bluuebunny/crossref_metadata_2025 huggingface dataset:
SOME CHARACTERISTICS OF PARENT-OFFSPRING REGRESSION IN BODY WEIGHT OF MUS MUSCULUS AT DIFFERENT AGES
Authors: Nishida Akira
Published: November 2014

This study was undertaken to test the linearity assumption of parent-offspring regression in body weight of Mus musculus. A highly significant non-linearity of parent-offspring regression was found in the raw data. Three methods of data correction were tested and found equally effective in adjusting the data for sex and litter size. It made the parent-offspring regression more linear. But after such adjustment, non-linearity of parent-offspring regression still existed at almost all ages reported in this paper. Four types of curvilinear parent-offspring regression and linear regression were recognized in all 11 days of age reported.Neither a characteristic which is common to the types of parent-offspring regression at all days of age nor a tendency of the change in curvilinearity according to the growth of Mus musculus could be found.
THE GENETICS OF DELTA, A DOMINANT SEX-LINKED MUTANT OF THE MOSQUITO, CULEX TRITAENIORHYNCHUS
Authors: Baker R. H. , Sakai R. K.
Published: November 2014

Delta, a new mutant of the mosquito Culex tritaeniorhynchus is described. Genetic analysis revealed that this gene is dominant and closely linked to sex. The possibility of using this gene to detect cryptic variabiltiy in the sex chromosomes of natural populations of this mosquito is discussed.
BARRIERS TO HYBRIDIZATION OFTRIFOLIUM REPENSWITH RELATED SPECIES
Authors: Chen Chi-Chang , Gibson Pryce B.
Published: November 2014

Pre-fertilization barriers to hybridization of Trifolium repens L. with its related species, T. nigrescens, T. occidentale, T. hybridum, T. ambiguum, and T. uniflorum, were studied by comparing pollen germination, pollen-tube growth, and fertilization following intra- and interspecific pollinations on T. repens. Pollen of T. repens began to germinate almost immediately after being placed on the stigmas of its own species; pollen germination approached 100% in 30 min. Pollen tubes grew rapidly. Eight hours after pollination the longer tubes had entered the micropyle of the most distant ovules. Fertilization was first observed at 8 hr. All ovules were fertilized within 24 hr. In interspecific pollinations using T. repens as the pistillate parent, the time required for pollen germination was longer and the frequency of germination was lower. Pollen tubes frequently swelled, coiled, or even burst in the styles. Pollen tubes of the species more closely related to T. repens appeared to grow faster and more normally. Fertilization occurred in all interspecific crosses. The highest frequency of ovules fertilized generally occurred in the species combinations in which pollen-tube growth was most similar to the control and the lowest frequency, in the combinations in which tube growth deviated the most from the control. These observations suggest that pre-fertilization barriers are not the only causes of cross-incompatibility of T. repens with related species. Post-fertilization barriers, which prevent zygotes from developing into viable seeds, also must exist.
GENETIC DIFFERENCES BETWEEN AEGILOPS LONGISSIMA, A. SHARONENSIS, AND A. BICORNIS
Authors: Waines J. Giles , Johnson B. Lennart
Published: November 2014

Electrophoretic patterns of 70% ethanol extracts of ground seed of Aegilops longissima, A. sharonensis, and A. bicornis biotypes show consistent genetic differences among the three taxa, even though there are some intrataxon differences. There are more bands with homologous migration velocity common to A. sharonensis and A. bicornis than to A. sharonensis and A. longissima. This suggests that A. sharonensis is a valid species and that it should not be relegated to a variety of A. longissima as it was on evidence from chromosome pairing studies. The protein patterns suggest that A. sharonensis may have originated as a segregant from a hybrid between A. longissima and A. bicornis.
EFFECTS OF ATRAZINE ON CHROMOSOMAL BEHAVIOR IN SORGHUM
Authors: Liang G. H. , Liang Y. T. S.
Published: November 2014

A widely used chemical herbicide, atrazine (2-chloro-4-ethylamino-6-isopropyl amino-s-triazine), applied to sorghum plants, induced numerical and structural chromosome abnormalities in microsporocytes during meiosis. Results were the same in plants treated at seven growth stages at a normal rate (2.8 kg/ha, equivalent to 2.5 1b/acre). Aberrant cells contained extra pairs of chromosomes, ranging from a few extra pairs to more than ten times as many. Apparently some of the microsporogenous cells failed to undergo cytokinesis, though chromosome division was uninhibited.
GENETICAL STUDIES IN SOME WEST AFRICAN SOLANUM MELONGENA L.
Authors: Choudhuri H. C.
Published: November 2014

Heterosis for leaf index was found in the intervarietal hybrid, Solanum melongena L.var.Giwa-2 × var.Giwa-1. The indices of the hybrids exceeded significantly those of the parents. Inheritance of plant height is controlled by a pair of factors, T being dominant for tall and t recessive for dwarf. The deeply-lobed leaf form is controlled by a pair of factors, LL which is partially dominant over slightly lobed leaf, ll. An intermediate-lobed form is produced by the genotype, LLll. Fruit colour is controlled by a pair of factors: GM, green is partially dominant over white, gm. The mosaic green colour of the fruit, a mixed colour, is produced by the genotype, GMgm.
COMPENSATED MONOSOMIC 5B-TRISOMIC 5A PLANTS IN TETRAPLOID WHEAT
Authors: Mello-Sampayo T.
Published: November 2014

Tetraploid wheat plants monosomic 5B-trisomic 5A were obtained by crossing nullisomic 5B-tetrasomic 5A plants of Triticum aestivum with T. durum and backcrossing five times with T. durum. These plants were found to carry a translocated 5A-5D chromosome. By self-pollination they originated plants carrying both a 5A-5D and 5B-5D translocated chromosome. In the latter the break point was located distally to the pairing suppressor gene. The translocations must have occurred by homoeologous pairing and recombination in the long arm of chromosomes of the group 5. F1 hybrids of monosomic 5B-trisomic 5A plants with rye and Aegilops sharonensis showed high homologous pairing when 5B was absent. Pairing promotion associated with the terminal segment of the long arm of 5D attached to the 5B-5D chromosome end was detected. It was suggested that the long arm of chromosomes of the homoeologous group 5 of wheat might carry two separate loci with genes for antagonistic effects on the pairing of chromosomes.
CORRELATED RESPONSES IN EGG QUALITY TRAITS TO SELECTION FOR EARLY BODY WEIGHT IN MEAT-TYPE CHICKENS
Authors: Buvanendran V. , Merritt E. S.
Published: November 2014

The correlated responses in egg quality traits to selection for high early body weight were studied in seven meat-type populations comprising five selected and two control lines. Traits studied were specific gravity, egg weight, albumen height, Haugh units, shell color, egg shape, shell roughness, wrinkling and asymmetry, and incidence of blood spots, meat spots and double yolks. Significant (P < 0.05 or < 0.01) correlated changes, as determined by the regression of correlated response (egg quality traits) on primary response (body weight), were obtained for egg weight, albumen height, Haugh units, asymmetry of shell and blood spots. All but blood spots increased with selection for high body weight. Shell color showed a consistent trend towards a darker color with increasing body weight. Scores for roughness of shell and, with one minor exception, the incidence of double yolks, also showed consistent trends (positive) with increasing body weight. Estimates of genetic correlations, derived directly from intra-line genetic analyses of the six pedigreed populations in the experiment, were in most cases in reasonable agreement with realized estimates.
THE INHERITANCE OF RESISTANCE TO PUCCINIA RECONDITA IN HEXAPLOID TRITICALE
Authors: Quinones M. A. , Larter E. N. , Samborski D. J.
Published: November 2014

Rob. ex. Desm. f. sp. tritici, was studied in the hexaploid triticale cultivars 6A-190, Rosner, Armadillo, Bronco, and Toluca 160.Resistance in the triticales studied was monogenically inherited and each cultivar carried a single dominant gene. The genes conditioned resistance to races 15 and 30, and were designated genes A (6A-190), B (Rosner) C (Armadillo), D (Bronco), and E (Toluca 160). Gene A was linked in repulsion with gene C with a crossover value of 44.75 ± 1.44% and segregated independently from the other genes. Genes B and C were also independently inherited. Gene B was not linked with genes C, D, and E but observed distorted ratios with genes D and E suggested the presence of a modifying gene or genes. A similar distorted ratio was observed between genes C and D. Gene C assorted independently from gene E. No recombinants were recovered from the cross between Bronco × Toluca 160 suggesting that genes D and E were allelic or closely linked. The parental triticale cultivars Bronco and Toluca 160 carrying the genes D and E, respectively, appeared to carry modifying genes which inhibited the expression of resistance in certain crosses.The result obtained indicated that the genes governing resistance were derived from the tetraploid wheat parental species and that resistance to wheat leaf rust carried by the rye parent was not expressed in the triticale amphiploid. It was also found that genes conditioning resistance to wheat leaf rust were equally effective in conditioning resistance to rye leaf rust.
MULTIPLE ANEUPLOIDS FROM INTERSPECIFIC CROSSES INSOLANUM: FERTILITY AND CYTOLOGY
Authors: Lee Heiyoung Kim , Kessel R. , Rowe P. R.
Published: November 2014

Approximately 30% of the progeny from interspecific 3x-2x crosses were multiple aneuploids (2n = 26-29). Seven interspecific multiple aneuploids from the crosses Solanum magilia × S. berthaultii, S. maglia × S. microdontum, and (S. tuberosum × S. berthaultii) × S. berthaultii were studied to determine their chromosome complements and to assess their potential value for associating genes with particular chromosomes. These clones grew vigorously in the field but some were dwarf and compact in habit. Six of the seven clones were female fertile. At metaphase I, 0.54 to 0.72 trivalents were formed per extra chromosome. Chain and "Y" trivalents were found most frequently. The average number of chromosomes at prophase II and metaphase II was 13.31 for five triple trisomics. Pachytene analysis of six of the multiple aneuploids indicated that in five of the clones, one or two of the extra chromosomes were isochromosomes. Complete chromosomes II, III, IV, X, and XII and isochromosomes of I, III, and XI have been identified in these clones.
GENETIC ANALYSIS OF SEED SIZE IN PIGEON PEACAJANUS CAJAN
Authors: Sharma D. , Singh Laxman , Baghel S. S. , Sharma H. K.
Published: November 2014

Diallel analysis for seed size on 10 varieties of pigeon pea or arhar Cajanus cajan L. Millsp., representing different maturity groups and wide range of variability in seed size, was conducted to determine genetic parameters. The D and H1components indicated a predominance of additive gene effects and the degree of dominance was in the partial dominance range. Seed size was simply inherited with a high heritability value of 0.82. The scatter of parental arrays in a Wr, Vrgraph suggested that the genes controlling smaller seed size were dominant over the genes controlling larger seed size. The analysis indicated the possibility of improving seed size by simple selection procedures.
GENOME RELATIONS BETWEEN AN INTRASPECIFIC PASPALUM DILATATUM HYBRID AND TWO DIPLOID PASPALUM SPECIES
Authors: Burson Byron L. , Bennett Hugh W.
Published: November 2014

An intraspecific dallisgrass, Paspalum dilatatum, hybrid (2n = 45) was crossed with P. notatum (2n = 20) and P. juergensii (2n = 20). Four hybrids of the P. notatum × intraspecific dallisgrass hybrid cross were studied cytologically and had 30 chromosomes. Meiosis was irregular and the mean pairing relationships at metaphase I were 27.37 I and 1.31 II. Of 22 hybrids obtained from the intraspecific dallisgrass hybrid × P. juergensii cross, 21 hybrids had 30 chromosomes and 1 had 31. Meiosis was relatively regular with an average of 10.38 I and 9.81 II per cell. These findings indicate that the dallisgrass hybrid and P. notatum are not closely related, whereas the dallisgrass hybrid and P. juergensii apparently have a common genome. It was also shown that yellow anthered dallisgrass can generally be substituted cytologically for common dallisgrass. Megasporogenesis was normal in all hybrids. However, the sexual tissue generally deteriorated, resulting in complete abortion of the female gametophyte.
CYTOGENETIC STUDIES OF MEIOTIC ABNORMALITIES IN COLLINSIA TINCTORIA. II. DESYNAPSIS
Authors: Mehra R. C. , Rai K. S.
Published: November 2014

Certain plants of Collinsia tinctoria showing meiotic abnormalities were isolated from the segregating progenies of irradiated plants (Rai, 1967). In one of these plants, failure of chromosomal pairing was observed, which resulted in a varying number of univalents at metaphase I. Genetic analysis showed that this abnormality is controlled by a single recessive gene. This mutant has been found to be allelic with another meiotic mutant (chromosomal stickiness), reported elsewhere. The mutant showed considerable variation in the nature and extent of abnormal synapsis of the chromosomes. An abnormal chromosomal pairing, chromosomal breakage and sister chromatid reunion, bridges, laggards, neocentromeric activity and differential condensation of the chromosomes were also observed.
THE REACTION OF NEAR-ISOGENIC LINES OF FLAX TO THE RUST FUNGUS MELAMPSORA LINI I. HOST-PARASITE INTERFACE
Authors: El-Gewely M. R. , Smith W. E. , Colotelo N.
Published: November 2014

Two near-isogenic lines of the flax cultivar Redwing, differing in their reaction to M. lini (Pers.) Lev. f. sp. liniperda Koern race '300', were studied to elaborate on the nature of the resistance in flax. In the susceptible line (rr) the fungus developed normally, producing extensive mycelium and haustoria and finally uredospores. However, in line S-66-53 (RR) no haustoria were formed, but a hypersensitive reaction was induced upon inoculation. The fungus did not appear to establish any nutritional relationship in S-66-53. The genetic control of resistance as regulated by the R locus is discussed and a hypothesis is proposed to explain the induction of the hypersenitive reaction.
FINE STRUCTURE OF CHROMOSOME COILING AT MEIOTIC PROPHASE IN RHOEO DISCOLOR
Authors: Moens Peter B.
Published: November 2014

Most, if not all of the ends of synaptonemal complexes in Rhoeo discolor pollen mother cells are attached to the nuclear envelope. At least the first 4 μm of complex adjacent to the nuclear envelope is tightly coiled. Since each of the lateral elements is associated with one chromosome it means that the two homologues of the bivalent are relationally coiled in the distal segments.
RELATIONSHIP OF TAXA IN THE GENUS MEDICAGO AS REVEALED BY HYBRIDIZATION. VI. M. LACINIATA × M. SAUVAGEI
Authors: Singh S. M. , Lesins K.
Published: November 2014

Medicago laciniata (L) Mill. and M. sauvagei Nègre were intercrossed in both directions. The F1's of the cross M. sauvagei ♂ × M. laciniata ♀ were chlorophyll deficient, and F1's of the reciprocal cross were normal green, indicating cytoplasmic influence. In the F2 of chlorophyll deficient F1's, segregation for chlorophyll deficiency took place, revealing interaction of cytoplasmic factor/s with gene/s of M. laciniata. Some transmission of the cytoplasmic factor through pollen of M. sauvagei was indicated by somatic chlorophyll deficiency in sectors of a few leaves of F1's of M. laciniata ♂ × M. sauvagei ♀. The serrate margin leaf character of M. sauvagei and the apical coil spininess of M. laciniata were transmitted as recessives. Because of the poor seed set in F1's and high seedling mortality of F2's, the number of genes determining these characters is not certain. The two taxa are considered separate species because of low interfertility; their close phylogenetic relationship, however, is indicated by normal meiosis in F1's and by hybridization.
CHROMOSOME HOMOLOGY AT PACHYTENE IN DIPLOIDMEDICAGO SATIVA,M.FALCATAAND THEIR HYBRIDS
Authors: Ho K. M. , Kasha K. J.
Published: November 2014

One line of diploid M. sativa, two lines of diploid M. falcata and 68 F1hybrid plants were investigated. The meiotic processes were regular in the F1hybrids and their pollen fertility was similar to the parent species. The idiograms of the pachytene chromosomes of M. sativa, M. falcata and their F1hybrid were prepared from a total of 60 cells in which all the chromosomes were analysable. Although the idiograms differed in total lengths their patterns were very similar and indicate that the chromosomes of these lines are essentially identical. Based on meiotic behaviour and high pollen fertility of F1hybrids and the idiograms at pachytene stage, it was concluded that the chromosomes of M. sativa and M. falcata appear to be homologous. It was suggested that genetical studies of the two species (especially linkage studies) can be combined and that trisomic plants produced from crosses between M. sativa and M. falcata could be used to identify the alfalfa chromosomes.
ULTRASTRUCTURE OF USTILAGO HORDEI (PERS.) LAGERH. II. SEPTATION IN THE METABASIDIUM
Authors: Robb Jane
Published: November 2014

In the metabasidium of Ustilago hordei cross walls are complete. The pattern of septation resembles that found in actinomycetes, in Coccidioides immitis and in Exidia nucleata. Elaborate membrane complexes are associated with the initiation of the cross wall.
KARYOLOGICAL RELATIONSHIPS IN TURTLES (REPTILIA: CHELONIA)
Authors: Stock A. Dean
Published: November 2014

The mitotic chromosomes of 33 species of chelonians representing 22 genera and six families were investigated. Chromosome number and morphology are the same for most members of a given family and range from 66 in Trionyx to 34 in Pelomedusa. Most emydid genera have 50 chromosomes. The karyotype of Chelydra (2n = 52) is similar to those of some testudinid and emydid genera and is unlike the 56 chromosome karyotype of kinosternid turtles. The three genera of tortoises examined, Gopherus, Testudo, and Geochelone, have 52 chromosomes, but Gopherus differs in karyotypic details. The karyotype of Geochelone is like that of Chelydra and the 52 chromosome genera of emydid turtles. The African pleurodiran Pelomedusa has three additional pairs of small acrocentric or telocentric chromosomes not present in the earlier described karyotype of Podocnemis. Examination of meiotic chromosomes revealed frequencies of chiasmata formation similar to those reported earlier. Sex chromosomes were not distinguishable.
STABILITY OF TRISOMIC (47, 18+) CELLS IN LONG-TERM MOSAIC SKIN FIBROBLAST CULTURE
Authors: Beratis Nicholas G. , Hsu Lillian Y. F. , Kutinsky Enid , Hirschhorn Kurt
Published: November 2014

Skin fibroblasts from a subject with trisomy 18 mosaicism (47, XY, 18+) were maintained in culture over a period of 5 months. Mitotic preparations obtained after 8, 14, and 20 weeks from the time of the biopsy did not demonstrate any essential advantage of cells with one chromosomal constitution over the other. It appears that cultured skin fibroblasts are a reliable method to assess the proportion of normal and trisomic 18 cells.
GENOTYPIC AND CYTOLOGICAL INFLUENCES ON THE MEIOSIS OF HEXAPLOID TRITICALE
Authors: Thomas J. B. , Kaltsikes P. J.
Published: November 2014

Two groups of hexaploid triticale were synthesized from the crosses of two cultivars of diploid rye (Secale cereale L.) with (a): two cultivars of tetraploid macaroni wheat (durum-group of Triticum turgidum L.), and (b): extracted AABB tetraploids of three cultivars of hexaploid bread wheat (T. aestivum L. em. Thell.).The extracted triticales, as a group, showed the greater chromosome regularity in the division of their PMC's. This was attributed to the prior adaptation of the extracted AABB component to the hexaploid meiosis of bread wheat. There was much variation in chromosome behaviour among triticales which had in common the same parental cultivars of wheat and rye. This genetic variability most likely came from the heterogeneity of gametes that were contributed by the two outbred cultivars of rye.AI was delayed in PMC's in which there was a low level of synapsis at MI. This effect was related to the total number of chromosome arms that were paired in each cell (arm pairs), regardless of how many univalents each cell contained. Non-randomness in the distribution of paired chromosome arms suggested that some chromosomes (possibly derived from rye) were less likely to pair than others.The rate at which univalents were formed in cells with a particular number of arm pairs was clearly influenced both by the genotype and by the environment of the triticale in question.
THE CHROMOSOMAL NATURE OF LESIONS RESPONSIBLE FOR LETHAL SECTORING IN YEAST
Authors: James A. P.
Published: November 2014

The location of the damage responsible for radiation-induced lethal sectoring in diploid yeast was investigated in three strains of independent origin. The damage was attributable to mutations that were chromosomal, recessive, and nonallelic. Tetrad analysis implied that the mutations were tightly linked to centromeres or to each other.
THE LOCALIZATION OF CELLS WHICH MANIFEST REPLICATING INSTABILITY IN YEAST COLONIES
Authors: Nasim A. , James A. P.
Published: November 2014

The incidence of replicating instabilities was compared among cells sampled from different portions of primary mosaic colonies resulting from treatment with the mutagen ethylmethanesulfonate. The comparisons were carried out using both a plating technique and a method involving the micromanipulation of single cells. Results clearly indicated that unstable cells are concentrated towards the centre of mosaic coloniees.
CYTOTAXONOMY OF BOMBYLIIDAE (DIPTERA)
Authors: Boyes J. W. , Shewell G. E.
Published: November 2014

The karyotypes of 34 species of Bombyliidae are described, some in greater detail than others. It is suggested that two subfamilies, the Bombyliinae (for Homoeophthalmae) and Anthracinae (for Tomophthalmae) be recognized. In the Bombyliinae, one species has 2n = 8, one 2n = 10, three 2n = 12 and one 2n = 14. In the Anthracinae, two species have 2n = 10, four 2n = 12, six 2n = 14, three 2n = 16 and thirteen 2n = 18. Seventeen complements of Bombyliinae averaged 41.4 μ in total complement length (TCL) and thirtyeight of Anthracinae averaged 46.6 μ; so the 55 complements of the Bombyliidae averaged 44.9 μ in TCL, the complements with lower chromosome numbers averaging less than those with higher numbers. Thus Bombyliinae species have lower chromosome numbers and shorter complements than Anthracinae species which tend to have longer metacentric sex chromosomes. Thus both morphologically and karyotypically the Bombyliinae appear to be more advanced whereas the Anthracinae are a more primitive but highly variable group of species.
EFFETS DES MICROIRRADIATIONS SUR LES MICROSPOROCYTES ET MICROSPORES DE TRADESCANTIA PALUDOSA. III. NOTE PRÉLIMINAIRE SUR LES EFFETS DES MICROIRRADIATIONS ULTRAVIOLETTES
Authors: Garot G. , Dujardin M. , Gilles A.
Published: November 2014

Microsporocytes of Tradescantia paludosa have been irradiated with ultraviolet microbeams of 2 to 10 microns. At a wavelength of 2570 A, we observe a selective destruction, total or partial, of the spindle in the first division, anaphase bridges and interruption in the second division.At a wavelength of 2750 A, the most remarkable effect is the "paling" of some parts of the chromosome structure as well as of interphase nuclei, and also stickiness bridges in the bivalents of the first division.
DEVELOPMENTAL DIFFERENCES IN ACTION OFRANDBALLELES IN MAIZE
Authors: Styles E. Derek , Ceska Oldriska , Seah Kim-Tek
Published: November 2014

Alleles of the B and R loci collected from different geographic races of maize differ with respect to concentration, pattern, and tissue specificity of anthocyanin formation. No differences were found between the pigments formed by B action and those formed by R action. The activities of four B alleles and five R alleles when compared in a common genetic background and described in terms of the whole life cycle show differences in the following respects: In a given tissue, for example the aleurone, there are differences in a) rate of activity, b) time of onset of activtiy, c) time that activity ceases. Apparent tissue specificity is shown when the development of a tissue coincides with the period during which the gene is active. True tissue specificity is shown by alleles that have different activities in tissues that develop at the same time. This latter type of specificity was shown only by alleles known to consist of more than one synaptically homologous region, or by those derived in some way from such complex alleles. It is suggested that for most genetic systems there probably exists potential for change in level of action, change in time of onset and termination of activity, and change toward tissue specificity. The type and extent of the change tolerated will depend on the system involved.
GENETICS OF PATHOGENICITY IN THREE RACES OF LEAF RUST ON FOUR WHEAT VARIETIES
Authors: Haggag M. E. A. , Samborski D. J. , Dyck P. L.
Published: November 2014

Populations of self-fertilized cultures of races 9, 11 and 161, "backcross" selfed progeny of race 11, F1 cultures of races 9 × 11 and 11 × 161, and F2 cultures of races 9 × 161 were used to study the genetics of virulence on the wheat varieties Democrat, Sinvalocho, Bage and Klein Aniversario and backcross lines developed from them.Race 9 was homozygous avirulent on all the host varieties tested. Selfed populations of race 11 segregated for a recessive gene, p3, for virulence on Democrat × Thatcher6 (Lr3), Sinvalocho and Sinvalocho × Thatcher2. Race 11 has an additional dominant gene for virulence on the latter two varieties. Race 11 appears to have p3 plus a second gene(s) for virulence or a modifier(s) of the dominant allele of p3 for virulence on Sinvalocho × Prelude6 (Lr3). This would correspond to a modifier or suppressor in the genetics of resistance of Sinvalocho × Prelude6. Race 11 was homozygous for avirulence on Bage, heterozygous for p3 and one other gene for virulence on Bage × Thatcher8. This race was heterozygous for two genes for virulence on Klein Aniversario and for one gene on backcross lines derived from this variety. These genes were independent of p3. The data of the "backcross" selfed progeny of race 11 agreed in general with the above. Race 161 was segregating for a dominant gene for virulence on Democrat, Democrat × Thatcher6 and Sinvalocho × Prelude6, and for a recessive gene on Bage and Klein Aniversario × Thatcher6. It was homozygous avirulent on Klein Aniversario and homozygous virulent on Bage × Thatcher8. The pathogenicity of the F1 cultures of races 11 × 161 suggested that the two races have virulence genes at the same locus. These data and those from the F2 populations of races 9 × 161 supported the results from the selfed populations.
SATELLITE NUMBER AND SIZE IN TRITICUM MONOCOCCUM L. AND THE EVOLUTION OF THE POLYPLOID WHEATS
Authors: Waines J. Giles , Kimber Gordon
Published: November 2014

Biotypes of Triticum monococcum from Europe and Iran were surveyed for variations in the number and size of the chromosomal satellites. Biotypes with both one and two pairs of satellited chromosomes were found, and the satellite size varied both within and between biotypes. It is concluded that existing phylogenetic and evolutionary schemes within Triticum and Aegilops, which are based mainly on karotype evidence, are suspect. The hypothesis that Ae. speltoides is the donor of the B genome of the tetraploid and hexaploid wheats is questioned.
RADIOCYTOGENETIC EFFECTS ON BONE MARROW CELLS OF OPOSSUM IN VIVO
Authors: Prasad N. , Bushong S. C. , MacIntyre R. S.
Published: November 2014

Bone marrow cells of the opossum (Didelphis virginiana) were examined 24 hr following a whole-body 60Co radiation dose of 100, 300, 500 and 700 rads. Analysis of the number of chromosomes and the chromosomal aberrations resulted in a radiation sensitivity of 0.000605 aberrations/cell/rad and 0.59 × 10−6 aberrations/cell/rad2 for single-hit and multihit type damage respectively.
THE INHERITANCE OF LEAF RUST RESISTANCE IN FOUR COMMON WHEAT VARIETIES POSSESSING GENES AT OR NEAR THE Lr3 LOCUS
Authors: Haggag M. E. A. , Dyck P. L.
Published: November 2014

The inheritance of seedling resistance to leaf rust was studied in the wheat varieties Democrat, Sinvalocho, Bage and Klein Aniversario and in the backcross lines developed from them. The Lr3 gene from Democrat and Sinvalocho conferred resistance to races 1, 9 and 11. Genetic analysis of the Sinvalocho × Prelude0 line (with Lr3), using a rust culture that was avirulent on Democrat × Thatcher6 and Sinvalocho etc., but virulent on Sinvalocho × Prelude6, indicated the presence of a suppressor gene in Prelude. The variety Bage has two genes for resistance to races 9 and 11, one giving a 0; reaction and the other a type 2. The former gene was present in Bage × Thatcher8 and was allelic to, or closely linked with, the Lr3 gene. It is temporarily designated Lr3bg. Klein Aniversario may have two independently inherited genes conferring resistance to race 11 and two to race 161. One of the genes conferred resistance to both races and was transferred to Thatcher and Prelude. This gene was also allelic to, or closely linked with, the Lr3 gene and is designated Lr3ka. These results suggest a complex Lr3 locus with a series of alleles or closely linked genes.
THE CHARACTERIZATION OF TWO ESTABLISHED HETEROPLOID LINES (INDIAN MUNTJAC AND RAT KANGAROO) WITH A LOW CHROMOSOME NUMBER. I. IN VITRO KARYOTYPE EVOLUTION AND CELL CYCLE DYNAMICS
Authors: Brown Judith A. , Cohen Maimon M.
Published: November 2014

Chromosome morphology, cell cycle dynamics and in vitro karyotype evolution are described for two heteroploid cell lines. For the male muntjac line, karyotypic changes are not correlated with gross shifts in the cell cycle.
THE CHARACTERIZATION OF TWO ESTABLISHED HETEROPLOID LINES (INDIAN MUNTJAC AND RAT KANGAROO) WITH A LOW CHROMOSOME NUMBER. II. CHROMOSOME IDENTIFICATION BY AUTORADIOGRAPHY AND SPECIFIC BANDING TECHNIQUES
Authors: Brown Judith A. , Cohen Maimon M.
Published: November 2014

Combined autoradiography, giemsa and fluorescence banding studies have been completed on the chromosomes of the rat kangaroo (Potorous tridactylis) and the Indian deer (Muntiacus muntjac). Autoradiographic analyses of these established heteroploid lines revealed an absence of a late replicating sex chromosome. For the muntjac complements there appeared to be a correlation between grain concentration and regions of bright fluorescence or dark giemsa stain. Specific banding studies revealed that numeric chromosome changes had taken place in the muntjac lines, with the chromosomes showing no obvious structural alterations from the diploid state. Karyotype changes in the rat kangaroo line were complex and involved structural rearrangements.
DIFFERENCES IN β-AMYLASE ACTIVITY BETWEEN CYTOPLASMS AND AMONG INBREDS IN MAIZE,ZEA MAYSL.
Authors: Peterson Peter A. , Reddy M. N. , Tipton C. L.
Published: November 2014

In a comparison of the cytoplasms of Normal (N) and Texas (T) cytoplasmic male-sterile, consistently higher total and specific β-amylase activity was found in 10-day-old leaves of N plants. This was evident in all nine lines tested although the lines differed markedly in total amylase activity ranging from a low of 2.7 to a high of 112.5 (mg maltose/g/hr). Statistically significant differences were confirmed between cytoplasms and between inbred lines in β-amylase activity. On the basis of the activity ratio of N/T, the analysis of variance did not show any interaction between cytoplasms and lines, β-amylase activities from leaves of B37 N and T plants were identical with respect to Km, pH optimum, temperature sensitivity and mobility on gel electrophoresis. This difference between the N and T cytoplasms indicates that the β-amylase, though originating from chromosomal genes, is influenced by the cytoplasm in its total and specific activity and that this is correlated with male sterility.
IDENTIFICATION OF CYTOLOGICAL AND AGRONOMIC CHARACTERS AFFECTING THE REPRODUCTIVE BEHAVIOUR OF HEXAPLOID TRITICALE
Authors: Hsam S. L. K. , Larter E. N.
Published: November 2014

A study was made of the inter-relationships between cytological and agronomic characters, and the extent of their effects on the reproductive behaviour in the parental and F1 hybrids of hexaploid triticale. A significant positive correlation was established between seed set and normal pollen percentage. These characters exhibited no correlation, however, with any of the meiotic disturbances studied, including univalents frequency, laggards, excluded chromosomes, and micronuclei, which among themselves were highly inter-correlated. Both kernel weight and seed protein percentage showed a positive correlation with meiotic disturbances and a negative correlation with seed set. The total variability in fertility attributable to the cytological variables was 35.6% [Formula: see text], and of these, normal pollen percentage made the largest contribution to total variance. From the cytological and agronomic attributes collectively, six common factors were extracted which explained 85.1% of the total variance.
KARYOTYPE ANALYSES OF PISSODES WEEVILS: EVIDENCE FOR TWO ADDITIONAL PUTATIVE TAXA
Authors: Smith Stanley G.
Published: November 2014

The utility of marker chromosomes as a taxonomic tool is demonstrated by the discovery of two apparently undescribed Pissodes taxa, YT3 and P27.
FIFTY PER CENT TIME TO PUPATION AS A MEASURE OF DEVELOPMENTAL TIME INTRIBOLIUM
Authors: Yamada Yukio
Published: November 2014

A technique for measuring developmental time in insects is proposed. The method is similar to the widely used 50% lethal dose (LD50). The major advantage for this technique, TP50for pupation time and TE50for adult emergence time, is the complete avoidance of introducing environmental correlations to the relationship among traits by handling. Standard deviations for TP50and TE50are obtained from the slope fitted to the data without resorting to individual observations.
THE EFFECT OF THE GENOTYPE OF TRITICUM SPELTOIDES ON THE PAIRING OF HOMOLOGOUS CHROMOSOMES
Authors: Larsen Jørgen , Kimber Gordon
Published: November 2014

Two lines of Triticum speltoides that affect chromosome pairing in hybrids with T. aestivum were treated with colchicine and autotetraploid sectors were induced. The chromosome pairing and chiasma frequency of the diploid lines and the induced autotetraploids were recorded. No differences were detected between the diploids or between the autotetraploids. It is concluded that the genotype of the low-pairing line of T. speltoides does not reduce homologous chromosome pairing and, therefore, the low pairing observed in hybrids of this line and T. aestivum must be taken to indicate a lack of homology between the chromosomes of T. speltoides and T. aestivum.
TEMPERATURE-SENSITIVE MUTATIONS INDROSOPHILA MELANOGASTER. XVI. THE GENETIC PROPERTIES OF SEX-LINKED RECESSIVE COLD-SENSITIVE MUTANTS
Authors: Mayoh Helen , Suzuki David T.
Published: November 2014

Among 3,919 EMS-treated X chromosomes, 25 were retained as cold-sensitive (cs) lethals. That is, more than 20% of flies carrying a cs lethal survive at 22 °C and none at 17 °C and for cs semi-lethals, >30% at 22 °C and <13% at 17 °C. The cs mutations are not randomly distributed, seven being located at the X tip and three being alleles to the right of car. Over half exhibited female sterility or reduced fertility and seven exhibited visible phenotypes characteristic of bobbed and Minute mutations. The possible enrichment for ribosomal protein defects by screening for cold-sensitivity is discussed.
A GENETIC STUDY OF ELECTROPHORETICALLY VARIANT EXTRACELLULAR AMYLOLYTIC ENZYMES OF WILD-TYPE STRAINS OF ASPERGILLUS NIDULANS
Authors: Kurzeja K. C. , Garber E. D.
Published: November 2014

Ninety strains assigned to Aspergillus nidulans produced extracellular amylolytic enzymes in a defined medium containing soluble starch as the organic carbon source. Acrylamide gel electrophoresis of freeze-dried culture filtrates gave 6-9 sites of amylolytic activity accommodated by nine patterns. Eighty-one strains exhibited pattern 1 or 2 and not more than two displayed one of the remaining seven patterns. Crosses between strains with different patterns succeeded only for strains with pattern 1 or 2. Esterase and phosphatase zymograms for mycelial extracts indicated that strains with amylase pattern 1 or 2 are A. nidulans, while the strains with the other amylase patterns are probably cryptic or sibling species. Two codominant alleles are responsible for the different electrophoretic mobility of one pair of amylolytic sites in zone 2 which distinguishes patterns 1 and 2. The pair of sites may be determined by duplicate loci.
THE USE OF MONOSOMICS TO DETECT GENES CONDITIONING LIPID CONTENT IN ZEA MAYS L. EMBRYOS
Authors: Plewa Michael J. , Weber David F.
Published: November 2014

The effects of monosomy of specific chromosomes on the lipid content of Zea mays embryos were studied. The lipid content of single kernels was measured by wide-line nuclear magnetic resonance spectroscopy. Significantly less lipid was found in embryos monosomic for chromosomes 2, 6, or 10 of a uniform genetic background than in their diploid controls. Thus, genes or gene complexes determining lipid content that exhibit dosage effects are located on these chromosomes. The distribution of lipid content of monosomic 8 embryos is the same as in the control; thus, monosomy per se does not decrease lipid content. Genetic control of lipid content within the embryo of monosomic 2 plants is a function of lipid concentration and not of embryo size. This study demonstrates that monosomic analysis can be used to determine whether genes expressing dosage effects reside on a given chromosome.
SEEDLESSNESS IN TRIPLOID GUAVA (PSIDIUM GUAJAVA L.) — EMBRYOLOGICAL STUDIES
Authors: Rangasamy S. R. Sree , Das L. D. Vijendra
Published: November 2014

The cause for seed collapse in triploid Psidium guajava is described. The ovule of guava is anatropous and of the monosporic type. Ovule degeneration in the triploid occurs at all periods of post meiotic development. Prior to anthesis, 52.7% of embryo sacs were defective. Post anthesis degeneration or abortion of embryos and endosperm were observed in 95 to 97% of the ovules. It was presumed that the degeneration was due either to unbalanced aneuploidy in the embryo sac, egg cells, embryo and endosperm or to chromosomal imbalance arising out of the triploid nature of the mother plant.
GIEMSA-BANDING PATTERN OF MUNTJAC CHROMOSOMES
Authors: Sharma T. , Garg G. S.
Published: November 2014

The Giemsa-banding patterns of Indian muntjac chromosomes stained after denaturation and renaturation of DNA were similar to the fluorescent staining patterns reported by others using quinacrine mustard.
A STUDY OF SOMATIC ASSOCIATION OF WHEAT CHROMOSOMES
Authors: Dvorak J. , Knott D. R.
Published: November 2014

The distances between homologous, homeologous and unrelated telocentrics in hexaploid wheat and between homologous telocentrics in wheat-Aegilops speltoides amphiploids were measured in somatic metaphases. No significant differences were found in the mean distances between telocentric chromosomes of the four groups. Except for the homologous telocentrics in the amphiploids, the other three groups of measurements differed significantly from the theoretical distribution described for randomly distributed chromosomes by Feldman et al. (1966). The chromosomes of these three groups appeared to be closer to each other than expected for randomly distributed chromosomes according to the relationship proposed by Feldman et al. It is suggested that the theoretical distribution is only an approximation of the actual situation.
CYTOGENETIC STUDIES OF CHROMOSOME REPLICATION IN ZEA MAYS L.: I. Analysis of quantitative autoradiographic data using Principal Components Analysis
Authors: Douglas George R. , Walden David B.
Published: November 2014

A quantitative, autoradiographic study of 3H-TdR uptake at 18 °C was undertaken in the nuclei of primary root meristems of a highly inbred stock of maize. Plots of the mean number of silver grains over nuclei vs. hours after removal from 3H-TdR (replication profiles) revealed fluctuation in DNA replication. Wilcoxon's signed-ranks test showed that some chromosome arms had replication profiles different from the profile of the nucleus. A Principal Components Analysis (PCA) was used to characterize empirically and further compare the replication of chromosome arms. The PCA results confirm the Wilcoxon's signed-ranks test results and also suggest unique replication behavior for some additional chromosome arms. To quantitatively compare the position of individuals in the scatter diagram of the first three factor axes from the PCA, the standardized Euclidean distance of each individual from the centroid was employed. Since some chromosome arms were found to be different from the others, at least limited autonomy of replication among chromosome arms is proposed.
EFFECT OF TWO CHEMOSTERILANTS APHOLATE AND HEMPA ON THE BONE-MARROW CHROMOSOMES OF MICE
Authors: Manna G. K. , Das P. K.
Published: November 2014

Mice were injected with 0.1% solution of apholate and hempa at the rate of 1.5 ml per 100 gm body weight and their bone-marrow cells were fixed at different intervals between 15 min and 144 hr. Specimens injected with distilled water served as controls.Only three aberrations were found in 4,100 metaphases in the control series. In the hempa-treated series, out of 4,100 metaphases examined one chromatid break, one subchromatid break, two gaps and one exchange were found at 24 hr only.In the apholate-treated series aberrations were absent only at 15 min and 144 hr post injection. At other times the aberrations were single chromatid breaks, subchromatid breaks, aniso- and isochromatid breaks, constrictions, gaps and lesions and exchanges. The aberration peak of 28.2% was reached at 24 hr, and fell to 0.3% at 120 hr. The breaks were non-randomly distributed between and within chromosome groups. Groups I and II and distal region of all affected groups were most susceptible.The mode of action of apholate and hempa in the induction of chromatid aberrations in mice, their localization and non-random distribution are discussed. The role of the aziridine groups in inducing aberrations has been considered. It is suggested that the breaks were due to some direct action and that the chromatids of mice contain some weaker regions.
DIRECT AND MATERNAL GENETIC RESPONSES RESULTING FROM SELECTION FOR 12-DAY LITTER WEIGHT IN MICE
Authors: Elsen E. J.
Published: November 2014

Response to selection for 12-day litter weight in mice was evaluated in terms of average direct and average maternal genetic responses. Comparisons were made among selected and control parental lines, reciprocal F1crosses, F2's and backcrosses. Selection response in 12-day body weight was primarily due to average direct genetic effects. Correlated responses in body weight at 21, 31, 42 and 70 days also were due to average direct effects. Average maternal genetic effects contributed little to direct or correlated weight responses. Heterosis for direct genetic effects was not significant for 12- and 21-day body weights but was important for postweaning weights. In contrast, heterosis for maternal genetic effects was important at 12 and 21 days but declined after weaning. These results suggest that the maternal genetic influence on neonatal mammalian growth may play a key role in fitness of the offspring. Thus, natural selection would tend to reduce additive maternal genetic variance, leaving mainly non-additive maternal genetic variance. This, coupled with the large maternal environmental component influencing neonatal growth, suggests that selection for additive direct effects influencing preweaning growth in livestock would be most efficiently carried out by standardizing or eliminating the postnatal maternal environment.
IN VIVO EFFECTS OF VINBLASTINE AND PODOPHYLLIN ON DIVIDING CELLS OF DBA MOUSE FETUSES
Authors: Joneja M. G. , LeLiever W. C.
Published: November 2014

Vinblastine (highly teratogenic) and podophyllin (non-teratogenic) each induced significant accumulations of metaphase plate in fetal and maternal tissues when injected intraperitoneally into day 9 pregnant DBA mice. Chromosome fragments and bridges also were slightly more frequent in the treated fetuses than in the controls. These findings clearly indicate that both compounds or their products can easily cross the placental barrier and that metaphase arrests do not necessarily lead to teratogenic effects. Prolonged persistence of the mitotic block and the presence of extensive necrosis in podophyllin-treated fetuses contrasted with the vinblastine results and suggest that teratogenicity may result from the recovery pattern rather than the initial lesion.
SOME OBSERVATIONS ON THE DISTRIBUTION AND MOLECULAR ARRANGEMENT OF NUCLEIC ACIDS IN SALIVARY GLAND NUCLEI OF DROSOPHILA MELANOGASTER
Authors: Gersh Eileen Sutton , Gersh Isidore
Published: November 2014

A new technique is described for preparation of salivary gland chromosomes for viewing with the electron microscope, with selective staining of nucleic acids. The DNA double helix is coiled in a second order helix with period and diameter of about 400A. These secondary helices are aggregated in compact masses in bands, especially in the proximal heterochromatic regions. Larger bands, however, consist of alternating DNA-rich and RNA-rich lamellae and the DNA is compacted only in the DNA-rich lamellae. In RNA-rich lamellae, as well as in interbands and puffs, the second order helices are separated from one another. In the nucleolus the DNA secondary helices form small aggregates. RNA-containing granules are found not only in the nucleolus but also in the nucleoplasm, especially around chromosomal puffs, and also in the puffs, in interbands, and in the RNA-rich lamellae of bands.
CHROMOSOME PAIRING IN POA ANNUA L.
Authors: Ellis W. M. , Lee B. T. O. , Calder D. M.
Published: November 2014

Cytological studies carried out on six tetraploid and one diploid population and a synthesized tetraploid plant have shown regular bivalent formation at meiosis. This regularity appears to be genetically controlled in this species. Plants from all the populations behave as diploids. The implications of this regular disomic chromosome pairing on recombination, variation and the breeding system of P. annua are considered.
BEHAVIOUR OF NEUROSPORA TETRASPERMA MATING-TYPE GENES INTROGRESSED INTO N. CRASSA
Authors: Metzenberg Robert L. , Ahlgren Sandra K.
Published: November 2014

The two alleles of the mating-type gene of Neurospora tetrasperma have been introgressed into a largely N. crassa genetic background. Under these circumstances, they are no longer able to coexist without inhibition in heterocaryons, nor can they do so with their opposite mating-type allele from N. crassa. Neither are they compatible with the latter in partial diploids heterozygous for the mating-type alleles. The implications of this are briefly discussed.
DIFFERENTIAL GIEMSA STAINING OF THE TELOMERES OF ALLIUM CEPA CHROMOSOMES: OBSERVATIONS RELATED TO CHROMOSOME PAIRING
Authors: Stack S. M. , Clarke C. R.
Published: November 2014

We have used a Giemsa staining technique, which is thought to indicate the site of repetitive DNA and constitutive heterochromatin, to stain the telomeres of Allium cepa chromosomes differentially. These differentially stained telomeres are equally visible throughout the mitotic cycle including interphase. We observed fusions of telomeres that included both homologous and non-homologous associations. Evidence that repetitive DNA plays a role in chromosome pairing is presented.