Natural Hybrids of Elymus cinereus x Sitanion hystrix

1962 ◽  
Vol 89 (4) ◽  
pp. 217 ◽  
Author(s):  
Douglas R. Dewey ◽  
A. H. Holmgren
Keyword(s):  
Natural Hybrids ◽  
Sitanion Hystrix

INVESTIGATIONS ON RUBBER-BEARING PLANTS: IV. CYTOGENETIC STUDIES IN ASCLEPIAS (TOURN.) L.

1946 ◽  
Vol 24c (3) ◽  
pp. 66-73 ◽  
Author(s):  
Raymond J. Moore
Keyword(s):  
Chromosome Number ◽  
Natural Hybrids ◽  
Rubber Bearing ◽  
Cytogenetic Studies

The chromosome number of eight species and varieties of Asclepias (A. syriaca, A. incarnata and variety pulchra and forma albiflora, A. Sullivantii, A. tuberosa, A. curassavica, A. speciosa) was found to be 2n = 22.Various interspecific pollinations were attempted without success. A cross of A. incarnata with forma albiflora was successful.Possible natural hybrids between A. syriaca and A. speciosa and between A. incarnata and var. pulchra and forma albiflora are described. Two unusual chimaeral plants of A. incarnata that produced several stems of forma albiflora are described.

CYTOLOGY OF POPLAR SPECIES AND NATURAL HYBRIDS

1938 ◽  
Vol 16c (11) ◽  
pp. 445-455 ◽  
Author(s):  
F. H. Peto
Keyword(s):  
Size Distribution ◽  
Genetic Factors ◽  
Chromosome Complement ◽  
Pollen Grains ◽  
Pollen Size ◽  
Cell Nuclei ◽  
Good Pollen ◽  
Natural Hybrids ◽  
Pollen Diameter ◽  
High Degree

Complete analyses of pollen-mother-cell nuclei at first metaphase, percentage good pollen, pollen diameter and pollen-size distribution were determired for the following poplar species and natural hybrids: Populus grandidentata Michx., P. tremuloides Michx., P. eugenei Simon Louis, P. alba L., P. canescens Sm., natural hybrids of P. alba × P. grandidentata and of P. alba × P. tremuloides.Both of the P. alba and two of the four P. canescens trees examined were triploids (2n = 57) while all other trees examined were diploids (2n = 38). Meiotic observations on the natural hybrids indicated a high degree of homology between the chromosomes of P. alba and the native aspens (P. grandidentata and P. tremuloides), since 17 to 19 bivalents were usually found at first metaphase. In collections from one triploid P. canescens and two diploid alba-grandidentata hybrid trees, failure of a high proportion of the chromosomes to pair was attributed to genetic factors limiting pairing, rather than to non-homology.Pollen characters such as percentage good pollen, pollen diameter, and pollen size distribution were, in most cases, not indicative of the chromosome number or pairing relations at first metaphase. Consequently, triploids could not be detected by pollen observations under the conditions of this experiment. In spite of the lack of correlation between first metaphase and pollen observations, abnormally large pollen grains were observed in collections from several of the trees, and these were considered to contain the diploid or unreduced chromosome complement. The tendency for the poplars to produce unreduced pollen grains probably accounts for the number of triploid trees discovered in Canada and Sweden.

Pollen Transfer by Natural Hybrids and Parental Species in an Ipomopsis Hybrid Zone

Evolution ◽  
1998 ◽  
Vol 52 (6) ◽  
pp. 1602 ◽  
Author(s):  
Diane R. Campbell ◽  
Nickolas M. Waser ◽  
Paul G. Wolf
Keyword(s):  
Hybrid Zone ◽  
Parental Species ◽  
Pollen Transfer ◽  
Natural Hybrids

Natural Hybrids of Primula elatior Schreb.

1936 ◽  
Vol 148 (3) ◽  
pp. 161-165 ◽  
Author(s):  
R. Melville
Keyword(s):  
Natural Hybrids

CYTOGENETICS OF SOME SPECIES AND NATURAL HYBRIDS IN PROSOPIS (LEGUMINOSAE)

1975 ◽  
Vol 17 (2) ◽  
pp. 253-262 ◽  
Author(s):  
J. H. Hunziker ◽  
L. Poggio ◽  
C. A. Naranjo ◽  
R. A. Palacios ◽  
A. B. Andrada
Keyword(s):  
Chromosome Number ◽  
Interspecific Hybrids ◽  
Vegetative Reproduction ◽  
General Lack ◽  
Cytological Data ◽  
Natural Hybrids ◽  
Regular Meiosis ◽  
Putative Hybrids

Cytological results on 12 species and 4 putative hybrids of Prosopis are presented. Of these, 5 species and 4 hybrids have been hitherto unknown cytologically. The following species proved to be diploid (2n = 28) and constitute new chromosome number determinations for the genus: P. algarobilla Griseb., P. hassleri Harms, P. nigra (Griseb.) Hieron., P. patagonica Speg., P. tamarugo Phil. The diploid nature of some races of P. juliflora (Sw.) DC. is established; apparently under this taxon there are also tetraploid populations. The following putative interspecific hybrids showed regular meiosis with formation of 14 bivalents: P. vinalillo Stuck. (P. ruscifolia × P. alba?), P. alba × P. nigra? and P. hassleri × P. ruscifolia?.So far 28 taxa of the genus have been studied cytologically; 27 of these are diploid. The scarcity of polyploidy in the genus (3.5%) might be a consequence of the almost general lack of means of vegetative reproduction and of the absence of chromosome repatterning in primary speciation. Results of other authors concerning cytological data are also discussed.

Tetrodotoxin distribution in natural hybrids between the pufferfish species Takifugu rubripes and Takifugu porphyreus

2018 ◽  
Vol 85 (1) ◽  
pp. 237-245
Author(s):  
Ryohei Tatsuno ◽  
Yumi Miyata ◽  
Hiroyuki Yoshikawa ◽  
Yasuko Ino ◽  
Tsubasa Fukuda ◽  
...  
Keyword(s):  
Takifugu Rubripes ◽  
Natural Hybrids

Law and Science: An Essay on Links and Socio-Natural Hybrids

2001 ◽  
Author(s):  
David S. Caudill
Keyword(s):  
Natural Hybrids ◽  
Law And Science

Experimental trypanosomiasis of natural hybrids between house mouse subspecies

1999 ◽  
Vol 29 (7) ◽  
pp. 1011-1016 ◽  
Author(s):  
Jean-Marc Derothe ◽  
Claude Loubes ◽  
Marco Perriat-Sanguinet ◽  
Annie Orth ◽  
Catherine Moulia
Keyword(s):  
House Mouse ◽  
Natural Hybrids

The use of flavonoid glycosides for the identification of elm hybrids

1993 ◽  
Vol 23 (4) ◽  
pp. 611-616 ◽  
Author(s):  
Daniela Heimler ◽  
Andrea Pieroni ◽  
Lorenzo Mittempergher ◽  
Pietro Buzzini
Keyword(s):  
High Performance ◽  
Parental Species ◽  
Flavonoid Glycoside ◽  
Flavonoid Glycosides ◽  
Natural Hybrids ◽  
Probable Presence ◽  
Multivariate Discriminant ◽  
Number Of Individuals ◽  
Layer Chromatography ◽  
Putative Hybrids

The utilization of elm leaf flavonoids as biochemical markers for the identification of artificial and natural hybrids of elm species is discussed. Two to 11 individuals from controlled crosses of Ulmuscarpinifolia Gled., Ulmuspumila L., Ulmusparvifolia Jacq., and Ulmusjaponica (R.) Sarg. were examined. Five to seven individuals from each parental species, and a number of putative hybrids between U. carpinifolia and U. pumila that naturally occur in central and northern Italy, were also examined. Quantitative data on leaf flavonoid glycosides were obtained by means of high-performance thin layer chromatography and examined by multivariate discriminant analysis. The results show that it is possible to identify the hybrid obtained between these species even if the parents are unknown, provided a number of individuals of the parental species are examined; therefore, it is also possible to certify putative hybrids. The higher variability of the flavonoid glycoside data of U. carpinifolia and U. pumila and the probable presence of F2 generation individuals make the certification of natural hybrids between these two species in some cases difficult or even impossible.

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