bluuebunny/crossref_metadata_2025 huggingface dataset:
DESYNAPSIS INPISUM SATIVUMINDUCED THROUGH GENE MUTATION
Authors: Gottschalk W. , Baquar S. R.
Published: November 2014

A mutant of Pisum sativum showing various meiotic anomalies was isolated from X-irradiated material. These irregularities are due to a severe reduction of chiasmata frequency in pachytene resulting in univalent formation in the following meiotic stages. The action of this recessive gene shows considerable variations from PMC to PMC. As a consequence of this behaviour a large number of microspores is produced in each PMC having different chromosome numbers. The mutant is completely sterile in both sexes. Only very negligible differences were noted in the meiotic behaviour of this mutant in subsequent generations demonstrating that the action of gene ds82Ais not influenced by extrinsic factors. It has been demonstrated that mutant 82A attains an extreme position in the scheme as compared with other desynaptic genotypes.
CYTOPLASMIC INCOMPATIBILITY AND BREEDING ISOLATION IN BARK BEETLES (COLEOPTERA: SCOLYTIDAE)
Authors: Lanier Gerald N.
Published: November 2014

Unequal fertility of reciprocal crosses between certain bark beetles and increased fertility of the F1, with respect to the original cross, appear to result from nuclear-controlled cytoplasmic incompatibility. This mechanism, also implicated in instances of reciprocal mating sterility, may be an important factor in the reproductive isolation of closely related species.
CYTOGENETIC STUDIES OF CALCIUM CYCLAMATE IN MERIONES UNGUICULATUS (GERBIL) IN VIVO
Authors: Majumdar S. K. , Solomon Martin
Published: November 2014

Cytogenetic studies in Mongolian gerbils, Meriones unguiculatus, have shown that calcium cyclamate when given intraperitoneally can induce hyperploidy and chromosomal breaks, gaps, and fragments in bone marrow cells in vivo. Increasing concentrations of the sweetener produced increasing incidence of chromosomal abnormalities. Analysis of means showed that a 'saturation effect' of calcium cyclamate to induce hyperploidy, breaks and fragments was reached at 150 mg/kg; whereas a dose-response relationship was found between increasing concentrations (except at 50 mg/kg) and increasing percentage of cells showing gaps. The ability of calcium cyclamate to produce hyperploid cells and fragments is revealed for the first time in this study.
CHROMOSOME PAIRING, FERTILITY, AND CROSSING BEHAVIOR OF HAPLOIDS OF TETRAPLOID ALFALFA, MEDICAGO SATIV A L.
Authors: Bingham E. T. , Gillies C. B.
Published: November 2014

Chromosomes paired mainly as bivalents at metaphase in 15 haploids (2n=2x=16) from 10 unrelated stocks of cultivated alfalfa (2n=4x=32). The apparent high degree of chromosome homology and hence autopolyploid chromosome behavior exhibited by the comparatively large sample agreed with that previously reported in independent studies of three other 2x haploids. No gross structural rearrangements of the chromosomes were detected. Haploids produced as much as 50% stainable pollen, but it was only 1-2% germinable in vitro, and they were all effectively male sterile, even when derived from normal male fertile stocks. Two haploids had normal female fertility, whereas forty-eight others were reduced in female fertility in varying degrees. Only four were completely sterile. Since meiosis was normal, the reduction in fertility was due to factors operating postmeiotically. Haploids used as seed parents produced mostly diploid progeny in crosses with diploid M. sativa and M. falcata, and mostly tetraploid progeny in crosses with tetraploids. A few trisomics, other aneuploids, and a pentaploid were also produced. Haploids and diploids derived from them produced a higher frequency of unreduced female gametes than wild diploids. 2x haploids of alfalfa appear to be useful in new approaches to genetic and breeding research, since large numbers can he obtained, they are crossable with wild and derived diploids, and their germplasm can be transferred back to the tetraploid level by unreduced gametes.
COMPLEMENTARY GENES CONTROLLING A 'PHENODEVIANT' IN JAPANESE QUAIL
Authors: Sittmann K.
Published: November 2014

Pose-hatch crooked neck in Japanese quail is a 'phenodeviant' by virtue of a consistently low population incidence (< 0.5%) and because of a very low recurrence risk among full-sibs of affected quail (< 5%). Genetic determination of phenodeviants is generally assumed to be essentially polygenic. In this study, however, a significantly large inbreeding effect and other evidence indicated that this 'phenodeviant' is controlled by recessive genes at only two loci.
MONOSOMIC ANALYSIS OF THE CORRODED CHARACTERISTIC IN WHEAT
Authors: Wenzel W. G.
Published: November 2014

A corroded leaf mutation which was first reported by Sears (1954) was found in the variety Kurrachee. The present investigation includes a more detailed phenotypic description of this mutant. The expressivity of this mutation was more pronounced under greenhouse conditions than in the field. A monosomic analysis was carried out in which the Koga monosomics were crossed with the variety Kurrachee. The mutation behaved as a deletion and was located on chromosome 6D. To obtain normal green plants, more than four of the six homoeologous alleles on the chromosomes of group 6 had to be present. With only four or less wild-type alleles the mutant characteristic was always evident, no matter on which of the homoeologous chromosomes the particular alleles were present.
MEIOSIS IN THE MALE OF CULEX PIPIENS AND AEDES ALBOPICTUS AND FERTILIZATION IN THE CULEX PIPIENS-COMPLEX
Authors: Jost Erich
Published: November 2014

As a result of close somatic pairing of the chromosomes visible leptotene stages do not occur in either Culex pipiens or Aedes albopictus. Bouquet stages were not observed during early meiotic prophase. The sperm of C. pipiens consist of a head 14 μ long and a tail 200 μ long. More than 80% of sperm treated with 3H-Tdr could be sufficiently labeled by feeding fourth instar larvae 10 μCi/ml/larva 3H-Tdr for about 3 days. An almost complete label could be found in the sperm head and only some few grains in the DNA of the mitochondrial bodies of the tail.In the C. pipiens female, meiosis is activated by the entrance of the sperm and karyogamy is effected about 50 minutes after oviposition. During the meiotic divisions the sperm moves to the center of the egg and fuses with the pronucleus. If supernumerary sperm are present they most often are found near the micropylar pole of the egg.Although the frequency of polyspermy is low, one or two sperm are usually present in the fertilized eggs.In incompatible crosses with strains of different geographical origins (♂ Hamburg ♀ Paris) the egg is activated by the sperm and the meiotic divisions begin but the sperm does not succeed in fusing with the pronucleus. The developing embryos are haploid and embryogenesis leads to irregular differentiation; 99.9% of the embryos die. Apparently reactions between sperm and egg cytoplasm prevent karyogamy. The different models of cross-reactions in the C. pipiens-complex are discussed; mitochondrial DNA is suggested to be involved in fertilization.
CHROMOSOME POLYMORPHISM IN INTERBRED SUBSPECIES OF PEROMYSCUS MANICULATUS (DEER MOUSE)
Authors: Sparkes Robert S. , Arakaki David T.
Published: November 2014

Karyotype analyses of eight animals from an interbreeding colony of three subspecies of Peromyscus maniculatus (P.m. gambelli, P.m. rubidus, and P.m. sonoriensis) demonstrated a chromosomal polymorphism, probably due to pericentric inversions involving at least seven chromosomes. This polymorphism may require consideration in the cytogenetic taxonomy of these animals, and may be related to the widespread distribution of deer mice in North America and their apparent adaptability to many different environments.
THE FREQUENCY OF CHROMOSOMAL TRANSLOCATIONS AMONG THE OFFSPRING OF LOCALLY IRRADIATED RATS
Authors: Savković N. , Pečevski J.
Published: November 2014

The aim of our investigation was to examine the frequency of chromosomal translocations among the male F1 generation of rats at the first meta-phase stage of meiosis. Cytological examination of primary spermatocytes of the offspring of rats was made 12 weeks after they were born. The results obtained show that irradiation induces chromosomal translocations in male offspring originating from irradiated parents.
INHERITANCE OF PER CENT TOTAL ALKALOIDS INNICOTIANA TABACUML. II. GENETIC EFFECTS OF TWO LOCI IN BURLEY 21 × LA BURLEY 21 POPULATIONS
Authors: Legg Paul D. , Collins G. B.
Published: November 2014

The genetic effects and the relative contribution of two loci to the level of total alkaloids in burley tobacco (Nicotiana tabacum L.) were determined. The nine genotypes for a two-locus system were developed and evaluated in two environments. Significant additive effects were found at both loci, a dominance effect was significant at one locus, and the additive × additive epistatic effect was significant. All interactions between genetic effects and environments were nonsignificant. The relative dosage effects of the loci were approximately 2.4 to 1.
CYTOGENETICS OF 6X-AMPHIPLOID × AVENA SATIVA L. F1 HYBRIDS
Authors: Forsberg R. A. , Wang S.
Published: November 2014

Avena abyssinica (2n=28) × A. strigosa (2n=14) 6x amphiploids were crossed with 13 different A. sativa (2n=42) varieties or selections. There was considerable variation in chromosome number within and among F1 plants. The mode was 40 in root tip cells and 41 in pollen mother cells (PMC's). The number of univalents in PMC's ranged from 10 to 27 with a mean of 18.9. The average number of bivalents was 7.1, ranging from 2 to 13. Multiple associations were common. Only 10.8% of the pollen grains contained normally developed nuclei, i.e. one vegetative and two elongated sperm nuclei. Forty of 41 F1 plants were completely self-sterile and only one seed was obtained from 16,950 florets. Seed set in backcross pollinations with A. sativa was 1.25%, providing some opportunity for perpetuation of desirable genes from lower ploidy levels.
RELATIONSHIP OF TAXA IN THE GENUS MEDICAGO AS REVEALED BY HYBRIDIZATION. V. SECTION INTERTEXTAE
Authors: Lesins K. , Singh S. M. , Erac A.
Published: November 2014

Urban (1873) characterized Medicago L. division Intertextae Urb. as having black seeds. An exception to this was found among M. granadensis Willd.; there were accessions with black as well as with brown seeds. Black seed color was dominant over brown and segregated in F2 in ratio 3:1. Two other M. granadensis marker characters: colored vs. green stems, hairy stems vs. smooth stems similarly segregated in a 3:1 ratio, the first named characters being dominant. The colored and white patch in the middle of leaflets appeared to be determined by a gene P for patching, a gene C being responsible for the presence of color. No recombinations were found between colored patch in leaflets, colored stems, and black seeds, indicating that there is only one gene for color with pleiotropic action, or that the genes are closely linked M. granadensis did not hybridize with M. intertexta and M. ciliaris. It clearly is a separate species.M. intertexta Mill., M. ciliaris All. and M. muricoleptis Tin. could be intercrossed. Marker characters, red basal patch vs. no patch in leaflets and hairs vs. no hairs on pods, segregated in F2 in a normal 3:1 ratio, the first named characters being dominant, Segregation did not indicate that there was any linkage between the two characters. Seed weight difference was determined by two genes acting in an additive manner. Distribution of leaf marking in seed weight classes indicated an independent segregation. Pollen fertility of F1's was less than 50%. There were observed irregularities in 30% of meiotic metaphases studied in F1 of M. muricoleptis × M. ciliaris. Because of some interbreeding barrier the taxa may be considered separate species though their hereditary material can be interchanged.
PREWEANING WEIGHT AS A MEASURE OF MILK PRODUCTION IN MICE
Authors: Nagai J.
Published: November 2014

A cross-fostering experiment with random-bred mice was performed to determine the importance of milk production in 12-day weight of a litter containing either six or eight young and in litter weight gains (litter weight gain from birth to 12 days, and litter weight gain from 1-hour nursing at 12 days). Three and four dams that produced young on the same day formed a cross-fostering set in the six-young and eight-young groups, respectively.In the six-young and eight-young groups, milk production accounted for 65 and 66% of the variance, respectively, in 12-day litter weight. Litter weight gain from birth to 12 days and litter weight gain from 1-hour nursing at 12 days had 74 and 61% of their variance accountable to milk production in both young groups. The findings indicate that the importance of milk production (phenotype) in 12-day litter weight and litter weight gains is virtually the same in the two groups. The conclusion was drawn that unless the values of genetic parameters involved are different for litters of six and eight young, the accuracy of estimating the additive genotype of milk production from 12-day litter weight or litter weight gains is similar when a mother suckles six to eight young.
A SUGGESTION FOR THE NOMENCLATURE OF THE FLUORESCENT BANDING PATTERNS IN HUMAN METAPHASE CHROMOSOMES
Authors: Lin C. C. , Uchida Irene A. , Byrnes Elizabeth
Published: November 2014

With the application of fluorescent technique, it is now possible to recognize characteristic banding patterns in human chromosomes. A simple nomenclature for the bands is suggested according to their visual identification.
INFLUENCE OF TEMPERATURE ON THE INDUCTION AND REPAIR OF RADIATION INDUCED ABERRATIONS IN THE HUMAN CHROMOSOME
Authors: Bora K. C. , Soper L.
Published: November 2014

Investigations were carried out by (i) X-irradiating human peripheral blood lymphocyte cultures in vitro at 37 or 5 °C with 306 R at 102 R/min, and maintaining these at the respective temperatures for 65 min following irradiation, and before incubation at 37 °C, and by (ii) reversing the temperature of half the cultures immediately or 30 min following irradiation. Metaphase chromosomes were analysed in 54-hr cultures for induced aberrations. Aberration frequency was significantly higher in cultures irradiated at 37 °C and maintained at 37 °C for 65 min following irradiation than in cultures receiving parallel treatments at 5 °C. Reversal of temperature from 37 to 5°C and vice versa resulted in intermediate frequencies. Reduction of postirradiation treatment time from 65 to 30 min at 37 °C before reversal to 5 °C did not influence the exchange frequency. However, similar treatment at 5 °C and reversal to 37° showed an increase. It is suggested that the increase in the aberration frequency at high temperature is not due to an enhanced sensitivity of the human chromosome to radiation, but to an influence on the repair and exchange formation processes.
THE EVOLUTION OF CHROMOSOME-ARM RATIO IN WHEAT
Authors: Kimber Gordon
Published: November 2014

The coefficient of concordance between arm-ratio measurement and homoeologous group in two varieties of hexaploid wheat was found to be highly significant. This is taken to indicate considerable cytological stability in the evolution of the wheats. This stability in the evolution of the cultivated forms of the subtribe Triticinae differs from the evolutionary patterns found in other species of the subtribe. It is possible that this difference is related to the artificial selection pressures imposed by cultivation.
PRODUCTION OF ALIEN SUBSTITUTION LINES INTRITICUM AESTIVUM
Authors: Bielig L. M. , Driscoll C. J.
Published: November 2014

Chromosomes of related species are being substituted within the seven homoeologous groups of wheat. In this way a series of 21 monosomic alien substitution (MAS) lines and the related disomic alien substitution lines can be developed. Three substitutions within each of homoeologous groups 3, 5, 6 and 7 have been isolated by the authors. Substitution of alien chromosomes in the remaining groups, viz 1, 2 and 4, is discussed.
CHROMOSOME LOCATION OF THREE GENES FOR LEAF RUST RESISTANCE IN COMMON WHEAT
Authors: Dyck P. L. , Kerber E. R.
Published: November 2014

Genes Lr10 and Lr16 for seedling resistance and gene Lr12 for adult-plant resistance to leaf rust in common wheat were located on specific chromosomes by monosomic analysis using the Rescue monosomic series. Gene Lr10 is on chromosome 1A and genes Lr12 and Lr16 are on chromosome 4A. The latter two genes must be more than 50 crossover units apart since they segregated independently. These three genes were backcrossed into Thatcher from the variety Exchange. The variety Chinese Spring probably carries gene Lr12.
GENETIC COMPONENTS FROM FULL, HALF AND QUARTER DIALLELS FOR THE CULTIVATED STRAWBERRY
Authors: Watkins R. , Spangelo L. P. S.
Published: November 2014

It is predicted chat satisfactory estimates of genetic variance parameters could be obtained from quarter diallels at a considerable reduction in the cost compared to obtaining similar information from full diallels. It is also predicted that, for breeding procedures designed to exploit all the genetic variance, estimates of genetic progress obtained from half and quarter diallels would be almost identical to those obtained from full diallels.No genetic progress was indicated for strawberry yield for any reasonable selection intensity when only the additive variance was exploited.It is suggested that long-term genetic progress for an economic complex of characters may be obtained by exploiting major gene differences following classical Mendelian principles and using the resulting selections as one source of parents for crosses designed to exploit all the genetic variance – additive, dominant and epistatic.
ULTRASTRUCTURAL CHANGES IN CHLOROPLASTS OF AUTUMN LEAVES
Authors: Stearns Mark E. , Wagenaar E. B.
Published: November 2014

The phenomenon of aging of leaves in autumn was studied in three deciduous trees, viz. Acer ginnala Maxim., Populus tremuloides Michx. and Rhus typhina L. The leaves were collected at three stages of development: at maximum summer development, at early senescence, and at a full senescence. Electron microscope studies of fully matured leaves generally showed lens-shaped chloroplasts fairly uniform in shape and size with extensive granalamellae, large starch granules and a few small lipid globules. Green, partly senescent leaves had somewhat smaller chloroplasts with large lipid globules within the reduced stroma-lamellae; virtually no starch granules were present. Fully senescent, brightly coloured, autumn leaves showed a definite decrease in size and number of chloroplasts. These plastids had lost their typical summer structure, were small and cylindrical, and contained densely packed globules that replaced the membrane structures. The presence of the carotenoids in these globules probably contributed to the autumn pigmentation of the leaves. Not all leaf cells followed the above described pattern of senescence at the same rate. The chloroplasts of palisade cells degraded earlier than those in the mesophyll cells.
THE 4C NUCLEAR DNA CONTENT OF SEVERAL HORDEUM GENOTYPES
Authors: Bennett Michael D. , Smith J. B.
Published: November 2014

The 4C nuclear DNA content was estimated for 17 wild Hordeum species and five cultivated Hordeum vulgare varieties which were chosen to include examples varying greatly in geographical origin and in morphological and physiological characters. Nuclear DNA was measured on an integrating microdensitometer using prophase nuclei in Feulgen stained root-tip squashes. There were no significant differences in DNA content between any or the 15 diploid genotypes measured, and the seven polyploid genotypes all had nuclear DNA contents which were simple multiples of the diploid genotypes. This result, namely that the DNA content of diploid Hordeum species is invariable, differs from results obtained from diploid species in several other plant genera which differed greatly in nuclear DNA content.
CHROMOSOME PAIRING IN HEXAPLOID TRITICALE
Authors: Thomas J. B. , Kaltsikes P. J.
Published: November 2014

A durum wheat background was shown to suppress the meiotic pairing of chromosomes of Secale montanum Guss. with homoeologues of S. cereale L. in hexaploid triticale. This effect was attributed to the activity of the 5BL diploidising system, apparently active in tetraploid wheat. It was considered unlikely that the SBL system was important in conditioning the normal level of pairing failure found in disomic triticales.
GENETIC DETERMINATION OF HIGH MEIOTIC REVERSION FREQUENCIES IN ISOLEUCINE-VALINE 1 HOMOALLELIC CROSSES INNEUROSPORA
Authors: Bausum Howard T.
Published: November 2014

High frequency reversion in homo- and heteroallelic crosses of isoleucine-valine-1 (iv-1) group 2 alleles was reported previously. The genetic determination of homoallelic reversion in a single allele, Tiv 318, is reported here.The property of yielding prototrophs in test crosses underwent 2:2 segregation in tetrads and showed close linkage to spray (sp) and actidione-2 (act-2). Crosses of ordered segregants from a reverting lysine-1 (lys-1) iv × iv sp cross and of random spore isolates from six reverting lys-1 iv × iv act-2 crosses identified a disparity of origin of the pertinent chromosome region as an enhancing factor, but not a sine qua non of reversion. This region exists in at least three states such that a combination of two is effective. Direct involvement of outside markers was excluded. The cytogenetic nature and mode of operation of the enhancing factor are unknown.Prototroph frequency did not differ in reciprocal crosses, and the growth rate of revertants was unaffected by isoleucine and valine.
CROSSING OVER IN A DOUBLE TRANSLOCATION INDROSOPHILA
Authors: Robinson A. S. , Curtis C. F.
Published: November 2014

The production and fertility of a double translocation heterozygote in Drosophila melanogaster are reported. A difference in the fertility of male and female double heterozygotes was recorded and explained on the basis of crossing over, occurring in the differential segments of female double heterozygotes, producing extra unbalanced gametes. It was shown that crossing over was absent from one differential segment but the amount of crossing over occurring in the other differential segment was measured. The possible use of multiple translocation systems for pest control is discussed with particular reference to the use of double translocation heterozygotes.
QUANTITATIVE GENETICS OF FERTILITY. IV. CHROMOSOMES AFFECTING EGG PRODUCTION INDROSOPHILA MELANOGASTER
Authors: Fitz-Earle Malcolm
Published: November 2014

Chromosomal combinations of the X, 2 and 3 chromosomes were synthesized from two inbred lines of Drosophila Melanogaster. Egg production determinations over the productive lifetime of sibling matings from the lines were fitted to a new model of lifetime egg production. The two parameters in the model which had been shown to be essentially genetic were related to specific chromosome effects. Chromosomes X and 3 but not 2, influenced the rate of decline in oviposition α and the time of cessation of egg-laying tq. In addition, interactions of chromosomes 2 and 3 upon these parameters were detected. The chromosome or interaction between chromosomes which decreased α concomitantly increased tqand vice versa.
TRISOMICS IN CYAMOPSIS PSORALOIDES
Authors: Singh Avtar
Published: November 2014

Cytology of three trisomic plants of Cyamopsis psoraloides DC (Leguminosae) has been studied. The trisomic plants did not differ from one another in morphology but the trivalent frequency differed in each plant. The extra chromosome was not identified.
STERILITY ENHANCEMENT IN THE MOSQUITO, CULEX TRITAENIORHYNCHUS
Authors: Sakai Richard K. , Baker Richard H. , Mian Afsar , Said Shahina
Published: November 2014

The sterilities of stocks with chromosomal aberrations were enhanced by re-irradiation. Males heterozygous for two independent aberrations were synthesized and their sterilities determined. The possible advantages of the double heterozygote males over either completely sterile males or those heterozygous for only one aberrational complex are discussed.
INTERSPECIFIC CROSSES INVOLVING ALFALFA. VII. MEDICAGO SATIVA × M. RHODOPEA
Authors: Lesins K.
Published: November 2014

On crossing Medicago sativa L. with M. rhodopea Velen., two hybrids were obtained. One was a triploid 2n = 24. It was produced by crossing a self-incompatible, diploid (2n = 16) M. sativa plant with an artificially chromosome-doubled (2n = 32) M. rhodopea plant. In this hybrid almost no fully analyzable MI plates were found. The range of observed univalents in 57 MI plates examined was one to seven per plate; in 38 of these plates one to four trivalents were seen. The chromosomes were doubled in the triploid to produce a hexaploid hybrid (2n = 48) which was self-sterile. This was probably the influence of the self-incompatible parent. The amount of plasma-filled pollen was approximately 64% in the hexaploid hybrid, as compared to less than 20% in its triploid progenitor. On backcrossing the hexaploid hybrid to hexaploid and tetraploid alfalfa, seeds were readily obtained. The other hybrid, which was obtained by crossing a tetraploid (2n = 32), male-sterile M. sativa with the chromosome-doubled M. rhodopea; had 2n = 31. It is assumed that in this and similar rarely successful crosses, some incompatibility factor/s is eliminated with the eliminated chromosome or the genic ratio is changed favoring compatibility. Transfer of M. rhodopea genic material to cultivated alfalfa may be through crossing over at meiosis involving chromosomes of the two species. Such occurrences were indicated on examination of meiosis in the triploid hybrid. Another way to include M. rhodopea chromosome complements in alfalfa would be to produce hexaploid auto-alloploids consisting of two sets of M. rhodopea (Rp) and four sets of M. sativa (S) chromosomes.
THE GENETIC STRUCTURE OF CHROMOSOMES CARRYINGSEGREGATION-DISTORTER
Authors: Miklos George L. Gabor
Published: November 2014

This study deals with the polygenic modifying systems of a specific recombinant SD chromosome. By recombining this chromosome with a multiply marked homologue and by testing the subsequent SD and non-SD bearing recombinant chromosomes in both cis and trans configurations, it has been possible to grossly localize major modifiers of distortion. These are located between the loci of cinnabar+and curved+, as well as between curved+and plexus+. It has been further shown that some of these enhancers produce significant effects only when present in coupling with the SD locus.
MORPHOLOGY OF THE PACHYTENE CHROMOSOMES INPRUNUS PERSICA
Authors: Jelenkovic G. , Harrington E.
Published: November 2014

Morphology of the pachytene chromosomes was studied in three genotypes of Prunus persica (L.) Batsch. Each of the eight bivalents has been identified by its distinctive morphological features such as length, position of the centromere, and distributional pattern of the heterochromatic chromomeres. On the basis of total length the chromosomes were numbered from one to eight, the last being the shortest of the complement. In all bivalents the heterochromatin is clustered around the centromere. The chromosomes of the three clones are alike. A heterochromatic knob is present in the distal part of the shorter arm of chromosome five from 'Raritan Rose'. This knob was not present in the other two genotypes studied.Two pairs of chromosomes participate in the organization of a single nucleolus. At pachytene and later stages of prophase, small nucleoli-like bodies associated with or close to the bivalents were frequently observed.
EFFECTS OF CYTOPLASMIC MALE STERILITY ON CERTAIN CHARACTERS OF FLUE-CURED TOBACCO,NICOTIANA TABACUM
Authors: Povilaitis Bronius
Published: November 2014

Cytoplasmically male-sterile flue-cured tobacco cultivars, which were derived by backcrossing normal male-fertile cultivars to a male-sterile one containing Nicotiana megalosiphon cytoplasm, were compared to cultivars which were used as a recurrent parent. The male-fertiles produced significantly higher yield, return index, and percentage of reducing sugars than the male-steriles. The latter gave slightly improved grade index, and maturity index, higher total alkaloid content, and lower lamina weight than the fertiles but these differences were not significant.
PRELIMINARY ESTIMATES OF INBREEDING IN NATURAL POPULATIONS OF BLACK SPRUCE, PICEA MARIANA
Authors: Morgenstern E. K.
Published: November 2014

Experiments were conducted with seed and seedlings from populations of black spruce Picea mariana (Mill.) B.S.P. in six ecological regions of Ontario, sampled along a transect from Lake Erie to James Bay. Progeny of the three southern populations showed some inbreeding depression and larger values of Wright's inbreeding coefficient, F, than progeny of northern populations.
THE DURATION OF MEIOSIS IN DIPLOID AND AUTOTETRAPLOID BARLEY
Authors: Finch R. A. , Bennett M. D.
Published: November 2014

The duration of meiosis and its constituent stages are given for diploid and autotetraploid Ymer barley grown at 20 °C in continuous light. In the diploid, the total meiotic time was about 39 ± 1 hr in both cultured anthers and on whole plants. In the tetraploid, the total meiotic time was about 31 ± 1 hr in cultured anthers. In both genotypes, each meiotic stage occupied about the same proportion of the total meiotic time as in other species.In unsampled anthers the tapetal nuclei divided synchronously while the pollen mother cells were at pachytene and each tapetal cell became binucleate. Normal development in the tapetum and archesporium was much more easily upset by sampling techniques during pachytene than at any other stage.The duration of meiosis in diploid Ymer agrees closely with our previous estimate for diploid Sultan barley. The shorter meiotic duration of the auto-tetraploid compared with that of the diploid is to be expected in the light of the decreased meiotic time of tetraploid Svalöf 4x rye compared wih diploid Petkus Spring rye (Bennett and Smith, 1972) and the interspecific comparisons of meiotic times made by Bennett (1971).The development timing differential between adjacent spikelets was much less during meiosis than at the primordial stage.Abnormal tetrads which occurred spontaneously at a low frequency in tetraploid Ymer are discussed. They were probably associated with spindle abnormalities.
MODE OF INHERITANCE AND GENE ACTION FOR YIELD AND ITS COMPONENTS INPHASEOLUS AUREUS
Authors: Singh Tejinder P. , Singh K. B.
Published: November 2014

A diallel study of yield and its components in F1, F2, F3and backcross generations was used to estimate components of genetic variation and type of gene action. Graphical and components of variance analyses revealed the importance of non-additive gene action for yield, pods per plant and clusters per plant. Additive gene action was important for 100-seed weight. Partial dominance for yield and seed size and partial- to over-dominance for pods per plant, clusters per plant and pods per cluster was evident from the graphic analysis. Dominant genes seem to govern inheritance of high yield and fewer pods per plant. The study indicated the appropriateness of studying one additional generation, either F2or backcross, to confirm the F1results. Implication of this study on breeding methodology is discussed.
GENETIC STUDIES OF ISOZYMES INNEUROSPORA. II. ESTERASES
Authors: Reddy M. Mohan , Threlkeld S. F. H.
Published: November 2014

Acrylamide gel electrophoretic analysis of mycelial extracts revealed that a slow moving esterase is specific to Neurospora crassa strains and a fast moving esterase to N. sitophila strains. These two isozymes of esterases appear to be under the control of two unlinked, codominant duplicate genes.
GENERAL FORMULAE FOR ESTIMATING HERITABILITY IN A POPULATION WITH RELATED PARENTS
Authors: Fujishima Tohru , Fredeen Howard T.
Published: November 2014

In populations encountered in practice, families will be of variable and unequal size and there will be genetic relationships among the breeders. This paper develops general formulae for estimating heritabilities based on analysis of variance for populations with a hierarchical structure. It is shown that such heritability estimates must be corrected according to the genetic relationships among members in the population and that the conventional technique, ignoring the genetic relationships, may lead to both over- and underestimation of the heritability depending on the parental relationships in non-inbred populations.Procedures for calculating the genetic relationship among members in the population from that among their parents are also presented. It is also demonstrated that the genetic relationships between half-sibs, r2, may have a range of [Formula: see text] and those between members of different sire families may range between [Formula: see text] in a non-inbred population.
POLYMORPHISM AND QUINACRINE FLUORESCENCE KARYOTYPES OF RED FOXES (Vulpes vulpes)
Authors: Lin C. C. , Johnston D. H. , Ramsden R. O.
Published: November 2014

Chromosome studies in 20 red foxes (Vulpes vulpes Linn.), sampled from Southern Ontario, have shown an intraspecific numerical variation of chromosomes. The modal numbers vary from 34 to 39 inclusive in the population studies. Half of the males and half of the females had a modal 2n number of 36. Most of the fox chromosomes showed very specific reproducible patterns by quinacrine fluorescence technique and the identification of all macrochromosomes in the complement became possible. However, exact identification of the Y chromosome still remains a problem.
LINKAGE GROUP IV OFTRIBOLIUM CASTANEUM
Authors: Dawson Peter S.
Published: November 2014

A new recessive eye color mutant, hazel, of the flour beetle, Tribolium castaneum, has been mapped in linkage group IV near the white locus, thus establishing the existence of a fourth pair of closely linked eye color genes in this species. A revision of linkage group IV is proposed.
KARYOTYPIC VARIATION WITHIN THE GENUS LEIOPELMA (AMPHIBIA: ANURA)
Authors: Stephenson E. M. , Robinson E. S. , Stephenson N. G.
Published: November 2014

The chromosome complements of four specimens of the anatomically primitive frog Leiopelma hochstetteri are described from cultured cells and squashes. The basic karyotype in all cases consists of 22 chromosomes, 12 of which are acrocentric. Supernumerary chromosomes are either absent or variable in number, but appear to be constant in the somatic cells of any one individual. The limited evidence available suggests that the supernumerary chromosomes do not pair during male meiosis.The karotype of L. archeyi is described for the first time. Only the smallest pair of the total complement of 18 chromosomes is acrocentric. Supernumeraries are absent.The distribution and probable relationships of the species of Leiopelma are discussed. The karyotypes of Leiopelma and the North American ascaphid frog Ascaphus truei are compared, with particular reference to the relationship of the supernumerary chromosomes of Leiopelma and the microchromosomes of Ascaphus.
CYTOGENETIC EFFECTS OF 2,4-D AND AMITROLE IN RELATION TO NUCLEAR VOLUME AND DNA CONTENT IN SOME HIGHER PLANTS
Authors: Mohandas T. , Grant W. F.
Published: November 2014

The cytological effects of 2,4-D and amitrole were studied for 12 species (Tradescantia clone 02, Allium cepa, Vicia faba, Triticum aestivum, T. dicoccum, Hordeum vulgare, Secale cereale, Centaurea jacea, Cirsium vulgare, Chrysanthemum leucanthemum, Plantago major and Erigeron canadensis). Ethyl methane sulfonate (EMS) was used as a positive control. The cytological abnormalities induced in root-tip cells by both 2,4-D and amitrole included chromosome bridges, fragments, lagging chromosomes, and chromatin bodies; 2,4-D also induced chromosome contraction, and C-mitoses. Studies following seed treatments of Hordeum vulgare on M2 seedlings showed that 2,4-D and EMS induced albina mutants. Interphase nuclear volumes of the various species were measured from root-tip meristems. Nuclear DNA values were determined cytophotometrically for seven species. The relative DNA values were found to be positively correlated with nuclear volumes. The lack of any clear relationship between the number of cytological abnormalities induced by the chemicals and the nuclear and interphase chromosome volumes of the plants probably reflects a lack of synchrony of the treated cell population.
LOW CHROMOSOME NUMBER AND POST-REDUCTIONAL XO IN GELUS CALIFORNICUS (LEC.) (COLEOPTERA: CURCULIONIDAE)
Authors: Ennis T. J.
Published: November 2014

Gelus californicus is a unique example, among Curculionoidea, of evolutionary mutation to a post-reductional sex-determining mechanism, autosomal behavior having remained perfectly conventional. It has the lowest reported chromosome number in the superfamily, 2n = 12 + XO, and is the only member known with certainty to lack a y. Ovarial preparations were unsuccessful, but of 11 males examined, 9 carried a minute chromosome, presumably a B, a 10th having two, and the 11th, two or four B's in different nuclei. B's are also post-reductional. The X and B only occasionally associate physically at metaphase I, but are more narrowly distributed than expected of non-homologous markers. This spatial association persists until early anaphase II, which finds both elements lagging on the equator. Persistent ectopic association apparently distorts segregation ratios, as the X and B were at the same pole in 17 of 21 late A II plates examined. The A II behavior of these elements effectively rules out an X + y or XO xo ♀ system. The origin of the mechanism and its relationship to other coleopteran examples are discussed.
SEED PROTEIN HOMOLOGIES AND THE EVOLUTION OF POLYPLOIDY IN AVENA
Authors: Ladizinsky G. , Johnson B. L.
Published: November 2014

Crude seed protein of the nine oat species was fractionated by disc electrophoresis on polyacrylamide gel. Correlation coefficients calculated from optical density curves obtained from the stained gels showed that individual species possessed characteristic, albeit variable, profiles. Pattern variability among and within species was greater in the case of the diploids than in the case of the polyploids. The very few profile types in A. strigosa 4x and in the hexaploid A. sativa suggested that the variation in these polyploids is due more to independent origin of the types than to differentiation following polyploidization. Virtual identity between individual A. strigosa 2x and 4x profiles suggested a strict autopolyploid origin for some 4x types while complementing pairs of A. strigosa 2x profiles indicated an intervarietal origin for other A. strigosa 4x types. A diagnostic band at 11.0 cm in the profiles of A. magna and A. murphyi suggested that these species rather than A. strigosa 4x had functioned as the tetraploid parent of the hexaploid A. sativa. The profile of A. murphyi complemented by a specific A. strigosa 2x profile simulated a specific A. sativa type. The adaptive success of the genus is assessed in the light of variation and homologies in the seed protein patterns of the various species.
REMARQUES SUR LE CONTROLE GENETIQUE DE LA RESISTANCE AU CUIVRE CHEZ SACCHAROMYCES CEREVISIAE HANSEN
Authors: Lumaret Roselyne , Galzy P.
Published: November 2014

not available
THE ISOLATION AND IDENTIFICATION OF POLYPLOID STRAINS OF USTILAGO VIOLACEA
Authors: Day Alan W.
Published: November 2014

A method for the synthesis of polyploid strains of Ustilago violacea and the criteria for their identification are described. Cell length increases directly in proportion to the ploidy and thus the volume of the cell increases very rapidly at higher ploidies. The volume of the nucleus also increases but remains at a constant 3-4% of the cell volume. Stability and growth rate decrease with increasing ploidy. The a2 mating-type allele acts as a simple dominant allele in log phase cells, but there is no dominance in stationary phase cells.
NON-HOMOLOGOUS ASSOCIATIONS OF HAPLOID BARLEY CHROMOSOMES IN THE CYTOPLASM OF HORDEUM BULBOSUM L.
Authors: Sadasivaiah R. S. , Kasha K. J.
Published: November 2014

Haploids obtained from interspecific crosses between H. bulbosum (2n=14) and H. vulgare (2n=14) resembled the male parent (H. vulgare) with regard to vegetative and spike characteristics. The somatic chromosomes of these plants resembled those of the haploid complement (x=7) of the male parent H. vulgare. Thus, the haploids produced were considered androgenetic possessing the cytoplasm of H. bulbosum and the nucleus of H. vulgare. Detailed meiotic studies from pachytene to metaphase I in these haploids revealed non-homologous chromosome pairing, identical to that of haploids produced in the cytoplasm of H. vulgare. It was concluded that the influence, if any, of bulbosum cytoplasm on meiotic behavior of vulgare chromosomes is not different from that of vulgare cytoplasm.
UNE ANALYSE DES COMPLEMENTS CHROMOSOMIQUES DE CERTAINS ORTHOPTERES DU QUEBEC ET SA SIGNIFICATION TAXONOMIQUE ET EVOLUTIONNAIRE
Authors: Beaudry Jean R.
Published: November 2014

The chromosome numbers were determined and the complements analyzed for certain Orthoptera of Quebec, the karyology of which had not yet been studied. The taxa reported on are: Oecanthus quadripunctatus, 2n (♀) = 19; Metrioptera roeseli, 2n (♀) = 31; Amblycorypha oblongifolia, 2n (♀) = 31; Scudderia pistillata, 2n (♀) = 29; S. curvicauda, 2n (♀) = 31; S. texensis, 2n (♀) = 31; S. furcata furcata, 2n (♀) = 31; and Melanoplus punctulatus punctulatus, 2n (♀) = 23.The chromosome complement of Oecanthus quadripunctatus and that of O. nigricornis already studied by Johnson (1931) are apparently identical, but the chromosome complements of O. longicauda and O. indicus of Japan differ so much from those of the two above-mentioned North American species that the association of the American and Japanese entities with the same genus is subject to doubt.The data supplied by the karyological analysis of Metrioptera roeseli, Amblycorypha oblongifolia, Scudderia pistillata, S. curvicauda, S. texensis and S. furcata furcata corroborate the classification made on the basis of morphological characters. The origin of the karyological differences which distinguish the members of this group of Tettigonioidea is discussed.
THE USE OF NITROUS OXIDE FOR PRODUCING EUPOLYPLOIDS AND ANEUPLOIDS IN WHEAT AND BARLEY
Authors: Dvorak J. , Harvey B. L. , Coulman B. E.
Published: November 2014

The use of N2O as a polyploidizing agent in barley and wheat proved to be effective in both species when applied in the interval from 4 to 24 hr after pollination in barley and 24 to 48 hr after pollination in wheat. When treated in these intervals with four atmospheres pressure, 75% of the barley and 54% of the wheat embryos were polyploid. There was a marked difference between the two species in the proportion of aneuploids produced. In barley 5% of the treated embryos were aneuploid whereas 42% of the wheat embryos were aneuploid in the critical treatments.Evidence is presented to show that most of the aneuploids originated from disturbances in the anaphase distribution of chromosomes or from a scattering of chromosomes before the formation of restitution nuclei rather than from multipolar divisions.A potential use of N2O for producing homozygous diploid plants of Hordeum vulgare L. emend Lam. from crosses between Hordeum vulgare and H. bulbosum L. is discussed.
SEGREGATION OF HERMAPHRODITES IN SWINE LITTERS
Authors: Sittmann K.
Published: November 2014

Segregation analysis of published samples of swine litters with intersexes suggests that many cases of hermaphroditism in chromosomal females are caused by recessive genes at two loci. Females may be homozygous at one, and males at both, of these loci without showing an overt loss in reproductive fitness.
KARYOTYPE ANALYSIS OF MULTIPLE TRANSLOCATION STOCKS OF BARLEY
Authors: Tuleen N. A.
Published: November 2014

Karyotype analysis of multiple translocation stocks of barley in which the translocated chromosomes could be distinguished from each other and from the remaining pairs revealed that chromosome 1 is not the longest chromosome in the normal karyotype. Estimates of the lengths of chromosomes 2 and 3 and the position of the breakpoints in T2-5a and T3-7d were also obtained. The data indicate that the breakpoint of T3-7d is in the short arm of chromosome 3 and not in the long arm as previously reported.
RELATIONSHIPS OF TAXA IN THE GENUS MEDICAGO AS REVEALED BY HYBRIDIZATION. VIL M. TORNATA COMPLEX
Authors: Lesins K. , Singh S. M.
Published: November 2014

Different taxa of Medicago tornata Mill, were investigated on their relationships using hybridization and inheritance studies. It was found that taxa with lenticular pods, spiny and spineless, could be intercrossed and the inheritance of spininess in F2 was 3 spiny and intermediate to 1 spineless (35:1s). Hybrids between lenticular and cylindric pods segregated 3:1 spiny: spineless; 3:1 anticlockwise pod coiling: clockwise coiling (3C:1c), and 1:4:6:4:1 for number of coils per pod (1-2:2-3:3-4:4-5:5-6) indicating that two genes acted additively. Spininess and pod coiling direction segregated independently. M. striata was recognized as a variety of M. tornata because no serious impairment in vitality of hybrid progenies was observed and the inheritance of pod coiling direction in F2 followed closely the normal 3:1 segregation ratio. M. tornata var. shepardii has a complete incompatibility barrier with the M. tornata tested and should not be considered as belonging to M. tornata.
CHROMOSOME PAIRING IN TOMATO TERTIARY TRISOMICS
Authors: Chaney Lee Anne , Reeves II Alvin F.
Published: November 2014

Seven different tertiary trisomics of the tomato were compared as to their chromosome pairing patterns at diakinesis. The differences between these results and some previously reported work indicated that (a) varietal differences may influence chromosome pairing, and (b) environmental interactions will also affect the pairing relationships of some of the trisomics.
INITIAL CHROMOSOMAL LESIONS INDUCED BY X-IRRADIATING PRIMARY SPERMATOCYTES OF MICE
Authors: McGaughey R. W. , Chang M. C.
Published: November 2014

Ten adult Swiss Webster male mice were X-irradiated at 500 R and their testes examined according to an air-dry technique for chromosomal aberrations at 2, 4, 8, 24 and 48 hr after irradiation. Chromosomal aberrations were found in 85 to 92% of cells examined from 4 to 48 hr after exposure compared with 1% of damaged cells observed in control testes and 68% in testes examined 2 hr after irradiation. The proportions of cells with chromosomal lesions but without rearrangements decreased significantly from 51% at 2 hr to 19% at 8 hr. The combined means per cell of unrejoined breaks and breaks accounted for by rearrangements increased linearly from 0 to 8 hr after irradiation, whereas the mean numbers of unrejoined breaks increased linearly only up to 4 hr after irradiation. It seems that initial radiation damage to the chromosomes of primary spermatocytes of mice (late pachytene to metaphase I) consisted predominantly of unrejoined lesions at 2 hr after exposure, and that by 8 hr a high proportion of lesions had combined to form rearrangement figures involving two, three or four bivalents. These results emphasize the importance of the time of examination for comparative studies of irradiation-induced chromosomal anomalies.
THE INHERITANCE OF ASCORBIC ACID IN RED RASPBERRY
Authors: Fejer S. O. , Johnston F. B. , Hammill Madeleine M.
Published: November 2014

Combining ability for ascorbic acid was studied in fruit and leaves of red raspberry (Rubus idaeus, R. strigosus) progenies produced by crossing each of four cultivars with three other cultivars and their S2 selections. General combining abilities were significant in two fruit samples, but specific combining abilities in the second sample only. In the leaf sample, specific combining abilities were significant; but general combining abilities were not. General effects of the cultivars for fruit ascorbic acid were similar to previous effects on the cultivars themselves. Ascorbic acid levels of these crosses were higher than those of two parental clones grown in this experiment.