Cytogenetic analyses of intersectional hybrids between Parthenium argentatum and Parthenium confertum

Genome ◽  
1989 ◽  
Vol 32 (1) ◽  
pp. 134-140 ◽  
Author(s):  
A. Hashemi ◽  
A. Estilai ◽  
J. G. Waines
Keyword(s):  
Natural Rubber ◽  
Growth Habit ◽  
Backcross Progeny ◽  
Woody Species ◽  
Herbaceous Species ◽  
Parthenium Argentatum ◽  
Preferential Pairing ◽  
Homologous Chromosomes ◽  
Multivalent Formation ◽  
Cytogenetic Analyses

Induced tetraploid guayule (Parthenium argentatum Gray, a rubber-producing and woody species of section Parthenicaeta) was crossed to P. confertum var. lyratum Gray, a herbaceous species of section Argyrocheta. Hybrids were obtained when guayule was used as female. Like their diploid progenitors, induced tetraploids were sexual and self-incompatible. At meiosis, they averaged 0.30 I, 29.63 II, 0.12 III, and 3.02 IV. Parthenium confertum had 69 chromosomes and was apomictic. At meiosis, it averaged 1.00 I, 32.98 II, and 0.51 IV. Hybrids received 36 chromosomes from guayule and 34 chromosomes from P. confertum. At meiosis, they averaged 0.52 I, 33.44 II, 0.20 III, and 0.50 IV. F1 plants behaved like an amphidiploid in which homologous chromosomes of guayule genome paired with each other and homologous chromosomes of P. confertum genome also paired preferentially. Chromosome association in the hybrids indicated that P. confertum parent may be a tetraploid with suppressed multivalent formation. Although hybrids were partially fertile and produced backcross progeny, the transfer of desirable traits (rapid growth and herbaceous growth habit) from P. confertum into guayule will depend on elimination of preferential pairing in the hybrids.Key words: guayule, natural rubber, meiosis, chromosome pairing.

Secondary Tetrasomic Segregation of MDH-B and Preferential Pairing of Homeologues in Rainbow Trout

Genetics ◽  
1997 ◽  
Vol 145 (4) ◽  
pp. 1083-1092 ◽  
Author(s):  
Fred W Allendorf ◽  
Roy G Danzmann
Keyword(s):  
Allelic Variation ◽  
Male Meiosis ◽  
Proximal Region ◽  
Stage Model ◽  
Preferential Pairing ◽  
Homologous Chromosomes ◽  
Tetrasomic Inheritance ◽  
Segregation Ratios ◽  
Homeologous Chromosomes ◽  
Duplicated Loci

We examined the inheritance of allelic variation at an isozyme locus, MDH-B, duplicated by ancestral polyploidy in salmonid fishes. We detected only disomic segregation in females. Segregation ratios in males were best explained by a mixture of disomic and tetrasomic inheritance. We propose a two-stage model of pairing in male meiosis in which, first, homologous chromosomes pair and recombine in the proximal region of the chromosome. Next, homeologous chromosomes pair and recombine distally. We suggest that this type of tetrasomic inheritance in which centromeres segregate disomically should be referred to as “secondary tetrasomy” to distinguish it from tetrasomy involving entire chromosomes (i.e., “primary tetrasomy”). Differences in segregation ratios between males indicate differences between individuals in the amount of recombination between homeologous chromosomes. We also consider the implication of these results for estimation of allele frequencies at duplicated loci in salmonid populations.

Influence of Sulfonylurea and Other Herbicides on Selected Woody and Herbaceous Species

Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 249-255 ◽  
Author(s):  
Robert E. Meyer ◽  
Rodney W. Bovey
Keyword(s):  
Plant Cover ◽  
Woody Species ◽  
Herbaceous Plant ◽  
Herbaceous Species ◽  
Grass Cover ◽  
Weed Cover ◽  
Broadleaf Species ◽  
Honey Mesquite

Chlorsulfuron and metsulfuron were effective on Texas whitebrush, killing 70 to 75% of the plants at 0.28 kg ai ha, marginally effective on Macartney rose, killing 15 to 43% of the plants at 1.12 kg ha, but ineffective on honey mesquite and huisache, killing no more than 10% of the plants at 1.12 kg ha. Sulfometuron was ineffective on all woody species at 1.12 kg ai ha. Clopyralid and picloram were effective, killing 70 to 92% of the huisache at 2.24 kg ae ha. Tebuthiuron killed 72% of the Texas whitebrush at 1.12 kg ai ha. Sulfometuron generally reduced herbaceous plant cover the year of application. Chlorsulfuron and metsulfuron often resulted in increased grass cover the year of application. Most herbicides reduced broadleaf weeds the year of application. Woolly croton often was the first prominent broadleaf species to return to areas treated with clopyralid and sulfometuron. Few differences occurred among herbicides in herbaceous weed cover the year following treatment.

Phylogeny and Character Evolution in Nierembergia (Solanaceae): Molecular, Morphological, and Cytogenetic Evidence

2009 ◽  
Vol 34 (1) ◽  
pp. 198-206 ◽  
Author(s):  
Jennifer A. Tate ◽  
M. Cristina Acosta ◽  
Joshua McDill ◽  
Eduardo A. Moscone ◽  
Beryl B. Simpson ◽  
...  
Keyword(s):  
Woody Species ◽  
Herbaceous Species ◽  
Chromosome Counts ◽  
Nucleolar Organizing Regions ◽  
Molecular Phylogenetic ◽  
Cytogenetic Evidence ◽  
Nuclear Its ◽  
Phylogenetic Hypotheses ◽  
Genus One ◽  
Petunia Axillaris

Nierembergia (Solanaceae) contains 21 species found primarily in South America, with one species occurring disjunctly in Mexico. Among other features, a pollination system not found elsewhere in the Solanaceae typifies this genus. In most species, nectaries are absent, but oil-producing elaiophores are present on the corolla limb and these attract oil-collecting bees. Molecular phylogenetic hypotheses based on nuclear ITS and chloroplast rpl16 intron data support the monophyly of Nierembergia, which is sister to a clade composed of Bouchetia plus Hunzikeria. The data reconstruct two clades within the genus: one composed primarily of herbaceous species with broad stigmas and the second containing woody species with crescent-shaped stigmas. Morphological homoplasy is frequent among the species of the herbaceous clade, while the woody clade is morphologically cohesive. Chromosome counts are confirmed and karyotype features are given for 13 Nierembergia species (including six varieties) and for Bouchetia anomala, Leptoglossis linifolia, and Petunia axillaris. The two clades are also supported by karyotypic features: one has asymmetrical karyotypes, small chromosomes, and two chromosome pairs with nucleolar organizing regions (NOR) and the other has symmetrical karyotypes, large chromosomes, and only one NOR.

Expérimentation sur la compétition interspécifique par élimination sélective d'espèces forestières

1983 ◽  
Vol 13 (3) ◽  
pp. 522-532 ◽  
Author(s):  
P. Bellefleur ◽  
Y. Pétillon
Keyword(s):  
Experimental Study ◽  
Sugar Maple ◽  
Woody Species ◽  
Growth Increment ◽  
Herbaceous Species ◽  
Height Increment ◽  
Yellow Birch ◽  
Soil Temperatures

We conducted an experimental study of competition for water, heat, and space between woody species and herbaceous species by selective exclusion of a few species in a sugar maple stand. We found large differences in diameter and height increment for all three species under investigation: sugar maple, yellow birch, and beech. Large differences were also found in soil temperatures to a depth of 30 cm which were correlated with cover and growth increment. We concluded that there is indeed a severe competition between woody and herbaceous species for both heat and space.

scholarly journals How small and constrained is the genome size of angiosperm woody species

2015 ◽  
Vol 64 (1-6) ◽  
pp. 20-32 ◽  
Author(s):  
Deepak Ohri
Keyword(s):  
Genome Size ◽  
Cell Size ◽  
Large Population ◽  
Size Variation ◽  
Woody Species ◽  
Herbaceous Species ◽  
Wood Fibers ◽  
Genome Size Variation ◽  
Woody Habit ◽  
Taxonomic Groups

AbstractAngiosperm hardwood species are generally considered to show an average smaller genome size with a narrow range of variation than their herbaceous counterparts. Various explanations pertaining to limitations of cell size exerted by wood fibers, the requirement of smaller stomata, longer generation time, large population size, etc., have been put forward to account for their small and constrained genome size. Yet studies done in the past several years show that genomically as well as evolutionarily, hardwoods are as diverse and active as their herbaceous counterparts. This is entirely supported by the presence of well developed inter and intraspecific polyploid series and natural triploidy in many genera. Polyploidy, in some instances has been shown to confer adaptability to arid and salt stress conditions and in colonization of new areas. Moreover, hardwoods also show reasonable amenability to the induced polyploidy which abruptly changes the balance between nuclear and cell size. Polyploidy has been induced in many hardwoods to restore fertility in interspecific hybrids and for the production of triploids.Furthermore, some cases studied show that genome size variation in hardwoods can be as variable as that of herbaceous species. Genome size has been shown to vary remarkably both at homoploid level as well as by polyploidy in certain genera. In the same way, the genome size is not correlated with the habit in certain groups having both herbaceous and woody taxa. This point is further proved by the presence of secondary and insular woody habit in certain cases where either the transition to woodiness is not followed by any diminution in the genome size, or the genome size of insular woody species may be even more than that of the congeneric herbaceous species. This shows that woody habit does not by itself put any constraints on the genome size either at homoploid or at polyploidy levels. The genome size in fact, not only varies significantly in many congeneric woody species but also may not show any correlation with the habit when woody and herbaceous species are compared in some narrow taxonomic groups studied.

Cytogenetics of decaploid Agropyron elongatum (Elytrigia elongata) (2n = 70). I. Frequency of decavalent formation

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 811-817 ◽  
Author(s):  
Mikio Muramatsu
Keyword(s):  
High Frequency ◽  
Chromosome Association ◽  
Agropyron Elongatum ◽  
Homologous Chromosomes ◽  
Ring Shape ◽  
Meiotic Configuration ◽  
Multivalent Formation ◽  
A Cell ◽  
Chromosome Associations ◽  
Metaphase I

The multivalents that appeared in the decaploid strain of Agropyron elongatum (2n = 10x = 70), a relative of wheat, ranged from trivalent to decavalent. Few univalents occurred. The metaphase I chromosome association in 12 cells where all configurations could clearly be identified averaged 0.42 ring X + 0.17 chain X + 0.42 ring VIII + 0.17 branched VIII + 0.25 chain VIII + 0.17 chain VII + 1.17 ring VI + 0.33 branched VI + 0.5 chain VI + 1.67 ring IV + 0.42 branched IV + 0.58 chain IV + 0.08 branched III + 0.17 chain III + 12.58 ring II + 3.75 open II + 0.25 I. The occurrence of decavalents, up to two in one cell, and of a cell with five multivalents, each of which involved more than five chromosomes, and many multivalents of ring shape indicated that the strain is autodecaploid.The chromosome associations of each cell can be interpreted as seven groups of 10 homologous chromosomes. The high frequency of bivalents indicated a tendency toward reduced multivalent formation, for which an explanation is suggested.Key words: Agropyron elongatum, meiotic configuration, decaploid, multivalent.

scholarly journals Short Communication: Floristic composition and relationships between plant species abundance and soil properties in common hazel (Corylus avellana) mountainous forest of northern Iran

2018 ◽  
Vol 19 (5) ◽  
pp. 1835-1841
Author(s):  
GHADER POURRAHMATI ◽  
ASADOLLAH MATAJI ◽  
HASSAN POURBABAEI ◽  
ALI SALEHI
Keyword(s):  
Soil Properties ◽  
Plant Species ◽  
Short Communication ◽  
Species Abundance ◽  
Floristic Composition ◽  
Woody Species ◽  
Corylus Avellana ◽  
Herbaceous Species ◽  
Northern Iran ◽  
Total N

Pourrahmati G, Mataji A, Pourbabaei H, Salehi A. 2018. Short Communication: Floristic composition and relationships between plant species abundance and soil properties in common hazel (Corylus avellana) mountainous forest of northern Iran. Biodiversitas 19: 1835-1841. Mountainous forests are valuable terrestrial ecosystems because of their useful services for the human being. Here, we explored the floristic composition and the relationships between plant species abundance distribution and soil physical and chemical properties in common hazel (Corylus avellana L.) in the mountainous forest of northern Iran. Within the forest stand, 30 quadrats (20 m × 20 m and 1 m × 1 m for woody and herbaceous species, respectively) were selectively sampled along an altitudinal range from 1300 m to 1800 m a.s.l. to assess plant species composition and abundance, and soil samples were taken to perform chemical and physical analyses. The results showed that a total of 43 herbaceous and 15 woody species belonging to 23 and 8 families were identified. The abundance of herbaceous species was significantly correlated with soil properties (pH and total N). Furthermore, the abundance of woody species had a non-significant correlation with soil properties.

Compétition pour le rayonnement solaire en début de succession secondaire dans une érablière à bouleau jaune et hêtre

1983 ◽  
Vol 13 (3) ◽  
pp. 514-521 ◽  
Author(s):  
P. Bellefleur ◽  
G. LaRocque
Keyword(s):  
Solar Radiation ◽  
Sugar Maple ◽  
Woody Species ◽  
Herbaceous Species ◽  
Yellow Birch ◽  
Radiation Interception ◽  
Clear Cutting ◽  
Surface Soil Temperature ◽  
Succession Secondaire ◽  
Rayonnement Solaire

We demonstrate that sugar maple (Acersaccharum Marsh.), yellow birch (Betulaalleghaniensis Britton), and beech (Fagusgrandifolia Ehrh.) compete for solar radiation against other woody species (noncommercial) and herbaceous species, following clear-cutting. The experiment was carried out at the Duchesnay Forest Station (Quebec, Canada) in a sugar maple – yellow birch – beech community and consisted of one control and two treatments: (1) elimination of noncommercial woody species and (2) elimination of noncommercial woody species and herbaceous species. The graph of solar radiation interception versus cover indicates that crown overlapping does not contribute significantly to any increase in solar radiation interception. Surface soil temperature is strongly linked to the decrease in solar radiation due to its interception by plants.

Sign in / Sign up

Export Citation Format

Share Document