Progeny Trials in an Introgressive Hybrid Population of Anigozanthos Labill. (Haemodoraceae)

1978 ◽  
Vol 26 (3) ◽  
pp. 309 ◽  
Author(s):  
SD Hopper
Keyword(s):  
Floral Morphology ◽  
Natural Hybridization ◽  
F1 Hybrids ◽  
Hybrid Population ◽  
Evolutionary Significance ◽  
Gene Exchange ◽  
Present Evidence ◽  
Close Proximity ◽  
Two Generations ◽  
Open Question

The floral morphology and pollen fertility of progeny from open-pollinated plants in a hybrid population of A. manglesii and A. humilis were measured to investigate patterns of gene exchange occurring between hybrid and parental individuals. Introgression occurs where the two species and F1 hybrids grow in close proximity in the population but the possibility of more backcrossing to A. manglesii than to A. humilis remains an open question on present evidence. The morphological effects of hybridization became cryptic in some cases within one and in most cases within two generations of backcrossing. The possible evolutionary significance of natural hybridization between A. manglesii and A. humilis is discussed in the light of these results.

Contrasting Success of Natural Hybridization in Two Eucalyptus Species Pairs

1980 ◽  
Vol 28 (2) ◽  
pp. 167 ◽  
Author(s):  
DW Drake
Keyword(s):  
Principal Component ◽  
Flowering Phenology ◽  
Natural Hybridization ◽  
F1 Hybrids ◽  
Hybrid Population ◽  
Eucalyptus Species ◽  
Major Barrier ◽  
Species Pairs ◽  
Plant Hybridization ◽  
Hybrid Number

A morphological study with univariate and principal component analyses of mature tree and open-pollinated seedling populations shows that natural hybridization is occurring between Eucalyptus melanophloia and E. crebra, and E. populnea and E. crebra (subgenus Symphyomyrtus, section Adnataria). The level of successful hybridization in these two systems, where fundamental genetic (reproductive) and ecological (habitat and spatial) barriers are absent, is examined. Within the ecotone, hybrids between E. melanophloia and E. crebra are about one-fifth as frequent as those between E. populnea and E. crebra. Analyses of the phenotype/genotype compositions of the hybrid populations, the patterns of segregation, and outcrossing frequencies between the species pairs indicate the level of development of the hybrid populations. All E. melanophloia × E. crebra hybrids appear to be F1 hybrids. In contrast, the E.populnea x E. crebra hybrid population attains a much higher level of development in terms of both hybrid number and genotypic complexity. Flowering phenology is a major barrier to E. melanophloia × E. crebra hybrid formation compared with the other hybrids, although it is considered an incomplete barrier and alone may not explain the diversity of hybrid success which occurs.A theory of plant hybridization which incorporates the concept of hybridization success is presented and discussed in relation to the two hybridizing systems, as a basis for further investigating the mechanisms involved.

The structure and dynamics of a hybrid population of Anigozanthos manglesii D. Don and A. humilis Lindl. (Haemodoraceae)

1977 ◽  
Vol 25 (4) ◽  
pp. 413 ◽  
Author(s):  
SD Hopper
Keyword(s):  
Interspecific Hybridization ◽  
Pollen Fertility ◽  
Census Data ◽  
F1 Hybrids ◽  
Hybrid Population ◽  
Floral Colour ◽  
Gene Exchange ◽  
Structure And Dynamics ◽  
Threefold Increase ◽  
The Face

The structure of a hybrid kangaroo paw population (Anigozanthos Labill.) in the shire cemetery at Gingin, Western Australia, was analysed from multivariate morphometric, pollen fertility and floral colour data. A. manglesii D. Don. comprised 87% of the population of 9547 flowering individuals in 1976, and occupied the lower, wetter areas of the cemetery to the exclusion of A. humilis Lindl. A. humilis (11 % of the population) occurred at the greatest density on the higher, drier areas. The intervening ecotonal regions were occupied by both species, and by the majority of F1 hybrids (0.5 % of the population) and backcrosses (c. 2%). Census data documented a threefold increase in the number of A. manglesii individuals, a slight increase in the number of F1 hybrids, and a decrease in the number of A. humilis by a third over a 3-year study period. These data suggest the occurrence of a limited amount of introgressive gene exchange in the face of potent barriers to interspecific hybridization.

scholarly journals Natural hybridization between two butterfly bushes in Tibet: dominance of F1 hybrids promotes strong reproductive isolation   

2020 ◽  
Author(s):  
Rongli Liao ◽  
Weibang Sun ◽  
Yongpeng Ma
Keyword(s):  
Reproductive Isolation ◽  
Parental Species ◽  
Morphological Characters ◽  
Natural Hybridization ◽  
Hybrid Origin ◽  
F1 Hybrids ◽  
Evolutionary Significance ◽  
Sympatric Populations ◽  
Hybrid Species ◽  
Intergenic Spacers

Abstract Background: F1 hybrids acting as a bridgehead for producing later generation hybrids can have evolutionary significance through strengthening reproductive isolation or facilitating gene flow between parental species, depending on whether backcrossing can occur. It had been suggested that the Tibetan plant Buddleja wardii was a hybrid species between B. alternifolia and B. crispa based on their sympatric distributions and the morphological characters in last century. Till now however, we still have limited evidence to prove key issues to B. wardii, like if it is of hybrid origin indeed and whether it is currently a true hybrid species already.Results: In the present study, two sympatric populations of these three taxa were examined and compared using four nuclear genes and three chloroplast intergenic spacers, as well as with 10 morphological characters. Our results suggest that at both sites B. × wardii was likely to be a hybrids between B. alternifolia and B. crispa, and moreover, most of the hybrids present were confirmed to be F1s. This was further supported by morphology as no transgressive characters were detected. B. crispa was found to be the maternal parent in one population (BH), while in the second population (TJ), it was difficult to distinguish the hybridization direction due to shared haplotypes of cpDNA between B. alternifolia and B. crispa. Conclusions: These results provide evidence that the natural hybrids between B. alternifolia and B. crispa mainly comprise F1 hybrids, which have subsequently been given the name B. wardii. The F1 hybrids have also contributed to strong reproductive isolation between parental species.

scholarly journals Natural Hybridization between Two Butterfly Bushes in Tibet: Dominance of F1 Hybrids Promotes Strong Reproductive Isolation

2020 ◽  
Author(s):  
Rongli Liao ◽  
Weibang Sun ◽  
Yongpeng Ma
Keyword(s):  
Reproductive Isolation ◽  
Parental Species ◽  
Morphological Characters ◽  
Natural Hybridization ◽  
Hybrid Origin ◽  
F1 Hybrids ◽  
Evolutionary Significance ◽  
Sympatric Populations ◽  
Hybrid Species ◽  
Intergenic Spacers

Abstract Background: F1 hybrids acting as a bridgehead for producing later generation hybrids can have evolutionary significance through strengthening reproductive isolation or facilitating gene flow between parental species, depending on whether backcrossing can occur. It had been suggested that the Tibetan plant Buddleja wardii was a hybrid species between B. alternifolia and B. crispa based on their sympatric distributions and the morphological characters in last century. Till now however, we still have limited evidence to prove key issues to B. wardii, like if it is of hybrid origin indeed and whether it is currently a true hybrid species already.Results: In the present study, two sympatric populations of these three taxa were examined and compared using four nuclear genes and three chloroplast intergenic spacers, as well as with 10 morphological characters. Our results suggest that at both sites B. × wardii was likely to be a hybrids between B. alternifolia and B. crispa, and moreover, most of the hybrids present were confirmed to be F1s. This was further supported by morphology as no transgressive characters were detected. B. crispa was found to be the maternal parent in one population (BH), while in the second population (TJ), it was difficult to distinguish the hybridization direction due to shared haplotypes of cpDNA between B. alternifolia and B. crispa. Conclusions: These results provide evidence that the natural hybrids between B. alternifolia and B. crispa mainly comprise F1 hybrids, which have subsequently been given the name B. wardii. The F1 hybrids have also contributed to strong reproductive isolation between parental species.

EVALUATION OF HYBRID SPRING WHEAT POPULATIONS

2018 ◽  
pp. 37-39
Author(s):  
O. V. Gladysheva ◽  
Т. А. Barkovskaya
Keyword(s):  
Correlation Coefficient ◽  
Spring Wheat ◽  
Dominant Role ◽  
F1 Hybrids ◽  
Hybrid Population ◽  
Selection Of

This article presents the results of a study of hybrid spring wheat populations. Revealed different patterns of inheritance of important traits in F1 hybrids, which is caused by hereditary features of the original forms and circumstances. Analysis of hybrid populations showed that the dominant role in the formation of 1000 grains mass belongs to productivity and weight of grain with an ear, correlation coefficient r = 0.90 and amounted to r = 0.73, respectively. Found that the hybrid population in F4-5, created on the basis of grades Moscow 35, Esther, Agatha, Rome, Saratovskaya 29 (Russia), Ostinka (Ukraine) are a valuable material for selection of highly productive genotypes for future use breeding process. 

Natural hybridization between an outcrossing and a selfingPhlox (Polemoniaceae): The maternal species of F1 hybrids

1999 ◽  
Vol 218 (1-2) ◽  
pp. 153-158 ◽  
Author(s):  
Carolyn J. Ferguson ◽  
Donald A. Levin ◽  
Robert K. Jansen
Keyword(s):  
Natural Hybridization ◽  
F1 Hybrids

scholarly journals Addressing Practical Issues Related Tto Nursing Care For International Visitors To Hiroshima

2014 ◽  
Vol 48 (2) ◽  
pp. 299-307 ◽  
Author(s):  
Mariko Nishikawa ◽  
Kiyoka Niiya ◽  
Masako Okayasu
Keyword(s):  
Foreign Language ◽  
Tourist Destinations ◽  
Word Analysis ◽  
Quality Of Patient Care ◽  
Close Proximity ◽  
Open Question ◽  
Japanese Nurses ◽  
Nursing Professionals ◽  
International Visitors

When nine million foreigners visited Japan in 2013, the federal government set a goal to attract an additional two and a half million visitors including medical tourists by 2020. This research investigates the attitudes and concerns of Japanese nurses when they are in a situation dealing with foreign patients. The data were collected from March through September 2010, from 114 nurses at three hospitals, in close proximity to popular tourist destinations in Hiroshima. A questionnaire was developed for this research, named Mari Meter, which included a section to write answers to an open question for the nurses to express their opinions. These responses were examined statistically and by word analysis using Text Mining Studio. Japanese nurses expressed greatest concern about payment options, foreign language skills, and issues of informed consent, when dealing with foreigners. The results confirm that, in order to provide a high quality of patient care, extra preparation and a greater knowledge of international workers and visitors are required by nursing professionals in Japan.


scholarly journals Reciprocal F1 hybrids of two inbred mouse strains reveal parent-of-origin and perinatal diet effects on behavior and expression

2018 ◽  
Author(s):  
Daniel Oreperk ◽  
Sarah A Schoenrock ◽  
Rachel McMullan ◽  
Robin Ervin ◽  
Joseph Farrington ◽  
...  
Keyword(s):  
Complex Traits ◽  
Detection System ◽  
Inbred Mouse ◽  
F1 Hybrids ◽  
Hybrid Population ◽  
Psychiatric Disease ◽  
Mouse Strains ◽  
Imprinted Genes ◽  
F1 Hybrid ◽  
Parent Of Origin

ABSTRACTParent-of-origin effects (POEs) in mammals typically arise from maternal effects or from imprinting. Mutations in imprinted genes have been associated with psychiatric disorders, as well as with changes in a handful of animal behaviors. Nonetheless, POEs on complex traits such as behavior remain largely uncharacterized. Furthermore, although perinatal environmental exposures, such as nutrient deficiency, are known to modify both behavior and epigenetic effects generally, the architecture of environment-by-POE is almost completely unexplored. To study POE and environment-by-POE, we employ a relatively neglected but maximally powerful POE-detection system: a reciprocal F1 hybrid population. We exposed female NOD/ShiLtJxC57Bl/6J and C57Bl/6JxNOD/ShiLtJ mice, in utero, to one of four different diets, then after weaning recorded their whole-brain gene expression, as well as a set of behaviors that model psychiatric disease. Microarray expression data revealed an imprinting-enriched set of over a dozen genes subject to POE; the POE on the most significantly affected gene, Carmil1 (a.k.a. Lrrc16a), was validated using qPCR in the same and in a new set of mice. Several behaviors, especially locomotor behaviors, also showed POE. Interestingly, Bayesian mediation analysis suggests Carmil1 expression suppresses behavioral POE, and Airn suppresses POE on Carmil1 expression. A significant diet-by-POE was observed on one behavior, one imprinted gene, and over a dozen non-imprinted genes. Beyond our particular results, our study demonstrates a reciprocal F1 hybrid framework for studying POE and environment-by-POE on behavior.

scholarly journals Clumps in stellar winds

2014 ◽  
Vol 1 ◽  
pp. 39-41 ◽  
Author(s):  
J. S. Vink
Keyword(s):  
Mass Loss ◽  
Massive Stars ◽  
Stellar Winds ◽  
Present Evidence ◽  
Close Proximity ◽  
Stellar Photosphere ◽  
Loss Rates

Abstract. We discuss the origin and quantification of wind clumping and mass–loss rates (Ṁ), particularly in close proximity to the Eddington (Γ) limit, relevant for very massive stars (VMS). We present evidence that clumping may not be the result of the line-deshadowing instability (LDI), but that clumps are already present in the stellar photosphere.

Chromosomal Differentiation Among Ecotypes of Phalaris aquatica L.

1980 ◽  
Vol 28 (6) ◽  
pp. 645 ◽  
Author(s):  
E Putievsky ◽  
RN Oram ◽  
K Malafant
Keyword(s):  
Pollen Grains ◽  
F1 Hybrids ◽  
Male Sterile ◽  
Geographic Origins ◽  
Meiotic Irregularities ◽  
Structural Differences ◽  
Two Generations ◽  
Chromosomal Differentiation ◽  
Mother Cells ◽  
F2 Progeny

Seventy-two hybrids of P. aquatica were made among 13 diverse Mediterranean ecotypes and cv. Australian, and five indicators of hybrid abnormality were measured in the first two generations. The proportions of stainable, apparently normal pollen grains formed by F, hybrids varied between 5 and 98% and their spikelet fertility ranged from 19 to 77%. Of the 43 hybrids that were derived from pairs of self-incompatible parents, 13 were highly self-compatible. Crosses between lines from different groups of parents produced F2 progeny containing up to 17% of lethal seedlings and up to 39% of male sterile plants. In the cross between cv. Australian and the Moroccan ecotype, CPI 19331: the frequency ofzebra-striped lethal seedlings was as high as 33% in F2 progenies, but only 0 or 1% in back-crosses to either parent. Hence the zebra-striped phenotype was not caused by a mutation existing in the parents but rather by deletions or duplications generated during meiosis in the F1 hybrids. Many meiotic irregularities were observed in the pollen mother cells of the F1 and F2 hybrids between cv. Australian and CPI 19331. These included small loops, acentric fragments, univalents and multivalents at diakinesis, and bridges at anaphase I, indicating that the genomes of these two lines differed by several inversions and interchanges. These structural differences would lead to a range of duplications and deficiencies in the gametes. and hence could account for each of the five kinds of hybrid abnormality observed in the F1 and F2 generations. One aneuploid F2 plant with 25 chromosomes was found. A dihaploid plant in cv. Australian had an average of 4.3 bivalents per pollen mother cell, whereas virtually all chromosomes in the tetraploid parental lines paired as bivalents. Thus, P. aquatica is a segmental allotetraploid with a system which prevents homoeologous pairing in tetraploids but not in dihaploids. The partial barriers to hybridization between P. aquatica lines are not closely related to their geographic origins or varietal classifications. These barriers may hinder but have not prevented the recombination of parental traits during the development of improved cultivars.

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