scholarly journals Hybridization potential between Amaranthus tuberculatus and Amaranthus albus

2021 ◽  
Author(s):  
Brent P Murphy ◽  
Laura A Chatham ◽  
Danielle M McCormick ◽  
Patrick J Tranel
Keyword(s):  
Interspecific Hybridization ◽  
Backcross Progeny ◽  
Field Studies ◽  
Phenotypic Traits ◽  
Spontaneous Generation ◽  
Dioecious Species ◽  
Female Progeny ◽  
High Fecundity ◽  
Primary Driver ◽  
Amaranthus Tuberculatus

The genus Amaranthus is composed of numerous annual herbs, several of which are primary driver weeds within annual production agricultural systems. In particular, Amaranthus tuberculatus, a dioecious species, is noteworthy for rapid growth rates, high fecundity, and an expanding geographic distribution. Interspecific hybridization within and between the subgenera Amaranthus and Acnidia is reported both in controlled environment and field studies, however a gap in knowledge exists with the subgenus Albersia. Interspecific hybridization may contribute to genetic diversity, and may contribute to the current range expansion of A. tuberculatus. Recently, a herbicide resistance survey of A. tuberculatus across five Midwestern states reported alleles of PPX2 similar to sequences of Amaranthus albus, a monoecious species. Here, we seek to generate empirical data for the hybridization potential of A. albus and A. tuberculatus through replicated, controlled crosses in a greenhouse. Of 65,000 progeny screened from A. albus grown with A. tuberculatus males, three were confirmed as hybrids. Hybrids were dioecious, possessed phenotypic traits of both species, and had limited to no fertility. DNA content analysis of backcross progeny suggested a polyploid state may be required for hybrid formation. Screening of 120 progeny of A. tuberculatus females grown with A. albus identified no hybrids, though a skew to female progeny was observed. The female skew may be due to apomixis or auto-pollination, the spontaneous generation of male flowers on otherwise female plants. Our results indicate that introgression between A. albus and A. tuberculatus will occur less frequently than what has often been reported from hybridization studies with different pairs of Amaranthus species.

scholarly journals Maternal effects as a recruitment mechanism in Lake Michigan yellow perch (Perca flavescens)

2001 ◽  
Vol 58 (7) ◽  
pp. 1477-1487 ◽  
Author(s):  
Christopher J Heyer ◽  
Thomas J Miller ◽  
Fred P Binkowski ◽  
Elaine M Caldarone ◽  
James A Rice
Keyword(s):  
Maternal Effects ◽  
Null Hypothesis ◽  
Yellow Perch ◽  
Lake Michigan ◽  
Gonadosomatic Index ◽  
Perca Flavescens ◽  
Dry Weight ◽  
Phenotypic Traits ◽  
High Fecundity ◽  
Larval Traits

Changes that occurred in the distribution of adult Lake Michigan yellow perch (Perca flavescens) phenotypic traits suggest that maternal effects on larval traits may be substantially influencing the recruitment of this heavily exploited species. We investigated maternal effects on yellow perch larvae at hatching in 10 maternal lines to test the null hypothesis of no effect of maternal phenotype on offspring phenotype and condition. Analyses lead to a rejection of the null hypothesis and indicated that the observed maternal effects likely resulted from differences among females in size, age, gonadosomatic index, and egg production. The observed maternal effects were expressed in the offspring by differences in larval total length, yolk volume, dry weight, and DNA quantity. Older, larger females were found to have high fecundity, yet low gonadosomatic index. Furthermore, older, larger females produced offspring that were, on average, short with large yolk sacs and high quantities of body reserves, as measured by dry weight and total DNA content. We conclude that the distribution of Lake Michigan yellow perch larval traits at hatching is linked to maternal influences and that this linkage may provide a mechanism through which managers can help rebuild the population.

Establishing a Weed Nursery with Low Construction Costs and Maintenance Requirements

1988 ◽  
Vol 2 (1) ◽  
pp. 77-80
Author(s):  
Loren J. Moshier ◽  
Clarence W. Swallow
Keyword(s):  
Healthy Plant ◽  
Annual Species ◽  
Labor Costs ◽  
Construction Costs ◽  
Dioecious Species ◽  
Amaranthus Tuberculatus ◽  
Winter Annual ◽  
Labor Requirements ◽  
Maintenance Requirements ◽  
Salsola Iberica

A nursery of economically important weeds in Kansas field crops, representing 15 families, was designed to include 32 species from the Magnoliopsida (dicotyledons) class and 16 species from the Liliopsida (monocotyledons) class. Using hydraulically operated equipment, 48 facricated metal cylinders 60 cm in both diameter and length were inserted in 4 h. Cylinders were inserted 40 cm deep on an established turf site and were filled with Muir silt loam collected near Manhattan, KS. Thirty summer annual species, nine perennial species, and one biennial species were transplanted in the spring; and eight winter annual species either were seeded or were transplanted in the fall. All species except tall waterhemp (Amaranthus tuberculatus (Moq.) J.D. Sauer # AMATU), a dioecious species, Russian thistle (Salsola iberica Sennen & Pau # SASKR), and unicorn-plant [Proboscidea louisianica (Mill.) Thellung # PROLO] successfully propagated themselves from either seed or buds. Labor requirements for healthy plant growth and overall nursery attractiveness were estimated at 50 h/yr. Installation costs prorated over a 10-yr period plus annual labor costs totaled $300/yr.

Maturation and the Evolution of Imitative Learning in Artificial Organisms

1995 ◽  
Vol 4 (1) ◽  
pp. 29-50 ◽  
Author(s):  
Federico Cecconi ◽  
Filippo Menczer ◽  
Richard K. Belew
Keyword(s):  
Empirical Support ◽  
Field Studies ◽  
Phenotypic Traits ◽  
Age At Maturity ◽  
Behavioral Skills ◽  
Early Maturity ◽  
Juvenile Mortality ◽  
Early Maturation ◽  
Trade Offs ◽  
Delayed Maturation

The traditional explanation of delayed maturation age, as part of an evolved life history, focuses on the increased costs of juvenile mortality due to early maturation. Prior quantitative models of these trade-offs, however, have addressed only morphological phenotypic traits, such as body size. We argue that the development of behavioral skills prior to reproductive maturity also constitutes an advantage of delayed maturation and thus should be included among the factors determining the trade-off for optimal age at maturity. Empirical support for this hypothesis from animal field studies is abundant. This article provides further evidence drawn from simulation experiments. Latent energy environments (LEE) are a class of tightly controlled environments in which learning organisms are modeled by neural networks and evolve according to a type of genetic algorithm. An advantage of this artificial world is that it becomes possible to discount all nonbehavioral costs of early maturity in order to focus exclusively on behavioral consequences. Despite large selective costs imposed on parental fitness due to prolonged immaturity, the optimal age at maturity is shown to be significantly delayed when offspring learn from their parents' behavior via imitation.

Effects of pollen competition on the reproductive performance in cucurbit hybrids (Cucurbitaceae): F1 and backcross generations

1996 ◽  
Vol 74 (7) ◽  
pp. 1113-1118 ◽  
Author(s):  
Mauricio Quesada ◽  
Andrew G. Stephenson ◽  
James A. Winsor
Keyword(s):  
Reproductive Performance ◽  
Reproductive Output ◽  
Backcross Progeny ◽  
Field Studies ◽  
Field Conditions ◽  
Pollen Competition ◽  
Plant Fitness ◽  
Pollen Loads ◽  
Pollen Performance ◽  
Small Pollen

We examined the effect of pollen competition on the reproductive performance of Cucurbita F1 and backcross progeny while attempting to control for nongenetic maternal effects and nonrandom seed abortion as possible explanations for the data. We compared the vigor of F1 and backcross progeny produced from large and small pollen loads under field conditions. The results from both field studies indicated that the progeny produced from large pollen loads outperformed the progeny produced from small pollen loads for several measures of vigor. The F1 progeny produced from large pollen loads germinated faster, and produced 12% more staminate flowers and 9% more pistillate flowers than the progeny from the small pollen loads. Similarly, the backcross progeny produced from large pollen loads germinated faster, and produced 8% more pistillate flowers and 20% more fruits than the progeny from the small pollen loads. This study demonstrates a positive correlation between the size of the pollen load and the vigor of the resulting progeny under field conditions. Keywords: pollen competition, pollen performance, nonrandom fertilization, plant fitness, reproductive output.

scholarly journals On the role of sex differences for evolution in heterogeneous and changing fitness landscapes: insights from pygmy grasshoppers

2018 ◽  
Vol 373 (1757) ◽  
pp. 20170429 ◽  
Author(s):  
Anders Forsman
Keyword(s):  
Sex Differences ◽  
Developmental Plasticity ◽  
Common Garden ◽  
Field Studies ◽  
Fitness Landscapes ◽  
Phenotypic Traits ◽  
Environment Interaction ◽  
Local Adaptations ◽  
Changing Environments

Much research has been devoted to study evolution of local adaptations by natural selection, and to explore the roles of neutral processes and developmental plasticity for patterns of diversity among individuals, populations and species. Some aspects, such as evolution of adaptive variation in phenotypic traits in stable environments, and the role of plasticity in predictable changing environments, are well understood. Other aspects, such as the role of sex differences for evolution in spatially heterogeneous and temporally changing environments and dynamic fitness landscapes, remain elusive. An increased understanding of evolution requires that sex differences in development, physiology, morphology, life-history and behaviours are more broadly considered. Studies of selection should take into consideration that the relationships linking phenotypes to fitness may vary not only according to environmental conditions but also differ between males and females. Such opposing selection, sex-by-environment interaction effects of selection and sex-specific developmental plasticity can have consequences for population differentiation, local adaptations and for the dynamics of polymorphisms. Integrating sex differences in analytical frameworks and population comparisons can therefore illuminate neglected evolutionary drivers and reconcile unexpected patterns. Here, I illustrate these issues using empirical examples from over 20 years of research on colour polymorphic Tetrix subulata and Tetrix undulata pygmy grasshoppers, and summarize findings from observational field studies, manipulation experiments, common garden breeding experiments and population genetics studies. This article is part of the theme issue ‘Linking local adaptation with the evolution of sex differences’.

Characterization of multiple herbicide–resistant waterhemp (Amaranthus tuberculatus) populations from Illinois to VLCFA-inhibiting herbicides

Weed Science ◽  
2019 ◽  
Vol 67 (4) ◽  
pp. 369-379 ◽  
Author(s):  
Seth A. Strom ◽  
Lisa C. Gonzini ◽  
Charlie Mitsdarfer ◽  
Adam S. Davis ◽  
Dean E. Riechers ◽  
...  
Keyword(s):  
Dose Response ◽  
Field Experiments ◽  
Survival Rates ◽  
Acetolactate Synthase ◽  
Field Studies ◽  
Complete Control ◽  
Herbicide Resistant ◽  
Amaranthus Tuberculatus ◽  
Als Inhibitors ◽  
And Control

AbstractField experiments were conducted in 2016 and 2017 in Champaign County, IL, to study a waterhemp [Amaranthus tuberculatus (Moq.) J. D. Sauer] population (CHR) resistant to 2,4-D and 4-hydroxyphenylpyruvate dioxygenase (HPPD)-, photosystem II–, acetolactate synthase (ALS)-, and protoporphyrinogen oxidase–inhibiting herbicides. Two field experiments were designed to investigate the efficacy of very-long-chain fatty-acid (VLCFA)-inhibiting herbicides, including a comparison of active ingredients at labeled use rates and a rate titration experiment. Amaranthus tuberculatus density and control were evaluated at 28 and 42 d after treatment (DAT). Nonencapsulated acetochlor, alachlor, and pyroxasulfone provided the greatest PRE control of CHR (56% to 75%) at 28 DAT, while metolachlor, S-metolachlor, dimethenamid-P, and encapsulated acetochlor provided less than 27% control. In the rate titration study, nonencapsulated acetochlor controlled CHR more than equivalent field use rates of S-metolachlor. Subsequent dose–response experiments with acetochlor, S-metolachlor, dimethenamid-P, and pyroxasulfone in the greenhouse included three multiple herbicide–resistant (MHR) A. tuberculatus populations: CHR-M6 (progeny generated from CHR), MCR-NH40 (progeny generated from Mclean County, IL), and ACR (Adams County, IL), in comparison with a sensitive population (WUS). Both CHR-M6 and MCR-NH40 are MHR to atrazine and HPPD, and ALS inhibitors and demonstrated higher survival rates (LD50) to S-metolachlor, acetochlor, dimethenamid-P, or pyroxasulfone than ACR (atrazine resistant but HPPD-inhibitor sensitive) and WUS. Based on biomass reduction (GR50), resistant to sensitive (R:S) ratios between CHR-M6 and WUS were 7.5, 6.1, 5.5, and 2.9 for S-metolachlor, acetochlor, dimethenamid-P, and pyroxasulfone, respectively. Values were greater for MCR-NH40 than CHR-M6, and ACR was the most sensitive to all VLCFA inhibitors tested. Complete control of all populations was achieved at or below a field use rate of acetochlor. In summary, field studies demonstrated CHR is not controlled by several VLCFA-inhibiting herbicides. Greenhouse dose–response experiments corroborated field results and generated R:S ratios (LD50) ranging from 4.5 to 64 for CHR-M6 and MCR-NH40 among the four VLCFA-inhibiting herbicides evaluated.

Herbicide Programs for Control of Waterhemp (Amaranthus tuberculatus) Resistant to Three Distinct Herbicide Sites of Action in Corn

2020 ◽  
pp. 1-28
Author(s):  
Christian Willemse ◽  
Nader Soltani ◽  
Lauren Benoit ◽  
David C. Hooker ◽  
Amit J. Jhala ◽  
...  
Keyword(s):  
Field Experiments ◽  
Field Trials ◽  
Effective Control ◽  
High Fecundity ◽  
Field Corn ◽  
Amaranthus Tuberculatus ◽  
Excellent Control ◽  
Density And Biomass ◽  
Sites Of Action ◽  
Herbicide Programs

Abstract Control of waterhemp is becoming more difficult in Ontario as biotypes have evolved resistance to four herbicide sites of action (SOA) including groups 2, 5, 9, and 14. The objective of this study was to compare PRE, POST, and PRE followed by (fb) POST herbicide programs and their effect on control, density, and biomass of multiple herbicide-resistant (MHR) waterhemp as well as corn injury and grain yield. Two separate field experiments, each consisting of five field trials, were conducted over a two-year period (2018 and 2019) in corn in Ontario, Canada. The first experiment evaluated MHR waterhemp control with 4-hydroxyphenyl-pyruvate dioxygenase (HPPD) inhibitor containing programs applied PRE, HPPD-inhibitor containing programs applied PRE fb glufosinate applied POST, and glufosinate applied POST. The second experiment evaluated MHR waterhemp control with non-HPPD inhibitor containing programs applied PRE, non-HPPD inhibitor containing programs applied PRE fb atrazine + mesotrione applied POST, and atrazine + mesotrione applied POST. Atrazine + isoxaflutole caused 3 to 5% corn injury at E1; no corn injury was observed with PRE and POST herbicide programs at other environments. In general, atrazine/bicyclopyrone/mesotrione/S-metolachlor and dimethenamid-P/saflufenacil, applied PRE, controlled MHR waterhemp ≥ 95% 12 weeks after POST application (WAA). A POST application of glufosinate following atrazine + tolpyralate PRE, and a POST application of atrazine + mesotrione following atrazine/dicamba or atrazine/S-metolachlor PRE, improved control at 4, 8, and 12 WAA in most environments. In general, PRE fb POST applications resulted in better control of MHR waterhemp throughout the growing season than PRE and POST applications (P<0.05). It is concluded that herbicide programs based on multiple effective SOA are available for effective control of MHR waterhemp in field corn and it is advisable that when choosing a herbicide program, excellent control of MHR waterhemp should be the goal given its high fecundity and competitive ability.

scholarly journals Effective Size and F-Statistics of Subdivided Populations. II. Dioecious Species

Genetics ◽  
1997 ◽  
Vol 146 (4) ◽  
pp. 1465-1474 ◽  
Author(s):  
Jinliang Wang
Keyword(s):  
Inbreeding Coefficient ◽  
Effective Size ◽  
Dioecious Species ◽  
Female Progeny ◽  
Migration Rates ◽  
Recurrence Equations ◽  
Subdivided Populations ◽  
Males And Females ◽  
Special Case ◽  
F Statistics

For a dioecious diploid population subdivided into an arbitrary number of subpopulations, we have derived recurrence equations for the inbreeding coefficient and coancestries between individuals within and among subpopulations and formulas for effective size and F-statistics. Stable population size and structure, discrete generations, autosomal inheritance, and the island migration model are assumed, and arbitrary distributions of the numbers of male and female progeny per family, different numbers and variable migration rates of males and females are incorporated in our derivation. Some published equations for effective size and F-statistics for a subdivided population are shown to be incorrect because several incorrect probabilities are used in the derivation. A more general equation for effective size is obtained by finding eigenvalue solutions to the recurrence equations for inbreeding coefficient and coancestry in this article, which reduces to the simple and familiar expressions derived by previous authors for the special case of a single unsubdivided population. Our general expressions for F-statistics also reduce to the classical results Of Wright's infinite island model and its extensions. It is shown that population structure is important in determining effective size and F-statistics and should be recognized and incorporated into programs for genetic conservation and evolution.

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