bluuebunny/crossref_metadata_2025 huggingface dataset:
MORPHOLOGICAL AND CYTOLOGICAL CHANGES INDUCED IN BARLEY (HORDEUM VULGARE) SEEDLINGS FOLLOWING SEED TREATMENT WITH FUNGICIDES
Authors: George Mary K. , Aulakh Kirpal S. , Dhesi Jagtar S.
Published: November 2014

The treatment of barley seed with five fungicides (Brassicol, Ceresan Wet, Thiram, Ziram and Aureofungin) induced both morphological and cytological abnormalities. Germination was reduced up to 10 days over controls and a reduction in seedling height occurred. Chromosomal abnormalities consisted of fragments, aneuploidy, bridges, lagging and unequal distribution of chromosomes, tripolar spindles and spindle inhibition. Of the fungicides tested, Ziram was most effective in producing morphological and cytological abnormalities.
DIFFERENTIAL DNA REPLICATION IN THE XX AND XY CELLS OFMUSCA DOMESTICAL.OCRASTRAIN
Authors: Jan K. Y. , Boyes J. W.
Published: November 2014

The karyotype of Musca domestica L. ocra strain, consists of the sex chromosomes and five autosomal pairs. The heteromorphic sex chromosomes are heterochromatic and mitotically unpaired, whereas the autosomes are euchromatic and mitotically paired. All autosomal pairs and both X and Y chromosomes are cytologically recognizable.The relative labelling rate, R (in terms of the number of grains counted per 100 labelled metaphases per μ of chromosome length) for the sex chromosomes and for each autosomal pair was followed from 1.5 hours to 8 hours after H3TdR injection. The pattern of labelling rate was similar for the different autosomal pairs in the XX cells but this pattern for the autosomal pairs in the XY cells, though also similar for the different pairs, differed appreciably from that found in the XX cells. The pattern of the labelling rate for the X chromosomes was similar in the XX and XY cells. Also the pattern of labelling rate for the X and Y chromosomes was similar during the final part of the replication period. The two X chromosomes in the XX cells and the X and Y chromosomes in the XY cells completed labelling later than the autosomes.
INHERITANCE OF OAT STEM RUST RESISTANCE IN A TUNISIAN STRAIN OF AVENA STERILIS
Authors: McKenzie R. I. H. , Martens J. W. , Rajhathy T.
Published: November 2014

The strain CW490-2 of Avena sterilis L. possesses a single recessive gene, pg-13, for oat stem rust resistance. It confers resistance to a wide range of stem rust races. Gene pg-13 is not linked to Pg-1 or pg-9 but appears tightly-linked or allelic with Pg-4. A high level of sterility in the progeny of crosses between Avena sativa varieties and CW490-2 is apparently due to four interchange differences.
ANEUPLOIDS FROM NATURAL AND COLCHICINE-INDUCED AUTOTETRAPLOIDS OFSOLANUM
Authors: Hermsen J. G. Th. , Wagenvoort M. , Ramanna M. S.
Published: November 2014

Haploids grown from unfertilized egg cells of autotetraploid Solanum (4x = 48) were found to be either euploid (2x = 24) or hyperploid (25 through 28 chromosomes), the proportion of hyperploids being 7.6% for S. tuberosum Group Tuberosum, 1.5% for S. tuberosum Group Andigena and 9.4% for the colchicine-induced autotetraploid S. chacoense. Female transmission of the extra chromosome in eight single trisomics varied from 10.0 to 47.1%. Pachytene analysis was carried out in one clone with 27 chromosomes and in two single trisomic clones from S. chacoense. The three extra chromosomes in the first clone were identified as chromosome 2 (nucleolar chromosome), chromosome 5 and chromosome 9 following the numbering system of Yeh and Peloquin (1965). One single trisomic appeared trisomic for chromosome 5, the other probably for chromosome 7. Association of the chromosomes at MI, AI and AII was studied in eight single, two double and one triple trisomic plants. Two plants showed desynapsis. From the meiotic studies of the synaptic trisomics it was apparent that all arc primary trisomics.
PTERIDINES IN THE TU-H STRAIN OFDROSOPH1LA MELANOGASTER
Authors: Knowles Barbara
Published: November 2014

Sepiapteridine was found in higher concentration in the eyes and bodies of females from the tu-h strain than in wild-type females. After inclusion of a large number of pteridine mutants in the tu-h background, it was found that only the purpleoid mutant appeared to act synergistically with the tu-h background in producing a higher concentration of sepiapteridine in the bodies of both homo- and heterokaryotypes containing homozygous purpleoid second chromosomes. As the productivity of these females is extremely low, a correlation between high concentrations of sepiapteridine and decreased female productivity is suggested, although this is not felt to be a cause-effect relationship, but a pleitropic manifestation of a single unknown defect.
GENOTYPE VERSUS POPULATION FITNESS
Authors: Thoday J. M.
Published: November 2014

It is pointed out that the concepts of fitness discussed by F. J. Ayala and by J. M. Thoday are quite different concepts which should not be confused. Ayala's conclusion that Thoday's definitions imply that fitness will always decrease with time is not correct.
EARLY GENERATION TESTING AS A MEANS OF PREDICTING THE VALUE OF SPECIFIC CHROMOSOME SUBSTITUTIONS INTO COMMON WHEAT
Authors: McEwan J. M. , Kaltsikes P. J.
Published: November 2014

Two experimental methods were used in an attempt to establish tests by which the value of whole chromosomes for substitution could be determined. The first of these, the F1 method, depended on the comparison of the performance of reciprocal F1 monosomic × disomic hybrid combinations, in which the univalent chromosome from the two different sources was tested against the uniform genetic background provided by the F1 hybrid. The second method, the F3 bulk method, involved the establishment of the chromosome pair under test in a pure state in a F3 hybrid bulk by the use of the appropriate monosomic line. This material was tested against the F3 hybrid bulk of the parental varieties in which all the chromosomes were freely segregating, and also against existing substitution lines.The F1 method demonstrated marked differences between homologous chromosomes of different varieties when they were tested in the univalent condition for the characters investigated. From these differences the homologous chromosomes of the varieties could, in some cases, be arranged in a linear order of performance, an order which may indicate their relative contribution if they were used in the production of substitution lines.The F3 bulk method did not reveal appreciable differences between the chromosome lines studied and therefore could not be used as a predictive method.
SCALING EFFECTS AND THE INHERITANCE OF JUVENILE BODY WEIGHT IN CHICKENS
Authors: Carte I. F. , Siegel P. B.
Published: November 2014

Data are presented for 10 generations of selection for high and low body weight at 8 weeks of age. The response of males was greater than that of females in the high weight line, but not in the low weight line. The asymmetrical response of sexes in the high weight line was eliminated by adjustment for scaling effects. Although heritabilities were greater in the high line than in the low line, they were essentially equal for both sexes within a line.
CYTOLOGY OF INTERSPECIFIC HYBRIDS IN SINNINGIA AND RECHSTEINERIA (GESNERIACEAE)
Authors: Clayberg Carl D.
Published: November 2014

The nature of meiosis in artificial interspecific hybrids of Sinningia and Rechsteineria is described, confirming the validity of cenospecies previously identified by pollen stainability. Metaphase I pairing is given for 25 hybrids involving 19 species. The importance of cenospecies to redefining generic and sectional limits is discussed, and it is recommended that additional sections be combined.
LEAKY MUTATION AND COORDINATE REGULATION OF THE ACCUMULATION OF LYSINE-PRECURSORS INSACCHAROMYCES
Authors: Bhattacharjee Jnanendra K.
Published: November 2014

One of the lysine auxotrophs (ly12) of Saccharomyces exhibits a residual ability (leakiness) to grow in minimal medium. This mutant accumulates homocitric, cis-homoaconitic and homoisocitric acids both in presence and in absence of lysine. These intermediates accumulate behind the biochemical block and overflow into the culture medium. Accumulation of these intermediates is reduced significantly and simultaneously in presence of lysine compared to the minimal medium.
CHROMOSOME PAIRING IN TWO INTERSPECIFIC HYBRIDS OF TRIFOLIUM
Authors: Chen Chi-Chang , Gibson Pryce B.
Published: November 2014

Both Trifolium repens (2n = 32) and T. nigrescens (2n = 16) formed bivalents during meiosis. However, their triploid hybrid showed an average of 4.27 trivalents per microsporocyte at metaphase I. The frequency of trivalents in the hybrid between T. nigrescens and autotetraploid T. occidentale (2n = 32) was 5.69. The data are interpreted to indicate: (1) a possible autotetraploid origin of T. repens; and (2) a close phylogenetic relationship among T. repens, T. nigrescens and T. occidentale.
MATERIAL AND GENIC CYTOPLASMIC DIFFERENCES IN RECIPROCALLY CROSSED TOMATOES
Authors: Shumaker James R. , Davis D. W. , Currence T. M.
Published: November 2014

A series of generations was synthesized to study reciprocal differences for three developmental periods, early yield and fruit size in tomatoes. A small fruited early cultivar, Johnny Jumpup, and a large fruited later cultivar, Bounty, were used as parents. From individual cloned parent plants and their reciprocal F1's, all possible first backcross and F2lines were derived. Maternal effects were demonstrated in BC1lines for each of three periods and for early yield. Increased earliness was expressed rather uniformly by BC1lines derived from F1females over those derived from either of the parental females.Genic-cytoplasmic differences were demonstrated in BC1lines for each of three development periods and for early yield. Earliness for each of these characters was associated with lines having common cytoplasmic-recurrent parentage, over those not having common such parentage. Magnitudinally, the differences were more closely associated with the Johnny Jumpup cytoplasmic-Bounty recurrent parent line than with the converse.Similarity in direction and magnitude of differences in F1and F2lines indicated that matroclinous reciprocal F1differences for the development periods and early yield were persistent through the F2. Therefore, the association of cytoplasm with an F1genotype, rather than maternal effects, appears to be the primary cause of differences for earliness in F1's resulting from reciprocal crosses. The larger fruited, earlier parent should be used as the female in F1hybrid seed production, if other considerations do not predominate.
THE IDENTIFICATION AND MEIOTIC BEHAVIOR OF A DITELOSOMIC LINE IN AVENA SATIVA L
Authors: Dubuc J. P. , McGinnis R. C.
Published: November 2014

A ditelosomic line was crossed with 12 identified monosomics. The metaphase I pairing was studied in the 40 + t – chromosome progenies. The telocentric chromosome was found to be homologous to the three previously identified monosomics namely, −7, −10, and −20 suggesting that the same chromosome is missing in all three lines. None of the chromosomes in monosomic condition used in the crosses except ST-7 and ST-17 from A. byzantina were involved in the reciprocal translocation present between Sun II and Garry and Rodney.The gene for normal vs. abaxial curling of the leaves was located on the short arm of chromosome 20. The genes for diploidisation and normal vs. kinky neck were located on 20L.
REGION-SPECIFIC RECOMBINATION IN THEan1-bz2INTERVAL IN MAIZE
Authors: Goldman S. L. , Coe Jr. E. R.
Published: November 2014

Study of coincidence data has revealed another occurrence of region-specific recombination in maize. In this experiment, when region 2 (an1-bz2) was involved in crossing over, it was involved unusually often in multiple exchanges. The models of effective pairing and fixed pairing regions were evaluated as possible explanations for the phenomena involved. These models proved to be unsatisfactory; it was therefore considered that the recombinational events were due to gene conversion.
ULTRAVIOLET LIGHT SENSITIVE MUTANTS OFUSTILAGO VIOLACEA
Authors: Day Alan W. , Day Lynne L.
Published: November 2014

Nine UV-sensitive mutants of U. violacea have been isolated and shown by analysis of complementation and recombination to represent four to five genes. Genes uvs-1 and uvs-3, unlike the other genes and the wild type, are incapable of postirradiation recovery on water agar and are therefore assumed to be deficient in dark repair. Gene uvs-2 does not affect dark repair but may affect photoreactivation. Mutants u7 and u9 which may represent one to two genes are defective in photoreactivation but not in dark repair. The dark recovery process on water agar is inhibited by caffeine.The survival of UV-sensitive mutants during intergenic complementation in a dicaryon was close to that of the wild type. This efficient complementation establishes that the repair enzymes are freely diffusible in the cytoplasm. None of the mutants are linked closely to each other or to the other marker genes used.
FLAVONOIDS ASSOCIATED WITH SPECIFIC GENE ACTION IN MAIZE ALEURONE, AND THE ROLE OF LIGHT IN SUBSTITUTING FOR THE ACTION OF A GENE
Authors: Kirby L. T. , Styles E. D.
Published: November 2014

A number of genes are known to be involved in the production of anthocyanin in maize aleurone. Thin layer chromatography has been used to detect specific flavonoids associated with the recessive forms of these genes. The results obtained so far indicate that the genes C1, C2, R and Pr all act before the formation of flavonol in the biosynthetic pathway, that A1 acts between flavanonol and 'flavenol' and that A2 acts between flavenol and anthocyanidin. Light substitutes for the action of the C1 gene in certain conditions and can be used to 'force' the system, causing a buildup of intermediate and side products beyond the C1 controlled step. The C1 gene probably controls a step between the C9 stage and flavanone.
PARAMUTATION OF THERLOCUS IN MAIZE TRISOMICS AND COMPARISON OF PARAMUTATION SYSTEMS IN MAIZE AND TOMATO
Authors: Styles E. D.
Published: November 2014

There is no effect of paramutable R allele dosage on the amount of paramutational change promoted by one paramutagenic allele in maize plants trisomic for chromosome 10 in which the R locus resides. It has been confirmed that paramutation at the R locus is not affected by chromosome 10 trisomy if one of the chromosomes carries a rgallele, which is a 'null' element with respect to paramutation. Paramutation systems at the R locus in maize, the B locus in maize, and the sulf locus in tomato, are compared.
THE ESTABLISHMENT AND CHROMOSOME ANALYSIS OF A NEW CELL LINE OF CHINESE HAMSTER FROM SPONTANEOUS TRANSFORMATION IN VITRO
Authors: Lin C. C. , Chang T. D. , Niewczas-Late Virginia
Published: November 2014

A male Chinese hamster cell line has been established through spontaneous transformation in a skin culture. Chromosome studies at passage 13 revealed one major and one minor type of pseudodiploid cells (77.3 and 20%). At passage 42, only the major subline persisted (78%). The two sublines, especially the major one, had selective advantage over other cell types in this cell line probably because they were more nearly genetically balanced. Autoradiographic studies indicated no overall increase in late replicating chromosomal elements in the two sublines. Both cell types lacked the X chromosome and chromosome 6, but they were largely compensated for by the presence of new marker chromosomes. However, more chromosomal material was missing in the minor type than in the major type, and this may account for the lower adaptability of the former.
STRAWBERRY SELECTION INDEX COMPONENTS
Authors: Watkins R. , Spangelo L. P. S.
Published: November 2014

Limiting values for the additive and non-additive variance components were estimated for the cultivated strawberry for mildew resistance, flower stalk number, berry appearance, berry numbers, marketable yield, leaf scorch, processing desirability, and for a discriminant function selection index involving the seven basic characters. It was estimated that, for the average of the seven characters and for the index, non-additive variance constituted as much as 40% of the total genetic variance. A method of attaining genetic progress significantly better than the commercially important Redcoat cultivar was suggested. It involved using a discriminant function selection index and a two-step selection procedure first applying progeny selection and then individual selection.
GENETIC NATURE OF TWO INDEXES OF COMPATIBILITY IN ALFALFA
Authors: Singh S. M. , Lesins K.
Published: November 2014

Seven clones selected for their high seed and forage yielding ability were crossed in a diallel manner to obtain the estimates of GCA, SCA and reciprocal effects of the parental clones in various hybrid combinations. The analysis of the diallel crosses revealed that the variances for GCA, SCA and reciprocal effects were significant (0.01 level) for percentage of pod set during the crossing program. Number of seeds per pod set were significant for the general combining ability. The general combining ability appeared to be of greater importance for both the characters studied, and the additive genetic variance seems to constitute approximately 63% of the total variance for percentage of pod set and 71% of the total variance for number of seeds per pod set. However, wide differences were found among the clones in the relative magnitude of GCA, SCA and reciprocal effects for both traits.
ASSOCIATION OF KARYOTYPE WITH BODY WEIGHT AND RESISTANCE TO DESICCATION INDROSOPHILA PSEUDOOBSCURA
Authors: Thomson J. A.
Published: November 2014

The effect of karyotype on body weight and resistance to desiccation has been examined for the Standard (ST) and Chiricahua (CH) gene arrangements of Drosophila pseudoobscura obtained from Mather, California. Mean body weights fall in the order ST/CH > CH/CH > ST/ST, and variability of body weight in the order CH/CH > ST/ST > ST/CH in adult flies of both sexes. The relative resistance to desiccation in mass survival tests at 0% relative humidity, without food, is [Formula: see text] in males and [Formula: see text] in females. Karyotype has an effect on survival under desiccation, apart from its effect on body size.The data provide a further example of pronounced heterosis associated with a gene-arrangement polymorphism under extreme environmental conditions.
EVIDENCE FOR AN EFFECT OF 5-FLUORODEOXYURIDINE ON CELLS IN THE G2 PHASE OF THE MITOTIC CYCLE
Authors: Socher S. H. , Davidson D.
Published: November 2014

Roots of Vicia faba were treated with 5-fluorodeoxyuridine (FUdR) for 3 hr. This compound has been used as a selective inhibitor of DNA synthesis but evidence is presented that it also arrests cells in G2 and prevents them from progressing to mitosis. Even with 10−7M solutions, inhibition is evident by 2 hr. The blockage of G2 cells occurs both in cells with a G2 of long duration (> 12 hr) and short duration (3.3 hr). The result is that any estimate of the duration of G2 in cells treated with FUdR is an underestimate. It appears that treated cells have a shorter G2 than have untreated cells but, in fact, it has been considerably extended. It is unclear why a compound that supposedly specifically inhibits DNA synthesis, by preventing the formation of thymidylic acid, should arrest cells that have already completed DNA synthesis and are in the G2 phase of the mitotic cycle.
THE GENETICS OF YIELD IN SPRING WHEAT (TRITICUM AESTIVUML.)
Authors: Walton P. D.
Published: November 2014

A diallel cross among eight spring wheat cultivars examined the inheritance of yield, its components, certain developmental stages and morphological characters above the flag leaf node. Additive genetic variance was important for all the characters studied. For yield, kernels per ear, ear volume and for the developmental stages considered dominance was also present. Results presented here agreed with the main conclusions drawn in four other diallels crosses which were reported previously.
AN INTERSPECIFIC DIPLOID HYBRID OF LOTUS (LEGUMINOSAE) WITH A B CHROMOSOME
Authors: Somaroo B. H. , Grant W. F.
Published: November 2014

The meiotic behavior of a B chromosome observed in an interspecific hybrid of Lotus (L. alpinus Schleich. × L. filicaulis Dur.) is briefly described. The B chromosome was also present in root tip cells. This is the first report of the occurrence of such a chromosome in this genus.
HOMOEOALLELISM IN TRITICUM AESTIVUM
Authors: Washington W. J.
Published: November 2014

EMS-induced and naturally occurring chlorophyll mutations on homoeolgous chromosomes were tested for homoeoallelism. In F1's of crosses between phenotypically similar recessive chlorophyll mutations, the mutant genes complemented each other only partially or not at all, indicating that the mutant genes are functionally similar, although located on chromosomes with different evolutionary histories. Thus they cannot be called alleles. This type of relationship is referred to as homoeoallelism. The chlorina mutations, chlorina-1 on chromosome 7A, chlorina-448 on 7B and chlorina-214 on 7D, presumably represent a homoeoallelic series. Viridis-508 on chromosome 3A and Neatby's virescent on 3B are also homoeoalleles. These loci are presumably identical in ancestry.
CHROMOSOME RELATIONSHIPS BETWEEN TETRAPLOID (2n=28) AVENA MURPHYI AND SOME DIPLOID, TETRAPLOID AND HEXAPLOID SPECIES OF OATS
Authors: Ladizinsky Gideon
Published: November 2014

On combined evidence of cytology and morphology it is apparent that the newly discovered tetraploid Avena murphyi shares a common genome with the tetraploid A. magna. Lack of crossability and limited pairing in triploid hybrids involving A. murphyi indicate that none of the presently known diploid oats participated in the formation of A. murphyi. Meiotic behavior of A. murphyi × A. sativa pentaploid hybrids shows considerable homology between the chromosomes of the parents. The origin of the hexaploid oats is discussed in the light of the cytogenetic status of A. murphyi.
INHERITANCE OF CROWN RUST RESISTANCE GENES IN AVENA STERILIS COLLECTIONS FROM ISRAEL, PORTUGAL, AND TUNISIA
Authors: Fleischmann G. , McKenzie R. I. H. , Shipton W. A.
Published: November 2014

The inheritance of genes in three collections of Avena sterilis wild oats conferring resistance to races 216, 264, 295, 305, 326, 330, 332, and 446 of crown rust, Puccinia coronata avenae, was investigated. C. I. 8081 from Portugal contained a partially dominant gene, designated Pc47, which conferred resistance to all eight races. CW486 from Tunisia had a dominant gene, designated Pc50, which gave resistance to all races except 295, 326, and 446. F158 from Israel had two dominant genes; one, designated Pc48, conferred resistance to all the races but 305, while the second, designated Pc49, conferred resistance to races 216, 326, 330, 332, and 446. Genes Pc47, Pc48, Pc49, and Pc50 were inherited independently of each other and of those genes previously isolated from A. sterilis.
NON-RANDOM CHROMOSOME ASSOCIATIONS AT DIPLOTENE AND DIAKINESIS IN A TETRAPLOID CLONE OFVACCINIUM AUSTRALESMALL
Authors: Jelenkovic G. , Harrington E.
Published: November 2014

In a cultivated tetraploid genotype (2n=4x=48) of Vaccinium australe Small the chromosome associations at late prophase of the first meiotic division and the separation of the chromosomes at anaphase I and anaphase II were investigated.Of the 223 PMC's analyzed one quarter of them displayed only bivalent associations; the remaining displayed both bivalent and quadrivalent associations. In about 3% of the PMC's, hexavalents were observed. No univalents, trivalents or pentavalents were found. The non-randomness of the chromosome associations is interpreted as resulting from obligatory pairing and localized distal chiasma.In spite of multivalent formation, in 115 PMC's studied, separation of the chromosomes at anaphase I is regular and in 95 daughter nuclei 24 chromosomes were counted. At anaphase II, the great majority of the nuclei revealed regular separation of the chromosomes and consequently numerically balanced gametes are produced.
GENETIC STUDIES OF ISOZYMES IN NEUROSPORA. I. A STUDY OF EIGHT SPECIES
Authors: Reddy M. Mohan , Threlkeld S. F. H.
Published: November 2014

Mycelial extracts of 34 strains representing eight species of the genus Neurospora were subjected to acrylamide and starch gel electrophoresis to detect sites of esterase, lactate dehydrogenase, amylase, peroxidase, and acid phosphatase activity. Nine isozymes of esterases, four isozymes of lactate dehyrogenases, three isozymes of peroxidases, and two isozymes of acid phosphatases were detected on the gels for the species. The application of zymograms as a biochemical means to characterize species is discussed.
INVERSION POLYMORPHISM INCHIRONOMUS STAEGERILUNDBECK
Authors: Martin Jon , Wülker W.
Published: November 2014

Populations of Chironomus staegeri are polymorphic for inversions in six chromosome arms. Many of these inversions do not conform to Hardy-Weinberg expectation, often with a significant deficiency of heterozygotes. Many combinations of the inversions two-at-a-time show a significant deviation from random assortment. Often this is due to the occurrence together in the same individual of rare sequences, but others, such as the association of sequences A1and C1, A2and C2, and A2and B4appear to be real effects.There is a marked dimorphism in the inversion sequences present in populations from deep water and those from shallow water in the northeastern U.S.A. and Canada. This may be associated with ability to withstand winter freezing.It is possible that a process of speciation, leading eventually to three different species, is in progress and a considerable degree of reproductive isolation may have already been achieved.
FUSION AND DIVISION OF NUCLEI IN MULTINUCLEATED SOYBEAN PROTOPLASTS
Authors: Miller R. A. , Gamborg O. L. , Keller W. A. , Kao K. N.
Published: November 2014

Protoplasts were produced from a soybean cell culture by enzymatic removal of the cell wall. The protoplasts were fixed after various periods of culture. There was a large amount of protoplast fusion during formation. The nuclear behaviour during division was observed. Nuclear fusion prior to nuclear division was common. Almost complete synchronization of multinucleates was found. Various abnormalities were present in nuclear and cellular division which could have led to aneuploid production.
MATING GROUP RATIOS IN DISTYLIC FORSYTHIA (OLEACEAE)
Authors: Sampson D. R.
Published: November 2014

A ratio of 3 thrums: 1 pin in a progeny from selfing a thrum plant of F. ovata, and ratios of 1:1 from eight crosses involving F. ovata, F. europaen, F. suspensa and the garden hybrid F. × intermedia support the hypothesis that the mating system is controlled by one locus, thrums being Ss and pins ss. However two crosses gave ratios of 2:1, and 1:2 instead of 1:1.
HERITABILITY AND GENETIC VARIANCE COMPONENTS FOR 20 FRUIT AND PLANT CHARACTERS IN THE CULTIVATED STRAWRERRY
Authors: Spangelo L. P. S. , Hsu C. S. , Fejer S. O. , Bedard P. R. , Rousselle G. L.
Published: November 2014

Heritability and genetic variance components for 20 fruit and plant characters were investigated in 64 progenies produced among 31 North American and 1 German strawberry clone under the crossing scheme similar to North Carolina Design II (Comstock and Robinson, 1952). The data were analyzed based on the assumption of random and/or mixed models of the parents. The estimation of the genetic variance components indicated that for more than half the 20 characters nonadditive variance (dominance + epistasis) constituted approximately 50% or more of the total genetic variance and that in most cases epistasis played an important role in the nonadditive variance. Heritability estimates were low (less than 18%) for total berry yield and some fruit quality characters such as firmness, easy capping, pH value, soluble solids, and external and internal appearances but were high (more than 37%) for a number of yield component characters such as average berry weight, berries/flower stalk, yield/flower stalk and flower stalk number, suggesting that substantial improvement in total berry yield could be achieved through selection on these yield components or a linear function of them.
INHERITANCE AND LINKAGE STUDIES WITH THE GRANDPA GENE IN BARLEY,HORDEUM VULGAREL.
Authors: Matchett R. W. , Nass H. G. , Robertson D. W.
Published: November 2014

This study was initiated to determine the chromosomal location of the grandpa (gp) gene within the barley genome. The gp gene was placed on the long arm of chromosome 2 as indicated by linkage association with liguleless (li).Tests of allelism showed the gp gene to the allelic with the gp-2 gene. Seven sources of "yellow" chlorophyll mutants when crossed to grandpa plants gave albino double recessive seedlings. Three other sources of "yellow" chlorophyll mutants in the double recessive combination with grandpa exhibited yellow and white bands on the leaves. Double recessive individuals carrying the mottled (mt2) and grandpa genes were also albino. This is evidence of gene interactions between chlorophyll mutant genes.
HUMAN MALE MEIOSIS: CHROMOSOME BEHAVIOUR AT PRE-MEIOTIC AND MEIOTIC STAGES OF SPERMATOGENESIS
Authors: McDermott Alan
Published: November 2014

Normal testicular material was obtained from 53 men. The morphology and behaviour of the chromosomes during pre-meiotic and meiotic stages of spermatogenesis are described in detail. Three types of spermatogonial metaphase chromosome have been identified; they are thought to be from spermatogonia of different generations. Homologous chromosomes appear to be paired at the beginning of spermatogonial prophase, and at the onset of the meiotic prophase (leptotene). Bivalents assume a "lampbrush" appearance during mid- to late pachytene.
KARYOTYPE ANALYSIS OF HEXAPLOID TRITICALE
Authors: Shigenaga S. , Larter E. N.
Published: November 2014

Karyotype analysis of hexaploid triticale cultivar 'Rosner' (2n = 42 = AABBRR) revealed that its chromosome complement consists of five satellited, five median, nine submedian, and two subterminal chromosomes. In addition to Rosner, the karyotype of the F1 hybrid (2n = 28 = ABRR) obtained from the cross between Rosner and rye cultivar 'Prolific' was analysed. Since in the ABRR hybrid only the chromosomes of the R genome were present in pairs, it was possible to classify the chromosomes of rye separately from the single chromosomes of the A and B genomes of wheat. From the idiogram constructed from these studies it was demonstrated that the rye chromosomes of the Rosner karyotype were the longest of the entire haploid complement; three of these were satellited, two were median, and two were submedian in structure.
IDENTIFICATION OF CHROMOSOMES CONTRIBUTING TO ANEUPLOIDY IN HEXAPLOID TRITICALE, CULTIVAR ROSNER
Authors: Shigenaga S. , Larter E. N. , McGinnis R. C.
Published: November 2014

Detailed karyotype analyses were conducted on root-tip cells of aneuploid plants of hexaploid triticale, cultivar 'Rosner.' Although complete meiotic stability in this cultivar has not as yet been achieved, it currently represents the standard for triticale improvement in Canada. Rosner characteristically exhibits an average of 0.8 univalents per cell at metaphase I and approximately 10% of its progeny are aneuploid. The results of the present study clearly indicated that both wheat and rye chromosomes of the triticale complement contribute to the aneuploid condition, not primarily those of rye as believed earlier.
DIURNAL RHYTHMS IN MITOSIS OF CELLS OF THE ONION ROOT TIP MERISTEM
Authors: Bishop Richard C. , Klein Richard M.
Published: November 2014

Seeds of Allium cepa were grown in complete darkness at constant temperature. The root tips, collected from hours 72 to 96 after the start of imbibition, exhibited four maxima and four minima in mitotic activity. The timing of this rhythm was dependent upon the time of imbibition and not upon the time of day.
A CHROMOSOMAL ANALYSIS OF X-RAY INDUCED GENETIC VARIANCE OF WING LENGTH INDROSOPHILA MELANOGASTER
Authors: Kidwell J. F. , Tracey M. L. , Glaser P. , Kidwell M. M.
Published: November 2014

A chromosomal analysis of genetic variation in wing length of Drosophila melanogaster was done using an isogenic line and a single derived irradiated line which differed significantly in wing length. Partitioning of the variance indicates no difference between X-ray induced genetic variance and that from other sources. Furthermore, the amount of additive variance is strongly dependent on chromosome frequency, and sex differences are present in all components.
ALLELIC SEX DETERMINATION IN A LOWER HYMENOPTERAN,NEODIPRION NIGROSCUTUMMIDD
Authors: Smith S. G. , Wallace D. R.
Published: November 2014

In the course of breeding from an original pair of N. nigroscutum, diploid ♀ ♀ (2n = 14), in addition to haploid ♀ ♀ (n = 7), were found by weighing the fourth generation of offspring. Diploid ♀ ♀ occurred only among the progeny of mated ♂ ♂, the progeny of virgins consisting solely of haploid ♀ ♀. Diploid ♀ ♀ are usually 20–30% heavier than their haploid brothers and are produced at the expense of sisters. The haploid ♀ ♀ mated readily but only 1 diploid ♀ out of 150 achieved successful copulation, as shown by the production of ♂ ♂. The ♂ ♂ produced were triploid (3n = 21} and as expected proved highly sterile. Although diploid ♀ ♀ have been known for about 45 years in some of the higher Apocrita, this is the first time they have been recorded in the primitive Symphyta. Pedigree analysis shows that the founding parents carried three complementary sex alleles, a, b, and c. Biparental heterozygotes, a/b, a/c, b/c, are ♂ ♂; biparental homozygotes, a/a, b/b, c/c, diploid ♀ ♀; and impaternate hemizygotes, a, b, c, haploid ♀ ♀.
BIOMETRICAL ANALYSIS WITH TWO OR THREE GENE LOCI
Authors: Jana S.
Published: November 2014

A linear combination model proposed by Seyffert (1966) has been applied for estimating the first-degree genetic parameters specifying additive, dominance and epistatic effects of two and three gene loci affecting quantitatively inherited characters. Using the data from some recently published reports, it has been found that a large part of epistatic gene action remains undetected by the standard biometrical techniques like factorial and diallel methods of analysis. These methods usually tend to overestimate the role of additive gene action in the inheritance of metrical characters. It is suggested that characters with less complex biological causes of variation tend to show more additive genetic effect than relatively more complex traits.
GENETIC SUPPRESSION OF HOMOEOLOGOUS CHROMOSOME PAIRING IN HEXAPLOID WHEAT
Authors: Driscoll C. J.
Published: November 2014

Greater genetic complexity has been revealed for the control of bivalency in hexaploid wheat. A suppressor of homoeologous pairing has been detected on chromosome 3A. Thus, there are two suppressors in homoeologous group 3. The 3A suppressor may be homoeoallelic to either the suppressor on 3Dβ or the promoter, detected in this study, on 3Dα. Individually these two suppressors are less effective than the suppressor on the long arm of chromosome 5B; however, their combined effect is yet to be studied. This greater complexity suggests that hexaploid wheat may not be too dissimilar to other polyploids as regards genetic control of bivalency. The mode of action of these suppressors appears to be consistent with a heteromultimeric hypothesis.
RECOMBINATION AT THE Ml-a LOCUS IN BARLEY CONDITIONING RESISTANCE TO ERYSIPHE GRAMINIS F. SP. HORDEI
Authors: Jørgensen J. Helms , Moseman J. G.
Published: November 2014

Attempts were made to recombine the dominant or semidominant resistance genes Ml-a, Ml-a3, Ml-a8 and Ml-a9 from the barley varieties Algerian Ricardo, Heil's Hanna and Monte Cristo, respectively. No recombinants with two resistance genes in the coupling phase were found in a total of 3117 test-cross seedlings from four crosses studied. The true recombination percentages between the genes Ml-a/Ml-a3, Ml-a/Ml-a8, Ml-a/Ml-a9 and Ml-a8/Ml-a9 are between zero and 0.5. One possible recombinant susceptible to Erysiphe graminis f. sp. hordei suggests that the recombination percentage between the recessive genes ml-a/ml-a8 is 0.083.
VARIATIONS BETWEEN STRAINS OF DROSOPHILA MELANOGASTER AND D. SIMULANS IN GIVING OFFSPRING IN INTERSPECIFIC CROSSES
Authors: Parsons P. A.
Published: November 2014

Differences between strains set up from single inseminated founder females collected in the wild were found in both Drosophila melanogaster and D. simulans, for the number of interspecific crosses giving offspring. The differences were mainly controlled by the strain of the female, but to a lesser extent by the strain of the male, especially in D. simulans. More crosses with offspring occurred over-all for female D. melanogaster strains, as compared with female D. simulans strains. The variability between strains implies that the founder females collected in the wild differ. Thus, in natural populations, there is variability determining the likelihood of offspring in interspecific crosses determined mainly by the strain of the females in the intraspecific populations.
THE DISTRIBUTION AND LOCALIZATION OF DRUG-INDUCED SECONDARY CONSTRICTIONS IN HUMAN CHROMOSOMES
Authors: Brown J. A. , Palmer C. G. , Yu P. L.
Published: November 2014

BUdR, mitomycin C and hydroxylamine hydrochloride induce secondary constrictions in particular human chromosomes. The increased frequency of constriction formation in certain chromosomes is time and drug dependent, and correlates well with the timing of DNA synthesis. The frequency at which some of these constrictions can be induced by specific drugs at specific times increases the usefulness of these landmarks in chromosome identification.
INTERACTION BETWEEN PTERIDINE SYNTHESIS AND RIBOFLAVIN ACCUMULATION INDROSOPHILA MELANOGASTER
Authors: Nickla Harry
Published: November 2014

Using chromatographic and spectrophotometric methods, riboflavin was determined to be the major component of yellow pigment in the Malpighian tubes of wild-type Drosophila melanogaster. While reduced yellow pigment accumulation in larvae of eye color mutants is consistently correlated with a reduction of drosopterin formation in adults, reduction of drosopterin synthesis is not always associated with decreased yellow pigment in Malpighian tubes.In the light mutant, reduced yellow pigment accumulation per se is not responsible for reduced drosopterin synthesis; however, a labile cytoplasmic factor associated with the light maternal effect does influence yellow pigment accumulation in Malpighian tubes.
MEIOSIS IN DIABROTICA (COLEOPTERA: CHRYSOMELIDAE): CHIASMA FREQUENCY AND VARIATION
Authors: Ennis Terry
Published: November 2014

Fifteen species of Diabrotica have been examined cytologically. Except for the variable presence of supernumeraries in three of the species, the karyotype is uniform throughout, with 18 meta- or submetacentric autosomes and an XX ♂: XO ♀ sex-determining mechanism. Chiasma frequency is quite variable; in addition to the basic nine per cell, formation of a second chiasma (in the other arm) results in ring frequencies ranging from zero to nine per cell. Analysis of chiasma frequency and distribution at diakinesis and metaphase reveals that the rings are bi-chiasmate and not the result of ectopic pairing. With this in mind, chiasma formation is discussed in terms of interference. Intra-arm interference is complete; the upper limit of chiasmata per arm is invariably one. The strength of interference across the centromere determines the probability of formation of a chiasma in the other arm. When interference is strong, a second chiasma is rarely formed; as interference weakens, a chiasma is more easily formed in the other arm, resulting in a higher chiasma frequency. Associated with decreasing interference and an elevated chiasma frequency is an increase in cell variance; chiasma formation is less rigorously controlled, and variability in the number of rings per cell increases. The variability of ring formation in the genus militates against distinguishing taxa on this basis. However, the importance of increased chiasma frequency (coupled as it is with greater variance) resides in its influence on the genetic plasticity and adaptive potential of the species.
SOMATIC CHROMOSOME NUMBERS IN CERTAIN TRIFOLIUM SPECIES
Authors: Anderson M. K. , Taylor N. L. , Collins G. B.
Published: November 2014

In the present study chromosome numbers of 13 Trifolium species were determined, making a total of 155 species for which chromosome numbers have been reported. Four species which have been reported only once were confirmed. Eleven of the 17 species observed have 16 chromosomes (n = 8). T. bocconei Savi was found to have 12 chromosomes (n = 6) and T. desvauxii Boess. and Bl. was found to have 10 chromosomes (n = 5). Karyotype analyses of T. bocconei and T. desvauxii revealed that the chromosomes of each species could be differentiated on the basis of arm ratios and chromosome lengths.
CYTOLOGICAL EFFECTS OF THE PESTICIDES PHOSDRIN AND BLADEX ON TRADESCANTIA AND VICIA FABA
Authors: Ahmed M. , Grant W. F.
Published: November 2014

The cytological effects of the insecticide Phosdrin (mevinphos) and the herbicide Bladex on root tips of Tradescantia and Vicia faba were observed and compared with those of the chemical mutagen ethyl methane sulfonate (EMS). In addition, plants of Vicia faba were sprayed prior to floral initiation and pollen mother cells examined for chromosomal abnormalities. Phosdrin and Bladex produced the same kinds of chromosome abnormalities as EMS, namely, fragments, bridges, multipolar anaphases and lagging chromosomes. Bladex produced a higher percentage (3.47%) of chromosome aberrations in root tips of Tradescantia than did Phosdrin (2.56%), but fewer in Vicia faba than did either EMS or Phosdrin. Bladex was more toxic to cells of Vicia faba. The greater percentage of chromosome fragments induced by both pesticides in Vicia faba may be the result of highly specific and localized action of the pesticides in heterochromatic regions. Vicia faba seedlings sprayed with Phosdrin had a greater percentage of chromosome aberrations in the pollen mother cells than were found in root tips after Phosdrin treatment. Bladex sprayed at the same concentration as Phosdrin (200, 400, 600 ppm) was lethal to the plants. The frequency of chromosomal aberrations induced by both pesticides deviated significantly from that of the control.
GENETIC CONTROL OF VIRULENCE IN USTILAGO HORDEI III. IDENTIFICATION OF GENES FOR HOST RESISTANCE AND DEMONSTRATION OF GENE-FOR-GENE RELATIONS
Authors: Sidhu Gurmel , Person Clayton
Published: November 2014

The genetics of resistance of three barley varieties, Excelsior (E), Hannchen (H) and Vantage (V), was investigated against two known virulence genes (Uhv-1 and Uhv-2) present in two test cultures of Ustilago hordei. Segregations obtained from F3 progenies derived from crosses EXH and EXV revealed that resistance and susceptibility to the two test cultures were inherited independently of one another; the resistance was expressed as a dominant characteristic at both loci. The host alleles discovered through the interactions with culture UhV1UhV1Uhv2Uhv2 were designated as UhR1 and Uhr1; those revealed by interactions with culture Uhv1Uhv1UhV2UhV2 were designated as UhR2 and Uhr2. The genotype UhR1UhR1Uhr2UhV2 was thus assigned to varieties Hannchen and Vantage and UhR1Uhr1UhR2UhR2 to variety Excelsior. The interrelationships between two loci for resistance in the host and the two corresponding loci for virulence in the pathogen thus lead us to conclude that a gene-for-gene relationship also exists in the Hordeum vulgare: Ustilago hordei system.
VALEUR COMPETITIVE DES PLANTES AUTOTETRAPLOIDES D'ARABIDOPSIS THALIANA
Authors: Bouharmont J. , Macé F.
Published: November 2014

In mixed cultures, an induced autotetraploid strain of Arabidopsis thaliana could supersede the original diploid. The fitness of these tetraploid plants was elucidated by comparing some factors acting on plant competition. The tetraploids were generally higher for seed germination and number of pods, but generally showed a later flowering and a lower seed number per pod. The whole balance was on behalf of the tetraploid strain. On the other hand the chromosome doubling did not impair the mitotic activity in Arabidopsis meristematic cells, and this fact may explain the growth and fitness of the tetraploid plants of that species.
ANALYSIS OF SPECIES RELATIONSHIPS IN AVENAE BY THIN-LAYER CHROMATOGRAPHY AND DISC ELECTROPHORESIS
Authors: Dass H. C.
Published: November 2014

Thin-layer chromatographic studies on flavonoids, and disc electrophoretic studies on proteins and esterase isoenzymes were conducted with Avena to determine species relationships and genome homologies. Distinctness of Avena ventricosa and A. pilosa was observed in comparison to other diploid species. Closeness of the diploid species of the A. strigosa group (including hirtula and wiestii) was evident from the similarity of their protein and esterase spectra. The tetraploid species, A. barbata and A. abyssinica, were found to be very close to A. hirtula and A. strigosa, respectively, by TLC studies. Proteins and esterases also showed that the tetraploid species are very close to the A. strigosa group of diploid species. The contribution of a genome by the A. strigosa group to the tetraploids and hexaploids was confirmed. The hexaploids showed different protein and esterase patterns. The involvement of A. ventricosa as the C genome donor to the hexaploids was shown by the protein and esterase spectra. A few extra protein bands observed may have been from the D genome.
DEVELOPMENT OF D-GENOME DISOMIC ADDITION LINES OF DURUM WHEAT
Authors: Joppa L. R. , McNeal F. H.
Published: November 2014

Seven lines of 'Chinese Spring' (Triticum aestivum L. em Thell.), each tetrasomic for one of the D-genome chromosomes, were crossed to 'Wells' and to 'Lakota' durum (T. durum Desf.). Nearly all F1 plants had 15 pairs plus six univalents, as expected.The D-genome disomic addition lines 1D, 3D, 4D, 5D and 6D were obtained in the F3. The 1D, 3D and 6D disomic addition lines proved to be male-sterile. The 4D and 5D disomic addition lines had stable chromosome numbers, were partially male-fertile and could be maintained by selfing. The 2D and 7D disomic addition lines were not obtained.
ETUDE DES REARRANGEMENTS CHROMOSOMIQUES PRODUITS DANS LES SPERMATOGONIES DU RAT ET DE LA SOURIS PAR UNE EXPOSITION AUX RAYONS X
Authors: Gilliavod N. , Léonard A.
Published: November 2014

Adult male BALB/c mice and adult male Wistar rats were given whole body X-irradiation with 300 R. Irradiated and control animals were killed after 120 days to study in dividing spermatocytes the rate of translocation induced in spermatogonial stages. No significant difference was recorded between the two species with respect to the rate of cells with translocation configurations.
INHERITANCE OF RESISTANCE TO BLACKROT IN CAULIFLOWER
Authors: Sharma B. R. , Swarup Vishnu , Chatterjee S. S.
Published: November 2014

Resistance to blackrot was found to be dominant over susceptibility and governed by polygenes. The dominance component of variation was greater than the additive in almost all the crosses. Breeding methods to be adopted for incorporating genes for resistance into susceptible varieties like Snowball are suggested.
ANALYSIS OF PATTERN IN DISTRIBUTION OF BREAKAGE POINTS IN THE CHROMOSOMES OF ZEA MAYS L. AND D. MELANOGASTER MEIGEN
Authors: Jancey R. C. , Walden D. B.
Published: November 2014

Analyses of the populations of breakage points from the chromosome arms of Zea mays L. and Drosophila melanogaster Meigen demonstrate significant deviations from equidistributions. In both organisms, greater than expected frequencies of breakage points were found in regions near the centromere and, in the case of maize, in the centromere. After correction for the distribution of breakage points, departures from an equidistribution of pair reassociation were described in maize. Reassociation frequencies found in maize chromosome arms VL, VIIIS, VIIIL, IXL and XS were mainly responsible for the large deviations from expected values.