THE INHERITANCE AND HISTOLOGY OF A CHLOROPHYLL-DEFICIENT CHARACTER IN MEDICAGO SATIVA L.

1961 ◽  
Vol 39 (4) ◽  
pp. 847-853 ◽  
Author(s):  
W. R. Childers ◽  
H. A. McLennan
Keyword(s):  
Recessive Gene ◽  
Single Recessive Gene ◽  
Mesophyll Cells ◽  
Genetic Studies ◽  
Continuous Layer ◽  
Mesophyll Tissue ◽  
Plant Stage ◽  
Chlorophyll Production ◽  
Medicago Sativa L ◽  
Palisade Cells

Further support for tetrasomic inheritance in alfalfa was shown from genetic studies of a chlorophyll-deficient seedling character. The character was determined by a single recessive gene for which the symbol Viridis-1 or v1 is proposed. At the mature-plant stage, low and intermediate classes for chlorophyll production were observed. Histological examination and chlorophyll analyses confirmed this classification. The low-chlorophyll-producing class was characterized by a lack of plastids in the leaf blades although some plastids occurred in mesophyll tissue around the midrib. The intermediate chlorophyll-deficient class was characterized by yellowish-green leaf blades, associated with colorless palisade cells that overlay a single continuous layer of mesophyll cells in which the plastids were well developed.

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.

scholarly journals (248) New Four Genes Related to Seed Characteristics, Flower Appearance, and Red Color

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1019A-1019
Author(s):  
Zhoo-Hyeon Kim
Keyword(s):  
Recessive Gene ◽  
Single Recessive Gene ◽  
Young Plant ◽  
Breeding Lines ◽  
Red Color ◽  
Plant Stage ◽  
Ethylmethane Sulfonate ◽  
V Gene ◽  
Limited Base ◽  
Seed Characteristics

New four traits not yet reported were founded. One mutant plant was from a population of 81-1251-D-20M treated with EMS (ethylmethane sulfonate), which had tubular petals. This tubular petal plant had normal pollens in anthers, but could almost not produce its seeds without artificial pollination. It was controlled by one single recessive gene. One new spontaneous dwarf mutant line, R3-10, which bore seedcoatless-like seeds with short pappus, was crossed with normal breeding lines GL5 and 87-25M-2M. From F2 and F3 results, it was found that the two traits (seedcoatless-like and short pappus) were governed by each one single recessive gene. A stem lettuce type cultivar, `Baimach', seemed to be almost green, but was really tinged red, which was extremely suppressed in red color expression. Its tinged red color could not be seen, except on only very limited base parts of the stem and dorsal petal. In two F2 population experiments of the crosses of `Baimach' with `Oakleaf' and 98-43-3, it was found that the suppression of red color expression in `Baimach' was caused by a single recessive gene. It looked different from that of gene “v” (vanishing) by Lindqvist, because the red color of plants with “v” gene of Lindqvist were typically tinged and could be identified easily at a young plant stage, but not that of `Baimach'. I designated these new four genes as Tu-tu (Tu = normal, tu = tubular petal), Pp-pp (Pp = normal, pp = short pappus), Scl-scl (Scl = normal, scl = seedcoatless-like), and In-in (In = normal, in = inhibiting red color expression extremely).

scholarly journals PROPOSED METHODOLOGY FOR BREEDING SOUTHERNPEA CULTIVARS WITH PERSISTENT GREEN SEED COLOR

HortScience ◽  
1994 ◽  
Vol 29 (7) ◽  
pp. 728b-728
Author(s):  
R. L. Fery ◽  
P. D. Dukes
Keyword(s):  
Vigna Unguiculata ◽  
Recessive Gene ◽  
Seed Color ◽  
Seed Traits ◽  
Single Recessive Gene ◽  
Genetic Studies ◽  
Green Color ◽  
Green Seed ◽  
Green Cotyledon ◽  
Selection Methodology

The results of recently completed genetic studies indicate that the green cotyledon trait exhibited by the southernpea [Vigna unguiculata (L.) Walp.] cultivar Bettergreen is conditioned by a single recessive gene. This gene, designated green cotyledon and symbolized gc, is neither allelic to nor linked with the gt gene that conditions the green testa trait exhibited by the cultivar Freezegreen. The color of seeds harvested from plants homozygous for both the gc and gt genes is superior and more uniform than the color of seeds harvested from either Better-green or Freezegreen plants. This observation suggests that efforts should be initiated to study the feasibility of using both the gc and gt genes to develop cultivars that produce seed with an enhanced, persistent green color. The selection methodology for both seed traits is rapid and reliable. The green cotyledon trait can be selected in the seed stage.

THE INHERITANCE OF RESISTANCE TO STEM RUST RACES 56 AND 15B-1L (CAN.) IN THE WHEAT VARIETIES HOPE AND H-44

1968 ◽  
Vol 10 (2) ◽  
pp. 311-320 ◽  
Author(s):  
D. R. Knott
Keyword(s):  
Adult Plant Resistance ◽  
Recessive Gene ◽  
Adult Plant ◽  
Inheritance Of Resistance ◽  
Single Recessive Gene ◽  
Wheat Varieties ◽  
Adult Plant Stage ◽  
Plant Stage ◽  
Physiological Resistance ◽  
Dominant Genes

The inheritance of resistance to races 56 and 15B-1L was studied in back-crosses of Hope and H-44 to Marquis. The results indicated that both varieties carry the same three genes. Resistance to race 56 is controlled by two dominant genes, Sr 1 which conditions seedling or physiological resistance and Sr 2 which conditions adult plant resistance. At either the seedling or adult plant stage both genes must be present to provide full resistance to race 56. A single recessive gene, not yet named, provides resistance to race 15B-1L.The gene Sr 1 was transferred from Hope to Marquis by backcrossing and the line was crossed to the Chinese Spring monosomics. The gene proved to be on chromosome 2B (XIII).

THE NATURE AND INHERITANCE OF A YELLOW-LEAF CHARACTER IN MEDICAGO SATIVA L.

1962 ◽  
Vol 40 (1) ◽  
pp. 89-93 ◽  
Author(s):  
W. R. Childers
Keyword(s):  
Medicago Sativa ◽  
Leaf Morphology ◽  
Histological Study ◽  
Recessive Gene ◽  
Yellow Leaf ◽  
Single Recessive Gene ◽  
Green Leaves ◽  
Normal Green ◽  
Leaf Character ◽  
Medicago Sativa L

An alfalfa mutant with yellow cotyledons and yellow leaves is described. The few seedlings that live to maturity are dwarfs. The character is determined by a single recessive gene (Xantha-1 or X1) inherited tetrasomically. A histological study of the leaf morphology indicated that the tissues of the mutant have similar structure to those of green leaves. The plastids are well formed but take up stain weakly in comparison with the plastids in normal green leaves.

scholarly journals A new allele of the lpr locus, lprcg, that complements the gld gene in induction of lymphadenopathy in the mouse.

1990 ◽  
Vol 171 (2) ◽  
pp. 519-531 ◽  
Author(s):  
A Matsuzawa ◽  
T Moriyama ◽  
T Kaneko ◽  
M Tanaka ◽  
M Kimura ◽  
...  
Keyword(s):  
Recessive Gene ◽  
Mutant Gene ◽  
Inbred Strains ◽  
Lymphoid Hyperplasia ◽  
Lymphoid Cells ◽  
Autoantibody Production ◽  
Genetic Studies ◽  
Inbred Strains Of Mice ◽  
Backcross Populations ◽  
Generalized Lymphadenopathy

Several mice with generalized lymphadenopathy were found in the CBA/KlJms (CBA) colony maintained at our institute. A new mutant strain of mice that develop massive lymphoid hyperplasia at 100% incidence within 5 mo after birth was established by crossing these diseased mice. Genetic studies on lymphadenopathy were conducted in F1, F2, and backcross populations from crosses between mutant CBA (CBA-m) and various inbred strains of mice. The results supported the control of lymphadenopathy by a single autosomal recessive gene. Since C3H/He-gld/gld (C3H-gld), MRL/MpJ-lpr/lpr (MRL-lpr), and C3H/HeJ-lpr/lpr (C3H-lpr) mice develop the same type of lymphoid hyperplasia, allelism of the mutant gene with gld or lpr was tested by investigating lymphadenopathy in F1 and backcross populations from crosses between CBA-m and C3H-gld, MRL-lpr, or C3H-lpr mice. The gene was confirmed to be allelic with lpr but not with gld. Interestingly, however, the mutant gene interacted with gld to induce less severe lymphadenopathy. Thus, the mutant gene was named lprcg, an lpr gene complementing gld in induction of lymphoproliferation. The genetic conclusion was supported by the same profile of surface markers of lymphoid cells with gld/gld, lpr/lpr, lprcg/lprcg, lprcg/lpr, and +/gld +/lprcg genotypes, as well as by massive lymph node hyperplasia and high titers of autoantibodies in the first four genotypes, but slight hyperplasia and insignificant autoantibody production in the last. The discovery of lprcg provided strong genetic evidence for the parallels between anomalous phenotypes of gld and lpr, and CBA/KlJms-lprcg/lprcg mice will contribute to elucidation of the mechanism of induction of the same abnormal differentiation and functions of lymphocytes by gld and lpr.

scholarly journals A Proposed Model for Inheritance of Primocane Fruiting in Tetraploid Erect Blackberry

2000 ◽  
Vol 125 (2) ◽  
pp. 217-221 ◽  
Author(s):  
Jose Lopez-Medina ◽  
James N. Moore ◽  
Ronald W. McNew
Keyword(s):  
Negative Relationship ◽  
Recessive Gene ◽  
Segregation Ratio ◽  
Breeding Strategies ◽  
Single Recessive Gene ◽  
Tetrasomic Inheritance ◽  
Proposed Model ◽  
Inheritance Model ◽  
Diallel Crossing ◽  
Scheme Selection

Inheritance of the primocane-fruiting (PF) characteristic was studied in seedling populations of tetraploid (4x) blackberries (Rubus subgenus Rubus). Four selections (A-1836, A-593, A-830, and A-1680) and two cultivars (`Arapaho' and `Shawnee') were used as parents in a full diallel crossing scheme. Selection A-593 was used as the main source for PF due to its origin (`Brazos' × `Hillquist,' the latter an old PF cultivar). All parents except `Shawnee' have A-593 in their parentage; among the parents, only A-1836 fully expresses PF. Selfing of A-1836 resulted in 100% PF offspring, indicating that A-1836 is homozygous for this trait. Selfing of A-593, A-830, and `Arapaho' produced either a 35:1 or a 20.8:1 FF (floricane or summer-fruiting):PF segregation ratio, fitting a tetrasomic inheritance model under either random chromosome assortment (RCSA) or random chromatid assortment (RCTA), respectively, also suggesting that PF is controlled by a single recessive gene and that the parents are duplex (AAaa) for this trait. Selection A-1680 and `Shawnee' selfed did not produce PF progeny, but when crossed with the nulliplex A-1836, gave a 27:1 FF:PF ratio, indicating RCTA and that they are triplex (AAAa) for PF. According to these research, both gametic outputs (RCSA and RCTA) seem to operate in 4x blackberry. The intensity in expression of PF had a negative relationship with time to harvest, with those seedlings showing the highest PF scores producing a crop in early to mid-August. This knowledge will be helpful in implementing breeding strategies to produce PF blackberry cultivars.

The inheritance and chromosomal location of a gene for chocolate chaff in durum wheat

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 229-233 ◽  
Author(s):  
C. F. Konzak ◽  
L. R. Joppa
Keyword(s):  
Durum Wheat ◽  
Chromosomal Location ◽  
Triticum Turgidum ◽  
Recessive Gene ◽  
Single Recessive Gene ◽  
Chromosome Substitution ◽  
Substitution Lines ◽  
D Genome ◽  
B Genome ◽  
Aneuploid Chromosome

The durum wheat (Triticum turgidum L. var. durum) cultivar 'Vic' was treated with the chemical mutagen N-methyl-N′-nitrosourea and among the M2 progeny a mutant with "chocolate chaff" (designated cc) was identified. Genetic analyses indicated that chocolate chaff is due to a single recessive gene mutation. The penetrance of the gene for chocolate chaff was environmentally influenced and varied from dark blotches on the glumes to complete coloration of culms as well as spikes. To determine the chromosomal location of the gene, the mutant was crossed with a set of 'Langdon' durum disomic substitution lines in which each of the 14 A- and B-genome chromosomes of durum wheat were replaced by their respective D-genome homoeologues. The segregation of cc was normal in all of the crosses except for those with the 7D(7A) and 7D(7B) lines. Cytogenetic analysis indicated that the gene was located on chromosome 7B, and that chromosome 7D has a gene that prevents the expression of cc when present in one or more copies. It was shown that the 'Langdon' D-genome disomic substitution lines can be used to determine the chromosomal location of genes in tetraploid wheat.Key words: Triticum turgidum, aneuploid, chromosome substitution, monosomic, cytogenetics.

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