NATURAL HYBRIDIZATION BETWEEN CARDUUS ACANTHOIDES AND CARDUUS NUTANS IN ONTARIO

1956 ◽  
Vol 34 (1) ◽  
pp. 71-85 ◽  
Author(s):  
R. J. Moore ◽  
G. A. Mulligan
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
First Generation ◽  
Natural Hybridization ◽  
Clear Correlation ◽  
Hybrid Index ◽  
Carduus Acanthoides ◽  
Hybrid Plants ◽  
Gametic Selection ◽  
Generation Hybrid

A survey was made of the occurrence of natural hybrids between two species of introduced thistles, Carduus acanthoides L. var. acanthoides and C. nutans L. var. nutans, in Grey County, Ontario. The population of one field was studied in detail. Specimens were taken and their morphological variation was evaluated by means of a hybrid index. These species have different chromosome numbers: C. acanthoidcs L., 2n = 22; C. nutans L., 2n = 16. All the intervening numbers were found in the hybrids. There is a clear correlation between chromosome number and hybrid index: plants with the chromosome number of a first generation hybrid have an index intermediate between those of the parental species. The chromosome numbers of seedlings raised from seed collected from hybrid plants were determined. It was found that seedlings with the number 2n = 22 were much more frequent than those with other numbers. It is suggested that both ecological and gametic selection are acting in this area to favor production and survival of plants with the chromosome number and morphology of C. acanthoides.

NATURAL SELECTION AMONG HYBRIDS BETWEEN CARDUUS ACANTHOIDES AND C. NUTANS IN ONTARIO

1961 ◽  
Vol 39 (2) ◽  
pp. 269-279 ◽  
Author(s):  
Gerald A. Mulligan ◽  
Raymond J. Moore
Keyword(s):  
Natural Selection ◽  
Morphological Variation ◽  
Natural Hybridization ◽  
Hybrid Index ◽  
Local Conditions ◽  
Carduus Acanthoides ◽  
Carduus Nutans ◽  
Waste Land ◽  
Southern Half

Natural hybridization is occurring between two introduced thistles, Carduus acanthoides L. and C. nutans L., in the southern half of Grey County, Ontario. The morphological variation of plants in 37 fields, including a field near Priceville previously studied in 1952, was evaluated by means of a hybrid index in 1957. Carduus nutans was first established in the hybrid area and C. acanthoides was introduced later, probably from the region northwest of Owen Sound, into waste land near Flesherton, where hybridization first occurred. Many large hybrid populations were found in the southern portion of Grey County and most of these hybrids were very similar to C. acanthoides in morphology. It was concluded that there is a numerical supremacy of acanthoides-type hybrid segregates in the hybrid area, and that such hybrids are better adapted for survival under local conditions than C. nutans and will probably supplant the latter species.

Intergeneric hybidization of sunflower (Helianthus annuus L.) with spiny plumeless thistle (Carduus acanthoides L.)

Helia ◽  
2020 ◽  
Vol 43 (72) ◽  
pp. 83-98
Author(s):  
Miroslava Hristova-Cherbadzhi
Keyword(s):  
Helianthus Annuus ◽  
Wild Species ◽  
Rapd Markers ◽  
Morphological Characters ◽  
Hybrid Progeny ◽  
Intermediate Type ◽  
Carduus Acanthoides ◽  
Hybrid Plants ◽  
Generation Hybrid ◽  
Heterosis Breeding

AbstractCarduus acanthoides L (spiny plumeless thistle) a biannual wild species with 2n = 22 chromosomes was crossed with Helianthus annuus L. When crossing, pollen from C. acanthoides germinated and pollinated the stigmas of sunflower lines HA 89A after 48 h. The crossability rate was low, but seeds and hybrid plants were obtained. The F1 plants strongly resembled the cultivated sunflower with the most important bio-morphological characters, even though they had an intermediate type of heritability. The hybrid nature was confirmed by RAPD markers. The polymorphism between H. annuus, C. acanthoides, and their F1 hybrids was studied using RAPD. The result showed introgression of C. acanthoides in the hybrid progeny. It was established that the wild species carried Rf genes for the CMS PET-1. After self-pollination and sib-pollination of the F1 plants and back-crossing with cultivated sunflower, F2, BC1 and next generation hybrid progenies were obtained. The investigation encompassed the period 2000–2007 and 2014–2018. Some of the new lines have been included in a heterosis breeding program for developing hybrids for the sunflower market.

FURTHER STUDIES ON NATURAL SELECTION AMONG HYBRIDS OF CARDUUS ACANTHOIDES AND CARDUUS NUTANS

1964 ◽  
Vol 42 (12) ◽  
pp. 1605-1613 ◽  
Author(s):  
R. J. Moore ◽  
G. A. Mulligan
Keyword(s):  
Natural Selection ◽  
Chromosome Number ◽  
Parental Species ◽  
Experimental Studies ◽  
Great Decrease ◽  
Carduus Acanthoides ◽  
Carduus Nutans ◽  
Experimental Plots ◽  
Better Than ◽  
Made In

A third 5-year survey made in 1962 of Carduus acanthoides, C. nutans, and their hybrids in Grey Co., Ontario, revealed that a great decrease in these populations had occurred. C. acanthoides and hybrids similar to this species had survived better than C. nutans but very little spread of either species seemed to have occurred in 1957–1962. In experimental plots the hybrid has been made and backcrossed to the parental species. The species differ in chromosome number (C. acanthoides, 2n = 22; C. nutans, 2n = 16) and hybrids have intermediate numbers. Evidence was found from field and experimental studies that the progeny of the F1 hybrid included a greater proportion of seedlings with the higher chromosome numbers than with the lower and intermediate numbers. It is suggested that this selection may operate through the rejection of the longer chromosomes received from C. nutans, which, in certain zygotic combinations may constitute an excess of chromatin lethal to the zygote.

scholarly journals Microsatellite-Based Genetic Structure and Hybrid Detection in Alpacas Bred in Poland

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2193
Author(s):  
Angelika Podbielska ◽  
Katarzyna Piórkowska ◽  
Tomasz Szmatoła
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
First Generation ◽  
Expected Heterozygosity ◽  
Hybrid Detection ◽  
Average Coefficient ◽  
Mixed Origin ◽  
Generation Hybrid

This study aimed to characterize the population structure and genetic diversity of alpacas maintained in Poland using 17 microsatellite markers recommended by the International Society for Animal Genetics. The classification of llamas, alpacas, and hybrids of both based on phenotype is often difficult due to long-term admixture. Our results showed that microsatellite markers can distinguish alpacas from llamas and provide information about the level of admixture of one species in another. Alpacas admixed with llamas constituted 8.8% of the tested individuals, with the first-generation hybrid displaying only 7.4% of llama admixture. The results showed that Poland hosts a high alpaca genetic diversity as a consequence of their mixed origin. More than 200 different alleles were identified and the average observed heterozygosity and expected heterozygosity values were 0.745 and 0.768, respectively, the average coefficient of inbreeding was 0.034, and the average polymorphism information content value was 0.741. The probability of exclusion for one parent was estimated at 0.99995 and for two parents at 0.99999.

scholarly journals New Contribution to the Knowledge on the Chromosome Numbers of Turkish Cerambycidae (Coleoptera)

2021 ◽  
Vol 69 (2) ◽  
pp. 93-99
Author(s):  
Yavuz Koçak ◽  
Elmas Yağmur
Keyword(s):  
Chromosome Number ◽  
Sex Determination ◽  
Chromosome Numbers ◽  
Chromosome Count ◽  
Chromosomal Number ◽  
The Poor ◽  
Karyological Data ◽  
First Time

Information on the karyotypes of Turkish species of Cerambycidae is scanty. Our study contributes to the knowledge of the karyological data (chromosomal number and mechanism of sex determination) of five Turkish longicorn beetles; karyotypes of four taxa, one endemic, are described for the first time and for the remaining one, Purpuricenus budensis (Götz, 1783), the previously published chromosome count is confirmed. The chromosome number of Purpuricenus desfontainii inhumeralis Pic, 1891 and Purpuricenus budensis (Götz, 1783) (Cerambycinae, Trachyderini) was found to be 2n = 28 (13 + Xyp); Clytus rhamni Germar, 1817 and Plagionotus floralis (Pallas, 1773) (Cerambycinae, Clytini) 2n = 20 (9 + Xyp); and the endemic Dorcadion triste phrygicum Peks, 1993 (Lamiinae, Dorcadionini) 2n = 24 (11 + Xyp). In view of the paucity of data available until now, our study is important for both to improve the poor karyological knowledge of Turkish Cerambycidae and to provide an incentive for other researchers.

scholarly journals Karyotype Analysis of Alnus Mill. (Betulaceae) Species Originating From Northeastern Asia

2010 ◽  
Vol 59 (1-6) ◽  
pp. 219-223 ◽  
Author(s):  
Liu Jun ◽  
Ren Bao-Qing ◽  
Luo Peigao ◽  
Ren Zhenglong
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Karyotype Analysis ◽  
Full Potential ◽  
Northeastern Asia ◽  
Ploidy Levels ◽  
Genetic Makeup ◽  
Fossil Records

Abstract Alnus Mill. (alder) is an ecologically valuable tree genus. It is essential to study its genetic makeup in order to use alder trees to their full potential. Five specimens from four Alnus species (A. mandshurica, A. pendula, A. sibirica, and A. sieboldiana), found in northeastern Asia, were subjected to karyotype analysis. The analysis showed that these tree samples could be divided into three categories based on chromosome numbers or ploidy levels: viz., 2n = (4x) = 28, 2n = (8x) = 56 and 2n = (16x) = 112. The differences in chromosome number and karyotype parameters among Alnus species and even within the same species possibly resulted from natural polyploidization. Comparing the chromosome numbers of Alnus species in China with those in Japan showed that there appear to be only two categories in China, whereas there are up to five categories in Japan. The earliest fossil records of Alnus pollen were also discovered in Japan. We conclude that the center origin of Alnus spp. is Japan rather than China.

The Chromosome Numbers and Nuclear Cytology of Some Common British Serpulids

1960 ◽  
Vol s3-101 (56) ◽  
pp. 395-400
Author(s):  
S. DASGUPTA ◽  
A. P. AUSTIN
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Somatic Cells ◽  
Diploid Chromosome Number ◽  
Iron Alum ◽  
Artificial Fertilization ◽  
Nuclear Cytology

The chromosome numbers of Hydroides norvegica, Mercierella enigmatica, and Pomatoceros triqueter were determined from squashes of somatic cells in young embryos obtained by artificial fertilization, and stained with iron-alum/aceto-carmine. All had a diploid count of zn = 26 chromosomes. Mitotic and meiotic divisions in the 5 species of Spirorbis examined, and in Filograna implexa, all revealed a diploid chromosome number of 2n = 20. A diploid chromosome number of 14 is suggested for the ancestral serpulid.

Chromosome studies on African plants. 9. Chromosome numbers in Ehrharta (Poaceae: Ehrharteae)

Bothalia ◽  
1989 ◽  
Vol 19 (1) ◽  
pp. 125-132 ◽  
Author(s):  
J. J. Spies ◽  
E. J. L. Saayman ◽  
S. P. Voges ◽  
G. Davidse
Keyword(s):  
Chromosome Number ◽  
Ploidy Level ◽  
Chromosome Numbers ◽  
Basic Chromosome Number ◽  
B Chromosomes ◽  
Basic Chromosome ◽  
Cytogenetic Studies ◽  
African Plants ◽  
First Time

Cytogenetic studies of 53 specimens of 14 species of the genus  Ehrharta Thunb. confirmed a basic chromosome number of 12 for the genus. Chromosome numbers for 13 species are described for the first time. The highest ploidy level yet observed in the genus (2n = lOx = 120) is reported for E. villosa var.  villosa. B chromosomes were observed in several specimens of four different species.

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