EVALUATION OF CROSS-ATTRACTION BETWEEN SYMPATRIC CHORISTONEURA OCCIDENTALIS AND C. RETINIANA (LEPIDOPTERA: TORTRICIDAE) POPULATIONS IN SOUTH-CENTRAL OREGON

1984 ◽  
Vol 116 (6) ◽  
pp. 827-840 ◽  
Author(s):  
Andrew M. Liebhold ◽  
W. Jan A. Volney ◽  
William E. Waters
Keyword(s):  
Interspecific Hybrids ◽  
Low Frequency ◽  
Choristoneura Occidentalis ◽  
Female Progeny ◽  
South Central ◽  
Pheromone Specificity ◽  
Laboratory Colonies ◽  
Pure Lines ◽  
Cross Attraction

AbstractThe pheromone specificity of female Choristoneura occcidentalis Freeman and C. retiniana (Walsingham) from several locales, laboratory colonies, and interspecific matings was determined by observing the numbers and wing maculations of males attracted at several sites in southern Oregon. Pheromone specificity of females reared from field-collected brown (typical of C. occidentalis) and green (typical of C. retiniana) larval morphs differed considerably but differed little among sites of origin. Field-collected females attracted more males than conspecific individuals from laboratory colonies. F1 and F2 interspecific hybrids most closely resembled C. occidentalis in the numbers and types of males attracted. As a group, progeny of backcrosses to C. retiniana appeared intermediate between pure lines of the species in their pheromone specificity. Females reared from intermediate-colored field-collected larvae varied considerably in attractiveness. Most attracted groups of males similar to those attracted to female C. retiniana, but others attracted males most similar to those attracted to female progeny of C. retiniana hybrid backcrosses. These findings support the conclusion that hybrid matings occur between these species at a low frequency in nature.

scholarly journals Induction of male sterility through manipulation of genetic mechanisms present in vector species of Triatominae. II. Partial restoration of male fertility

1976 ◽  
Vol 10 (6) ◽  
pp. 367-383
Author(s):  
Alina Perlowagora-Szumlewicz ◽  
M.V. Correia ◽  
A.M. Reis Trinchet
Keyword(s):  
Artificial Insemination ◽  
Interspecific Hybrids ◽  
Vector Species ◽  
Hybrid Male ◽  
Normal Complement ◽  
Female Progeny ◽  
Partial Restoration ◽  
Egg Hatchability ◽  
Genetic Mechanisms ◽  
Medical Importance

The development of integrated measures which involve sterile mate release to supplement the conventional insecticidal techniques used in controlagainst insects of medical importance, raised the question, whether the vectors of Chagas'disease possess the natural mechanisms by manipulation of which they may be controlled. Results of earlier expenments, that had been published previously, were restricted to fragmentary information that raised various questions, the answer to which became available in the study herein described. Interspecific hybrids were produced from reciprocal crosses between T. pseudomaculata and T. sórdida and from unilateral crosses between female T. pseudomaculata and male. T. infestans. These females mated with males, laid less than the normal complement of eggs, but offspring was relatively abundant. When T. pseudomaculata females were paired with T. brasiliensis males, hybridization was more difficult because few of the females mated and those that did had a strongly reduced fertility. Adults emerged from ali crosses but exhibited sex disproportion, females predominating in all populations but one. The two Rhodnius species tested were also found to cross, but only when female R. prolixus were paired with male R. neglectus. These females laid a relatively high complement o f eggs, had a strongly reduced fertility, but 50% of the fertile eggs developed into vigorous adults, males predominating females. Neither type of hybrid male elicited fertilized eggs from either parental type of female, through their vesicula seminal is were found to be packed with spermatozoa, some normal looking and moving, others underdeveloped and motionless. Although, no artificial insemination was performed, the sperm in itself did not appear to be the prime inducer of sterility. Females paired with these hybrids did mate, sperm was transfered, as evidenced by the discharged spermatophores smeared with sperm, but did notcontain spermatozoa in their spermatecae. The failure of the sperm to migrate to the spermatecae indicate prezygotic pos-copulation incompatibility, thus the hybrid male can't be used to suppress populations. The female hybrids mated with parent males of either species had reduced fertility and ther sons were sterile as were those of their fertile daughters. However, continous backcrossing of the hybrid females and their female progeny to parental males partially restored fertility of the males and increased fertility of females, as scored by egg hatchability. Fertility of hybrid females, measured by the yield of adults capable to reproduce, indicated that the reproductive perfomance decreased when hybrid females and their daughters were backcrossed additional generations to parental males. It is tentatively suggested that hybrid females could be used for suppression if they compete efficiently with wild females.

Subsurface imaging in south-central egypt using low-frequency radar: bir safsaf revisited

2003 ◽  
Vol 41 (7) ◽  
pp. 1672-1684 ◽  
Author(s):  
P. Paillou ◽  
G. Grandjean ◽  
N. Baghdadi ◽  
E. Heggy ◽  
T. August-Bernex ◽  
...  
Keyword(s):  
Low Frequency ◽  
Subsurface Imaging ◽  
South Central

scholarly journals Maternal Karyogene and Cytoplasmic Genotype Affect the Induction Efficiency of Doubled Haploid Inducer in Brassica napus

2021 ◽  
Author(s):  
Wei Zhang ◽  
YongTing Ma ◽  
ZhenDong Zhu ◽  
LiangJun Huang ◽  
Asif Ali ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Low Frequency ◽  
Genotypic Differences ◽  
Induction Effect ◽  
Haploid Induction ◽  
Ssr Analysis ◽  
Induction Process ◽  
Pure Lines ◽  
Chip Analysis ◽  
F1 Generation

Abstract Background Production of pure lines by double haploid induction provides a new way to achieve homozygosity earlier in Brassica napus. Previously, it is not known, whether the induction has obvious maternal genotypic differences. Results In this study, different karyogene and cytoplasmic genotype of Brassica napus was pollinated with the inducers Y3380 and Y3560. Using the identification of the ploidy, fertility and SSR analysis of the induced F1 generation, it was found that the ploidy and phenotype of the induced F1 plants were consistent with maternal parent. The SNP chip analysis revealed that induction efficiency was affected by the karyogene when the maternal cytoplasmic genotype was the same. However, this efficiency was affected by the cytoplasmic genotype when the karyogenes were same, and the offspring of the ogura cytoplasm easier to high-frequency inducer gene hybridization or low-frequency infiltration. Conclusion The induction effect is influenced by the interaction between maternal karyogene and cytoplasmic genotype, and the results from the partial hybridization of progeny chromosomes indicate that the induction process may be attributed to the selective elimination of paternal chromosome. This study provides a basis for exploring the mechanism of DH inducer in Brassica napus, and provides new insights for utilization of inducers inbreeding.

HOST ASSOCIATIONS IN SYMPATRIC POPULATIONS OF CHORISTONEURA OCCIDENTALIS FREEMAN AND C. RETINIANA (WALSINGHAM) (LEPIDOPTERA: TORTRICIDAE) IN SOUTH-CENTRAL OREGON AT HIGH POPULATION DENSITIES

1991 ◽  
Vol 123 (3) ◽  
pp. 713-715 ◽  
Author(s):  
Willis C. Schaupp
Keyword(s):  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Choristoneura Occidentalis ◽  
Western North America ◽  
Western Spruce Budworm ◽  
Population Densities ◽  
Sympatric Populations ◽  
Mixed Stands ◽  
South Central ◽  
White Fir

Sympatric, synchronous populations of conifer-feeding Choristoneura (Lepidoptera: Tortricidae) occur in western North America (Powell 1980). Choristoneura occidentalis Freeman, the western spruce budworm, co-exists with C. retiniana, the Modoc budworm, in mixed stands of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, and true firs, Abies spp. Choristoneura occidentalis has brown larvae and a broad geographic distribution associated with one of its principle hosts, Douglas-fir (Stehr 1967). Larvae of C. retiniana are green and feed on true firs, particularly white fir, Abies concolor (Gord. & Glend.) Lindl. (Stehr 1967; Carolin et al. 1987).

EFFECT OF TEMPORAL FACTORS ON REPRODUCTIVE ISOLATION BETWEEN CHORISTONEURA OCCIDENTALIS AND C. RETINIANA (LEPIDOPTERA: TORTRICIDAE)

1984 ◽  
Vol 116 (7) ◽  
pp. 991-1005 ◽  
Author(s):  
Andrew M. Liebhold ◽  
W. Jan A. Volney
Keyword(s):  
Circadian Rhythm ◽  
Reproductive Isolation ◽  
Effect Of Temperature ◽  
Choristoneura Occidentalis ◽  
Laboratory Studies ◽  
Male Attraction ◽  
South Central ◽  
Baited Traps ◽  
Laboratory Colony ◽  
Temporal Factors

AbstractThe seasonal distributions of Choristoneura occidentalis Freeman and C. retiniana (Walsingham) males attracted to pheromone sources overlapped considerably at two sites in south-central Oregon. Bimodality in the seasonal distributions of trapped males of both species was associated with a period of cool weather. The daily periods of female calling, and attraction of males to female-baited traps and to chemically baited traps overlapped greatly between the two species. However, these three aspects of C. occidentalis mating behavior began 1–2 h before those of C. retiniana. Under laboratory conditions, there was also considerable overlap in the calling periods of the two species; but again, C. occidentalis females initiated calling slightly earlier than did female C. retiniana. Females of both species continued to call many hours past the cessation of male attraction to pheromones in the field. Male attraction to pheromones occurred earlier on cool evenings than on warm evenings. Laboratory studies indicated a similar effect of temperature on timing of female calling. Little intraspecific variation in calling periodicity was observed among field-collected populations of each species. However, a C. occidentalis laboratory colony appeared to have partially lost its circadian rhythm of calling.

scholarly journals Selective fertilization in interspecific crosses of allotetraploid species of Gossypium

Botany ◽  
2012 ◽  
Vol 90 (3) ◽  
pp. 159-166 ◽  
Author(s):  
G.S. Pereira ◽  
R.L. Sousa ◽  
R.L. Araújo ◽  
L.V. Hoffmann ◽  
E.F. Silva ◽  
...  
Keyword(s):  
Upland Cotton ◽  
Interspecific Hybrids ◽  
Low Frequency ◽  
Pollen Competition ◽  
Interspecific Crosses ◽  
Gossypium Hirsutum L ◽  
Hybrid Production ◽  
Pollen Donor ◽  
Allotetraploid Species

The genus Gossypium is composed of both diploid and allotetraploid species. The five allotetraploid species of Gossypium are sexually compatible, and only partial sexual barriers have been described. Natural hybrids among them do not occur or occur in situ with very low frequency in Brazil in the rare places where cultivated upland cotton ( Gossypium hirsutum L.) occurs in a sympatric range with Gossypium barbadense L. or Gossypium mustelinum Miers. We evaluated the presence of pollen competition as a prezygotic barrier in crosses between upland cotton and G. barbadense and G. mustelinum. We found that G. barbadense pollinated with a mixture of 50% upland cotton and 50% G. barbadense pollen resulted in 17.4%–31.1% interspecific hybrids, depending upon the upland cotton genotype used as pollen donor. Mixtures containing pollen from G. mustelinum and upland cotton, used to pollinate G. mustelinum in proportions of 25%:75%, 50%:50%, and 75%:25%, produced 61.3%, 22.5%, and 3.6% interspecific hybrids, respectively. These low rates of hybrid production demonstrate that pollen competition is present with G. mustelinum and G. barbadense and confirms this mechanism as a sexual barrier.

Chromosome pairing affinities between Old and New World species of Bromus section Pnigma

1984 ◽  
Vol 62 (3) ◽  
pp. 581-585 ◽  
Author(s):  
K. C. Armstrong
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
New World ◽  
Genetic Factors ◽  
Low Frequency ◽  
World Species ◽  
The North ◽  
Evolutionary Pathways ◽  
Bromus Benekenii ◽  
Eurasian Species

A low frequency of allosyndetic chromosome pairing occurred in interspecific hybrids between species having large chromosomes (Bromus benekenii (Lange) Trimen, 2n = 4x = 28; B. ramosus Huds., 2n = 4x = 28; B. pacificus Shear, 2n = 4x = 28) and species having small chromosomes (B. erectus Huds., 2n = 4x = 28; B. inermis Leyss, 2n = 4x = 28; B. pumpellianus Scribn., 2n = 4x = 28; B. riparius Rehm, 2n = 10x = 70; and B. variegatus, 2n = 2x = 14). These results are consistent with the suggestion that the large (predominantly Eurasion) and small (predominantly American) chromosome species of section Pnigma have followed different evolutionary pathways. Chromosome pairing in interspecific hybrids revealed low affinities between the chromosomes of the Eurasian species B. ramosus and the North American species B. pacificus. Thus there was no evidence that B. ramosus contained a form of the L genome found in American species. However genetic factors suppressing homoeologous pairing could be present in the allotetraploid parents.

Sensory relationships of moths and bats sampled from two Nearctic sites

1983 ◽  
Vol 61 (8) ◽  
pp. 1752-1757 ◽  
Author(s):  
James H. Fullard ◽  
M. Brock Fenton ◽  
Caren L. Furlonger
Keyword(s):  
British Columbia ◽  
Low Frequency ◽  
Predation Pressure ◽  
Auditory Sensitivity ◽  
Frequency Sensitivity ◽  
South Central

The auditory sensitivity characteristics of moths sampled in southeastern Ontario and south-central British Columbia were compared in four separate bandwidths from 5 kHz to 110 kHz. British Columbian moths exhibit a significantly greater sensitivity to frequencies from 30 kHz to 75 kHz (midrange) then do their Ontario counterparts. Measurements taken of echolocating bats at both these sites reveal a greater diversity of acoustic frequencies emitted by British Columbia bats and we suggest sympatric moths have responded to this increased predation pressure by selectively maximizing their frequency sensitivity pertinent to the bats they are exposed to. The possibility exists that the low frequency British Columbia bat, Euderma maculatum, may be foraging on moths as a result of its echolocation signals for which sympatric moths show no particular sensitivity.

Recombination and chiasmata: few but intriguing discrepancies

Genome ◽  
1996 ◽  
Vol 39 (3) ◽  
pp. 473-484 ◽  
Author(s):  
J. Sybenga
Keyword(s):  
Meiotic Recombination ◽  
Interspecific Hybrids ◽  
Recombination Frequency ◽  
Low Frequency ◽  
Mapping Algorithm ◽  
Synaptonemal Complex Formation ◽  
Frequency Map ◽  
Local Relaxation ◽  
Homoeologous Chromosomes ◽  
Chiasma Interference

The paradigm that meiotic recombination and chiasmata have the same basis has been challenged, primarily for plants. High resolution genetic mapping frequently results in maps with lengths far exceeding those based on chiasma counts. In addition, recombination between specific homoeologous chromosomes derived from interspecific hybrids is sometimes much higher than can be explained by meiotic chiasma frequencies. However, almost the entire discrepancy disappears when proper care is taken of map inflation resulting from the shortcomings of the mapping algorithm and classification errors, the use of dissimilar material, and the difficulty of accurately counting chiasmata. Still, some exchanges, especially of short interstitial segments, cannot readily be explained by normal meiotic behaviour. Aberrant meiotic processes involving segment replacement or insertion can probably be excluded. Some cases of unusual recombination are somatic, possibly premeiotic exchange. For other cases, local relaxation of chiasma interference caused by small interruptions of homology disturbing synaptonemal complex formation is proposed as the cause. It would be accompanied by a preference for compensating exchanges (negative chromatid interference) resulting from asymmetry of the pairing chromatid pairs, so that one side of each pair preferentially participates in pairing. Over longer distances, the pairing face may switch, causing the normal random chromatid participation in double exchanges and the relatively low frequency of short interstitial exchanges. Key words : recombination frequency, map length, chiasmata, discrepancy, chromatid interference.

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