Life history and allozyme variation in populations of the weed species Setaria faberi

1987 ◽  
Vol 65 (7) ◽  
pp. 1396-1402 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black
Keyword(s):  
Life History ◽  
Significant Variation ◽  
Allozyme Variation ◽  
Growth Characteristics ◽  
Population Variation ◽  
Weed Species ◽  
Setaria Faberi ◽  
Single Genotype ◽  
Variable Population ◽  
Low Levels

Life-history features and allozyme variation were examined among and within eight populations of Setaria faberi collected at the northern limits of its distribution range from 39 to 45° N latitude. Statistically significant variation among the eight populations was evident for all 16 characters relating to morphology, phenology, and growth characteristics of the plants. Very low levels of allozyme variation were detected in the eight populations, i.e., only 3 of the 22 loci surveyed were polymorphic. Nine multilocus genotypes were present. Six of the eight populations contained a single genotype, whereas the most variable population (A) contained eight genotypes. Estimates of within-population variation of nine life-history features indicated that population A was the most variable with 7 of 9 characters showing statistically significant among-family variation.

Genecological variation in recently established populations of Abutilon theophrasti (velvetleaf)

1986 ◽  
Vol 64 (8) ◽  
pp. 1632-1643 ◽  
Author(s):  
S. I. Warwick ◽  
L. D. Black
Keyword(s):  
Life History ◽  
Local Environment ◽  
Allozyme Variation ◽  
Morphological Characters ◽  
Abutilon Theophrasti ◽  
Population Differences ◽  
Weed Species ◽  
Wide Range ◽  
Genetic Features ◽  
Multilocus Associations

Life history and electrophoretic variation were examined in 39 populations of Abutilon theophrasti L., velvetleaf, collected from southern Ohio (39° N) to central Ontario (45° N). These collections represent a climatic gradient at the northern extreme of the distribution range of this weed species in North America. Plants from each of the 39 populations were grown from seed in a standard garden trial. A total of 51 growth, germination, and morphological characters were measured for each population. Significant among-population differences (p < 0.05) were found for 33 of the 51 characters. Many of these population differences were correlated with latitude and climate. These patterns of variation may well represent the first stages of differentiation in response to local environment. Of particular importance was the wide range of differences among populations in proportions of seeds exhibiting dormancy. Results from an electrophoretic survey of 16 enzyme systems provided evidence for very low levels of allozyme variation among the 39 populations of A. theophrasti. Only two enzymes were variable and only four multi-locus electrophoretic genotypes were evident among the 39 populations. Velvetleaf exhibited a number of genetic features characteristic of successful colonizers: high levels of fixed heterozygosity as a result of polyploidy, multilocus associations providing a reduced number of genotypes, and high levels of population differentiation in morphometric and life-history traits.

Population genetic structure in duckweed (Lemna minor, Lemnaceae)

1996 ◽  
Vol 74 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Christopher T. Cole ◽  
Martin I. Voskuil
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic ◽  
Lemna Minor ◽  
Vegetative Reproduction ◽  
Low Frequency ◽  
Morphological Differentiation ◽  
Genotypic Diversity ◽  
Allozyme Variation ◽  
Low Levels

Allozyme variation in 11 Minnesota populations of Lemna minor L. was studied, using 11 enzyme systems, resolving 16 putative loci from 285 plants. Significant deviations from Hardy–Weinberg frequencies occurred in several populations that had excesses of heterozygotes at several loci. While genotypic diversity and evenness measures are similar to other vegetatively reproducing plants (D = 0.541, E = 0.607), very few multilocus genotypes per population were found (mean = 4.0). Substantial population structure was evident (FST = 0.407), apparently reflecting low levels of gene flow (Nm = 0.30) despite the capacity of this species for dispersal of plantlets. This low level of gene flow and apparent low frequency of sexual reproduction has produced substantial levels of genetic divergence among populations, despite an absence of morphological differentiation. Keywords: allozymes, genetic structure, hydrophily, Lemna, vegetative dispersal, vegetative reproduction.

Absorption, translocation, and metabolism of glufosinate in five weed species as influenced by ammonium sulfate and pelargonic acid

Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 636-643 ◽  
Author(s):  
Wendy A. Pline ◽  
Jingrui Wu ◽  
Kriton K. Hatzios
Keyword(s):  
Ammonium Sulfate ◽  
Chenopodium Album ◽  
Pelargonic Acid ◽  
Weed Species ◽  
Asclepias Syriaca ◽  
Perennial Weed ◽  
Setaria Faberi ◽  
Perennial Weeds ◽  
Treated Leaf ◽  
Tlc Analysis

Absorption, translocation, and metabolism of14C-glufosinate were studied in three annual and two perennial weed species. Young seedlings ofSetaria faberi, Chenopodium album, Cassia obtusifolia, Solanum carolinense, andAsclepias syriacawere treated with foliar-applied14C-glufosinate, and plant tissues were harvested 12, 48, and 72 h after treatment (HAT). Absorption of14C-glufosinate was initially rapid, but increased only slightly after 12 h in all species. Glufosinate absorption was highest inS. carolinense(73% of applied radioactivity), followed byS. faberi(54%),C. obtusifolia(44%),C. album(41%), andA. syriaca(37%) 72 HAT. Translocation of radioactivity out of the treated leaf was species dependent and did not increase much with time in all weed species.S. carolinenseandS. faberitranslocated the highest amounts of absorbed radioactivity out of the treated leaf with 49 to 59% moving to the upper foliage.S. faberitranslocated the highest amount of absorbed radioactivity to the roots (12 to 14%), whileC. albumtranslocated the least (2 to 3%). TLC analysis of plant extracts showed that14C-glufosinate was not metabolized inS. faberi, C. obtusifolia, S. carolinense, andA. syriaca. A glufosinate metabolite with an Rf value matching that of methyl-phosphinico propionate was detected inC. album. Treatment with ammonium sulfate (AMS) increased glufosinate absorption inS. faberiandC. obtusifolia12 HAT, but decreased absorption inC. album. Treatment with pelargonic acid (PA) did not affect glufosinate absorption in any of the species tested. Treatment with AMS and PA did not affect glufosinate translocation in any of the five weed species. Treatment with AMS and PA did not influence the metabolism of glufosinate in any of the five weed species studied. These results show that differential absorption and translocation seem to explain the greater sensitivity of the annual and perennial weeds to glufosinate. Treatment with ammonium sulfate may increase the efficacy of glufosinate in perennial weeds.

scholarly journals Individual variability in life-history traits drives population size stability

2012 ◽  
Vol 58 (2) ◽  
pp. 358-362 ◽  
Author(s):  
Ned A. Dochtermann ◽  
C. M. Gienger
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Individual Variability ◽  
Population Variation ◽  
Sceloporus Undulatus ◽  
Natural Systems ◽  
Size Stability ◽  
Population Sizes ◽  
The Individual ◽  
Dynamics Of Populations

Abstract Understanding how population sizes vary over time is a key aspect of ecological research. Unfortunately, our understanding of population dynamics has historically been based on an assumption that individuals are identical with homogenous life-history properties. This assumption is certainly false for most natural systems, raising the question of what role individual variation plays in the dynamics of populations. While there has been an increase of interest regarding the effects of within population variation on the dynamics of single populations, there has been little study of the effects of differences in within population variation on patterns observed across populations. We found that life-history differences (clutch size) among individuals explained the majority of the variation observed in the degree to which population sizes of eastern fence lizards Sceloporus undulatus fluctuated. This finding suggests that differences across populations cannot be understood without an examination of differences at the level of a system rather than at the level of the individual [Current Zoology 58 (2): 358–362, 2012].

Using AFLP markers to inform population management of the endemic Chatham Island toetoe, Austroderia turbaria (Poaceae).

2012 ◽  
Vol 18 (1) ◽  
pp. 33 ◽  
Author(s):  
Gary J Houliston ◽  
Murray I Dawson ◽  
Peter J De Lange ◽  
Peter B Heenan
Keyword(s):  
Management Practices ◽  
Flow Cytometric Analysis ◽  
Natural Populations ◽  
Source Material ◽  
Population Variation ◽  
Population Genetic Analysis ◽  
Flow Cytometric ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Low Levels

Austroderia turbaria Connor is a threatened grass endemic to the Chatham Islands. Although formerly more widespread, remaining natural populations consist of highly fragmented remnants and/or individuals. Population genetic analysis of seed-raised progeny from six of the extant natural populations on Chatham and Pitt islands, using amplified fragment length polymorphisms (AFLPs) and microsatellite markers, shows that there are very low levels of variation (expected estimated heterozygosity He 0.023–0.030, no. of effective alleles Na 1.039–1.053), and no significant differentiation within or between populations on the two islands. Flow cytometric analysis of endosperm to embryo ratios suggests a sexual breeding system. This lack of population variation and no discernable differences between the two islands suggest that management practices such as the establishment of new populations can be carried out irrespective of the location of source material. One caveat to this is the possibility of Fusarium wilt occurring on the islands, in which case measures should be taken to best prevent spread across the range of the species.

Response of Weed Seeds to Ethylene and Related Hydrocarbons

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 7-10 ◽  
Author(s):  
R. B. Taylorson
Keyword(s):  
Chenopodium Album ◽  
Active Form ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Hydrocarbon Gases ◽  
Common Lambsquarters ◽  
Setaria Faberi ◽  
Redroot Pigweed ◽  
Giant Foxtail ◽  
Common Purslane

AbstractGermination of seeds of 10 grass and 33 broadleaved weed species was examined for response to ethylene. Germination was promoted in nine species, inhibited in two, and not affected in the remainder. Of the species promoted, common purslane (Portulaca oleraceaL.), common lambsquarters (Chenopodium albumL.), and several Amaranths, including redroot pigweed (Amaranthus retroflexusL.), were affected most. Transformation of phytochrome to the active form (Pfr) gave interactions that ranged from none to syntergistic with the applied ethylene. In subsequent tests seeds of purslane, redroot pigweed, and giant foxtail (Setaria faberiHerrm.), a species not responsive to ethylene, were examined for germination response to 14 low molecular weight hydrocarbon gases other than ethylene. Some stimulation by the olefins propylene and propadiene was found for purslane and pigweed. Propionaldehyde and butyraldehyde were slightly stimulatory to purslane only.

scholarly journals Population structure of Opisthorchis felineus (Trematoda) and its second intermediate hosts — cyprinid fishes in the Ob-Irtysh focus of opisthorchiasis, based on allozyme data

2014 ◽  
Vol 51 (4) ◽  
pp. 309-317 ◽  
Author(s):  
O. Zhigileva ◽  
V. Ozhireľev ◽  
T. Stepanova ◽  
T. Moiseenko
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Allozyme Variation ◽  
Intermediate Hosts ◽  
Opisthorchis Felineus ◽  
Cyprinid Fishes ◽  
Low Levels

AbstractGenetic variability of West Siberian populations of Opisthorchis felineus and two species of cyprinid fish, its second intermediate hosts, was studied by isozyme analysis. Low levels of allozyme variation and genetic differentiation in O. felineus from the Ob-Irtysh focus of opisthorchiasis were detected. The proportion of polymorphic loci was 21.1 %, the average observed heterozygosity (Hobs) was 0.008, and expected heterozygosity (Hexp) was 0.052. For most loci in O. felineus deficit of heterozygotes (FIS = 0.7424) was observed. A comparison of population genetic structure of fish and parasites showed they were not congruent. Estimates of genetic differentiation of the parasite were smaller than for the fish — its intermediate host. Migration and population structure of the second intermediate hosts do not play an important role in formation of the population-genetic structure of O. felineus in the Ob-Irtysh focus of opisthorchiasis.

Banded herbicide, rotary hoeing and cultivation effects on weed populations in ridge-tilled soybean

2006 ◽  
Vol 21 (3) ◽  
pp. 151-158 ◽  
Author(s):  
Thomas W. Jurik
Keyword(s):  
Seedling Emergence ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Soybean Yield ◽  
Setaria Faberi ◽  
Giant Foxtail ◽  
Significant Difference ◽  
Tillage System ◽  
Polygonum Pensylvanicum ◽  
Ridge Tillage

Can banded herbicide be eliminated in ridge-tilled soybean (Glycine max)? The effects of banded herbicide, rotary hoeing and cultivation on weed populations and soybean yield in a ridge-tillage system were tested on three farms in Iowa, USA in 1989 and 1990. In 1989, plots either had no herbicide or had herbicide banded in the row at planting in mid-May; all plots received two rotary hoeings and two cultivations. In 1990, treatments were banded herbicide with no rotary hoeing, banded herbicide with one rotary hoeing, and no herbicide with one or two rotary hoeings; all plots received two or three cultivations. In both years, over all weed species [primarily giant foxtail (Setaria faberi), Pennsylvania smartweed (Polygonum pensylvanicum) and redroot pigweed (Amaranthus retroflexus)], seedling emergence was highest in late May and early June, with few seedlings emerging after mid-June. Weed populations were highest in May and June, after which rotary hoeing and cultivation reduced weed numbers in all plots. There were no consistent differences among treatments in weed numbers in early August for the 2 years. In both years, there was no significant difference in soybean yield among treatments. Within-farm mean yields ranged from 2.26 to 3.01 Mg ha−1among farms in 1989 and from 2.07 to 2.93 Mg ha−1among farms in 1990. Ridge-tillage without herbicide was generally equivalent to ridge-tillage with banded herbicide, with respect to total number of weeds and number of broad-leaved weeds remaining in August after tillage, and to soybean yield.

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