have one chromosome much longer than the other chromosomes of the complement. One pistillate plant was found to have 30 chromosomes, among which the largest chromosome is quite similar to the largest component of the diploid male plant. The longest chromosome has been designated as the Y chromosome. An XY-mechanism of the Drosophilia type has been suggested for the sex determination system in this species. One small supernumerary chromosome was observed in the microsporocytes of some male plants, but was absent in roots.
INHERITANCE OF YIELD AND OTHER AGRONOMIC CHARACTERS IN INDIAN MUSTARD (BRASSICA JUNCEA)
Authors: Singh Shree Pal , Singh Dharampal
Published: November 2014

Inheritance of eight characters, including yield, was studied in a 10 × 10 diallel cross of Indian mustard, Brassica juncea (L). Czern. and Coss., in space planting over two years, 1968 and 1969. The parental material included four experimental strains and six standard cultivars. Twenty-three hybrids significantly excelled the performance of the best cultivar for yield in 1968, and 10 in 1969.Additive and dominance gene effects were important for primary and secondary branches, plant height, and raceme length for both years. Days to flower, silique length, and seeds per silique also had both types of components operating in 1968, and only additive genes in 1969. Yield was found to be controlled mainly by dominance components. Heritability estimates were high for days to flower and plant height, and low for all other characters.
THE INHERITANCE OF GLUCOSURIA IN THE KK AND Ay MOUSE
Authors: Butler L.
Published: November 2014

Both the KK and the Ay mouse exhibit many symptoms of diabetes. Glucosuria is the most satisfactory test for this condition in mice. Glucosuria is inherited as a dominant in both strains, but many factors reduce its penetrance. The penetrance in the KK strain can be increased from 23 to 62% by crossing to C57BL/10J and then selecting the most effective background modifiers. The number of modifiers must be small because response was rapid and fixation fast. The cross KK × Ay gives yellow and black offspring in equal numbers. The yellows have the dominant genes for glucosuria from both strains, and the males all become glucosuric by the time they are 8 months old, in comparison to 7% of the males in the parental yellow strain. Of the yellow females, 88% are glucosuric by 1 year in comparion to 0% of the yellow strain or 2% of the KK's. The black males which lack the gene from the Ay strain but do have the gene from the KK have no glucosurics at 8 months and only 2% at 1 year. The F1 of the cross KK × Ay provides valuable research material since all yellow males will become glucosuric by 8 months of age and none of their black litter mates will.
ASPECTS OF THE MECHANISM OF COLCHICINE RESPONSE IN ALLIUM CEPA AND LUZULA PURPUREA. I. CYTOLOGY AND 3H-COLCHICINE AUTORADIOGRAPHY
Authors: Nelson Janet S. R.
Published: November 2014

Luzula purpurea, a plant with holokinetic chromosomes, has a colchicine response different from that of most plants, typified by Allium cepa. Following short treatments with colchicine concentrations of 10−4 to 10−3M, dividing cells of Luzula continue to higher ploidy levels and do not return to normal mitosis even after 72 hr recovery. This repeated arrest and reversion to interphase with subsequent doubling of chromosome number is opposed to the situation in most plants, which return to normal mitosis, with some tetraploid figures, after several hours in water. Luzula, labeled for short periods with 1.25 × 10−3M 3H-colchicine and placed in water to recover, shows autoradiographically detectable label retained within the cells up to 72 hr after treatment. The silver grains are found over cytoplasm and developing xylem elements. These are areas containing microtubules, the subunit protein of which, in animal systems, has been shown to bind colchicine. Allium treated with 3H-colchicine does not retain label after recovery periods, a result consistent with the observed rapid cytological recovery.