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

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.

1965 ◽  
Vol 43 (11) ◽  
pp. 1421-1448 ◽  
Author(s):  
Wray M. Bowden

A cytotaxonomic treatment is given for 10 native species, 4 introduced species, and 8 natural interspecific hybrids of the genus Agropyron Gaertner that occur in Canada. Five of the native Agropyron species, one introduced species, and one natural interspecific hybrid are also found in Alaska. Eight of the native species, the four introduced species, and four natural interspecific hybrids are present in the mainland United States. Four additional native species and five additional introduced species that occur in the mainland United States are considered briefly.Nomenclatural proposals include: Agropyron dasystachyum (Hook.) Scribn. var. riparium (Scribn. & Smith) Bowden; Agropyron × pseudorepens Scribn. & Smith (pro sp.) nm. pseudorepens and nm. vulpinum (Rydb.) Bowden (A. dasystachyum × A. trachycaulum); and Agropyron × brevifolium Scribn. (pro sp.) (A. scribneri × A. violaceum).Voucher specimens are cited for chromosome number determinations of the native and introduced Agropyron species and some natural and artificial interspecific hybrids. Chromosome numbers are reported for the first time for A. violaceum (2n = 28), A. yukonense (2n = 28), the natural hybrids A. × pseudorepens nm. pseudorepens and nm. vulpinum (2n = 28), A. dasystachyum × A. spicatum (2n = 21), and A. violaceum × A. yukonense (2n = 28), and four artificial interspecific hybrids. Seven natural hybrids and four artificial hybrids are reported for the first time.


1946 ◽  
Vol 24c (3) ◽  
pp. 66-73 ◽  
Author(s):  
Raymond J. Moore

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.


1993 ◽  
Vol 23 (4) ◽  
pp. 611-616 ◽  
Author(s):  
Daniela Heimler ◽  
Andrea Pieroni ◽  
Lorenzo Mittempergher ◽  
Pietro Buzzini

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.


2020 ◽  
Vol 27 (1) ◽  
pp. 27-35
Author(s):  
Emrah Şirin ◽  
Mehmet Cengiz Karaismailoğlu

The aim of this study was to document the taxonomical, morphological, anatomical, palynological and cytological characters, and geographical distribution of endemic Aubrieta pinardii Boiss. (Brassicaceae) from Turkey. The description of the taxon was revised as a consequence of comprehensive assessments of many specimens. The surface pictures belonging to seed and pollen of the taxon were obtained by Scanning Electron Microscope. The seed surface ornamentation was rugose. The pollen was radially and isopolar and prolate in forms, with polar axes of 19.52 ± 0.29 μm and equatorial axes of 13.04 ± 0.22 μm, with oval outlines in the equatorial axes, and elliptical in the polar axes. They were three–colpate and colpus sizes varied between 12.98 μm and 13.29 μm in length, and between 1.33 and 2.09 μm in width. Also, the anatomical structures of the root, stem and leaf of species were studied. In cytological studies, the chromosome number of species was found as 2n = 16 (x =8). This was the first work including taxonomical, morphological (macro and micro), anatomical and cytological data of endemic Aubrieta pinardii. Bangladesh J.Plant Taxon. 27(1): 27-35, 2020 (June)


1969 ◽  
Vol 47 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Bernard R. Baum

Most reports on natural hybrids between A. sativa and A. fatua are not supported by definitive experimental evidence. Those authorities who have proved that natural hybrids do occur were assisted by the fact that both parents were known and occurred with the putative hybrids. The present study was conducted on samples of foundation plots from Canadian origin. Very useful characters were found in the lodicules and in the epiblasts which made it possible to detect F1 hybrids with precision in seeds of cultivated oats irrespective of their external morphologic markers. A hypothesis that the epiblast of the Fatua-type is dominant over the Sativa-type in F1 hybrids is set forth on the basis of the present findings. Higher frequencies of the Fatua-type epiblast were found in the samples where the lowest frequency of the Fatua-type lodicule was observed, because these samples were cultivars which had in their breeding history more crosses with A. byzantina than the others had. The importance of the lodicule and epiblast characters as markers is reassessed, and their reliability was reevaluated in view of the similarity of characters found in the epiblast of A. fatua and A. byzantina, and in view of the present findings. The taxonomic status of A. fatua and A. sativa is also discussed.


1970 ◽  
Vol 18 (1) ◽  
pp. 99 ◽  
Author(s):  
S Smith-White ◽  
CR Carter ◽  
HM Stace

Chromosome number determinations and cytological observations are reported for 37 recognized taxonomic species and varieties, and for a number of undescribed species and chromosome races in Eubrachycome. Additionally, chromosome numbers are reported for six species of Metabrachycome and two species of related genera. A wide range of numbers has been found. It is inferred that x = 9 is the primitive base number in the group. Eubrachycome has used various modes of chromosomal change, including polyploidy, amphidiploidy, decrease in base number, and the establishment of B. chromosomes. The present taxonomy of the group requires revision, taking into account cytological data. Primitive Eubrachycome was probably a mesic perennial. The evolution of desert species has involved reduction in chromosome number and the adoption of the annual habit, but other methods of desert adaptation have been available. Many species are chromosomally unstable, and may have been subject to catastrophic selection.


1964 ◽  
Vol 42 (5) ◽  
pp. 547-601 ◽  
Author(s):  
Wray M. Bowden

A cytotaxonomic treatment is given for 12 native species, 2 introduced species, and 3 natural interspecific hybrids of the genus Elymus L. that occur in Canada. Five of the native Elymus species and an additional natural interspecific hybrid are found in Alaska. Eleven of the native species, one introduced species, and two of the natural interspecific hybrids are present in the mainland United States. Some additional native species and natural interspecific hybrids of Elymus from the mainland United States are treated briefly.Nomenclatural proposals include: Elymusglaucus Buckl. var. virescens (Piper) Bowden; E. ×uclueletensis Bowden (E. mollis Trin. f. mollis × E. glaucus Buckl. var. glaucus); E. × aleuticus Hultén (pro sp.) (E. mollis Trin. f. mollis × E. hirsutus Presl); E. canadensis L. var. wiegandii (Fern.) Bowden f. wiegandii and f. calvescens (Fern.) Bowden; E. ×maltei Bowden nm. maltei, nm. simulans Bowden, nm. churchii Bowden, and nm. brownii Bowden (E. virginicus L. × E. canadensis L.); E. virginicus L. var. jenkinsii Bowden; E. hystrix L. var. bigelovianus (Fern.) Bowden; E.piperi Bowden; E. innovatus Beal subsp. innovatus var. glabratus Bowden; and E. triticoides Buckl. var. pacificus (Gould) Bowden. Hystrixpatula Moench is here treated as Elymushystrix L.Voucher specimens are cited for the following chromosome number determinations:(1) diploid, 2n = 14: Elymusjunceus.(2) tetraploid, 2n = 28: Elymus canadensis var. canadensis, E. canadensis var. wiegandii f. wiegandii, E. diversiglumis, E. glaucus var. glaucus, E. glaucus var. virescens, E. hirsutus, E, hystrix var. hystrix, E. hystrix var. bigelovianus, E. innovatus subsp. innovatus var. innovatus, E. × maltei nm. maltei, E. riparius, E. sibiricus, E. villosus f. villosus, E. virginicus var. virginicus f. virginicus, and E. virginicus var. submuticus.Earlier literature reports (based on voucher specimens) are given for the following:(1) tetraploid, 2n = 28: Elymus mollis (two subsp. and three forms), E. piperi, and E. × vancouverensis nm. crescentianus.(2) hexaploid, 2n = 42: Elymus × vancouverensis nm. vancouverensis, and E. × vancouverensis nm. californicus.(3) octoploid, 2n = 56: Elymus arenarius, E. innovatus subsp. velutinus, and E. piperi.


1993 ◽  
Vol 5 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Françoise Hennion ◽  
Henri Couderc

New cytogenetical data are provided for the three Ranunculus species occurring on Iles Kerguelen. Chromosome morphometrical analysis (idiograms) strongly argues for a relationship between them, with some indications of a more recent origin for R. moseleyi. Aneuploidy was found within the three species for the first time. Whilst only a slight aneuploidy exists in R. pseudotrullifolius and R. moseleyi, R. biternatus shows a tendency to hyperaneuploidy. Vegetative reproduction is likely to increase the number of plants showing such chromosome number irregularities. Aneuploidy could explain some of the differences between the species in ecological tolerance and distributional area.


2019 ◽  
Author(s):  
Warren Williams ◽  
Isabelle M Verry ◽  
Helal A Ansari ◽  
S Wajid Hussain ◽  
Ihsan Ullah ◽  
...  

Abstract Background Trifolium ambiguum occurs as a 2x, 4x, 6x polyploid series in W Asia, The 6x form is the most agronomically desirable, having strong rhizomatous spread and drought tolerance. These traits would be potentially very valuable if they could be transferred to white clover (T. repens) which is the most important agronomic clover species. However, to-date, no fertile interspecific hybrids with 6x T. ambiguum are available. Previously, 2x T. occidentale from W Europe has produced synthetic fertile hybrids with both 2x and 4x T. ambiguum and these were inter-fertile with white clover. Here we ask whether 2x T. occidentale can form fertile hybrids with 6x T. ambiguum and act as a genetic bridge to white clover and bring these species together as part of a common gene pool. Results Ten verified F1 (6x T. ambiguum x 2x T. occidentale) hybrids were produced by embryo rescue and seven were studied further. All four investigated for chromosome number were 2n=4x=32 and FISH confirmed the expected 21 T. ambiguum and 8 T. occidentale chromosomes. Hybrid fertility was extremely low but 2n female gametes functioned with white clover pollen to produce seeds. Derived plants were confirmed using FISH and were successfully backcrossed to white clover to produce partially fertile breeding populations. Conclusions Although T. occidentale and 6x T. ambiguum are widely separated by geography and ecological adaptation they have maintained enough genomic affinity to produce partially fertile hybrids. Inter-fertility of the hybrids with allotetraploid T. repens showed that T. occidentale can provide a genetic bridge between 6x T. ambiguum and white clover to produce plants with new phenotypes combining the traits of all three species. Use of this information should enable potentially valuable stress tolerance traits from 6x T. ambiguum to be used in white clover breeding for the first time.


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