Identification and Utilization of Variation in Herbicide Tolerance in Soybean (Glycine max) Breeding

Herbicides marketed for selected crops were chosen on the basis that major cultivars of the specific crop were tolerant. Our work with soybeans [Glycine max(L.) Merr.] has demonstrated that variability exists with regard to sensitivity or tolerance to several herbicides. As a part of our breeding program to develop improved soybean cultivars, we have evaluated advanced breeding lines and germplasm for reaction to herbicides on the market as well as experimental herbicides. A breeding line was identified and released for production which showed very little injury from two over-the-top applications of a double rate of 2,4-DB [4-(2,4-dichlorophenoxy)butyric acid]. Other strains showed severe injury and depressed seed yield. Variation in reaction to glyphosate [N-(phosphonomethyl)glycine] has been observed. Lines tolerant to 0.56 kg ai/ha in one growing season were severely damaged the following season. When 200 germplasm lines from eastern Asia were treated with glyphosate, 6% showed less than 15% injury while 21% showed over 80% injury. The cultivar ‘Tracy′, selected for tolerance to 2,4-DB and a high level of resistance to the soil-borne disease causing phytophthora rot, was found to be sensitive to metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one]. Tracy has two major genes controlling resistance to phytophthora rot caused byPhytophthora megaspermaDrechs. f. sp.glycineaKuan and Erwin. One of these genes is closely linked with a gene controlling reaction to metribuzin. A crossover type was identified. The cultivar ‘Tracy-M’ retains the high level of resistance to phytophthora rot and is tolerant to metribuzin. A small percentage of germplasm lines evaluated were found to be sensitive to bentazon. Reaction to bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] is simply inherited.

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"DEFEATED" Rps1 GENE IN SOYBEAN

Canadian Journal of Plant Science ◽

10.4141/cjps88-026 ◽

1988 ◽

Vol 68 (1) ◽

pp. 225-227

Author(s):

T.R. ANDERSON ◽

R.I. BUZZELL

Keyword(s):

Glycine Max ◽

Specific Resistance ◽

Field Testing ◽

Residual Effects ◽

Phytophthora Megasperma ◽

Glycine Max L ◽

Phytophthora Rot

Field testing of 10 backcross-derived Rps1Rps1 cultivars/lines of soybean (Glycine max (L.) Merr.) and their recurrent rps1rps1 cultivars in the presence of compatible races of Phytophthora megasperma f. sp. glycinea showed no residual effects of race-specific resistance on tolerance of soybean to the disease.Key words: Soybean, race-specific resistance, tolerance, phytophthora rot

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Toxicity of MSMA, Fluometuron, and Propanil to Soybeans

Weed Science ◽

10.1017/s004317450003304x ◽

1977 ◽

Vol 25 (2) ◽

pp. 101-105 ◽

Cited By ~ 9

Author(s):

L.E. Bode ◽

C.G. McWhorter

Keyword(s):

Glycine Max ◽

Growing Season ◽

Yield Losses ◽

Stages Of Growth ◽

Over The Top ◽

Better Than

We investigated the toxicity of MSMA (monosodium methanearsonate), fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea], and propanil (3′,4′-dichloropropionanilide) to soybeans [Glycine max(L.) Merr. ‘Hill’]. Over-the-top treatments were applied to soybeans at four stages of growth using MSMA at 0.1, 0.2, and 0.4 kg/ha, propanil at 0.2, 0.4, and 0.9 kg/ha, and fluometuron at 0.05, 0.1, and 0.2 kg/ha. Each herbicide caused 10 to 30% soybean injury at the lowest rate, and 40 to 70% injury at the highest rate. Soybeans treated earliest in the growing season usually recovered from injury better than soybeans treated later in the season. Soybean yields were reduced 50 to 70% by MSMA at 0.4 kg/ha and 25 to 35% by propanil at 0.9 kg/ha. Yield losses increased with stage of soybean maturity at time of treatment. Fluometuron at 0.2 kg/ha significantly reduced yield only when applied to soybeans with 7 or 10 trifoliolates or in midbloom.

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Assessment of diversity in tropical soybean (Glycine max (L.) Merr.) varieties and elite breeding lines using single nucleotide polymorphism markers

Plant Genetic Resources ◽

10.1017/s1479262121000034 ◽

2021 ◽

Vol 19 (1) ◽

pp. 20-28

Author(s):

Abush Tesfaye Abebe ◽

Adesike Oladoyin Kolawole ◽

Nnanna Unachukwu ◽

Godfree Chigeza ◽

Hailu Tefera ◽

...

Keyword(s):

Genetic Diversity ◽

Single Nucleotide Polymorphism ◽

Glycine Max ◽

Snp Markers ◽

Fixation Index ◽

Nucleotide Polymorphism ◽

Single Nucleotide ◽

Breeding Lines ◽

Soybean Germplasm ◽

Elite Breeding Lines

AbstractSoybean (Glycine max (L.) Merr.) is an important legume crop with high commercial value widely cultivated globally. Thus, the genetic characterization of the existing soybean germplasm will provide useful information for enhanced conservation, improvement and future utilization. This study aimed to assess the extent of genetic diversity of soybean elite breeding lines and varieties developed by the soybean breeding programme of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. The genetic diversity of 65 soybean genotypes was studied using single-nucleotide polymorphism (SNP) markers. The result revealed that 2446 alleles were detected, and the indicators for allelic richness and diversity had good differentiating power in assessing the diversity of the genotypes. The three complementary approaches used in the study grouped the germplasm into three major clusters based on genetic relatedness. The analysis of molecular variance revealed that 71% (P < 0.001) variation was due to among individual genotypes, while 11% (P < 0.001) was ascribed to differences among the three clusters, and the fixation index (FST) was 0.11 for the SNP loci, signifying moderate genetic differentiation among the genotypes. The identified private alleles indicate that the soybean germplasm contains diverse variability that is yet to be exploited. The SNP markers revealed high diversity in the studied germplasm and found to be efficient for assessing genetic diversity in the crop. These results provide valuable information that might be utilized for assessing the genetic variability of soybean and other legume crops germplasm by breeding programmes.

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Penetration and growth of compatible and incompatible races of Phytophthora megasperma var. sojae in soybean hypocotyl tissues differing in age

Canadian Journal of Botany ◽

10.1139/b80-301 ◽

1980 ◽

Vol 58 (24) ◽

pp. 2594-2601 ◽

Cited By ~ 28

Author(s):

P. Stössel ◽

G. Lazarovits ◽

E. W. B. Ward

Keyword(s):

Glycine Max ◽

Epidermal Cells ◽

Mechanisms Of Resistance ◽

Hypocotyl Growth ◽

Phytophthora Megasperma ◽

Cell Layers ◽

Glycine Max L ◽

Incompatible Reaction ◽

Race 4 ◽

Incompatible Interactions

Intact 6-day old soybean hypocotyls (Glycine max L., cv. Altona) were inoculated with zoospores of Phytophthora megasperma Drechs. var. sojae Hildeb. either at the top (susceptible to compatible races, resistant to incompatible races) or the bottom (resistant to both compatible and incompatible races) and, after a 22-h incubation, were examined by light microscopy. Penetration at the top and bottom by both compatible (race 6) and incompatible (race 4) P. megasperma var. sojae was predominantly between anticlinal walls of epidermal cells. Both races, but especially race 4, also penetrated directly into the outer walls of epidermal cells, but epidermal cells rarely were invaded. Both races grew mainly intercellularly, but race 6 produced haustoria more frequently than race 4. Race 6 haustoria at the top of the hypocotyl were usually encased, those of race 4 were not. Growth of both races was equally dense in the first few cell layers, but the numbers of race 4 hyphae decreased rapidly while those of race 6 became more abundant in the deeper layers. With race 4, but not with race 6, most cells in the infected tissue were necrotic. Differences between the compatible and the incompatible interactions were not absolute; there were many unsuccessful invasion attempts by race 6 and individual hyphae of race 4 spread deeply into the tissue. At the bottom of the hypocotyl, growth of both races was more restricted. Race 6 produced fewer haustoria than at the top, and similarities to the incompatible reaction with race 4 at the top suggest that similar mechanisms of resistance may be involved.

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Effect of Date of Treatment of Johnsongrass (Sorghum halepense) on Soybean (Glycine max) Yields

Weed Technology ◽

10.1017/s0890037x0002827x ◽

1991 ◽

Vol 5 (2) ◽

pp. 381-386 ◽

Cited By ~ 4

Author(s):

Chester G. McWhorter

Keyword(s):

Glycine Max ◽

Field Study ◽

Growing Season ◽

Sorghum Halepense

In a 6-yr field study, johnsongrass growing in ‘Forrest’ soybeans for the entire growing season reduced yields 45% in the year with most rainfall and 69% in the year with least rainfall. Yields of soybeans grown without johnsongrass competition were 56% higher in the year with the most rainfall than in the year with least rainfall. Yields of soybeans with full-season competition were reduced 75% from those in the year with most rainfall as compared with those in the year with least rainfall. The number of weeks of johnsongrass competition required to significantly reduce soybean yields varied from 3 wk, in the year with least rainfall, to 8 wk, in the year with most rainfall. Nine applications of sethoxydim at 0.84 kg ai ha-1or haloxyfop at 0.55 kg ai ha-1each year did not reduce soybean growth or yields.

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In vitro answer of Bulgarian pepper (Capsicum annuum L.)

Genetika ◽

10.2298/gensr0602129r ◽

2006 ◽

Vol 38 (2) ◽

pp. 129-136

Author(s):

Velichka Rodeva ◽

Stanislava Grozeva ◽

Velichka Todorova

Keyword(s):

Culture Medium ◽

Culture Media ◽

Casein Hydrolysate ◽

Basal Medium ◽

Regeneration Ability ◽

Stem Explants ◽

Media Composition ◽

Breeding Lines ◽

High Level

Callusogenesis and regeneration ability of cotyledon and hypocotyl explants from three Bulgarian pepper varieties in MS basal medium supplemented with l-3mg/l BAP. l.0mg/1 IAA and 0.5mg/l GA3 was studied. In the different variants of culture medium was registered high level of callusogenesis and organogenesis in both type of explants from the all varieties. The highest percentage of plant-regenerants is established in cotyledon explants (from 3.3 to 18.3) in variant 3 of the culture medium containing 3mg/l BA. In the process of micropropagation by stem explants of the same studied pepper varieties the addition of the vitamins C. B12. Casein hydrolysate and Ferulic acid had a stimulation effect on the plant growth in height and rooting. In result of anther cultivation from three pepper varieties and four breeding lines the highest percentage of embryo structure formation was registered in varieties Albena and Strjama (12.0 and 13.8 respectively). The Bulgarian peppers are recalcitrant and their in vitro answer is different depending from the explants type, genotype and the culture media composition.

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Rust and leaf spot diseases on American elderberry plants

10.32469/10355/63371 ◽

2017 ◽

Author(s):

◽

Kaley Hensel

Keyword(s):

Leaf Spot ◽

Dry Weight ◽

Growing Season ◽

Significant Loss ◽

Leaf Wetness ◽

Conservative Estimate ◽

Sambucus Nigra ◽

Shoot Dry Weight ◽

Harvest Dates ◽

High Level

Elderberry rust (Puccinia sambuci Schewin.) Arthur (=P. bolleyana) and leaf spot diseases are frequently found in commercial American elderberry (Sambucus nigra L. subsp. canadensis L.) plantings throughout the growing season in Missouri. Thus, studies were conducted to ascertain if rust infections affect plant growth, fruiting, or berry puree quality. Rust symptoms were observed in early April at 9 to 18[degrees] C, [greater than or equal to] 3 h leaf wetness, and [greater than or equal to] 85% relative humidity. When young, potted elderberry plants averaged 3 to 6 rust pustules/plant, vegetative growth was not adversely affected. However, field-grown elderberry plants heavily infected with rust (137 pustules/cane) lost nearly twice as many leaves as controls during the growing season, indicating rust-induced defoliation. Shoot dry weight of these heavily infected canes was also 32% less than that of controls. First and last harvest dates were advanced by the high level of rust infection on 'Wyldewood' elderberry canes, but not by low pustules numbers ([less than] 6 pustules/plant) on 'Bob Gordon' or 'Ozark' plants. Similarly, berry yields were not significantly different at low infection levels, even though rust-infected 'Bob Gordon' plants had a 31% reduction in yield with an estimated $440/ha loss of income. Heavily-infected 'Wyldewood' canes had a significant loss in berry yield (47%) and potential income ($2,295/ha), assuming a conservative estimate of five canes/plan. In another study, Colletotrichum was isolated from elderberry leaf spot lesions and identified before subsequent re-inoculation of elderberry plants with this pathogen. Three species of Colletotrichum (C. salicis Funkel, C. kahawae subsp. ciggaro Wollenw., and C. aenigma C.M. Tian and Z. Li) were putatively identified as being casual agents of leaf spot indicating the diversity of species within this genus on elderberry plants.

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Factors Affecting the Toxicity of Glyphosate Applied in the Recirculating Sprayer to Johnsongrass (Sorghum halepense)and Soybeans (Glycine max)

Weed Science ◽

10.1017/s0043174500027776 ◽

1980 ◽

Vol 28 (1) ◽

pp. 59-63 ◽

Cited By ~ 2

Author(s):

C. G. McWhorter ◽

J. R. Williford

Keyword(s):

Glycine Max ◽

Field Experiments ◽

Sorghum Halepense ◽

Soybean Yield ◽

Factors Affecting ◽

Over The Top ◽

Uniform Droplet ◽

Better Than

Field experiments were conducted to determine optimum nozzle settings for applying glyphosate [N-(phosphonomethyl)glycine] in the recirculating sprayer for postemergence control of johnsongrass [Sorghum halepense(L.) Pers.] in soybeans [Glycine max(L.) Merr.]. Herbicide sprays were directed across the row to johnsongrass growing taller than soybeans in July and August. Herbicide not sprayed on johnsongrass was trapped and reused. Glyphosate at 0.56, 1.12, and 2.24 kg/ha applied with commercially available 25° spray nozzles provided johnsongrass control and soybean yields equal to those following applications with specialized uniform droplet nozzles. Glyphosate at 1.7 kg/ha applied in the recirculating sprayer using only one nozzle per row provided control of johnsongrass equal to or better than that from applications made with two, three, or four nozzles per row. Soybean yield following application of glyphosate at 1.7 kg/ha with one nozzle per row was equal to yields obtained following its application with two, three, or four nozzles per row, with or without surfactant at 0.1% in spray solutions. Soybean yield was higher with four nozzles per row than with one nozzle per row when 0.5% surfactant was included in spray solutions. Soybean injury was lower and yield was higher when glyphosate was applied in the recirculating sprayer rather than over-the-top with a conventional sprayer. Glyphosate at 1.12 kg/ha applied in the recirculating sprayer caused more injury to ‘Hill’ and ‘Bragg’ than to ‘Forrest’ or ‘Tracy’ soybeans.

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The Effect of Surfactant and Environment on the Toxicity of Metriflufen to Soybeans (Glycine max) and Johnsongrass (Sorghum halepense)

Weed Science ◽

10.1017/s0043174500046129 ◽

1979 ◽

Vol 27 (6) ◽

pp. 675-679 ◽

Cited By ~ 17

Author(s):

C. G. McWhorter

Keyword(s):

Glycine Max ◽

Methyl Ester ◽

Relative Humidity ◽

Air Temperature ◽

Sorghum Halepense ◽

Growth Chamber ◽

Propanoic Acid ◽

Herbicide Treatment ◽

Over The Top

Metriflufen {2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoic acid} was applied as the methyl ester at 0.28 and 0.56 kg/ha over-the-top to johnsongrass [Sorghum halepense(L.) Pers.] growing from rhizomes and to soybeans [Glycine max(L.) Merr. ‘Lee 68′]. After herbicide treatment, plants were grown in the growth chamber for 14 days at 16, 24, or 32 C with relative humidity (RH) at 40 or 100% at each air temperature. Johnsongrass was not controlled at 16 C regardless of metriflufen rate, RH, or the addition of nonoxynol [α-(p-nonylphenyl)-ω-hydroxypoly (oxyethylene)] (with 9.5 moles of polyoxyethylene) surfactant at 0.25 (g/100 ml) to spray solutions. Johnsongrass control at 24 C varied from 5 to 98%, with significantly better control at 100% than at 40% RH. The presence of surfactant increased johnsongrass control at 24 C and 40% RH but not at 24 C and 100% RH. Johnsongrass control at 32 C varied from 48 to 98%, and it was not increased by the presence of the surfactant, regardless of metriflufen rate or RH level. At 16 C metriflufen was more injurious to soybeans than to johnsongrass, but at 24 and 32 C johnsongrass control was significantly greater than soybean injury. The presence of surfactant in spray solutions generally did not increase soybean injury, regardless of temperature or RH level. These results suggest that metriflufen is most selective in controlling johnsongrass in soybeans at 24 C, especially under high RH.

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Weed Control from Imazaquin and Metolachlor in No-till Soybeans (Glycine max)

Weed Science ◽

10.1017/s0043174500072118 ◽

1989 ◽

Vol 37 (3) ◽

pp. 392-399 ◽

Cited By ~ 21

Author(s):

Douglas D. Buhler ◽

Virginia L. Werling

Keyword(s):

Glycine Max ◽

Weed Control ◽

Untreated Control ◽

Growing Season ◽

Common Lambsquarters ◽

No Till ◽

Herbicide Treatments

In 1985, when weed densities were low (169 plants/m2in untreated control), imazaquin applied at 0.07 kg ai/ha early preplant controlled over 90% of all weeds before no-till planting of soybeans. In 1986 and 1987 when weed densities were higher (589 plants/m2in untreated control), addition of 1.1 kg ai/ha or more of metolachlor to imazaquin (0.07 kg/ha) before soybean planting controlled 95% or more of the grass weeds and 83% or more of the broadleaf weeds. Imazaquin plus metolachlor applied less than 1 day after soybean planting controlled less than 70% of the emerged weeds in 1986 and 1987; common lambsquarters was most tolerant. Early preplant treatments controlled more weeds throughout the growing season than treatments applied after planting. Splitting herbicide treatments among application times generally did not increase weed control compared to single applications. Early preplant applications resulted in higher soybean densities and taller soybeans 30 days after planting in 1986 and 1987 than treatments applied after planting. Soybean yields increased as weed control increased. Weed control and soybean yields were greater with early preplant treatments than paraquat plus alachlor plus metribuzin applied preemergence in 1986 and 1987. No carryover of imazaquin residue was detected through corn bioassay in the field.

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