Conventional Soybean Cultivars Research Articles

Development of Glycine max Germplasm Highly Resistant to Sclerotinia sclerotiorum

Sclerotinia stem rot (SSR) of soybean caused by Sclerotinia sclerotiorum is a devastating disease of soybean, especially in the Upper Midwest region of the United States. To mitigate yield losses due to this disease, many control methods are available for producers, including cultural control practices, chemical control, and cultivars with quantitative resistance. However, due to there being few commercial cultivars with high levels of resistance, producers are often limited in their seed selection. The aim of this study was to develop novel conventional soybean cultivars with high levels of resistance to SSR, favorable agronomic traits, and resistance to additional economically important diseases. Initial crosses were conducted in 2016 with two different sources of SSR resistance. Across multiple generations of screening for resistance to SSR, three highly resistant soybean lines were identified as the elite lines. These elite lines were demonstrated to be highly resistant across multiple years in both greenhouse and field trials, including high levels of resistance to multiple diverse S. sclerotiorum isolates. The three selected elite lines also resulted in moderately high yields and favorable agronomic traits, such as low lodging and moderate branching, indicating their viability to be released for production. In addition to SSR resistance, these three elite lines demonstrated resistance to other economically important soybean diseases, such as frogeye leaf spot, anthracnose, Cercospora leaf blight, and brown stem rot. Overall, this work has led to three SSR-resistant soybean lines that could be useful for future breeding efforts or commercial soybean production. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

DESEMPENHO FISIOLÓGICO DE SEMENTES DE CULTIVARES SOJA CONVENCIONAL EM FUNÇÃO DO TAMANHO E TEOR DE UMIDADE NA GERMINAÇÃO

Quality test protocols for soybean seeds recommend a period of soaking and preconditioning without detailing the size of the seeds to be evaluated, as seeds of different sizes reach different degrees of humidity in each period owing to differences in their initial moisture level and size. Determining the degree of seed moisture during the preconditioning period is important when conducting accelerated aging, tetrazolium, and primary root protrusion tests. The objective of this study was to evaluate the physiological performance of two conventional soybean cultivars (BRS 284 and BRS 511) with three seed sizes (6.0, 6.5, and 7.0 mm) and three moisture levels, adjusted to 10%, 12%, and 14% and a control condition with 8.8% moisture. The experimental design was a randomized block scheme in a factorial arrangement of (3×3)+1 involving seed size and moisture. Regardless of the cultivar and moisture content, seeds with large diameters were more resistant to changes, such as accelerated aging, and resulted in larger seeds and higher numbers of developed seedlings than seeds with small diameters.

Registration of ‘S11‐16653C’ soybean: A high‐yielding conventional cultivar with broad resistance to diseases and nematodes

AbstractThe soybean [Glycine max (L.) Merr] line S11‐16653C (Reg. no. CV‐554, PI 700000) was developed and released as a cultivar by the University of Missouri, Fisher Delta Research, Extension, and Education Center (MU‐FDREEC). S11‐16653C is an early maturity group V (relative maturity 5.3), high‐yielding conventional (non‐genetically modified) cultivar with determinate growth habit. It is a chloride excluder and has a broad disease resistance package, including soybean cyst nematode (Heterodera glycines Ichinohe) races 1 (HG type 2.5.7), 2 (HG type 1.2.5.7), 3 (HG type 5.7), 5 (HG type 2.5.7), southern root‐knot nematode [Meloidogyne incognita (Kofold & White) Chitwood], peanut root‐knot nematode [Meloidogyne arenaria (Neal) Chitwood], reniform nematode (Rotylenchulus reniformis Linford & Oliveira), stem canker (Diaporthe aspalathi Jansen, Castlebury & Crous), Phytophthora root rot (caused by Phytophthora sojae M.J.Kaufmann & J.W.Gerdemann), and sudden death syndrome (Fusarium virguliforme O'Donell & T. Aoki). S11‐16653C was tested in 78 locations across nine states (Alabama, Arkansas, Kansas, Louisiana, Missouri, Mississippi, North Carolina, Tennessee, and Virginia) from 2012 to 2016. It was entered in internal yield tests at the MU‐FDREEC (2012–2014), USDA Uniform Soybean Tests (2014–2016), and soybean state variety tests (2015). It showed consistent high‐yielding performance and broad adaptability throughout the trials and locations. Overall, S11‐16653C is a high‐yielding conventional soybean cultivar that has potential for commercial production and serves as an exceptional germplasm for soybean breeding.

Oviposition preference and life-history parameters of Callosobruchus maculatus (Coleoptera: Chrysomelidae) on different soybean (Glycine max) cultivars.

Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) is one of the most destructive pests of stored legume seeds in many regions of the world. Evaluation of varietal resistance of host seeds to C.maculatus infestation can be useful in preventing severe damage. We studied the susceptibility and resistance of eight conventional soybean cultivars (Caspian, Kosar, L17, Nekador, Sari, Tapour, Williams and Zane) based on the oviposition preference (choice and no-choice tests) and population growth parameters of the pest. Compared with other cultivars tested, oviposition preference of C.maculatus was the lowest on Nekador. The developmental time of C.maculatus differed from 40.34 days on Nekador to 48.35 days on L17, and was negatively correlated with the seed protein content. Other performance measures of C.maculatus did not match the oviposition preference. Immature survival and female longevity were highest on Caspian. The intrinsic rate of increase (rm ) was higher on Tapour, Nekador and Caspian than on Zane, Williams, and Kosar. A positive correlation was observed between the rm value of the pest and moisture content of the cultivars. Cluster analysis showed that cvs Nekador, Sari, Tapour, and Caspian were relatively susceptible, and cvs Kosar, Zane, Williams and L17 were partially resistant to this pest. Protein and moisture contents of soybean cultivars play an important role in the development and population growth of C.maculatus, and these traits could be used to develop safe and effective management strategies for this pest on stored soybean seeds. © 2022 Society of Chemical Industry.

Registration of ‘S16‐14801C’: A high‐yielding determinate maturity group V soybean cultivar with multiple disease resistance, salt tolerance, and broad adaptation

AbstractThe demand for non–genetically modified soybean [Glycine max (L.) Merr.] cultivars has steadily increased in the last decade due to changes in consumers’ preferences and the growth of specialty niche markets. To meet this growing demand, the University of Missouri–Fisher Delta Research, Extension, and Education Center soybean breeding program has developed and released ‘S16‐14801C’ (Reg. no. CV‐553, PI 699901). It is a high‐yielding determinate maturity group 5 early (relative maturity 5.0) conventional soybean cultivar with resistance to multiple diseases, including soybean cyst nematode races 2 (HG type 1.2.5.7) and 5 (HG Type 2.5.7), southern root‐knot nematode, reniform nematode, stem canker, and salt tolerance. S16‐14801C was tested in a total of 111 environments across 12 states from 2017 to 2021, outyielding the commercial checks (on average) of similar maturity in 75 environments. Given its high‐yielding performance, multiple disease resistance package, and wide adaptability, S16‐14801C represents a good cultivar choice for soybean growers across the U.S. southern states, especially for crop systems targeting premium contracts associated with specialty markets.

Assessment of the Physiological Response and Productive Performance of Vegetable vs. Conventional Soybean Cultivars for Edamame Production

Because there is a close relationship between plant physiological response and crop performance, the current study aims to evaluate the photosynthetic efficiency and productive performance of vegetable versus conventional soybean cultivars for edamame production. The study was conducted at the School of Agriculture (FCA UNESP), Botucatu-SP, Brazil. The treatments in this study included soybean cultivars: vegetable-type BRS 267, vegetable-type BRSMG 790A), and type soybean cultivar grain 58HO124 EP RR, with ten repetitions per treatment in a completely randomized block design. Gas exchange and the response of the cultivars to light were evaluated for photosynthetic characterization. The first pod insertion height, plant height, number of pods per plant, and production in immature grains were all assessed for cultivar productive performance. The type of soybean cultivar grain and vegetable types of soybean showed different behaviors on physiology and yield. The vegetable-types BRS 267 and BRSMG 790A had the highest average for first pod insertion height. The vegetable type BRS 267, whose photoassimilates were designated for vegetative development, had the greatest average plant height. The conventional type 58HO124 EP RR showed greater assimilation of CO2; however, the photoassimilates were directed to floral emission because such features are inherent in its ability. Finally, vegetable-type BRSMG 790A produced the most immature grains per plant while also having the greatest first pod insertion height, being the best in converting photoassimilates for edamame production.

‘S16‐14730C’: A high‐yielding conventional soybean cultivar with indeterminate growth habit and multiple disease resistance adapted to the Mid‐South

Abstract‘S16‐14730C’ (Reg. no. CV‐546, PI 699632) is a conventional maturity group (MG) IV (relative maturity, 4.7) soybean [Glycine max (L.) Merr.] cultivar released by the University of Missouri–Fisher Delta Research Center breeding program in 2020. It has an indeterminate growth habit, averaging 89 cm in height with a 2.1 lodging score. Plants have purple flowers, tawny pubescence, and tan pod wall color, and seeds have black hilum and 402.8 g kg–1 of protein and 224.0 g kg–1 of oil concentrations. S16‐14730C underwent extensive yield testing and disease evaluation from 2017 to 2020 over a total of 104 environments across 12 states. During the USDA uniform trials in 2018 and 2019, S16‐14730C yielded 4,192 kg ha–1, equivalent to 99 and 108% of the best checks and overall check mean, respectively. S16‐14730C shows resistance to stem canker and soybean cyst nematode (SCN) HG type 2.5.7 (race 1) and HG type 5.7 (race 3) and moderate resistance to SCN HG type 1.2.5.7 (race 2), southern root‐knot nematode, peanut root‐knot nematode, and charcoal rot. It is susceptible to reniform nematode and phytophthora root rot. S16‐14730C may serve as an excellent choice in regions where a late MG IV conventional line is in demand.

Registration of ‘S16‐11651C’, a conventional soybean cultivar with high yield, resistance to multiple diseases, and broad adaptation

Abstract‘S16‐11651C’ (Reg. no. CV‐549, PI 699631) is an early maturity group (MG) V, semi‐determinate, conventional, high‐yielding soybean [Glycine max (L) Merr.] cultivar developed and released in 2020 by the University of Missouri–Fisher Delta Research Center Soybean Breeding Program. High global demand for soybean oil and animal feed and U.S. mid‐southern growers’ interest in early‐MG V conventional cultivars with high yield potential, desired protein and oil content, and broad disease resistance motivated the development and release of S16‐11651C soybean. S16‐11651C was tested in 94 environments in Missouri and 11 other mid‐southern states from 2017 to 2020 for yield and other agronomic traits. On average, S16‐11651C yielded 4,327 kg ha–1, which is 292 kg ha–1 higher than the all‐tests mean of 4,035 kg ha–1. S16‐11651C seed contains 413 (41.3%) and 220 (22%) g kg–1 of protein and oil, respectively, on a dry weight basis. S16‐11651C exhibits relative maturity of 5.3 and has white flowers, tawny pubescence, and tan pod walls. The seed is yellow with intermediate luster and black hila with a weight of 13.5 g 100–1 seed. S16‐11561C is 88 cm tall on average with resistance to lodging. It is resistant to cyst nematode (races 1, 2, and 5 with moderate resistance to race 3), peanut and southern root‐knot nematode, reniform nematode, brown stem rot, charcoal rot, and purple seed stain and moderately resistant to Phomopsis seed decay. S16‐11561C has the capacity to exclude chloride. In addition to its high yield potential, high seed protein and oil content, and early maturity, S16‐11561C has exhibited broad adaptation across mid‐southern states.

‘S16‐7922C’: A semi‐determinate maturity group IV conventional soybean cultivar with high yield and broad disease resistance

Abstract‘S16‐7922C’ (Reg. no. CV‐545, PI 699902) is a semi‐determinate maturity group IV (relative maturity: 4.9) conventional (nontransgenic) soybean [Glycine max (L.) Merr.] cultivar developed and released by the University of Missouri–Fisher Delta Research Center. S16‐7922C was derived from a cross of ‘S11‐16653C’ × ‘S11‐20124C’ designed to meet the growing demand for nontransgenic, high‐yielding soybean cultivars with resistance to yield‐limiting diseases. S16‐7922C contains seed protein and oil concentrations of 403 and 226 g kg−1, respectively, on a dry weight basis. S16‐7922C is resistant to southern root‐knot nematode, peanut root‐knot nematode, charcoal rot, frogeye leaf spot, and stem canker and moderately resistant to soybean cyst nematode and reniform nematode. It is tolerant to saline soil and moderately tolerant to waterlogging stress. S16‐7922C demonstrated excellent yield potential and adaptability in a total of 110 environments across 12 southern states in 2017–2020. As a high‐yielding soybean cultivar with a broad disease resistance package and high oil concentration, S16‐7922C may be suitable for soybean growers interested in a maturity group IV late nontransgenic soybean cultivar.

Registration of ‘S16‐15170C’ soybean: A high‐yielding indeterminate maturity group V cultivar with wide adaptability and multiple disease resistance

AbstractWith the rise of novel specialty markets and changes in consumers’ preferences, the demand for high‐yielding, non‐genetically modified (non‐GM) soybean [Glycine max (L.) Merr.] cultivars has been steadily increasing over the last decade. Interest from growers in non‐GM soybean cultivars has also increased because they may benefit from premium prices, reduced seed costs, and flexible farming systems. To meet this growing demand, the University of Missouri–Fisher Delta Research, Extension, and Education Center soybean breeding team has developed and released ‘S16‐15170C’ (Reg. no. CV‐550, PI 699900), a high‐yielding conventional soybean cultivar with multiple disease resistance and broad adaptation to the Southern states. S16‐15170C has an indeterminate growth habit and white flowers, gray pubescence, and tan pod wall color. This soybean cultivar has been extensively tested across 12 states from 2017 to 2020 and has outyielded commercial checks in 48 out of 78 environments, with the average yield being 102.7% of checks overall. S16‐15170C is resistant to soybean cyst nematode, stem canker, frogeye leaf spot, sudden death syndrome, brown stem rot, and phytophthora root rot. The combination of high yielding potential, broad adaptability, and multiple disease resistance in a non‐GM genetic background makes S16‐15170C a suitable soybean cultivar choice for growers adopting an alternative farming system and maximizing potential returns during the season.

Conventional and transgenic herbicide‐resistant soybean cultivars yielded similarly across five site‐years in Nebraska

AbstractSoybean [Glycine max (L.) Moench.] yield is determined by interactions amongst soybean cultivars’ genetic potential, agronomic practices, and environmental conditions. Despite the high adoption of herbicide‐resistant soybean cultivars across Nebraska and the United States, the comparative yield potential of non‐herbicide‐resistant (“conventional”) cultivars in not well understood. A field experiment was conducted at five locations across Nebraska in 2017 and 2018 to determine the effect of row spacing (15 and 30 in), cultivar maturity group (2.2–2.4 and 3.2), and herbicide resistance traits (conventional, glyphosate‐resistant, and glyphosate‐ and dicamba‐resistant) on soybean yield. Narrow row spacing increased the soybean yield in three of five research locations. The soybean yield in Auburn in 2017, Albion in 2018, and Cedar Bluffs in 2018 increased by 11.9, 10.2, and 11.4% in narrow compared with wide rows, respectively. Cultivar maturity group and herbicide resistance traits did not affect soybean yield under weed‐free experimental conditions. These results suggest that growers could benefit from earlier maturity groups, as they provide an opportunity for earlier harvest, allowing growers to better spread their field activities in the fall. The grain yield potential was similar between conventional and transgenic herbicide‐resistant cultivars. Therefore, conventional soybean cultivars can be a viable option when adequate weed management can be achieved through conventional weed management strategies.

Registration of ‘TN14‐5021’, a conventional soybean cultivar with elevated seed protein and resistance to soybean cyst nematode races 2, 3, and 5

Abstract‘TN14‐5021’ (Reg. no. CV‐543, PI 699124) is a late maturity group IV (relative maturity 4.9) determinate conventional soybean [Glycine max (L.) Merr.] cultivar developed and released by the University of Tennessee soybean breeding program. Soybean cultivars with resistance to soybean cyst nematode (SCN) race 2 are rare, but race 2 is becoming a predominant SCN population infecting farmers’ fields in regions of the U.S. Southeast and Mid‐South. TN14‐5021 also conveys resistance to stem canker [caused by Diaporthe phaseolorum (Cooke & Ellis) Sacc. var. caulivora K.L. Athow & R.M. Caldwell] and strong resistance to SCN races 3 and 5. In replicated trials across 70 environments from the Mid‐South to the Southeast, TN‐5021 showed high yield potential and adaptation to a broad range of growing conditions. TN14‐5021 has white flowers and gray pubescence. The pods have a tan pod coat, and the seeds are yellow with smooth seed coats. Across 48 environments over a 4‐yr period, with testing locations from Kansas to Alabama, TN14‐5021 averaged 406 and 226 g kg–1 protein and oil content, respectively. In comparison, the average protein and oil content of commercial cultivars grown in the same tests averaged 397 and 224 g kg–1, respectively. Its high yield coupled with elevated seed protein concentration and nematode resistance package make TN14‐5021 a valuable cultivar for Tennessee and the Mid‐South region.

Registration of ‘S13‐2743C’ as a conventional soybean cultivar with high oil content, broad disease resistance, and high yield potential

AbstractHigh demand for early‐maturing conventional (non‐genetically modified [GMO]) high‐oil soybean [Glycine max (L.) Merr.] cultivars in the food and special niche markets led to the development and release of ‘S13‐2743C’ (Reg. no. CV‐538, PI 695097). It is a tall, early maturity group IV (relative maturity 4.1) non‐GMO soybean developed and released by the University of Missouri–Fisher Delta Research Center soybean breeding program. This early maturing, indeterminate type cultivar is desired by growers in the southern United States to plant along with later maturity groups to allow flexibility during the harvest season. S13‐2743C has high oil content (238.4 g kg−1) and a broad disease resistance package, including resistance to soybean cyst nematode race 3, phytophthora root rot, stem canker, sudden death syndrome, and frogeye leaf spot. It has white flowers, grey pubescence, and brown pod walls. Seeds have buff hila and intermediate luster. S13‐2743C was tested in 103 environments across eight states and showed high yield potential in Missouri and other southern states, including Arkansas, Kansas, Kentucky, Louisiana, Mississippi, and Tennessee.

Final Health and Environmental Risk Assessment of Genetically Modified Soybean MON 87701

Soybean MON 87701 expresses the cry1Ac gene from Bacillus thuringiensis. The encoded Cry1Ac protein confers resistance against specific lepidopteran pests. Updated bioinformatics analyses of the inserted DNA and flanking sequences in soybean MON 87701 have not indicated a potential production of harmful toxins and allergens or polypeptides caused by the genetic modification. Genomic stability of the functional insert and consistent expression of the cry1Ac gene, have been shown over several generations of soybean MON 87701. Data from several field trials performed in USA, Canada, Chile and Argentina during 2005-2006 show that soybean MON 87701 is compositionally, morphologically and agronomically equivalent to its conventional counterpart and other commercial soybean cultivars. Subchronic feeding studies with rats as well as nutritional assessment with broilers have not revealed relevant adverse effects of MON 87701. These studies indicate that MON 87701 is nutritionally equivalent to and as safe as conventional soybean cultivars. The Cry1Ac protein produced in soybean MON 87701 do not show sequence resemblance to known toxins or IgE-dependent allergens, nor has the whole GM plant been reported to cause changes in IgE-mediated allergic reactions in patients reactive to soybean or in non-ectopic control individuals. Soybean is not cultivated in Norway, and there are no cross-compatible wild or weedy relatives of soybean in Europe. Based on current knowledge and considering the intended uses, which exclude cultivation, the VKM GMO Panel concludes that soybean MON 87701 with the Cry1Ac protein:
 
 - Is compositionally, morphologically and agronomically equivalent to its conventional counterpart and other commercial soybean cultivars
 - Is unlikely to introduce a toxic or allergenic potential in food or feed compared to conventional soybean cultivars
 - Is nutritionally equivalent to and as safe as its conventional counterpart and other conventional soybean cultivars
 - Does not represent an environmental risk in Norway.

Final Health and Environmental Risk Assessment of Genetically Modified Soybean 356043

Soybean 356043 expresses both the gat gene from the soil bacterium Bacillus licheniformis and the gm - hra gene, an optimised form of the endogenous acetolactate synthase (als) coding sequence from soybean (Glycine max; gm). The encoded GAT4601 protein, glyphosate acetyltransferase, confers the ability to inactivate the active herbicidal substances glyphosate and glyphosate-ammonium to N-acetyl glyphosate, which does not have herbicidal activity. The encoded GM-HRA protein confers increased tolerance to the active, ALS-inhibiting, herbicidal substances chlorimuron, thifensulfuron and sulfonylureas. Bioinformatics analyses of the inserted DNA and flanking sequences in soybean 356043 have not indicated a potential production of putative harmful proteins or polypeptides caused by the genetic modification. Genomic stability of the functional insert and consistent expression of the gat gene, have been shown over several generations of soybean 356043. Data from several field trials performed in USA, Canada, Chile and Argentina during 2005-2006 show that soybean 356043 contains higher levels of especially the acetylated amino acid N-acetyl aspartate, but also N-acetyl glutamate and the odd-chain fatty acids heptadecanoic, heptadecenoic and heptadecadienoic acids, in addition to expression of the newly expressed proteins. Otherwise the soybean 356043 is compositionally, morphologically and agronomically equivalent to its conventional counterpart and other commercial soybean cultivars. The acetylated amino acids and odd-chain fatty acids are normal constituents of plant and animal-derived foods and feeds, and an in-depth toxicity and intake assessment did not reveal safety concerns regarding consumer intake at the levels present in soybean 356043. Sub-chronic feeding studies with rats, repeated-dose toxicity studies with mice, as well as nutritional assessment trials with broilers and laying hens have not revealed adverse effects of soybean 356043. These studies indicate that soybean 356043 is nutritionally equivalent to and as safe as conventional soybean cultivars. The GAT4601 and GM-HRA proteins produced in soybean 356043 do not show sequence resemblance to known toxins or IgE-dependent allergens, nor has the whole GM plant been reported to cause changes in IgE-mediated allergic reactions in patients reactive to soybean or in non-ectopic control individuals. Soybean is not cultivated in Norway, and there are no cross-compatible wild or weedy relatives of soybean in Europe. 
 
 Based on current knowledge and considering the intended uses, which exclude cultivation, the VKM GMO Panel concludes that soybean 356043 with the GAT4601 and GM-HRA proteins:
 
 - Is – with the exception of the novel traits and resulting increased content of the acetylated amino acids NAA and NAG, and the odd-chain fatty acids heptadecanoic, heptadecenoic and heptadecadienoic acids – compositionally, morphologically and agronomically equivalent to its conventional counterpart and other commercial soybean cultivars
 - Are unlikely to introduce toxic or allergenic potentials in food or feed compared to conventional soybean cultivars
 - Is nutritionally equivalent to and as safe as its conventional counterpart and other conventional soybean cultivars
 - Does not represent an environmental risk in Norway.

Physiological quality of conventional soybean cultivars of seeds as a function of pod position in plant canopy

Soybean cultivars have different growth habits, and the cultivation of those of indeterminate habit has increased significantly in Brazil. Thus, the aim of this study was to evaluate the physiological quality of soybean seeds produced in two harvests, from cultivars with different growth habits and ripening cycles, harvested in different canopy thirds of the plant in the canopy. The seeds were produced in Ipameri, Goiás –Brazil, in two crop harvests, 2014/15 and 2015/16. A completely randomized design was used in a 4x3 factorial scheme with four replications. The treatments consisted of four soybean cultivars with different growth habits and ripening cycles (BRS 6780, BRS 6980, BRS 7980 and BRS 8381), harvested in three positions of the plant canopy (upper, middle and lower). Germination, first count, accelerated aging and electrical conductivity tests were performed. It was observed that the physiological quality of genetic materials studied was influenced by the variable environmental conditions. Soybean cultivars the early cycles produced seeds of superior physiological quality, regardless of plant growth habit. Seeds of soybean cultivars of indeterminate and determined growth habits and earlier cycle, harvested from the upper and middle thirds of the plant, are of better quality. Finally, cultivars with semi-determined and determined habits and late cycles will produce lower quality batches of seeds, regardless of which third of the plant they were harvested.

Plant-parasitic nematode assemblages associated with glyphosate tolerant and conventional soybean cultivars in South Africa

Information about the non-target effects of glyphosate, a broad-spectrum systemic herbicide on soil-borne nematodes is scarce and not well documented for South African agricultural fields. In the present study, the abundance and identity of plant-parasitic nematodes in roots and rhizosphere soil of commercial glyphosate- tolerant (genetically modified; GM) and conventional (non-glyphosate-tolerant) soybean cultivars from cultivated fields were obtained for two consecutive growing seasons. Grass and soil from adjacent natural vegetation were sampled, representing the reference system. Thirty plant-parasitic nematode species, belonging to 13 genera were identified in the roots and rhizosphere soil of soybean cultivars and natural vegetation. In rhizosphere soil, Meloidogyne (for glyphosate-tolerant and conventional soybean), followed by Helicotylenchus (for glyphosate-tolerant soybean) and Scutellonema (for conventional soybean), were the predominant genera. Seven species, namely Pratylenchus flakkensis, Pratylenchus scribneri, Pratylenchus vulnus, Rotylenchus brevicaudatus, Telotylenchus avaricus, Tylenchorhynchus brevicaudatus and Quinisulcius capitatus are first reports for soybean in South Africa. Although it was not possible to define the impact of each ecosystem on the plant-parasitic nematode assemblages, this study suggested that glyphosate had no deleterious effects on plant-parasitic nematodes.

Seed Yield and Quality of Transgenic High‐Oleic and Conventional Soybean as Influenced by Foliar Manganese Application

Manganese deficiency in soybean [Glycine max (L.) Merr.] reduces seed yield and alters the oil profile. The objective of this study was to evaluate the effect of foliar Mn fertilizer on seed yield, protein and oil concentration, and the oil profile of transgenic high‐oleic soybean (‘Plenish’) and soybean with a normal oil profile (referred to here as “conventional”). Research trials were established in 2014 and 2015 at two locations in Ohio. Treatments included soybean cultivar (four to six Plenish cultivars and two conventional cultivars) and foliar Mn fertilizer application at the R3 soybean growth stage (none, Mn–SO4, and Mn–EDTA). In 2014, the Mn–SO4 application increased soybean seed yield by 140 kg ha‐1 at the Wood County location where soybean plants were deficient in Mn. Although Mn‐SO4 also supplies S, no S deficiencies were detected. At the other three site‐years, soybean seed yield was not affected by Mn application. Manganese application did not influence the oil or protein content of the soybean seed or alter the oil profile. The high‐oleic cultivars produced similar yield to the conventional cultivars at the Wood County location both years. In 2014 and 2015 at the Clark County location, the high‐oleic cultivars yielded 410 and 270 kg ha‐1 less than cultivars with a conventional oil profile, respectively. Plenish soybean cultivars did not need to be managed differently from the conventional soybean cultivars tested in terms of Mn foliar application.

Molecular, physiological, and agronomical characterization, in greenhouse and in field conditions, of soybean plants genetically modified with AtGolS2 gene for drought tolerance

Water deficit may occur at any stage of crop development, affecting productivity and causing economic losses. In response to drought, raffinose family oligosaccharides (RFOs) are accumulated in plant tissues stabilizing and protecting cell membranes and keeping the vital functions. The enzyme galactinol synthase (GolS, EC 2.4.1.123) catalyzes the first step in the biosynthesis of RFOs. In our study, soybean events overexpressing 35S:AtGolS2 were molecularly, physiological, and agronomical characterized, under drought simulated in greenhouse and in field conditions during the crop season 2014/2015. The conventional soybean cultivar BRS 184 was transformed and five positive events were obtained. Four events transmitted the transgene to further generations and in the events 2Ia1 and 2Ia4, two to four copies of AtGols2 gene were observed. Results in greenhouse showed that the overexpression of AtGolS2 in genetically modified (GM) plants led to increased galactinol transcripts, probably resulting in changes in carbohydrate metabolism. Accumulation of these transcripts that may have acted as osmoprotectors, lead to higher drought tolerance and survival rate of 2Ia4 plants. In addition, in field conditions, higher yield was observed for 2Ia4 plants under irrigated (IRR) and non-irrigated (NIRR) treatments. This result can be due to the increased synthesis of RFOs even under well-watered conditions. This field screening showed promising results for drought tolerance, suggesting that 2Ia4 plants may be useful in a breeding program for the development of drought-tolerant plants. However, additional studies are needed in further crop seasons and other sites to better characterize how these plants may outperform the WT plants under water deficit.

Performance of Conventional and Transgenic Soybean Cultivars in the South and Alto Paranaiba Regions of Minas Gerais, Brazil

The aim of this study was to compare transgenic and conventional soybean cultivars in regard to yield performance and agronomic traits. Six soybean cultivars were tested: three conventional cultivars and their three isogenic transgenic derivatives, in two locations, Lavras and Patos de Minas in Minas Gerais, Brazil, in the 2012/13 crop season. Data on yield (kg&middotha-1), plant height (cm), and tolerance to lodging were collected. The cultivars had different responses. The cultivar BRS/MG46 Conquista had lower yields than its isogenic derivative BRS Valiosa RR, but this was not seen with the conventional cultivar M-SOY 6101, which produced more than its isogenic derivative M-SOY 7211 RR. Between the isogenic cultivars BRS/MG68 Vencedora and BRS Favorita RR, there were no significant differences. Nevertheless, the contrast between the mean values of the transgenic and conventional cultivars shows that the conventional cultivars had mean values greater than the transgenic cultivars.