Seed Protein Levels Research Articles

Ecophysiological mechanisms underlying the positive relationship between seed protein concentration and yield in soybean under field heat and drought stress

AbstractA positive relationship between protein concentration and yield has been documented in different combinations of genotype and environment, often under potential conditions. However, the ecophysiological bases underlying this positive relationship under heat stress (HS) and drought stress (DS) during seed filling are still lacking. Our objective was to evaluate the relationship between seed protein content and concentration with yield in field experiments exposed to HS, DS and HS × DS interaction during the seed filling. Two field experiments were conducted and assimilates accumulation, remobilization and redistribution patterns were analysed in high and low seed protein soybean genotypes. The crop was exposed to four treatments: control (ambient temperature and soil water content near field capacity), HS (episodes above 32°C, 6 h d−1) during 15 days, DS (soil water content ≤25% of field capacity) during the whole seed filling and HS × DS. Significant and positive relationships between seed protein content and concentration with yield were observed across treatments and genotypes. Under DS and HS × DS, assimilates available during the seed filling decreased, and assimilates remobilization and partition to seeds were limited, responses significantly associated with seed protein content and concentration, and yield reductions. Furthermore, we demonstrated here that the high leaf N content at the beginning of seed filling, the short early reproductive phase duration, the high source to sink ratio and the high dry matter stem remobilization capacity, as well as the low seed number and high seed weight are intrinsic characteristics of the high protein genotype that could be associated with its high seed protein content and concentration and yield under stressful conditions. This knowledge is key to develop soybean management strategies to improve seed protein level and yield under contrasting productive scenarios.

High lysine and high protein‐containing salinity‐tolerant rice grains (Oryza sativa cv IR64)

AbstractLysine cannot be synthesized by the human body, and it is, therefore, an indispensable amino acid in the human that must be consumed in adequate amounts to prevent disease. Unfortunately, lysine is not abundant in many important food sources such as rice grains. Efforts to fortify rice and other monocotyledonous crops with high lysine have proved to be challenging because of their effects on plant growth. The present study was designed to avoid the problems that are often encountered in engineering lysine metabolism. We generated different over‐expression constructs for the key anabolic enzyme, dihydrodipicolinate synthase (DHDPS and cdapA) and knockdown (KD) constructs for the catabolic enzyme—lysine ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH), with expression under the control of either the CaMV35S promoter or the endosperm‐specific glutelinD1 promoter. The use of the endosperm‐specific promoter together with the lysine feedback‐insensitive cdapA for over‐expression provides distinct advantages, as does silencing of LKR/SDH under the control of this promoter. Rice plants produced by over‐expressing cdapA together with silencing of LKR/SDH showed a 58% increase in grain lysine content, as well as higher amounts of total seed protein levels. Moreover, the transgenic seedlings were more tolerant to salinity. These results demonstrate that it is possible to generate high lysine stress‐tolerant rice varieties, which have the potential to reduce the need for dietary supplementation.

Combination of the Elevated Stearic Acid Trait with Other Fatty Acid Traits in Soybean

AbstractStearic acid is one of five major fatty acids found in soybean oil. It is a fully saturated lipid and is known for neutral or positive effects on LDL cholesterol when consumed by humans. Unfortunately, stearic acid only accounts for about 4% of the total seed oil produced in commodity soybean. Previous work has shown that stearic acid can reach levels as high as 28% of the total oil fraction when the SACPD‐C gene, encoding the delta‐9‐stearoyl‐acyl carrier protein desaturase responsible for most of the stearic acid variation in soybean seed, is ablated in combination with other loci. In order to increase stearic acid content and create soybeans with improved utility based on fatty acid composition, we combined mutations in SACPD‐C with other mutations in the fatty acid biosynthetic pathway. Soybean plants carrying mutant alleles of both SACPD‐C and FAD2‐1A produce seed with stearic acid levels from 14% to 21%, and with elevated levels of oleic acid. Soybeans carrying mutations in both SACPD‐C and FAD3A or FAD3C have both statistically significantly elevated levels of stearic acid (from 15–21%) and statistically reduced linolenic acid levels. Neither mutant combination appears to affect other agronomic properties such as plant morphology or seed protein levels making this a potentially viable trait.

Evaluation of Protein and Micronutrient Levels in Edible Cowpea (Vigna Unguiculata L. Walp.) Leaves and Seeds

Cowpea is the most important seed legume in Africa. Its leaves and seed are consumed to meet the dietary requirements of protein and micronutrient in rural African communities. In this study, leaf protein of 32 cowpea genotypes was 23-40% at Taung (South Africa), 28-40% at Wa and 24-35% at Manga (Ghana). Seed protein level was also up to 40% landrace Bengpla and more than 30% in nine other genotypes planted at Taung. Trace elements in cowpea leaves showed markedly high concentrations of Fe (2011 μg.g-1), Zn (150 μg.g-1) Mn (325 μg.g-1) and B (43 μg.g-1) in genotype Apagbaala, in contrast to the very low levels of Fe (273 μg.g-1), Zn (40 μg.g-1), Mn (219 μg.g-1) and B (32 μg.g-1) in genotype Encore. Leaf Fe concentration was highest in genotype Apagbaala (2011μg.g-1), followed by Fahari (2004 μg.g-1), Iron Grey (1302 μg.g-1), Line 2020 (944 μg.g-1), Bensogla (927 μg.g-1), Omondaw (605 μg.g-1), IT96D-1951(591 μg.g-1), IT93K-452-1 (574 μg.g-1), Ngonji (569 μg.g-1) and Mchanganyika (566 μg.g-1), and lowest in Bechuana white (268 μg.g-1). Cowpea seed also showed greater concentrations of Fe in genotype Soronko (67 μg.g-1), IT93K-452-1 (67 μg.g-1), Brown Eye (65 μg.g-1), Bensogla (61 μg.g-1) and TVU11424 (62 μg.g-1). Trace elements in cowpea seed differed among genotypes, and ranged from 45.1 to 67.0 μg.g-1 for Fe, 33.9 to 69.2 μg.g-1 for Zn, 10.1 to 17.4 μg.g-1 for Mn, 14.7 to 21.4 μg.g-1 for B, and 5.2 to 8.1 μg.g-1 for Cu. Genotypes Apagbaala, Fahari, Iron Grey and Line 2020 respectively exhibited 34.2-, 34.0-, 22.5- and 18.3-fold higher Fe concentration in leaves than seed, and 3.5-, 2,0-, 2,0-, and 3.5-fold greater Zn in leaves than seed (in that order). The genotypes that accumulated significantly high levels of protein and trace elements in cowpea leaves and seed, were generally high N2-fixers, thus suggesting a link between N2 fixation and cowpea’s ability to synthesize protein and accumulate nutrient elements in leaves and seed. Therefore, identifying cowpea genotypes that can enhance protein accumulation and micronutrient density in edible leaves and seed throμgh breeding has the potential to overcome protein-calorie malnutrition and trace element deficiency in rural Africa.

A small-scale tofu test for soybean breeding programs

Soybean breeding programs targeting tofu production must identify cultivars that are well suited for making tofu. A small-scale (SS) test of tofu texture was developed to evaluate breeding lines. The SS tofu test was developed to complement the larger scale Harrow tofu test but to use smaller samples of seed and soymilk to make tofu. The SS tofu test uses both magnesium chloride (MgCl2) and glucono-delta-lactone (GDL) coagulants to produce tofu samples of 20 mL. In comparisons of the SS and Harrow tofu texture tests, using lines with varying protein subunit profiles, both tests ranked lines similarly. In plant breeding trials, the SS tofu test was useful in ranking varieties for tofu texture. Multiple-year testing should be used for a thorough evaluation of varieties. When the SS tofu test was used with a population of lines with a wide range of seed protein, GDL-coagulated tofu texture was independent of seed protein content; however, MgCl2-coagulated tofu texture was moderately inversely correlated with seed protein. With the SS test, it may be best to compare tofu texture within groups of lines with similar seed protein levels. The SS tofu test is useful to test tofu texture of breeding lines using small amounts of seed.

Identification and characterization of high protein oat lines from a mutagenized oat population

Oat is an excellent source of high-quality proteins. The protein content in cultivated oat is about 12%–15%. Oats with even higher protein contents would have great potential as a vegetative protein source. From a mutagenized oat population, 230 lines with seed protein levels of 15% or higher were identified from green house grown plants. Fifteen lines with protein levels ranging between 17 and 24% were chosen for further studies. The high protein character was confirmed by two consecutive propagations in the field. Crossings showed that the trait was stable and segregated in a Mendelian fashion. SDS-PAGE analysis revealed that the major increase was in globulin like proteins. In addition, total dietary fibre, β-glucan and lipid levels were quantified. No correlation between any of these characters and the high protein trait could be found. Thousand Kernel Weight was also monitored and shown to be stable in the high protein lines. Thus, starting from the lines presented here a further development of commercial oat varieties with protein levels of 20% or higher is feasible. Such a high protein oat would be very important to meet the consumers need for high-quality high-protein oat for the food and feed industry.

Connecting Source with Sink: The Role of Arabidopsis AAP8 in Phloem Loading of Amino Acids.

Allocation of large amounts of nitrogen to developing organs occurs in the phloem and is essential for plant growth and seed development. In Arabidopsis (Arabidopsis thaliana) and many other plant species, amino acids represent the dominant nitrogen transport forms in the phloem, and they are mainly synthesized in photosynthetically active source leaves. Following their synthesis, a broad spectrum of the amino nitrogen is actively loaded into the phloem of leaf minor veins and transported within the phloem sap to sinks such as developing leaves, fruits, or seeds. Controlled regulation of the source-to-sink transport of amino acids has long been postulated; however, the molecular mechanism of amino acid phloem loading was still unknown. In this study, Arabidopsis AMINO ACID PERMEASE8 (AAP8) was shown to be expressed in the source leaf phloem and localized to the plasma membrane, suggesting its function in phloem loading. This was further supported by transport studies with aap8 mutants fed with radiolabeled amino acids and by leaf exudate analyses. In addition, biochemical and molecular analyses revealed alterations in leaf nitrogen pools and metabolism dependent on the developmental stage of the mutants. Decreased amino acid phloem loading and partitioning to sinks led to decreased silique and seed numbers, but seed protein levels were unchanged, demonstrating the importance of AAP8 function for sink development rather than seed quality. Overall, these results show that AAP8 plays an important role in source-to-sink partitioning of nitrogen and that its function affects source leaf physiology and seed yield.

Effect of Various Levels of NPK Fertilizer on the Yield Attributes of Soybean (Glycine max L.) Varieties

Indonesian soybean production can only meet about 30% of national demand. Efforts to increase soybean production include the use of improved seed quality and fertilizer application. The aims of this research were to 1) examine the responses of six genotype soybeans to the application of different doses of NPK fertilizer; 2) determine the seed protein content of the six soybean genotypes following NPK application; 3) determine the interaction between soybean genotypes with NPK doses in affecting growth and yield. This research was conducted under a plastic house at the Faculty of Agriculture, University of Jenderal Soedirman, Central Java, Indonesia. The experiment was arranged in a randomized block design with three replications using six soybean varieties and four levels NPK fertilizer. Soybean varieties tested were “L/S: B6-G1” (V1), “L/S:B6-G3” (V2), “L/S:B6-G4” (V3), “Grobogan” (V4), “Burangrang” (V5), and “Argomulyo” (V6). Four levels NPK fertilizer tested were: without fertilizer (N0), 0.6 g per plant (N1) 1.2 g per plant (N2), and 18.g per plant (N3), or 0, 100, 200 and 300 kg.ha-1. “L/S: B6-G1” had the greatest number of seeds per plant (184) following treatment with 300 kg.ha-1 of NPK. The seed protein content increased with the increase doses of NPK. “Argomulyo” treated with NPK at 300 kg.ha-1 had the highest seed protein content (34.5%). Soybean responses to NPK treatment differed with varieties, particularly in the number of fl owers per plant, number of seeds per plant, grain weight per plant and seed protein levels.

Improvement of pea biomass and seed productivity by simultaneous increase of phloem and embryo loading with amino acids.

The development of sink organs such as fruits and seeds strongly depends on the amount of nitrogen that is moved within the phloem from photosynthetic-active source leaves to the reproductive sinks. In many plant species nitrogen is transported as amino acids. In pea (Pisum sativum L.), source to sink partitioning of amino acids requires at least two active transport events mediated by plasma membrane-localized proteins, and these are: (i) amino acid phloem loading; and (ii) import of amino acids into the seed cotyledons via epidermal transfer cells. As each of these transport steps might potentially be limiting to efficient nitrogen delivery to the pea embryo, we manipulated both simultaneously. Additional copies of the pea amino acid permease PsAAP1 were introduced into the pea genome and expression of the transporter was targeted to the sieve element-companion cell complexes of the leaf phloem and to the epidermis of the seed cotyledons. The transgenic pea plants showed increased phloem loading and embryo loading of amino acids resulting in improved long distance transport of nitrogen, sink development and seed protein accumulation. Analyses of root and leaf tissues further revealed that genetic manipulation positively affected root nitrogen uptake, as well as primary source and sink metabolism. Overall, the results suggest that amino acid phloem loading exerts regulatory control over pea biomass production and seed yield, and that import of amino acids into the cotyledons limits seed protein levels.

Identification of a plant introduction soybean line with genetic lesions affecting two distinct glycinin subunits and evaluation of impacts on protein content and composition

Unlike other oilseeds, soybean (Glycine max [L.] Merr) is also valuable due to its direct conversion into human food. One notable example is the cheese-like product tofu. The quality of tofu is improved when protein subunits derived from two glycinin genes, Gy1 and Gy4, are reduced or absent. Here we report the discovery that one exotic soybean plant introduction line, PI 605781 B, has not only a previously described loss-of-expression mutation affecting one glycinin gene (gy4), but also bears an extremely rare, potentially unique, frameshift mutation in the Glycinin1 gene (gy1-a). We analyzed glycinin gene expression via qRT-PCR with mRNA from developing seeds, which revealed that the novel allele dramatically reduced Gy1 mRNA accumulation. Similarly, both A4A5B3 and A1aB1a protein subunits were absent or at undetectable levels, as determined by two-dimensional protein fractionation. Despite the reduction in glycinin content, overall seed protein levels were unaffected. The novel gy1-a allele was found to be unique to PI 605871B in a sampling of 247 diverse germplasm lines drawn from a variety of geographic origins.

RNA Interference Can Rebalance the Nitrogen Sink of Maize Seeds without Losing Hard Endosperm

BackgroundOne of the goals of plant breeding is to create crops to provide better nutrition for humans and livestock. Insufficient intake of protein is one of the most severe factors affecting the growth and development of children in developing countries. More than a century ago, in 1896, Hopkins initiated the well-known Illinois long-term selection for maize seed protein concentration, yielding four protein strains. By continuously accumulating QTLs, Illinois High Protein (IHP) reached a protein level 2.5-fold higher than normal maize, with the most increased fraction being the zein protein, which was shown to contain no lysine soon after the long-term selection program initiated. Therefore, IHP is of little value for feeding humans and monogastric animals. Although high-lysine lines of non-vitreous mutants were based on reduced zeins, the kernel soft texture precluded their practical use. Kernel hardness in opaque 2 (o2) could be restored in quality protein maize (QPM) with quantitative trait loci called o2 modifiers (Mo2s), but those did not increase total protein levels.MethodsThe most predominant zeins are the 22- and 19-kDa α-zeins. To achieve a combination of desired traits, we used RNA interference (RNAi) against both α-zeins in IHP and evaluated the silencing effect by SDS-PAGE. Total protein, amino acid composition and kernel texture were analyzed.ConclusionsThe α-zeins were dramatically reduced, but the high total seed protein level remained unchanged by complementary increase of non-zein proteins. Moreover, the residual zein levels still allowed for a vitreous hard seed. Such dramatic rebalancing of the nitrogen sink could have a major impact in world food supply.

New Diversity Arrays Technology (DArT) markers for tetraploid oat (Avena magna Murphy et Terrell) provide the first complete oat linkage map and markers linked to domestication genes from hexaploid A. sativa L.

Nutritional benefits of cultivated oat (Avena sativa L., 2n = 6x = 42, AACCDD) are well recognized; however, seed protein levels are modest and resources for genetic improvement are scarce. The wild tetraploid, A. magna Murphy et Terrell (syn A. maroccana Gdgr., 2n = 4x = 28, CCDD), which contains approximately 31% seed protein, was hybridized with cultivated oat to produce a domesticated A. magna. Wild and cultivated accessions were crossed to generate a recombinant inbred line (RIL) population. Although these materials could be used to develop domesticated, high-protein oat, mapping and quantitative trait loci introgression is hindered by a near absence of genetic markers. Objectives of this study were to develop high-throughput, A. magna-specific markers; generate a genetic linkage map based on the A. magna RIL population; and map genes controlling oat domestication. A Diversity Arrays Technology (DArT) array derived from 10 A. magna genotypes was used to generate 2,688 genome-specific probes. These, with 12,672 additional oat clones, produced 2,349 polymorphic markers, including 498 (21.2%) from A. magna arrays and 1,851 (78.8%) from other Avena libraries. Linkage analysis included 974 DArT markers, 26 microsatellites, 13 SNPs, and 4 phenotypic markers, and resulted in a 14-linkage-group map. Marker-to-marker correlation coefficient analysis allowed classification of shared markers as unique or redundant, and putative linkage-group-to-genome anchoring. Results of this study provide for the first time a collection of high-throughput tetraploid oat markers and a comprehensive map of the genome, providing insights to the genome ancestry of oat and affording a resource for study of oat domestication, gene transfer, and comparative genomics.

Registration of N6202 Soybean Germplasm with High Protein, Favorable Yield Potential, Large Seed, and Diverse Pedigree

‘N6202’ soybean [Glycine max (L.) Merr.] (Reg. No. GP‐366, PI 658498) was cooperatively developed and released by the USDA–ARS and the North Carolina Agricultural Research Service in October 2009 as a mid–Maturity Group VI germplasm with high‐protein seed, favorable yield potential, large seed size, and diverse pedigree. The unusual combination of high protein and favorable yield in this germplasm, plus its diverse genetic background, makes it a potentially desirable breeding stock for both specialty and commodity breeding programs. N6202 was developed through conventional breeding and is adapted to the southern United States. Average seed protein level was 457 g kg−1 (zero moisture basis), which was 33 g kg−1 greater (p < 0.05) than that of the control cultivar NC‐Roy. Average yield of N6202 was more than 90% of NC‐Roy over 65 environments. The 100‐seed weight of N6202 (21.4 g) was significantly greater (p < 0.05) than that of the largest‐seeded control cultivar Dillon (15.2 g).Twenty‐five percent of N6202's pedigree is derived from Japanese cultivar Fukuyataka. Fukuyataka is not known to be related to the genetic base of U.S. soybean. An additional 25% of N6202's pedigree traces to the Japanese cultivar Nakasennari, which appears in the pedigree of only one cultivar (its parent ‘N6201’). Thus, the release of N6202 broadens the genetic range of materials adapted for soybean breeding in the United States. N6202 exhibits a moderate level of the bleeding hilum trait in some environments.

Relationship between assimilate supply per seed during seed filling and soybean seed composition

Developing soybean cultivars with high seed protein concentration has been hampered by the negative correlation between seed protein and seed yield. While previous in vitro studies have documented the impact of assimilate supply to the seed in determining seed protein, in planta studies generally have failed to link seed protein accumulation directly with assimilate supply per plant during seed filling. It may be possible to reconcile this apparent contradiction by expressing the relationship between seed protein and assimilate supply in planta on a per seed basis. We evaluated the association between seed composition and assimilate supply per seed in closely related experimental lines varying in seed protein concentration and in several elite varieties from the Iowa State University breeding program. High seed protein content was associated with greater leaf area per seed at R5.5, which was a consequence of fewer seeds set per plant. The more favorable source/sink ratio provided greater assimilate per seed during grain filling, but limited the yield potential of the high protein lines because of reduced seed set. Depodding during grain filling increased seed size of low protein lines and increased seed protein concentration to levels comparable to those in the untreated high protein lines. Seed size was far less responsive to depodding in the high protein lines. These results suggest that high protein lines maintain assimilate supply per seed at or near saturating levels during seed filling. Improving seed protein levels in high yielding varieties will require increasing assimilate supply per seed without sacrificing seed numbers.

Katrina Soybean

Katrina is a 2950 crop heat unit (CHU) soybean [Glycine max (L.) Merrill] cultivar with excellent yield potential, good lodging resistance and above average seed size and seed protein levels. It was developed by the Ridgetown Campus, University of Guelph, and is adapted to the 2900–3100 CHU areas of Ontario. Katrina was issued registration number 6015 on 205 Nov. 28 by the Variety Registration Office, Plant Production Division of the Canadian Food Inspection Agency. Key words: Soybean, cultivar description

Seed Nitrogen Mobilization in Soybean: Effects of Seed Nitrogen Content and External Nitrogen Fertility

ABSTRACT Soybean breeding programs have developed genetic lines with relatively low seed protein, which could negatively impact early seedling growth in low fertility conditions commonly encountered in the field. In these experiments, seed protein mobilization and its regulation in situ in soybean lines with different seed protein levels was investigated. The results showed that rates of nitrogen (N) release from cotyledons were much lower with decreasing levels of N in seed. Patterns of proteolysis of the storage proteins glycinin and β -conglycinin and their subunits were not different, but breakdown rates were slower. Seed N release rates increased somewhat when external N was supplied to roots of the developing seedlings, suggesting the involvement of source/sink controls. The effect appeared to be down-stream from proteolysis, as rates of protein breakdown were not altered. The results indicate that low seed protein levels will lead to reduced seedling fitness in low fertility soil conditions unless fertilizer N is applied.

Nitrogen and sulphur fertilizer management for growing canola on sulphur sufficient soils

Canola is a crop that demands high nitrogen (N) and sulphur (S) inputs to achieve maximum seed yield. The practice of balancing these two nutrients by applying them in a fixed ratio has shown yield benefits on soils deficient in both these nutrients. A 9 site-year study was conducted between 2002 and 2004 to determine whether this practice is necessary for soils containing sufficient S levels. The practice was tested for both hybrid (HC) and open pollinated (OPC) canola cultivars by applying six rates of N (0, 40, 80, 120, 160 and 200 kg N ha-1) and supplementing N rates with S, so that three N:S ratios (1.5, 6 and 12 to 1) were achieved. Seed yield, protein and oil content responses of both HC and OPC cultivars were obtained primarily with N, with no evidence for a need of balancing this nutrient with S additions to achieve a ratio within those applied at this study. Hybrid canola cultivars overall yielded 23.7% more than OPC cultivars when they received the N application rate at which maximum yield of the OPC cultivars was obtained (120 kg N ha-1). Application of an additional 30 kg ha-1 to obtain maximum HC seed yield only resulted in an additional 1.5% yield advantage for the OPC. As N application rate was increased, small increases in seed protein levels (≈2.5%) were accompanied by a small reduction (≈2%) in seed oil content. Increased yield by HC compared with OPC canola reduces N residual fertility, hence, assessment of soil fertility status by soil testing after growing HC canola is a highly beneficial management practice. Our results indicate that the practice of balancing N and S to a fixed ratio is unnecessary and wasteful on canola grown on soils containing sufficient S. Key words: Hybrid canola, N:S ratio, open pollinated, residual soil fertility

Accumulation of Nitrogen and Dry Matter by Soybean Seeds with Genetic Differences in Protein Concentration

ABSTRACTSoybean [Glycine max (L.) Merrill] yields often decline as seed protein levels increase, but the processes responsible are not clearly understood. We compared dry matter and N accumulation by individual seeds of three high protein genotypes (K 1431, KS 4402sp, NE 3396) and three commercial cultivars (Pennyrile, Flyer, Hutcheson) in the field near Lexington, KY (38° 01′ N lat; 84° 35′ W long) for 3 yr to determine if increasing protein concentration decreased the seed growth rate. Plants were grown in 76.2‐cm rows using conventional production practices and overhead irrigation to minimize soil moisture deficits. The rate of dry matter accumulation by individual seeds (SGRDM) varied from 4.2 to 6.1 mg seed−1 d−1 and this variation was closely associated with mature seed size, but it was not affected by seed N concentration. The rate of N accumulation (SGRN, mg N seed−1 d−1) was closely associated with seed N concentration at maturity across all genotypes and years (r2 = 0.76). Thus, SGRN and SGRDM seemed to vary independently as the N concentration in mature seeds increased. The duration of seed filling (estimated by the effective filling period) was not related to mature seed N concentration. Since higher seed N concentration had no effect on the rate or duration of seed dry matter accumulation by individual seeds, the purported negative effect of seed protein levels on yield may be more closely associated with whole plant phenomena than those operating at the individual seed level.

RCAT Wildcat soybean

RCAT Wildcat is a 2950 crop heat unit (CHU) soybean [Glycine max (L.) Merrill] cultivar with excellent yield potential, good lodging resistance and above-average seed protein levels. It was developed by the Ridgetown College, University of Guelph, and is adapted to the 2800–3100 CHU areas of Ontario. RCAT Wildcat was issued registration number 5568 on 2002 Dec. 11 by the Variety Registration Office, Plant Production Division of the Canadian Food Inspection Agency. Key words: Soybean, cultivar description

RCAT Corbett soybean

RCAT Corbett is a 2850 crop heat unit (CHU) soybean [Glycine max (L.) Merrill] cultivar with excellent yield potential, moderate lodging resistance and above-average seed protein levels. It was developed by the Ridgetown College, University of Guelph, and is adapted to the 2800-3000 CHU areas of Ontario. Key words: Soybean, cultivar description