Cone clusters in jack pine

1986 ◽  
Vol 16 (6) ◽  
pp. 1180-1184 ◽  
Author(s):  
Thomas D. Rudolph ◽  
Nicholas C. Wheeler ◽  
Narinder K. Dhir
Keyword(s):  
Low Frequency ◽  
Recessive Gene ◽  
Jack Pine ◽  
The Other ◽  
Single Recessive Gene ◽  
Seed Cone

Regularly repeated seed cone clustering on two jack pine (Pinusbanksiana Lamb.) trees, one in Alberta, Canada, and the other in Wisconsin, U.S.A., is described. The clusters on the Alberta tree apparently result from the replacement of dwarf shoots by ovulate cones; those on the Wisconsin tree apparently result from replacement of staminate cones by ovulate cones. The low frequency of cone clustering in open-pollinated progenies of the two trees suggests that the clustering trait may be controlled by a single recessive gene.

Genetics, cytology, and crossing behavior of an alfalfa (Medicago sativa) mutant resulting in failure of the postmeiotic cytokinesis

1983 ◽  
Vol 25 (4) ◽  
pp. 390-397 ◽  
Author(s):  
T. J. McCoy ◽  
L. Y. Smith
Keyword(s):  
Medicago Sativa ◽  
Low Frequency ◽  
Recessive Gene ◽  
Microspore Mother Cell ◽  
Developmental Sequence ◽  
Single Recessive Gene ◽  
Single Nucleus ◽  
Medicago Sativa L ◽  
Jumbo Pollen ◽  
Is Failure

During pollen investigations on diploid alfalfa (Medicago sativa L.) several plants were identified which produced "jumbo" pollen. The cause of the jumbo pollen is failure of the postmeiotic cytokinesis. These plants produce a single, four-nucleate microspore from one microspore mother cell (MMC) rather than the normal four, single-nucleate microspores from one MMC. Subsequent gametophyte development is characterized by fusion of the four nuclei into a single nucleus in most cases (range of 80 to 100%), followed by a developmental sequence comparable to normal alfalfa. Mature 4n male gametophytes are thus formed from 2n sporophytes. Genetic control of the postmeiotic cytokinesis failure is by a single recessive gene, designated jp. Although a low frequency of jumbo pollen does germinate (range of 3.1 to 37.8%), crossing studies demonstrate jumbo pollen is incapable of effecting fertilization. The use of the jp mutant in breeding studies, and interspecific hybridization research, is discussed.

Effects of dam and sire group on the propensity for twin calving in cattle

1990 ◽  
Vol 51 (3) ◽  
pp. 481-488 ◽  
Author(s):  
C. A. Morris ◽  
A. M. Day
Keyword(s):  
Recessive Gene ◽  
The Other ◽  
Single Recessive Gene ◽  
National Rate ◽  
Sire Group

ABSTRACTThe incidence of twin calvings and double ovulations was studied in two Milking Shorthorn herds and one Friesian herd, each with above-average annual twin calving rates (average 0·031, compared with a national rate of 0·01). The proportions of double ovulations were calculated from records comprising 1237 cow × years (cows over 2·0 years of age); means were 0·08, 0·27 and 0·50, for three groups which had previously produced 0, 1 or >1 sets of twins, respectively. All cows (whether still present or no longer in the herd) were then allocated a twin production status, to indicate the number of twin sets (0, 1 or >1) produced, or produced so far, in their lifetime. There were records from 1559 cows, with sire and dam also known. Twin production status was significantly influenced by dam group (P < 0·01), i.e. the twin production status of the cow's dam. Sires were classified into two groups, according to whether any daughters had produced two or more sets of twins. After allowing for ascertainment, sires in the two groups were found to differ (P < 0·01) by 0·06 in the probability of their daughters producing at least one set of twins in their lifetime (i.e. 0·08 to 0·14). One sire and dam combination in particular had prolific daughters with a probability of 0·39 of producing at least one set of twins in their lifetime (compared with a probability of 0-07 for the other extreme combination). The possibility of these observations being explained by the segregation of a single recessive gene was considered, but the necessary interaction between sire group and dam group was not significant.

scholarly journals Inheritance of Resistance to Loquat Canker (Group C) in Progenies Derived from ‘Shiromogi’ Loquat

2012 ◽  
Vol 137 (3) ◽  
pp. 152-156 ◽  
Author(s):  
Naofumi Hiehata ◽  
Yoshihiko Sato ◽  
Shinji Fukuda ◽  
Yukiko Tominaga ◽  
Osamu Terai ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Recessive Gene ◽  
The Other ◽  
Eriobotrya Japonica ◽  
Bacterial Suspension ◽  
Inheritance Of Resistance ◽  
Single Recessive Gene ◽  
Fruit Characteristics ◽  
Commercial Cultivar ◽  
Serious Disease

Loquat canker (Pseudomonas syringae pv. eriobotryae) is a serious disease of loquat (Eriobotrya japonica), and no commercial cultivar in Japan is resistant to all strains of the disease. Loquat cultivar Shiromogi, which was selected from progeny seedlings of ‘Mogi’, is resistant to loquat canker Group C and has good fruit characteristics. This study was conducted to determine the inheritance of resistance to loquat canker Group C in ‘Shiromogi’. Seedlings produced from crosses between two resistant and 13 susceptible genotypes were classified as either resistant (R) or susceptible (S) based on the appearance of black–brown cankers ≈2 months after inoculation with a bacterial suspension of loquat canker Group C. Cross combinations between resistant parents ‘Champagne’ and ‘Shiromogi’ and selfing of ‘Shiromogi’ produced all resistant seedlings. Most crosses between ‘Shiromogi’ and susceptible parents either produced only susceptible seedlings or segregated for resistance in a ratio of 1 R:1 S. Seedlings produced by selfing two of the susceptible parents segregated in a ratio of 1 R:3 S. These results indicate that the resistance to loquat canker Group C of ‘Shiromogi’ is conferred by a single recessive gene, designated pse-c. Based on the crossing tests, we conclude that resistant parents ‘Shiromogi’ and ‘Champagne’ are homozygous for pse-c; the susceptible parents ‘Fukuharawase’, ‘Fusahikari’, ‘Gold Nugget’, ‘Kusunoki’, Nagasaki No. 2, ‘Tanaka’, ‘Tsukumo’, and ‘Yougyoku’ are homozygous for Pse-c; and the other susceptible parents in this experiment (‘Mogi’, ‘Nagasakiwase’, Nagasaki No. 3, ‘Taisho’, and 75-142) are heterozygous. Based on the pedigree of ‘Shiromogi’ and the results reported here, pse-c is probably derived from ‘Mogi’, a major cultivar in Japan.

INHERITANCE OF VIRULENCE IN WHEAT LEAF RUST ON THE STANDARD DIFFERENTIAL WHEAT VARIETIES

1968 ◽  
Vol 10 (1) ◽  
pp. 24-32 ◽  
Author(s):  
D. J. Samborski ◽  
P. L. Dyck
Keyword(s):  
Leaf Rust ◽  
Dominant Gene ◽  
Recessive Gene ◽  
The Other ◽  
Wheat Leaf Rust ◽  
Single Recessive Gene ◽  
Wheat Varieties ◽  
Wheat Leaf ◽  
Recessive Genes ◽  
Race 1

Populations of self-fertilized cultures from races 1, 9, 15 and 161 of wheat leaf rust were studied for inheritance of virulence on the eight standard differential wheat varieties. Race 9 was homozygous at all loci tested while the other races segregated at a number of loci. Recessive genes controlled virulence on the varieties Malalkof (gene Lr1) and Hussar (gene Lr11) respectively. Virulence to Mediterranean and Democrat was governed by a single recessive gene in race 1 and a single dominant gene in race 161. One recessive gene in races 1 and 15 governed virulence to the various alleles of the Lr2 locus, while in race 161 a second dominant gene altered the expression of avirulence of this gene on Loros (Lr24). An additional recessive gene for virulence interacted with gene LrB in Carina and Brevit. It is not known whether the gene for virulence, which corresponds to a particular host gene for resistance, is the same in each race of leaf rust that was studied. All genes for virulence segregated independently.

Use of mutants to establish (+)-scytalone as an intermediate in melanin biosynthesis by Verticillium dahliae

1976 ◽  
Vol 22 (6) ◽  
pp. 787-799 ◽  
Author(s):  
A. A. Bell ◽  
J. E. Puhalla ◽  
W. J. Tolmsoff ◽  
R. D. Stipanovic
Keyword(s):  
Physical Properties ◽  
Verticillium Dahliae ◽  
Recessive Gene ◽  
The Other ◽  
Thielaviopsis Basicola ◽  
Single Recessive Gene ◽  
Wild Type ◽  
Melanin Biosynthesis ◽  
In The Wild ◽  
Verticillium Dahliae Kleb

Melanin biosynthesis in Verticillium dahliae Kleb. was studied with mutants deficient for normal black melanin or for production of microsclerotia. Seven genetically different mutants had apparent blocks in melanin biosynthesis. Four mutants (brm-I to -4) produced brown microsclerotia and extruded pigments into media; three (alm-1 to -3) produced albino microsclerotia. Other mutants produced no microsclerotia (nms) or had greatly reduced numbers of microsclerotia (rms). Mutation alm-1 was due to a single recessive gene; the other melanin-deficient characters were recessive but their genetic bases were not determined. Cultures of the brown mutants brm-1 and -3 extruded and accumulated a metabolite that blackened the albino microsclerotia of alm-1 to -3. The metabolite was identified as (+)-scytalone (3, 4-dihydro-3, 6, 8-trihydroxy-1(2H)naphthalenone). Pigment formed by alm-1 microsclerotia from (+)-scytalone had chemical and physical properties identical with those of melanin in the wild-type fungus. (+)-Scytalone was produced and converted to melanin by microsclerotia but not by conidia or hyphae. Conversion of (+)-scytalone to melanin appeared to involve two or more enzymes and probably involved conversions to 1, 3, 8-trihydroxynaphthalene and 1, 8-dihydroxynaphthalene. Albino mutants of Thielaviopsis basicola, Drechslera sorokiniana, Pleospora infectoria (Alternaria), Ulocladium sp., and Curvularia sp. also converted scytalone to pigments indistinguishable from the melanins found in their respective wild types. Scytalone melanin may be common in fungi with dark brown or black pigments.

scholarly journals Nucleotide Variation at theCHALCONE ISOMERASELocus inArabidopsis thaliana

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 863-872 ◽  
Author(s):  
Helmi Kuittinen ◽  
Montserrat Aguadé
Keyword(s):  
Nucleotide Diversity ◽  
Direct Relationship ◽  
Selective Sweep ◽  
Balancing Selection ◽  
Neutral Theory ◽  
Low Frequency ◽  
The Other ◽  
Nucleotide Variation ◽  
Rapid Population Growth ◽  
History Of

AbstractAn ~1.9-kb region encompassing the CHI gene, which encodes chalcone isomerase, was sequenced in 24 worldwide ecotypes of Arabidopsis thaliana (L.) Heynh. and in 1 ecotype of A. lyrata ssp. petraea. There was no evidence for dimorphism at the CHI region. A minimum of three recombination events was inferred in the history of the sampled ecotypes of the highly selfing A. thaliana. The estimated nucleotide diversity (θTOTAL = 0.004, θSIL = 0.005) was on the lower part of the range of the corresponding estimates for other gene regions. The skewness of the frequency spectrum toward an excess of low-frequency polymorphisms, together with the bell-shaped distribution of pairwise nucleotide differences at CHI, suggests that A. thaliana has recently experienced a rapid population growth. Although this pattern could also be explained by a recent selective sweep at the studied region, results from the other studied loci and from an AFLP survey seem to support the expansion hypothesis. Comparison of silent polymorphism and divergence at the CHI region and at the Adh1 and ChiA revealed in some cases a significant deviation of the direct relationship predicted by the neutral theory, which would be compatible with balancing selection acting at the latter regions.

scholarly journals A Single Recessive Gene for Resistance to the Root-Knot Nematode (Meloidogyne Javanica) in Cucumis sativus var. hardwlckii

1997 ◽  
Vol 88 (1) ◽  
pp. 66-69 ◽  
Author(s):  
S. A. Walters ◽  
T. C. Wehner ◽  
K. R. Barker
Keyword(s):  
Cucumis Sativus ◽  
Recessive Gene ◽  
Meloidogyne Javanica ◽  
Single Recessive Gene ◽  
Root Knot Nematode

scholarly journals Dynamics and Protein–Solvent Interactions of Hemoglobin in T and R Quaternary Conformation

2002 ◽  
Vol 16 (3-4) ◽  
pp. 227-233 ◽  
Author(s):  
Chiara Caronna ◽  
Antonio Cupane
Keyword(s):  
Quaternary Structure ◽  
Dynamic Properties ◽  
Low Frequency ◽  
Helical Structure ◽  
Blue Shift ◽  
Peak Frequency ◽  
The Other ◽  
Solvent Interactions ◽  
Reported Data ◽  
Increasing Temperature

In this work we report the thermal behaviour of the amide I′ band of carbonmonoxy and deoxy hemoglobin in 65% v/v glycerolD8/D2O solutions and in the temperature interval 10–295 K. Following recent suggestions in the literature, we analyze the amide I′ band in terms of two components, one at about 1630 cm−1and the other at about 1650 cm−1, that are assigned to solvent‒exposed and buried α‒helical regions, respectively.For deoxy hemoglobin (in T quaternary structure) both components are narrower with respect to carbonmonoxy hemoglobin (in R quaternary structure), while the peak frequency blue shift observed, upon increasing temperature, for the component at about 1630 cm−1is smaller. The reported data provide evidence of the dependence of hemoglobin dynamic properties upon the protein quaternary structure and suggest a more compact α‒helical structure of hemoglobin in T conformation, with reduced population of low‒frequency modes involving the solvent and protein.

scholarly journals Diversity of and Selection Acting on CylindrospermopsincyrBGene Adenylation Domain Sequences in Florida

2011 ◽  
Vol 77 (7) ◽  
pp. 2502-2507 ◽  
Author(s):  
Mete Yilmaz ◽  
Edward J. Phlips
Keyword(s):  
United States ◽  
Low Frequency ◽  
Purifying Selection ◽  
The United States ◽  
The Other ◽  
Cylindrospermopsis Raciborskii ◽  
Adenylation Domain ◽  
Other Hand ◽  
Neutrality Tests ◽  
The One

ABSTRACTAphanizomenon ovalisporumis the only confirmed cylindrospermopsin producer identified in the United States to date. On the other hand,Cylindrospermopsis raciborskiiis a prominent feature of many lakes in Florida and other regions of the United States. To see the variation in cylindrospermopsincyrBgene adenylation domain sequences and possibly discover new cylindrospermopsin producers, we collected water samples for a 3-year period from 17 different systems in Florida. Positive amplicons were cloned and sequenced, revealing that approximately 92% of sequences wereA. ovalisporum-like (>99% identity). Interestingly, 6% of sequences were very similar (>99% identity) tocyrBsequences ofC. raciborskiifrom Australia and ofAphanizomenonsp. from Germany. Neutrality tests suggest thatA. ovalisporum-likecyrBadenylation domain sequences are under purifying selection, with abundant low-frequency polymorphisms within the population. On the other hand, when compared between species by codon-based methods, amino acids of CyrB also seem to be under purifying selection, in accordance with the one proposed amino acid thought to be activated by the CyrB adenylation domain.

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