Pollen-Mediated Gene Flow of Sulfonylurea-Resistant Kochia (Kochia scoparia)

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 95-102 ◽  
Author(s):  
George P. Stallings ◽  
Donald C. Thill ◽  
Carol A. Mallory-Smith ◽  
Bahman Shafii

The movement of sulfonylurea herbicide-resistant (R) kochia pollen was investigated in a spring barley field near Moscow, ID, using a Nelder plot design in 1991 and 1992. Each 61 m diameter plot had 16 rays spaced 22.5° apart and contained 211 kochia plants. There were 12 susceptible (S) plants and one R plant along each ray. The R and S plants were 1.5 m and 3.0 to 30.5 m from the center of the plot, respectively. Wind direction and speed in the 16 vectors, air and soil temperature, and rainfall were monitored continuously. Mature kochia seed was collected from individual plants, planted in the greenhouse, and sprayed with chlorsulfuron to test for resistant F1progeny. Results from the 2-yr study showed outcrossing of R pollen onto S plants at rates up to 13.1% per plant 1.5 m from the R plants and declining to 1.4% per plant or less 29 m from the R plants. At least 35% of the total R x S crosses occurred in the direction of prevailing southeastward winds. Predicted percentages of R x S crosses per plant ranged from 0.16 to 1.29 at 1.5 m, and 0.00 to 0.06% at 29 m. Thus, resistant kochia pollen can spread the sulfonylurea-resistant trait at least 30 m during each growing season.

2021 ◽  
pp. 86-102
Author(s):  
Hugh J. Beckie ◽  
Sara L. Martin

Abstract Although herbicide-resistant (HR) weeds can be regularly monitored in fields via surveys, areawide monitoring of both cropland and ruderal (non-crop disturbed) areas is required for species with high propagule mobility. With increasing occurrence of HR weed populations in many agro-ecoregions, the relative contribution of independent evolution through herbicide selection and movement of HR alleles via pollen or seed needs to be elucidated to inform management and help preserve the remaining public good and common resource of herbicide susceptibility. Molecular markers available for many weed species can be utilized to assess regional gene flow accurately. In this chapter, we outline recommended principles and protocols for areawide monitoring of herbicide resistance gene flow in weed populations, exemplified by a case study of glyphosate resistance in kochia (Bassia scoparia A.J. Scott syn. Kochia scoparia (L.) Schrad.) in western Canada. Since being introduced from Eurasia to the Americas over a century ago, both seed- and pollen-mediated gene flow in the species have aided rapid range expansion and the spread of herbicide resistance.


Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 624-633 ◽  
Author(s):  
Hugh J. Beckie ◽  
Robert E. Blackshaw ◽  
Linda M. Hall ◽  
Eric N. Johnson

Efficient natural dispersal of herbicide-resistance alleles via seed and pollen can markedly accelerate the incidence of herbicide-resistant weed populations across an agroecoregion. Studies were conducted in western Canada in 2014 and 2015 to investigate pollen- and seed-mediated gene flow in kochia. Pollen-mediated gene flow (PMGF) from glyphosate-resistant (GR) to non-GR kochia was quantified in a field trial (hub and spoke design) at Saskatoon, Saskatchewan. Seed-mediated gene flow of acetolactate synthase (ALS) inhibitor-resistant kochia as a function of tumbleweed speed and distance was estimated in cereal stubble fields at Lethbridge, Alberta and Scott, Saskatchewan. Regression analysis indicated that outcrossing from GR to adjacent non-GR kochia ranged from 5.3 to 7.5%, declining exponentially to 0.1 to 0.4% at 96 m distance. However, PMGF was significantly influenced by prevailing wind direction during pollination (maximum of 11 to 17% outcrossing down-wind). Seed dropped by tumbleweeds varied with distance and plant speed, approaching 90% or more (ca. 100,000 seeds or more) at distances of up to 1,000 m and plant speeds of up to 300 cm s–1. This study highlights the efficient proximal (pollen) and distal (seed) gene movement of this important GR weed.


Author(s):  
O. A. Artyukhova ◽  
O. V. Gladysheva ◽  
V. A. Svirina

The effect of applying various norms of mineral fertilizers on the biological indicators of crop plants during their growth and development in the Central non-black earth region in 2017-2019 was studied on the varieties of spring barley Vladimir, Reliable and Yaromir.such indicators as plant height, photosynthetic apparatus area, green mass growth, and elements of the yield structure were Studied. It was revealed that on average during the growing season, when the norms of mineral fertilizers were increased, the area of leaf plates increased and, as a result, the increase in green mass growth relative to the control variants increased by 56.3 % at (NРК)30, 82.3 % at (NРК)60, and 126.7 % at (NРК)90. The introduction of mineral fertilizers also influenced the formation of the crop structure. There was an increase in the tillering coefficient of varieties by 15.7%, 5.7 % and 21.3 % (Vladimir, Reliable and Yaromir, respectively) relative to the control, an increase in the number of grains in the ear from 15.1 to 22.4 PCs., the weight of 1000 grains from 48.0 to 55.7 g. and the weight of grain per ear from 0.7 to 1.2 g. There was a strong correlation between the doses of mineral fertilizers and the grain yield from + 0.80 to +1.0, and the variability was calculated.      


Agrotek ◽  
2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Baso Daeng

<em>The rate of conversion of paddy fields and irrigation water crisis suggest to consider the development of upland rice.� Empowerment of organic-based dryland done to increase rice, as well as environmental sustainability efforts.� The purpose of this experiment was to determine the effect of organic fertilizer residue to upland rice in the second growing season.� Experiments using a split-split plot design.� The main plot consisted of a dosage of 50% and 100% organic fertilizer in the first growing season.� Sub plot consisted of chicken manure (20 tons ha<sup>-1</sup>), <span style="text-decoration: underline;">Centrosema</span>� <span style="text-decoration: underline;">pubescens</span> (4.3 tons ha<sup>-1</sup>) + chicken manure (10 tons ha<sup>-1</sup>), and <span style="text-decoration: underline;">Thitonia</span> <span style="text-decoration: underline;">diversifolia</span> (4.3 tons ha<sup>-1</sup>) + chicken manure (10 tons ha<sup>-1</sup>).� Sub-sub plot consist of Danau Gaung and Batu Tegi varieties.� The different types of fertilizer had no effect on plant productivity.� The addition of <span style="text-decoration: underline;">Thitonia</span> <span style="text-decoration: underline;">diversifolia</span> gave a good effect on some growth variable and its resistance due pathogen attack.� Batu Tegi varieties are varieties that give the best response from an organic fertilizer.� Interaction between dosage, type of fertilizer, and varieties do not provide areal impact.</em>


Author(s):  
O. A. Zadorozhna ◽  
T. P. Shyianova ◽  
M.Yu. Skorokhodov

Seed longevity of 76 spring barley gene pool samples (Hordeum vulgare L. subsp. distichon, convar. distichon: 56 nutans Schubl., two deficience (Steud.) Koern., two erectum Rode ex Shuebl., two medicum Koern.; convar. nudum (L.) A.Trof.: one nudum L. та subsp. vulgare: convar. vulgare: nine pallidum Ser., three rikotense Regel.; convar. coeleste (L.) A.Trof.: one coeleste (L.) A.Trof.) from 26 countries, 11 years and four places of reproduction was analyzed. Seeds with 5–8% moisture content were stored in chamber with unregulated and 4oC temperature. The possibility of seed storage under these conditions for at least 10 years without significant changes in germination has been established. The importance of meteorological conditions in the formation and ripening of seeds for their longevity is confirmed. The relationship between the decrease of barley seeds longevity and storage conditions, amount of rainfall, temperature regime during the growing season of plants is discussed.


Author(s):  
Donald C. Thill ◽  
Carol A. Mallory-Smith ◽  
Leonard L. Saari ◽  
Josephine C. Cotterman ◽  
Michael M. Primiani ◽  
...  

2007 ◽  
Vol 4 (6) ◽  
pp. 985-1003 ◽  
Author(s):  
M. K. van der Molen ◽  
J. van Huissteden ◽  
F. J. W. Parmentier ◽  
A. M. R. Petrescu ◽  
A. J. Dolman ◽  
...  

Abstract. Carbon dioxide and methane fluxes were measured at a tundra site near Chokurdakh, in the lowlands of the Indigirka river in north-east Siberia. This site is one of the few stations on Russian tundra and it is different from most other tundra flux stations in its continentality. A suite of methods was applied to determine the fluxes of NEE, GPP, Reco and methane, including eddy covariance, chambers and leaf cuvettes. Net carbon dioxide fluxes were high compared with other tundra sites, with NEE=−92 g C m−2 yr−1, which is composed of an Reco=+141 g C m−2 yr−1 and GPP=−232 g C m−2 yr−1. This large carbon dioxide sink may be explained by the continental climate, that is reflected in low winter soil temperatures (−14°C), reducing the respiration rates, and short, relatively warm summers, stimulating high photosynthesis rates. Interannual variability in GPP was dominated by the frequency of light limitation (Rg<200 W m−2), whereas Reco depends most directly on soil temperature and time in the growing season, which serves as a proxy of the combined effects of active layer depth, leaf area index, soil moisture and substrate availability. The methane flux, in units of global warming potential, was +28 g C-CO2e m−2 yr−1, so that the greenhouse gas balance was −64 g C-CO2e m−2 yr−1. Methane fluxes depended only slightly on soil temperature and were highly sensitive to hydrological conditions and vegetation composition.


2018 ◽  
Vol 40 (2) ◽  
pp. 153 ◽  
Author(s):  
Xuexia Wang ◽  
Yali Chen ◽  
Yulong Yan ◽  
Zhiqiang Wan ◽  
Ran Chao ◽  
...  

The response of soil respiration to simulated climatic warming and increased precipitation was evaluated on the arid–semi-arid Stipa steppe of Inner Mongolia. Soil respiration rate had a single peak during the growing season, reaching a maximum in July under all treatments. Soil temperature, soil moisture and their interaction influenced the soil respiration rate. Relative to the control, warming alone reduced the soil respiration rate by 15.6 ± 7.0%, whereas increased precipitation alone increased the soil respiration rate by 52.6 ± 42.1%. The combination of warming and increased precipitation increased the soil respiration rate by 22.4 ± 11.2%. When temperature was increased, soil respiration rate was more sensitive to soil moisture than to soil temperature, although the reverse applied when precipitation was increased. Under the experimental precipitation (20% above natural rainfall) applied in the experiment, soil moisture was the primary factor limiting soil respiration, but soil temperature may become limiting under higher soil moisture levels.


1972 ◽  
Vol 52 (2) ◽  
pp. 199-208 ◽  
Author(s):  
K. C. IVARSON ◽  
A. R. MACK

Studies were made on the root-surface fungi of soybean grown in field plots where various soil temperature and moisture environments had been maintained for five previous growing seasons. Washed-root segments were incubated on agar plates at temperatures corresponding to those of the field plots. Fusarium was the most abundant genus appearing on the plates. Species of Mucor, Trichoderma, Alternaria, Mortierella, Aspergillus, Corynespora, Rhizoctonia, Penicillium, Gliocladium, and sterile forms appeared fairly frequently. Statistical analysis of the data revealed that changes in soil and incubation temperature markedly affected the relative frequency of 12 genera, and age of plant significantly affected nine genera. Soil moisture influenced the frequency of only one genus. High soil and incubation temperature (28 C) encouraged greater root populations of Rhizoctonia early in the season, Trichoderma and Aspergillus throughout the growing season, and Fusarium late in the season. Low soil temperature conditions (12 C) favored growth of Pythium, Mortierella, Mucor, Alternaria, Cladosporium, throughout the growing season, and Corynespora and Cylindrocarpon, primarily during mid-season. Late in the season Gliocladium preferred the intermediate temperature of 20 C.


2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.


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