scholarly journals A Eurasia-wide polyploid species complex involving 6x Trifolium ambiguum, 2x T. occidentale and 4x T. repens produces interspecific hybrids with significance for clover breeding

2019 ◽  
Author(s):  
Warren Williams ◽  
Isabelle M Verry ◽  
Helal A Ansari ◽  
S Wajid Hussain ◽  
Ihsan Ullah ◽  
...  
Keyword(s):  
Chromosome Number ◽  
White Clover ◽  
Interspecific Hybrids ◽  
Species Complex ◽  
Embryo Rescue ◽  
Polyploid Species ◽  
Trifolium Ambiguum ◽  
Breeding Populations ◽  
Fertile Hybrids ◽  
First Time

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.

scholarly journals A Eurasia-wide polyploid species complex involving 6x Trifolium ambiguum, 2x T. occidentale and 4x T. repens produces interspecific hybrids with significance for clover breeding

2019 ◽  
Author(s):  
Warren Williams ◽  
Isabelle M Verry ◽  
Helal A Ansari ◽  
S Wajid Hussain ◽  
Ihsan Ullah ◽  
...  
Keyword(s):  
Chromosome Number ◽  
White Clover ◽  
Interspecific Hybrids ◽  
Species Complex ◽  
Embryo Rescue ◽  
Polyploid Species ◽  
Trifolium Ambiguum ◽  
Breeding Populations ◽  
Fertile Hybrids ◽  
First Time

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.

scholarly journals A Eurasia-wide polyploid species complex involving 6x Trifolium ambiguum, 2x T. occidentale and 4x T. repens produces interspecific hybrids with significance for clover breeding

2019 ◽  
Author(s):  
Warren Williams ◽  
Isabelle M Verry ◽  
Helal A Ansari ◽  
S Wajid Hussain ◽  
Ihsan Ullah ◽  
...  
Keyword(s):  
Chromosome Number ◽  
White Clover ◽  
Interspecific Hybrids ◽  
Species Complex ◽  
Embryo Rescue ◽  
Polyploid Species ◽  
Trifolium Ambiguum ◽  
Breeding Populations ◽  
Fertile Hybrids ◽  
First Time

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.

scholarly journals A Eurasia-wide polyploid species complex involving 6x Trifolium ambiguum, 2x T. occidentale and 4x T. repens produces interspecific hybrids with significance for clover breeding

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Warren M. Williams ◽  
Isabelle M. Verry ◽  
Helal A. Ansari ◽  
S. Wajid Hussain ◽  
Ihsan Ullah ◽  
...  
Keyword(s):  
Chromosome Number ◽  
White Clover ◽  
Interspecific Hybrids ◽  
Species Complex ◽  
Embryo Rescue ◽  
Polyploid Species ◽  
Trifolium Ambiguum ◽  
Breeding Populations ◽  
Fertile Hybrids ◽  
First Time

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.

CYTOTAXONOMY OF THE SPECIES AND INTERSPECIFIC HYBRIDS OF THE GENUS AGROPYRON IN CANADA AND NEIGHBORING AREAS

1965 ◽  
Vol 43 (11) ◽  
pp. 1421-1448 ◽  
Author(s):  
Wray M. Bowden
Keyword(s):  
United States ◽  
Chromosome Number ◽  
Introduced Species ◽  
Chromosome Numbers ◽  
Interspecific Hybrid ◽  
Native Species ◽  
Interspecific Hybrids ◽  
Natural Hybrids ◽  
Voucher Specimens ◽  
First Time

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.

Caucasian clover (Trifolium ambiguum Bieb.) × white clover (T. repens L.) – interspecific hybrids developed through tissue culture

2017 ◽  
Author(s):  
Fan Huang ◽  
Mingjiu Wang ◽  
Zhiyong Li
Keyword(s):  
Tissue Culture ◽  
White Clover ◽  
Embryo Rescue ◽  
Female Parent ◽  
Issr Markers ◽  
Hybrid Plant ◽  
Root Induction ◽  
Trifolium Ambiguum ◽  
Bud Induction ◽  
Growing Conditions

In order to create new forage variety, caucasian clover (Trifolium ambiguum Bieb.) with strong tolerance to drought and cold introduced from New Zealand as the female parent was hybridized with a white clover (T. repens L.) collected from northeast China, which has strong nitrogen fixation capacity. Hybrid embryos of caucasian clover×white clover were successfully raised using embryo rescue. 13.8% of these embryos grew to maturity. The successfully grown plants were transferred to sterilized vermiculite after 5-6 weeks and then to field after 3-4 months. The hybrid plant showed intermediate morphological features and a chromosomal number of 2n=5X=40. In order to obtain more plants for backcross, a tissue culture system was established for the hybrids, using MS+0.1mg l-1 2, 4-D+2mg l-1 6-BA, MS +0.5mg l-1 NAA+1mg l-1 6-BA+1mg l-1 KT and 1/2MS as the medium for bud-induction, differentiation and root-induction respectively. 80% of the cultured plantlets survived these growing conditions. Hybridity of the plant was also confirmed by ISSR markers using 16 primers.

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

scholarly journals A Novel Disease of Big-Leaf Mahogany Caused by Two Fusarium Species in Mexico

Plant Disease ◽  
2018 ◽  
Vol 102 (10) ◽  
pp. 1965-1972 ◽  
Author(s):  
R. Santillán-Mendoza ◽  
S. P. Fernández-Pavía ◽  
K. O’Donnell ◽  
R. C. Ploetz ◽  
R. Ortega-Arreola ◽  
...  
Keyword(s):  
Species Complex ◽  
Fusarium Species ◽  
Urban Landscapes ◽  
Western Region ◽  
New Disease ◽  
Molecular Systematic ◽  
Lateral Buds ◽  
Mango Malformation ◽  
First Time ◽  
Important Disease

Big-leaf mahogany (Swietenia macrophylla) is valued for its high-quality wood and use in urban landscapes in Mexico. During surveys of mango-producing areas in the central western region of Mexico, symptoms of malformation, the most important disease of mango in the area, were observed on big-leaf mahogany trees. The objectives of this research were to describe this new disease and determine its cause. Symptoms on big-leaf mahogany at four sites in Michoacán, Mexico resembled those of the vegetative phase of mango malformation, including compact, bunched growth of apical and lateral buds, with greatly shortened internodes and small leaves that curved back toward the supporting stem. Of 163 isolates that were recovered from symptomatic tissues, most were identified as Fusarium pseudocircinatum (n = 121) and F. mexicanum (n = 39) using molecular systematic data; two isolates represented unnamed phylospecies within the F. incarnatum-equiseti species complex (FIESC 20-d and FIESC 37-a) and another was in the F. solani species complex (FSSC 25-m). However, only F. mexicanum and F. pseudocircinatum induced malformation symptoms on 14-day-old seedlings of big-leaf mahogany. The results indicate that F. mexicanum and F. pseudocircinatum, previously reported in Mexico as causal agents of mango malformation disease, also affect big-leaf mahogany. This is the first report of this new disease and the first time that F. mexicanum was shown to affect a host other than mango.

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.

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 Chromosomal and DNA barcode analysis of the Melitaea ala Staudinger, 1881 species complex (Lepidoptera, Nymphalidae)

2021 ◽  
Vol 15 (2) ◽  
pp. 199-216
Author(s):  
Vladimir A. Lukhtanov ◽  
Anastasia V. Gagarina ◽  
Elena A. Pazhenkova
Keyword(s):  
Chromosome Number ◽  
Central Asia ◽  
Species Complex ◽  
Dna Barcode ◽  
Monophyletic Group ◽  
Geographic Proximity ◽  
Haploid Chromosome Number ◽  
East Central ◽  
North East ◽  
Peter The Great

The species of the Melitaea ala Staudinger, 1881 complex are distributed in Central Asia. Here we show that this complex is a monophyletic group including the species, M. ala, M. kotshubeji Sheljuzhko, 1929 and M. enarea Fruhstorfer, 1917. The haploid chromosome number n=29 is found in M. ala and M. kotshubeji and is, most likely, a symplesiomorphy of the M. ala complex. We show that M. ala consists of four subspecies: M. ala zaisana Lukhtanov, 1999 (=M. ala irtyshica Lukhtanov, 1999, syn. nov.) (South Altai, Zaisan Lake valley), M. ala ala (Dzhungarian Alatau), M. ala bicolor Seitz, 1908 (North, East, Central and West Tian-Shan) and M. ala determinata Bryk, 1940 (described from “Fu-Shu-Shi”, China). We demonstrate that M. kotshubeji kotshubeji (Peter the Great Mts in Tajikistan) and M. kotshubeji bundeli Kolesnichenko, 1999 (Alai Mts in Tajikistan and Kyrgyzstan) are distinct taxa despite their geographic proximity in East Tajikistan. Melitaea enarea is widely distributed in the southern part of Central Asia and is sympatric with M. kotshubeji.

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