bluuebunny/crossref_metadata_2025 huggingface dataset:
FRAGMENTS WITH ACCESSORY CHROMOSOME CHARACTERISTICS IN CULTIVATED BARLEY (HORDEUM VULGARE)
Authors: Sayed H. I. , Helgason S. B. , Larter E. N.
Published: November 2014

A number of fragment chromosomes were isolated from the progeny of barley triploids and their trisomic derivatives. They were smaller than normal barley telocentrics, with a globular appearance, and some carried a small satellite. Their number per cell varied in both somatic and germinal tissue. At meiosis, pairing was observed between fragments, but pairing with the normal chromosomes was virtually absent. Unlike normal chromosomes when univalent, the fragments were always positioned on the equatorial plate at MI. Paired fragments behaved normally, but univalent ones divided precociously, rarely lagging at MI. At second division, lagging occurred frequently, with micronuclei forming at the quartet stage. Fertility was reduced substantially only in plants carrying more than one fragment. The behavior of these fragments in general conformed to that of "accessory chromosomes." They were assumed to have arisen from normal chromosomes which had lost their pairing arms, and/or from fragmentation of satellited telocentrics.
PRODUCTION OF ANEUPLOIDS INAVENA SATIVAL. BY NITROUS OXIDE
Authors: Dvorak J. , Harvey B. L.
Published: November 2014

Oat plants were treated with nitrous oxide shortly after pollination. A high frequency of aneuploids in the progenies of treated plants indicates that this technique may be a useful tool for the production of aneuploid series in oats. Several 12-ploid, or nearly 12-ploid, oat plants were also obtained.
A DOMINANT ROUND SPORE MUTANT INNEUROSPORA TETRASPERMAAND ITS IMPLICATIONS FOR ASCOSPORE DEVELOPMENT
Authors: Novak Dennis R. , Srb Adrian M.
Published: November 2014

A new mutation (Rsp-1) in N. tetrasperma produces nearly all round spores when heterozygous in a cross. The gene maps 12 units from mating type in linkage group I and mutant cultures are female-sterile. Nongenetic reversal of dominance sometimes occurs, in that crosses heterozygous for round spores yield a few asci containing four spores of normal shapes. In the absence of crossovers between Rsp-1 and the centromere of its chromosome, these hetero-karyotic spores give rise to self-fertile mycelia which produce perithecia that contain round-spored asci. One never observes asci that contain both round and normal spores. Therefore, the nuclei included within ascospores do not determine the shape of the spores. Rather, dominance effects are exerted on the ascus as a whole, as if its development were controlled by the zygote.The round spores of N. tetrasperma contain two germ pores, and these are unsystematically situated. Evidence is presented to show that the position of pores is directly related to the development of the striation pattern.
ACTIVITY AND RELATIVE MOBILITY OF PEROXIDASE AND ESTERASE ISOZYMES OF FLAX (LINUM USITATISSIMUM) GENOTROPHS. I. DEVELOPING MAIN STEMS
Authors: Fieldes M. A. , Tyson H.
Published: November 2014

The effects of growth of one flax genotype in soil supplemented by either nitrogen, phosphorous and potassium (NPK) or nitrogen and potassium (NK) on its progeny produced by several generations of complete selfing were studied. The two types of progeny produced, L induced by NPK and S induced by NK, were examined at 4-day intervals from the 16th to the 36th day after sowing. Both activity and relative mobility of the anionic peroxidase and esterase isozymes displayed effects of the fertilizer treatments applied in the treatment generation. NPK, compared to NK, increased the relative mobility of all the peroxidase and esterase isozymes, while depressing the activities of the peroxidase isozymes and increasing those of the esterase isozymes, at all ages examined. Some differences in the rates of change, with age, of the characteristics of L and S were distinguished; the differences observed between L and S could not, however, be attributed to differences in their developmental ages.
EFFECT OF GAMMA RAYS AND SOME CHEMICAL MUTAGENS ON INDUCTION OF TELOTRISOMICS IN HORDEUM
Authors: Sayed H. I. , Helgason S. B. , Larter E. N.
Published: November 2014

Trisomic lines for each of chromosomes 1,3,4,5, and 7 of barley (Hordeum vulgare L.) were subjected to mutagens viz, EMS, DES, HA, FUdR and γ rays in an attempt to induce telocentrics in the extra chromosome. DES and EMS caused a relatively high degree of lethality of trisomies compared with that of disomics. Treatment with HA and γ rays at the time of meiosis caused almost complete sterility. No telotrisomics were recovered from these treatments. Irradiation of trisomic seedlings resulted in the isolation of 11 fragments of which 6 were true telocentrics. The frequency of telocentrics was significantly increased over non-treated material only in stocks of trisomic for chromosomes 1 and 7. All chromosome breaks induced in chromosome 7 were localized at the centromere and the adjacent region of the long arm.
THE DISTRIBUTION OF GENETIC AND ENVIRONMENTAL EFFECTS AND THE LINEARITY OF HERITABILITY
Authors: Nishida Akira , Abe Takeo
Published: November 2014

This study investigated the relationship between the skewness in the distributions of genotypic and environmental values and the linearity of heritability in terms of the regression of genotypic values on phenotypic values.It was shown that in some cases the skewness of these distributions is a cause of curvilinearity in heritability. A practical way to utilize the information of curvilinear heritability is given.
MEIOSIS IN COPRINUS: VI. THE CONTROL OF THE INITIATION OF MEIOSIS
Authors: Lu B. C.
Published: November 2014

Meiosis in Coprinus lagopus is normally initiated at night under normal diurnal conditions. This timing can be shifted to 0900-1000 h by using a 16h light-8h dark regime with the light cycle commencing at 1600 h. For the initiation of meiosis, C. lagopus is temperature sensitive (35 C) under continuous light. The temperature sensitivity can be overcome by a dark period. The sensitive period occurs within 7 h of karyogmay. Only the first 2 h, however, are sensitive to light and high temperature. A shift-up to restrictive conditions before the sensitive stage effectively arrests the process leading to karyogamy. The arrest is reversible within 20 h. Upon returning to a 25 C chamber, karyogamy begins in 6 h in all basidiocarps. Thus using this technique accurate control of the initiation of meiosis can be achieved. Howeevr, prolonged arrest beyond 16 h causes the basidia to revert to mitosis and mycelial growth. The nucleolus is reduced in size and exhibits a large vacuole and a lack of granular components as shown by electron microscopy.
KARYOTYPIC ANALYSES OF TWENTY-ONE SPECIES OF MOLOSSID BATS (MOLOSSIDAE: CHIROPTERA)
Authors: Warner Jerry W. , Patton James L. , Gardner Alfred L. , Baker Robert J.
Published: November 2014

Examination of 135 specimens representing 21 species from seven genera of the family Molossidae revealed diploid numbers ranging from 34 to 48. Seventeen species from six genera have diploid numbers of 48. Geographic variation and polymorphism were found only in Eumops glaucinus. Chromosomal variation within the family is presumed to be primarily due to changes in diploid number resulting from Robertsonian translocations.
A GENETICAL INVESTIGATION OF RESISTANCE TO "KNOCKDOWN" AND "KILL" BY DDT IN ADULTS OF THE MOSQUITO AEDES AEGYPTI L.
Authors: Hitchen Judith M. , Wood R. J.
Published: November 2014

A genetical investigation of DDT resistance in Aedes aegypti has provided similar values of recombination between the gene for DDT resistance and visible markers, whether the response to DDT was scored as knockdown or as kill, indicating that resistance to knockdown and resistance to kill are controlled at the same gene locus.
REDUCTION OF CHROMOSOME NUMBER IN ROOT TIP CELLS OF MEDICAGO
Authors: Sadasivaiah R. S. , Lesins K.
Published: November 2014

Cytological studies on progenies obtained from intercrosses between colchicine-induced octoploid (2n = 8x = 64) plants of alfalfa showed normal, haploid and aneuploid chromosome numbers in cells of the same root tip. Critical observations on cells at different divisional stages revealed the occurrence of meiosis-like mitotic divisions, resulting in a reduction of chromosome number. The frequency of cells showing reductional divisions appeared to vary with the ploidy level of the material. The possible significance of chromosome reduction in plant evolution is indicated.
RECOVERY OF SD CHROMOSOMES FROM DROSOPHILA MELANOGASTER MALES WHEN HETEROZYGOUS WITH STRUCTURALLY DIFFERENT SECOND CHROMOSOMES
Authors: Trippa G. , Marco A. De , Micheli A. , Nicoletti B.
Published: November 2014

Previous works to ascertain whether structural rearrangements of the second chromosome affect the strength of Segregation Distorter (SD) action yielded contradictory results. To settle this problem we tested a series of 19 inversions, 25 translocations, 8 deletions (all involving a second chromosome) and 7 normal chromosomes in males heterozygous for different SD chromosomes.The results show that segregation distortion is independent of the type or complexity of rearrangement or the position of the break points.Thus, it may be stated that pairing between the two homologous second chromosomes during meiosis is not necessary for SD action and does not influence the strength of SD action. It seems likely, therefore, that the degree of segregation distortion in SD heterozygous males depends on the presence of alleles on the various chromosomes tested which differ in their sensitivity to SD.
POSSIBLE USEFULNESS OF HYPOTRICHOTIC RATS FOR STUDIES ON SKIN TUMORIGENESIS
Authors: McGregor John F.
Published: November 2014

A new strain of hypotrichotic (hairless or partially hairless) rats was studied to determine whether such animals would be suitable for studies on radiation-induced skin carcinogenesis. Breeding experiments revealed that the condition is inherited in a simple Mendelian recessive manner, and that the hypotrichotic dams are defective in milk supply for nourishing their young. Histological. sections of hypotrichotic skin demonstrated the presence of hair-follicle and sebaceous gland cysts in young adults. Observations of older hypotrichotic rats showed that some of these microscopical cysts proliferate to form visible epidermal tumors. Notwithstanding this undesirable feature, the choice of hypotrichotic rats for studies of the types of skin tumors induced by ionizing radiation might well provide more meaningful data than that derived from normal rats or mice, particularly where the effects are to be extrapolated to man.
HISTOLOGICAL AND CYTOCHEMICAL STUDIES ON FIVE GENETIC MALE-STERILE LINES OF BARLEY (HORDEUM VULGARE)
Authors: Mian H. R. , Kuspira J. , Walker G. W. R. , Muntjewerff N.
Published: November 2014

The action of the genes msg5, msg9, msg10, msg14, and msg18 in barley (Hordeum vulgare L.) is almost entirely restricted to the sporogenous and tapetal tissues of the anther. No histological effects are found before the completion of meiosis except in msg18. Subsequently their behavior becomes distinctly deviant. In msg5, 9, 14 and 18 soon after a normal meiosis the microspores begin to deteriorate and are almost completely deformed at a period corresponding to that just before microspore division in normal anthers. In msg10 deleterious effects on microspores first appear midway between the end of meiosis and the beginning of microspore karyokinesis.The tapetum remains nondegenerate and persistent in msg5, 10 and 14 but suddenly collapses after the free microspore stage in msg9. In msg18 it shows an early effect during the meiotic period, when failure in the last tapetal nuclear division (karyokinesis) results in an early collapse of this tissue.Nuclear DNA and histone in male-sterile sporogenous and tapetal tissues as measured by microspectrophotometry increase at the normal rate during the premeiotic S phase. However, in the sporogenous tissues, the subsequent DNA and histone syntheses that normally culminate in microspore mitosis are distinctly lacking. Thus in all male-steriles except msg10, the microspore nuclei show an actual loss in these two macromolecules and in msg10 there is an initial rise only for a short period, followed by a dramatic drop.Nuclear DNA and histone in tapetal tissues subsequently show variable behavior, which seems to be specific for each male-sterile line.The behavior of sporogenous and tapetal tissues thus lends support to the hypothesis that there is transport of substances, critical to development, between the porogenous tissue and tapetum. The effects on DNA-histone turnover, first in the sporogenous tissue and then in the tapetum, suggest that the action of msg5 and 9 is initiated within the microspores when they are still invested in a callose wall. On the other hand, in msg10 and 14 a reverse sequence indicates that the action is initiated in tapetal tissues. The effect in msg18 is a direct consequence of defective tapetal functioning.All male-steriles at the free microspore stage show drastic reductions in nucleolar volume (and hence in rRNA synthesis) accompanied by a high frequency of binucleolate microspore nuclei.
ANALYSIS OF FRUIT YIELD AND RELATED FACTORS IN A DIALLEL OF SEVEN INBRED STRAWBERRY CLONES
Authors: Aalders Lewis E. , Craig Donald L.
Published: November 2014

A diallel of seven inbred clones of the domestic strawberry was evaluated for 5 variables and was compared with the standard cultivar Redcoat. For fruit yield, berry size, date of mid-harvest, and area covered by the clone, the Redcoat values were close to the mean of the diallel. Unexpectedly, all seedling crosses produced more than twice as many runners as did Redcoat.The additive component of variance was only 3.2 per cent for yield, but was 50.5, 83.0, 27.6, and 10.9 per cent for berry weight, mean date of harvest, runner number per clone, and area covered per clone respectively. Total fruit yield was significantly influenced by all of the other four variables, but the relationship was highly variable and did not present any consistent pattern. A cautious interpretation of results is required because of common parentage and inbreeding in the parental lines.The results of this study are in general agreement with similar studies at North Carolina and Ottawa, but all three of these studies gave quite different results from one in California using a parent-offspring regression method of analysis. It is suggested that the different methods of measuring genetic parameters may be as important in resolving this discrepancy as methods of culture, range of cultivars and climatic factors, which have been previously suggested.
THREE GENERATIONS OF INBREEDING AND S2 FACTORIAL TEST CROSSES IN RED RASPBERRY CULTIVARS
Authors: Fejer S. O. , Spangelo L. P. S.
Published: November 2014

In selfed (S1 to 33) progenies of red raspberry cultivars, inbreeding depression progressively reduced plant height in spite of selection for vigor. Parent-offspring correlations indicated high realized heritability of this character. High yield was correlated in this material with many laterals, early flowering, tall new canes, and good berry quality but not with winter resistance. Heritability in the broad sense was high for early vigor, plant height and winter resistance, lower for berry weight and flowering day, and very low for yield and its morphological components, but selection for vigor may have influenced these estimates.In a second experiment five S2 progenies and their parent cultivars Muskoka, Trent and Tweed were crossed with three tester plants, Ottawa Latham, Viking and 45-01-56. Some of the S2 × tester progenies were superior in a number of yield characters to those produced when their parent cultivar was crossed to the same testers. The results were similar to those with strawberry (Spangelo et al., 1971), suggesting that inbreeding may sometimes be a useful step in a raspberry breeding program for higher yield. However, inbred × inbred crosses were generally poor. General and specific combining abilities were mostly similar in three different samples of factorial ("¼ diallel") crosses, but there were many exceptions possibly due to genotype-environment interactions. Most of the correlations were significant in this trial and the highest ones were in agreement with the correlations in the inbreeding trial.
STOLAINE CASSIDINES (COLEOPTERA, CHRYSOMELIDAE) WITHXypSEX CHROMOSOMES AND A DERIVATIVE SYSTEMXpneoXneoYp
Authors: Vaio E. S. de , Postiglioni A.
Published: November 2014

Three species of Cassidines were cytologically studied. Chelymorpha indigesta and C. variabilis, with 10II + Xyp, have a relatively primitive Coleopteran karyotype and the sex chromosomes form a parachute-like bivalent. Botanochara angulata, belonging to the same tribe, Stolaini, presents an exceptional karyotype with a very high chromosome number (2n = 51 ♀) and multiple sex chromosomes XpneoXneoYp. This system has derived from the Xypby a yp-to-autosome translocation.
ANEUPLOIDS IN THE SOYBEAN,GLYCINE MAX
Authors: Palmer Reid G.
Published: November 2014

Aneuploids have been identified among progeny from the homozygous recessive asynaptic soybean (Glycine max (L.) Merr., 2n = 40) mutants T241 and T242. The majority of the progeny (206 of 217) examined were near the tetraploid level and were sterile. The only fertile F1aneuploid had 36 F2progeny, which ranged in chromosome number from 41 to 44. Among the F2progeny, pollen fertility, number of seed per plant, and plant height decreased as chromosome number increased. No morphological differences were observed among the F2trisomics or between them and fertile diploids. The progeny of 2 of 3 F2trisomic plants contained plants with 42 chromosomes, suggesting simultaneous transmission of the extra chromosome in both the pollen and the egg.
HIGH FREQUENCY OF HAPLOIDS FROM CROSSES OF HORDEUM LECHLERI (6x) × H. VULGARE (2x) AND H. JUBATUM (4x) × H. BULBOSUM (2x)
Authors: Rajhathy Tibor , Symko S.
Published: November 2014

About half of the plants obtained from Hordeum lechleri × H. vulgare crosses were haploids, the other half hybrids. Only haploids were obtained from crosses between H. jubatum and 2x H. bulbosum. Haploids from both crosses were of maternal origin.
MAMMALIAN MALE PACHYTENE CHROMOSOME INTERCONNECTIONS AND KARYOTYPES
Authors: Burdick Allan B. , Libbus B. L. , Athanassiou V. , Falek Arthur
Published: November 2014

Pachytene chromosomes from mammalian primary spermatocytes can be prepared by two new and related techniques. The first involves pretreatment of the dispersed spermatocytes with a mixture of serum and salts followed by a sodium chloride treatment. The second technique uses the same pretreatment, but is followed by a naphthylamine-sodium chloride treatment. Primary spermatocytes release their pachytene chromosomes in a spread that is three to five times the diameter of the intact spermatocytes. Interconnections between the paired chromosomes hold the configuration together in the absence of the nuclear membranes.
DDT INDUCED CHROMOSOME MUTATIONS IN MICE — FURTHER TESTING
Authors: Larsen Kenneth D. , Jalal Syed M.
Published: November 2014

Laboratory mice (Mus musculus L.) were investigated for DDT induced chromosome mutations. Twenty-four brown and Balb/c strain albino mice were intraperitoneally injected with 25, 50, 100 and 250 ppm (mg/kg body weight) of DDT in peanut oil, and killed 48 h later. Controls received either no injection or peanut oil only. Karyotypes from bone marow cells of femurs were analyzed for gaps, deletions, and stickiness. Data for chromosome aberrations were taken from 200 well spread cells per animal, and mitotic indices were calculated from 1000 cells per animal. Regression of aberrations on log DDT concentrations, and Dunnett's multiple comparison test were employed to determine the effect of DDT treatments. Gaps, stickiness and mitotic indices were not significantly affected by DDT treatments, but deletions and gaps plus deletions were significantly higher or approached the significant levels at 50 ppm and higher concentrations. DDT thus appears to act as a mutagen in concentrations encountered naturally in many secondary consumers.
INHERITANCE OF REACTION TO STEM RUST AND LEAF RUST IN THE WHEAT CULTIVAR ETOILE DE CHOISY
Authors: McIntosh R. A. , Dyck P. L. , Green G. J.
Published: November 2014

Triticum aestivum L. cv. Etoile de Choisy possesses two genes governing reaction to Australian and Canadian strains of Puccinia graminis tritici: Sr23, a gene causing chlorosis and necrosis of infected tissue which is completely linked with Lr16 for reaction to P. recondita, and a second gene, designated SrEC, resembling a gene previously reported by Bartos et al., that produces infection type "2" to "3" with avirulent cultures.
TEMPERATURE-SENSITIVE MUTATIONS INDROSOPHILA MELANOGASTER: XX. LETHALITY DUE TO TRANSLOCATIONS
Authors: Kaufman Thomas C. , Suzuki David T.
Published: November 2014

In a group of 10 γ-ray-induced temperature-sensitive (ts) lethal mutations on the X chromosome of Drosophila melanogaster, three were found to inhibit crossing over on this element. Subsequent studies showed that these three ts lethal mutations are associated with X [Formula: see text] autosome translocations. Developmental analysis has revealed that the patterns of temperature-sensitivity and lethality are similar to those found in other ts mutations. One of the mutations (T(X;2)X9ts) is unique, however, in that only males exhibit temperature-sensitive lethality while homozygous females are unaffected by a change in temperature. It is proposed that these three mutations may be exhibiting some new type of "position effect".
EQUILIBRIUM FREQUENCIES OF SPOROPHYTIC SELF-INCOMPATIBILITY ALLELES
Authors: Sampson D. R.
Published: November 2014

A deterministic model (Fortran computer program) was used to compute equilibrium frequencies of multiple S alleles The model permitted various numbers of alleles at three dominance levels in the pollen and with independent allele action in the stigma. Numerical solutions showed that the frequency of alleles at any one dominance level depends, in large measure, on the evenness with which the alleles are distributed among the three levels. The smaller the proportion at any one level, the greater the frequency per allele at that level. This is termed the "small number effect." It enables dominant alleles to become more frequent than recessive alleles.Recessive alleles are the more frequent at equilibrium when the dominance levels have equal numbers of alleles. The magnitude of this "recessive effect" diminishes rapidly as the number of alleles in the population is increased. Thus, its importance is less than that suggested by the previously solved cases with one or two alleles per level.With very large numbers of alleles in the population, the genotypic class frequencies at equilibrium approach frequencies generated by a modified use of the Hardy-Weinberg law. All alleles arrive at the same frequency at this limit, regardless of dominance or distribution along the dominance sequence.
QUANTITATIVE RELATIONSHIPS OF CELLULAR PROTEIN, RNA, AND NUCLEARHISTONE IN HEXAPLOID TRITICALE AS INFLUENCED BY SOURCE OF WHEAT CYTOPLASM
Authors: Hsam S. L. K. , Larter E. N.
Published: November 2014

Reciprocal F1 hybrids of hexaploid triticale (× Triticosecale Wittmack) differing only in their source of wheat (Triticum sp.) cytoplasm were studied to determine its influence on the synthesis of cellular protein and related compounds. Microphotometric methods revealed higher levels of total cellular protein and RNA in triticales with hexaploid-wheat cytoplasm (T. aestivum L. em Thell) than those with tetraploid wheat cytoplasm (T. durum Desf.). Conversely a higher level of nuclear histone was found in tritical hybrids possessing tetraploid wheat cytoplasm. The utilization of hexaploid-wheat cytoplasm in the improvement of the agronomic performance of hexaploid triticale is suggested.
EFFECTS OF ADDITIONS AND SUBSTITUTIONS OFAGROPYRON ELONGATUMCHROMOSOMES ON QUANTITATIVE CHARACTERS IN WHEAT
Authors: Dvořák J. , Sosulski F. W.
Published: November 2014

Alien disomic and ditelosomic addition lines and disomic substitution lines involving the recipient wheat cultivar Chinese Spring and each of the seven chromosomes of diploid Agropyron elongatum were used to study the distribution of genes affecting date of heading, maturity, tillering, plant height and weight, seed protein content and components of seed yield in the Agropyron genome. Four Agropyron chromosomes, III, IV, V, and VI, affected days to heading and maturity but only chromosome VI conditioned early heading date. Complementary genes on opposite arms of the alien chromosome were responsible for late maturity in disomic addition line V. Tillering was affected by chromosome II which reduced the number of tillers per plant and by chromosome IV which increased the number. Plant height was increased by chromosome II and decreased in the presence of chromosomes III, IV, V and VI. Seed weight was increased in disomic addition lines II, III and VI while it was decreased in dosomic addition line V. Seed shrivelling, which was apparent in the amphiploid, Ag. elongatum × Chinese Spring, is controlled by Agropyron chromosome II. The number of seeds per spike was affected by six and seed yield by seven Agropyron chromosomes. Except for one line, the disomic addition lines and one substitution line showed significantly higher seed protein content than Chinese Spring. However, it was shown that yield depression accounted for a large portion of the increase in protein content. To remove this factor, the actual protein content in each line was compared with the adjusted protein content obtained from the regression of protein content on yield. Then it appeared that five of the seven Agropyron chromosomes are implicated in the control of seed protein. The amino acid compositions of proteins in the Agropyron-wheat derivatives were uniform and did not differ from Chinese Spring. It was shown that genes on Agropyron and wheat homoeologous chromosomes frequently have related effects on the characters studied. Because of genetic similarity among Agropyron and wheat homoeologues, the alien substitution lines tend to be superior to the alien addition lines in which the deleterious characters are largely caused by gene dosage effects. It is suggested that interlocus gene interactions play a significant role in the control of quantitative characters in this Agropyron genotype.
CHROMOSOME STRUCTURE IN CHILOCORUS (COLEOPTERA: COCCINELLIDAE). I. FLUORESCENT AND GIEMSA BANDING PATTERNS
Authors: Ennis T. J.
Published: November 2014

Chromosomes of six species of Chilocorus have been examined for their reaction to Quinacrine (Q), and to Giemsa (G) after a variety of 'Denaturation-Renaturation' schedules and digestion with trypsin. Four types of chromatin can be distinguished with these techniques: 1, moderately stained with both Q and G; 2, brightly stained with Q and darkly stained with G; 3, unstained with Q but darkly stained with G; 4, unstained with Q but moderately stained with G. The last three of these types are restricted in chromosomally monomorphic species to the pericentric heterochromatin, but are variably distributed in the heterochromatic arms of C. stigma. Euchromatin per se does not react differentially. The relationship between karyotype stability and uniformity of banding patterns is discussed.
THE BLOOD GROUPS AND RED CELL ENZYMES OF A SAMPLE OF CREE INDIANS
Authors: Lucciola Lina , Kaita Hiroko , Anderson Jeanne , Emery Sandra
Published: November 2014

A random sample of Cree Indian women of child-bearing age was examined for their phenotypes in 17 blood group and 21 enzyme systems. Eleven of the blood group systems and ten of the enzyme systems proved to be polymorphic. The observed phenotypes and calculated gene frequencies are reported.
INVITATION PAPER: BEHAVIOR INDROSOPHILA MELANOGASTERA GENETICIST'S VIEW
Authors: Suzuki David T.
Published: November 2014

In screening Drosophila melanogaster for mutations which cause paralysis at 29cC and recovery of mobility at 22cC, 11 temperature-sensitive (ts) mutants were detected among 1.35 × 106flies screened. These mutations fell into 3 loci, paralytic (parats), shibire (shits) and stoned (stnts). All three loci affect neurological development. The best explanation for paratsappears to be an effect on the inhibitory neuronal system. The shi alleles affect an array of developmental events from early embryos to adults. The pattern of heat-induced changes in shits1electroretinograms (ERG) is consistent with a ts membranal defect. This is supported by a ts resistance of shitsflies to tetrodotoxin which specifically blocks the sodium channel of nerves.The final locus, stn, causes sensitivity to the trauma of temperature changes. A jump response observed when a light is turned off is related to a large "offtransient" in ERGs which is correlated with a simultaneous muscle spike. The property of temperature-sensitivity allows greater analytic powers in the study of neurological mutants.
A STUDY ON THE STRUCTURE OF GENERp3FOR RUST RESISTANCE INZEA MAYS
Authors: Saxena K. M. S. , Hooker A. L.
Published: November 2014

In maize (Zea mays L.) Rp3expresses itself as a dominant gene for resistance to Puccinia sorghi Schw. culture 90laba and as a recessive gene for resistance to culture 933a. Suspecting that Rp3is a complex locus consisting of two closely linked genes, efforts were made to separate the two putative genes by crossing over. Maize lines heterozygous for resistance and glossy leaf genes (Rp3- Gl6/rp3- gl6) were crossed with inbreds homozygous for susceptibility and glossy leaves (rp3- gl6/rp3- gl6). The testcross progeny, consisting of 4802 seedlings, was tested with culture 90laba. Fifty-seven recombinant seedlings, resistant to culture 90laba and glossy, were isolated and grown to maturity. These were selfed and their progeny tested to identify those that may have arisen from crossing over within region Rp3. No recombinants of this nature were found. If Rp3is a complex locus, the two genes comprising it could not be more than 0.06 map units apart.
MISE EN ÉVIDENCE DE TROIS NOUVELLES HOMÉOLOGIES CHROMOSOMIQUES ENTRE GOSSYPIUM ANOMALUM ET G. STOCKSII
Authors: Schwendiman Jacques A.
Published: November 2014

Several disomic addition lines in which chromosomes of G. anomalum Wav. et Peyr. or G. stocksii Mast, are added to the genome of G. hirsutum L. have been arranged in parallel pairs based on very similar phenotypic modifications. Analyses of chromosome pairing in F1 hybrids of morphologically related addition lines have shown that: (1) although certain analogies are clear, it is nevertheless difficult to come to any conclusions as to the structural relations that may exist between chromosomes considered to be homeologous, (2) the degree of pairing does not seem to be a good test for chromosome affinities in species hybrids, and (3) chromosome pairing seems to depend on a complex system of controls which act both globally on the whole genome and specifically on those chromosomes normally destined to pair.
QUANTIFICATION OF THE PICRATE TEST FOR CYANIDE IN PLANT GENETIC STUDIES
Authors: Mitchell N. D.
Published: November 2014

A method for the quick quantitative determination of cyanide released from cyanogenetic plants is described. The method is based on a standardized Guignard picrate test, the color developed being measured using a reflectance spectrophotometer.
IDENTIFICATION OF THE APPARENT B–GENOME DONOR OF WHEAT
Authors: Johnson B. Lennart
Published: November 2014

More than 1450 accessions of wild wheats were collected throughout their area of endemism in the Near East. Two types of diploids were distinguished by their seed protein electrophoretic pattern. One of these, Triticum boeoticum Boiss., was prevalent in all wild wheat areas. The other, occurring over the entire range of the tetraploids, was identified as T. urartu Tum., a species previously known only from Transcaucasia. The tetraploid T. diococcoides Körn. Schweinf. (AeAeBeBe), occupying the western arc of the Fertile Crescent, and T. araraticum Jakubz. (AtAtBtBt) occurring in the eastern arc and Transcaucasia, gave dissimilar but remarkably uniform albumin patterns from ethanol extracts of the seeds. A different combination of boeoticum and urartu biotypes accounted for all of the albumin bands in each of the tetraploid patterns obtained from water extracts. The morphological characters of the diploids were combined in the tetraploids. Hybrids between the wild diploid species were sterile, and showed 7 II at meiosis. The synthetic amphiploid from such a hybrid showed 10 II + 2 IV or 12 II + 1 IV. The triploid hybrid T. dicoccum × T. urartu showed 6-7 II. These observations implicate T. urartu as the missing B-genome donor to both of the tetraploids.
MAPPING OF THE GENE FOR HAIRY PEDUNCLE (Hp) ON RYE CHROMOSOME 5R
Authors: Chang T. D.
Published: November 2014

Wheat-rye addition plants monotelodisomic for 5RL and 5R and heterozygous for the hairy peduncle gene Hp were backcrossed to wheat. The analysis of offspring indicated that Hp is 44.1 to 49.5 crossover units from the centromere.
ANALYSIS OF GENOTYPE-ENVIRONMENT INTERACTIONS BASED ON THE METHOD OF PATH COEFFICIENT ANALYSIS
Authors: Tai G.C.C.
Published: November 2014

A method of investigating genotype-environment interactions of field crops is presented. Based on the concept that yield components are determined sequentially at different stages in the ontology of plants and the hypothesis that the environmental resources can be separated into independent groups with each contributing to the development of a component trait, a causal relationship between environmental resources, component traits and yield is established (Fig. 1). The GE interaction effect is then represented by three multiplicative terms which are composed of three genotypic and three environmental components. These components are estimated using the method of path coefficient analysis based on the postulated causal relationship. Data of marketable yield and yield components of seven potato cultivars collected from two series of trials are examined by the proposed method.
HYBRIDIZATION BETWEEN BETA VULGARIS AND B. PROCUMBENS AND TRANSMISSION OF NEMATODE (HETERODERA SCHACHTII) RESISTANCE TO SUGARBEET
Authors: Savitsky Helen
Published: November 2014

Triploid hybrids between tetraploid Beta vulgaris (4x = 36) and diploid B. procumbens (2x = 18) were used to transmit nematode resistance into sugarbeet. In meiosis of triploid hybrids, nine B. vulgaris bivalents and nine B. procumbens univalents were usually observed. In some pollen mother cells (PMC's) trivalent associations (8II + 8I + 1III) were formed. The second anaphase varied from near regular to very irregular. The regular anaphase produced normal quartets and viable gametes.The B1 plants and the plants of all succeeding backcross generations were tested for nematode resistance. From 6,750 B1 plants, four nematode-resistant trisomics were selected that had 18 B. vulgaris chromosomes and one B. procumbens chromosome responsible for resistance. The B. procumbens chromosome and nematode resistance were transferred to the eighth backcross generation with an average transmission rate of 12%. In meiosis of trisomies, trivalent associations of two B. vulgaris and one B. procumbens chromosomes were formed in a few PMC's. Two diploid nematode-resistant plants were selected from 8,834 backcross plants in the progenies of trisomies, and resistance was transferred from both of these plants to F1 hybrids. The segment of the B. procumbens chromosome bearing the gene for nematode resistance has been transferred to a sugarbeet chromosome.
VARIATION IN THE DIFFERENTIAL LEAF ABSORPTION OF A HIGH-MOLECULAR-WEIGHT PHOSPHATE BY PLANTS OF DIFFERING CYTOPLASMS OF THREE CORN (ZEA MAYS) INBREDS
Authors: Barèl Dirk , Peterson Peter A.
Published: November 2014

The absorption of foliarly applied tripolyphosphate is significantly greater in two different cytoplasmically male-sterile lines (Tcms and Ccms) of Zea mays L. than in isolines having normal (N) cytoplasm. A third cytoplasmic male-sterile (Scms) does not differ from the normal isoline in its absorption of foliarly applied tripolyphosphate. In none of the three comparisons of each of the cytoplasmic male-sterile lines and its normal isoline is there a difference in orthophosphate absorption, nor do any of the lines show a difference in the translocation of either source of phosphorus (P) inside the plant 10 days after application. The differential uptake of the large molecular P compound is not a property of all cytoplasmic male steriles, indicating that all cytoplasmic male steriles, do not have similar membrane permeability properties. Differences were found in the rate of absorption among lines for foliarly applied phosphates.
A NEW SOURCE OF EVIDENCE FOR THE POLARIZED NUCLEUS IN MAIZE
Authors: Jancey R. C.
Published: November 2014

Principal Components Analysis of data from maize chromosome aberrations has been employed to compute Euclidean spatial relationships among segments of all chromosome pairs. The position of the ten centric regions is shown to encompass a small arc of a sphere. This polarization is discussed in terms of an organized nucleus.
HETEROCHROMATIC CONNECTIVES BETWEEN THE CHROMOSOMES OFSECALE CEREALE
Authors: Godin Diane E. , Stack Stephen M.
Published: November 2014

A Giemsa staining technique that is thought to indicate the site of constitutive heterochromatin and repetitive DNA was used to stain the telomeres of Secale cereale (rye) chromosomes. Heterochromatic telomeres are visible throughout the mitotic cycle, and fusions and connections were observed between telomeres during prophase and metaphase. These observations are consistent with an earlier report of heterochromatic connections between telomeres of Allium cepa chromosomes and support the hypothesis that constitutive heterochromatin and repetitive DNA may be involved in chromosome associations.
SOME LEGAL IMPLICATIONS OF ADVANCES IN HUMAN GENETICS
Authors: Krever Horace
Published: November 2014

The law which, to some extent at least, reflects contemporary mores, has not kept pace with the recent scientific advances in genetics. Because of the rate of advance in the science of genetics there is a real risk that we shall know how to change the traditional nature of man before we possess the knowledge necessary to enable us to use the new knowledge for humane purposes. Clonal reproduction may produce a creature who, for the purposes of the law, especially the criminal law, which defines when a child becomes a human being in terms of "old-fashioned" motherhood, may not be a human being, so that putting him to death may not be homicide. Similarly, in vitro fertilization and development in an artificial uterus may result in the "birth" of one who, though having human attributes, may not, in law, be a human being. While cloning and in vitro fertilization may not have immediate legal implications because of the state of the art, genetic manipulation in the form of amniocentesis has very real legal implications now because it is a matter of current practice. The assumption that detection of genetic abnormality in the foetus is a beneficial development because it enables parents to have the option of terminating the pregnancy, though valid in the United Kingdom and the United States, is invalid in Canada. Abortion on demand is not part of the law in Canada and the liberalization of the abortion provisions of the Criminal Code of Canada in 1969 expressly avoided including as a criterion for therapeutic abortion the risk that the child, if born, would be likely to suffer from such physical or mental abnormalities as to be seriously handicapped. Beyond the more technical issues raised by scientific advances, however, lies the fundamental question whether a handicapped life is a life not worth living.
ADVANCES IN MEDICAL GENETICS
Authors: Miller J. R.
Published: November 2014

Although advances in medical genetics are designed ultimately to help human beings receive better health care, they pose many problems for society. Some of these concerns are real, but others result from misunderstanding and/or misrepresentation of the true implication of certain developments in genetics. It is obvious that the geneticist must play a dual role in society as scientist and as advocate. Although such a duality or role is not easy, it is not impossible. However, it does mean that the training of the medical geneticist must include more than exposure to the scientific approach.
LINKAGE AND ALLELIC RELATIONSHIPS AMONG GENES FOR RESISTANCE IN TOMATO (LYCOPERSICON ESCULENTUM) AGAINST MELOIDOGYNE INCOGNITA
Authors: Sidhu Gurmel S. , Webster J. M.
Published: November 2014

Linkage and allelic relationships among genes for resistance in tomato (Mi, LMiR1, LMiR2 and LMir3) against Meloidogyne incognita (Kofoid and White) were investigated. Two of the resistance genes, LMiR1 possessed by the cultivar Nematex and LMiR2 possessed by the cultivar Small Fry-1, are closely linked and are approximately 5.65 morgan units apart, while the resistance genes LMiR1 and Mi were found to be either identical or allelic. No relationship could be established between the recessive gene for resistance LMir3 possessed by the cultivar Cold Set-1 with other genes which may be due to cytoplasmic and temperature factors affecting the cultivar Cold Set-1.
EVOLUTION IN THE GENUSAVENA: INHERITANCE OF DIFFERENT FORMS OF RIBULOSE DIPHOSPHATE CARBOXYLASE
Authors: Steer M. W.
Published: November 2014

Disc electrophoresis of ribulose diphosphate carboxylases from Avena species in polyacrylamide gels of varying concentrations reveals the presence of two distinct forms of the enzyme. One migrates faster than the other and is found exclusively in species possessing the A genome. The other is confined to the C genome species (A. pilosa, A. ventricosa, A. clauda). The association of another characteristic of this enzyme (presence of stromacentres in the chloroplasts) with the A genome was reported previously. Observations on the recently described species A. prostrata, A. canariensis, A. damascena, and A. murphyi show that they all possess stromacentres, confirming reports that they all contain the A genome. Examination of amphiploid hybrids (from crosses between various diploid species and A. sativa) has shown that the mobility character is inherited maternally, and is located on the chloroplast genome. All these hybrids have the A genome and all have stromacentres. The results are discussed in the light of recent findings on the structure and synthesis of this enzyme. Consideration of the species distribution of the different forms of carboxylase places certain restrictions on the possible evolutionary paths from diploids to tetraploids and hexaploids.
KARYOLOGICAL DATA ON SOME SPECIES OF THE GENUS CURA (TRICLADIDA, PALUDICOLA)
Authors: Gourbault Nicole , Benazzi Mario
Published: November 2014

For the North American species Cura foremanii, the authors confirm a diploid complement of 12 chromosomes, and give a detailed description of the karyotype which is characterized by the presence of one long metacentric and five more or less subtelocentric chromosomes. A population of the Australian species C. pinguis possesses 36 metacentric chromosomes that are easy to assemble in six groups of six elements each. This suggests a hexaploid condition as do the karyometric results. Meiosis is normal in both germ lines and the development appears to be amphimictic.
GENETIC ANALYSIS OF TIME TO EAR EMERGENCE IN HEXAPLOID WHEAT, TRITICUM AESTIVUM, USING INTERVARIETAL CHROMOSOME SUBSTITUTION LINES
Authors: Halloran G. M.
Published: November 2014

Differences in days to ear emergence between the cultivars Chinese Spring and Hope, under long photoperiod, are under complex genetical control. A minimal estimate of ten genes of comparatively major effect and four of minor effect determine the difference in days to ear emergence under these conditions. The concept has been developed of the genetic control of time to ear emergence in wheat being determined by two types of gene action (i) a threshold response function and ((ii) a rate function. It appears that with vernalization response, at least, the threshold function is closely linked with, or a pleiotropic expression of, the rate function. The two chromosomes 7B and 5D of Hope in Chinese Spring appear to bear genes which exhibit strong expressions of these dual functions — 7B vernalization reducing and rate (to ear emergence) promoting and 5D vernalization promoting and rate retarding. However, in the case of chromosome 5D of Hope in Chinese Spring at least, the presence of a null allele for the gene for spring habit on 5D on Chinese Spring could mean that the retardation of development rate was a function of the rest of the genotype. Homoeologous group 5 possesses a distinctive role in the control of maturity of bread wheat. Intervarietal chromosome substitution in wheat, particularly for chromosomes 5A and 5D and in addition chromosomes 3B and 7B could play a significant role in breeding for altered time to ear emergence.
SACCHAROMYCES CEREVISIAEPETITE MITOCHONDRIAL DNA OF SUPPRESSIVE AND NEUTRAL HAPLOIDS AND OF [rho−] DIPLOIDS OBTAINED FROM CROSSING [rho+] TO A NEUTRAL PETITE
Authors: Robertson A. J. , Bech-Hansen N. T. , Rank G. H.
Published: November 2014

An unusual property of GR25a [rho+] was the production of 20 to 30 percent [rho−] zygote colonies when crossed to a tester strain lacking mitochondrial DNA. Spontaneous [rho−] isolates of GR25a [rho+] were observed to be highly suppressive and to contain mitochondrial DNA of a parental buoyant density (1.685 g/cm3). Three ethidium bromide induced neutral petites of GR25a [rho+] did not have detectable mitochondrial DNA and were neutral in crosses to [rho+] strains. Seven [rho−] zygote colony isolates obtained from crossing GR25a [rho+] to a neutral petite were shown to contain abnormal mitochondrial DNA. Six zygote colony isolates had mitochondrial DNA of a buoyant density less than, or equal to, GR25a (1.682–1.685 g/cm3), whereas one isolate had a buoyant density greater than GR25a (1.688 g/cm3). It was suggested that abnormal mitochondrial DNA is generated during the mating reaction.
GENOME RELATIONSHIPS IN BROMUS ERECTUS, B. PUMPELLIANUS SSP. DICKSONII AND B. PUMPELLIANUS
Authors: Armstrong K. C.
Published: November 2014

Chromosome pairing was studied in hexaploid (2n = 42) hybrids of B. erectus (2n = 28) × B. pumpellianus (2n = 56) and B. pumpellianus ssp. dicksonii (2n = 28) × B. pumpellianus. Chromosome pairing in the B. erectus × B. pumpellianus hybrid was complete with predominantly bivalent formation and a low frequency of quadrivalents. The pairing results support the contention that B. pumpellianus is an autoalloploid with an AAAABBBB genome formula. The B. pumpellianus ssp. dicksonii × B. pumpellianus hybrid has an AAABBB genome formula. The presence of quadrivalents, hexavalents and cells containing a total number of bivalents or bivalents plus trivalents in excess of 14 indicated pairing between the A and B genomes. However, a high univalent frequency showed that the A and B genomes were homoeologous rather than homologous. Evidence for genetic control of homoeologous chromosome pairing and homoeologous differentiation between the genomes of the species is discussed.
ACTION OF "COLONIE LISSE" MUTATION ON CELL MORPHOLOGY OF SACCHAROMYCES CEREVISIAE
Authors: Bizeau C. , Belin J.-M. , Galzy P.
Published: November 2014

The mutation of one of the genes of the series PLi in Saccharomyces cerevisiae HANSEN brings about a reduction in the size of the cells. Besides, the mutation of some genes (PLi 5 and PLi 7) induces a change in the scanning microscopy appearance of the cell wall.