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.

scholarly journals Inheritance of male sterility in apricot

2001 ◽  
Vol 7 (3-4) ◽  
Author(s):  
L. Burgos ◽  
J. Egea
Keyword(s):  
Male Sterility ◽  
Recessive Gene ◽  
Male Parent ◽  
Recessive Allele ◽  
Single Recessive Gene ◽  
Male Sterile ◽  
Proposed Model ◽  
Previous Hypothesis ◽  
Nuclear Locus

Progenies (total of 1,114 seedlings) from crosses representing all possible genotypic combinations between 4 male-fertile and 1 male-sterile apricot parents were scored for the male sterility trait. Crosses between putative heterozygous normal cultivars yielded 25% of male-sterile seedlings, which supports a previous hypothesis that male sterility is controlled by a recessive allele of one nuclear locus. Crosses between those parents and putative homozygous normal cultivars did not produce any male-sterile tree. Finally, the proportion of male-sterile progeny in crosses between a male-sterile and two male-fertile cultivars depended on the genotype of the male parent. When it was heterozygous approximately 50% of the progeny was sterile, whereas when a homozygous fertile parent was used, no male-sterile progeny was obtained. These results confirm a previously proposed model, in which the male sterility trait in apricot is controlled by a single recessive gene.

Inheritance of virulence of race 370, Melampsora lini

1976 ◽  
Vol 54 (1-2) ◽  
pp. 73-75 ◽  
Author(s):  
G. D. Statler ◽  
D. E. Zimmer
Keyword(s):  
Resistance Genes ◽  
Gene Pair ◽  
Rust Resistance ◽  
Single Gene ◽  
Recessive Gene ◽  
Segregation Ratio ◽  
Single Recessive Gene ◽  
Gene Pairs ◽  
Melampsora Lini

Race 370, Melampsora lini, was selfed and the progeny were tested for virulence on flax cultivars each of which contained a single gene pair for rust resistance. All cultures tested were virulent on flax cultivars with resistance genes L9, M, M1, M2, M4, N1, and P and avirulent on flax cultivars possessing the K, L2, L3, L5, L6, L7, L11, M3, M5, M6, N, N2, P1, P2, P3, and P4 genes for resistance. Segregation for virulence occurred on flax cultivars with the L, L1, L4, and L10 genes. Virulence on cultivars with the L4 and L10 genes was conditioned by single recessive gene pairs. The segregation ratio for virulence on the L1 gene more nearly fit a digenic recessive ratio than a monogenic ratio. Virulence on the cultivar containing the L gene appeared to be conditioned by two recessive gene pairs. Virulence on cultivars with gene L4 was apparently linked with L10, but no linkage was detected between L and L4 or L and L10.

scholarly journals INHERITANCE OF ANTHOCYANIN DEFICIENCY IN DEWBERRY (RUBUS TRIVIALIS)

HortScience ◽  
1994 ◽  
Vol 29 (7) ◽  
pp. 739a-739
Author(s):  
Creighton Gupton
Keyword(s):  
Marker Gene ◽  
Recessive Gene ◽  
Segregation Ratio ◽  
Marker Genes ◽  
Single Recessive Gene ◽  
Ripe Fruit ◽  
Low Concentration ◽  
Yellow Color ◽  
Mutant Trait

Anthocyanin deficient dewberry (Rubus trivialis Michx.) clones with translucent ripe fruit and green canes were studied to determine their possible utilization as a source of marker genes for blackberries. Albino dewberries from two locations designated Bonnette (BON and Harriel (H) were crossed with each other and with normal dewberry (DB). F1 plants were testcrossed. DB X H produced 62 plants all of which had red canes. BON X DB produced 59 plants all of which had red canes. BON X H produced nine plants all of which had green canes. The segregation ratio of each testcross supported the hypothesis that anthocyanin deficiency in dewberry is controlled by a single recessive gene. A recessive allelet known to cause a very low concentration of anthocyanin, giving fruit with yellow color and stems with non-pigmented spines, is probably responsible for the mutant trait. Its simple inheritance provides potential for anthocyanin deficiency to be used as a marker gene.

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.

Valuing DNA marker tested bulls for commercial beef production

2004 ◽  
Vol 55 (8) ◽  
pp. 825 ◽  
Author(s):  
B. J. Wood ◽  
J. H. J. van der Werf ◽  
P. F. Parnell
Keyword(s):  
Gene Flow ◽  
Allele Frequency ◽  
Gene Frequency ◽  
Dna Marker ◽  
Recessive Gene ◽  
Single Recessive Gene ◽  
Beef Herd ◽  
Thyroglobulin Gene ◽  
Commercial Breeder ◽  
Over Time

This paper quantifies the benefits of using a sire genotyped for a single recessive gene in a commercial beef herd. A modified gene-flow method was used to account for changing allele frequency over time. The benefits to a commercial breeder of using a genotyped sire were highest when initial allele frequency was moderate and when the sire was used in a self-replacing herd that had increased allele frequency over time. An example of the thyroglobulin gene affecting marbling in beef cattle was used. The value to a self-replacing herd of a sire homozygous for the favourable allele of the thyroglobulin gene was shown to be up to $338 more than of an ungenotyped sire, in a population where the initial gene frequency was 0.3 and the genotype accounted for 0.5 standard deviations of phenotypic variation.

Response of Corn (Zea maysL.) Inbreds and Hybrids to Sulfonylurea Herbicides

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 508-516 ◽  
Author(s):  
Jerry M. Green ◽  
Jim F. Ulrich
Keyword(s):  
Genetic Analysis ◽  
Safety Margin ◽  
Recessive Gene ◽  
Response Analysis ◽  
Hybrid Seed Production ◽  
Sulfonylurea Herbicides ◽  
Single Recessive Gene ◽  
Organophosphate Insecticide ◽  
Extensive Field ◽  
Varietal Response

Extensive field and greenhouse studies were done to characterize varietal response of three recently commercialized sulfonylurea corn herbicides: nicosulfuron, primisulfuron, and thifensulfuron. Most of the 94 varieties tested were highly tolerant to these herbicides. The 37 inbreds represented all major inbred families now used in hybrid seed production as well as several sensitive experimentals. Twenty-one defined hybrids from these inbreds as well as 36 commercially coded hybrids were also tested. Sensitive inbreds produced tolerant hybrids when crossed with tolerant inbreds. Sensitive hybrids occurred when both parents were sensitive. Genetic analysis of sensitive by tolerant crosses showed that sensitivity is controlled by a single recessive gene. Nicosulfuron had the widest corn safety margin and fewest sensitive varieties. Dose response analysis showed varieties can vary more than 40 000-fold in sensitivity. Only corn varieties with the AHAS-modified XA-17 gene showed any change in enzyme sensitivity. This gene overcame sensitivity to sulfonylureas, even when the organophosphate insecticide terbufos was present. Thus, breeders have three options to eliminate sulfonylurea sensitivity: backcross sensitive inbreds with tolerant, always use at least one tolerant hybrid parent, or use the XA-17 gene.

Progress in development of spotted medics (Medicago arabica L. Huds.) for Mediterranean farming systems

2006 ◽  
Vol 57 (4) ◽  
pp. 447 ◽  
Author(s):  
Ramakrishnan M. Nair ◽  
Steve J. Hughes ◽  
David M. Peck ◽  
Graham Crocker ◽  
Simon Ellwood ◽  
...  
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Agronomic Traits ◽  
South Australia ◽  
Recessive Gene ◽  
Principal Component ◽  
Farming Systems ◽  
Segregation Ratio ◽  
Early Flowering ◽  
Days To Flowering

Spotted medics (Medicago arabica) have become naturalised in Australia, but the spiny nature of their pods has prevented commercial release of any cultivar. Fifty-eight accessions representing Medicago arabica in the Australian Medicago Genetic Resources Collection were grown as spaced plants at Turretfield, South Australia, and the variation for important agronomic traits was studied. There was large variation for traits including days to flowering, dry matter production, pod and seed yield, and pod spininess. Principal component and cluster analyses conducted for 13 traits revealed 5 clusters. One of the clusters identified comprised accessions originating from Greece and Cyprus, which were found to have high agronomic potential. The study has helped in identifying the relationship among traits, namely pod spininess, days to flowering, dry matter yield, and pod and seed yield, which would be useful to breeders for future breeding and selection programs. A sward trial at Moree, New South Wales, comprising a selected cohort of spotted medic accessions, enabled the identification of 2 early flowering and high dry matter yielding accessions; however, both exhibited spiny pods. These 2 accessions were crossed with a smooth-podded accession, and the F1 plants were confirmed using a microsatellite marker. Days to flowering showed a continuous pattern of variation in the F2, suggesting that the trait is quantitatively inherited, whereas segregation ratio revealed that a single recessive gene controlled the smooth pod trait. Early flowering, smooth-podded F2 plants were selected for cultivar development.

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