The presence or absence of the soybean Kunitz trypsin inhibitor as a quantitative trait locus for seed protein content

Numerous quantitative trait loci (QTL) for various characters have recently been reported in different crop plants. However, information is limited about the molecular mechanisms behind QTL, because most of them have only been detected at a statistical level. Therefore, progeny from a cross between two soybean genotypes segregating for the presence vs. absence of the Kunitz trypsin inhibitor, a 21.5 kDa protein, have been analysed for possible effects of that protein on agronomic and seed quality characters. Protein content was reduced by, on average, 4.5 g/kg in segregants lacking the Kunitz protein, whereas oil content and other characters remained unaffected. This finding can be interpreted as a ‘model QTL’ for variation in seed protein content, because the molecular and genetic backgrounds of the soybean Kunitz trypsin inhibitor are well understood.     

The accumulation pattern in developing seeds and its relation to fatty acid variation in soybean

Sixty soybean cultivars from Japan and the USA formed five maturity groups (IIb‐Vc) based on number of days from sowing to flowering and number of days from flowering to maturity. Highly significant intervarietal differences in fatty acid composition were found in all the maturity groups, especially in IIc. Stearic and oleic acids showed a larger variation than palmitic, linoleic and linolenic acids. Principal component analysis suggested that the total variation of fatty acid composition depended mainly on the desaturation levels from oleic to linoleic acid. Three cultivars exhibiting unique fatty acid composition, together with a standard cultivar, were examined for the contents of the five fatty acids, as well as crude oil at eight seed‐filling stages. For all four cultivars, it was found that crude oil content increased sigmoidally with advancing filling stage, and that the accumulation patterns of palmitic, linoleic and linolenic acids were similar to that of crude oil. However, the accumulation pattern of stearic acid was different from that of crude oil and divided the cultivars into two distinct groups. For oleic acid, only the cultivar ‘Aburamame’ showed a rapid increase in proportion with advancing filling stage, although not differing markedly in accumulated content from the other cultivars. These results indicate that analysing the accumulation patterns of fatty acids could explain the latent genetic variation in fatty acid composition of soybean seeds.     

Characterization of genotype by environment interactions in soybean breeding programmes of southeast Europe

Southeast Europe is Europe's major production area of soybean of maturity groups (MG) 0, I and II, but genotype by environment interaction (GEI) for soybean traits in this region is still not characterized. The objective of this study was to characterize GEI in soybean grown in Croatia for seed yield, protein and oil content. Fourteen soybean cultivars of MG 0 and I were evaluated at 15 environments. In the combined anova , genotypes, environments and GEI were significant. All three seed traits were more affected by year than by location and seed yield and protein content were more sensitive to environmental changes than oil content. Genotype by environment interaction is generally of less importance than effects of genotypes and years, especially for oil content. High‐yielding genotypes had values of regression coefficient (b) close to 1, indicating that they were not responsive to extreme environments, either positive or negative. Means and b values were not correlated for yield and negatively correlated for protein and oil content, probably because of low‐input practice in the region. The absence of recognizable differences in means, b values and principal component scores of ammi analysis between two MGs for all traits indicated that soybean cultivars of MG 0 may be recommended for growing in the region because they responded similarly to environmental changes as do full‐season genotypes of MG I.     

Yield trade-off and the role of parental selection based on seed size when breeding for soybean seed protein

Alternative physiological strategies can increase protein concentration in soybean: (i) more-than-proportional increases in seed protein content (mg seed⁻¹) relative to increases in carbohydrate and oil content in large-seeded genotypes or (ii) more-than-proportional reductions in carbohydrate and/or oil content relative to protein content reductions in small-seeded genotypes. Because these strategies differentially affect crop growth and development, we hypothesized that populations developed from high-protein (HP) parents with contrasting seed sizes will present differences in how seed yield and protein concentration correlate. To test this, three breeding strategies were developed by mating high-yielding cultivars and HP ones that differ in seed sizes, reflecting the alternative strategies mentioned above. Neither tested crossing strategies showed differences in their correlation values between seed yield and protein concentration, as initially expected. Nevertheless, populations developed from crossing a HP-small-seeded parent to a HP-large-seeded one showed the highest number of transgressive segregants for protein yield. Our results showed that parent selection based on seed size has no beneficial effects on the development of high-yielding, HP soybean populations, but it might affect the number of transgressive segregants for protein yield.     

Agronomic performance and genetic progress of selected historical soybean varieties in the southern USA

This study was conducted to compare recently developed and historical soybean varieties and evaluate genetic gain in yield and other agronomic traits in the southern USA. A total of 45 southern varieties from public breeding programs, which were released from 1928 to 2008, were used in this study. Three experiments were conducted in 2007 and 2008 at Keiser, Stuttgart, and Marianna in Arkansas (USA). Varieties with maturity groups (MG) late IV to early V had a yield gain of 21.7 kg/ha/yr from the 1950s to the 2000s, mid to late MG V had a yield gain of 16.4 kg/ha/yr from the 1940s to the 2000s, and MG VIs had a yield gain of 12.4 kg/ha/yr from the 1920s to the 2000s. Yield increased linearly for all combined experiments by 16.8 kg/ha/yr. Plant height remained steady over time for most experiments. No significant changes were observed in maturity. Lodging scores decreased, protein concentration decreased, and oil concentration increased linearly over time for all combined experiments. Hutcheson, Narrow, R97‐1634, and Young were recommended as parent lines in future soybean breeding efforts.     

Effects of divergent selection for seed protein content in high‐protein vs. food‐grade populations of early maturity soybean

Due to the growing need for vegetable protein in Central European agriculture, there is interest in producing food‐grade soybeans, which are higher in seed protein and sucrose content and have a larger seed size than conventional soybeans. As protein content of conventional soybean is often below 400 g/kg, either high‐protein or food‐grade donors were crossed with adapted genotypes in order to increase their protein level. After divergent selection for protein content, lines were evaluated for seed quality characters across three environments in Austria. The objectives of this research were to determine the roles of genetic background and the selection for protein content on food‐grade soybean traits. While seed protein content of adapted parents was between 395 and 420 g/kg, its range was from 410 to 490 g/kg for the high‐protein and from 390 to 450 g/kg for the food‐grade lines, respectively. However, food‐grade populations were superior in seed size and sucrose content and revealed different correlation patterns between quality traits as compared to high‐protein populations, which demonstrates their usefulness for developing soybeans with improved quality.     

Environmental effects on lutein content and relationship of lutein and other seed components in soybean

Lutein is a major carotenoid in soybean [ Glycine max (L.) Merr.] seed, and has been shown to be beneficial for eye health in humans. Development of soybeans high in lutein is a goal of some breeding programmes. Little is known about how different growing environments affect lutein content. The objective of this study was to determine the variation of lutein and its relationship to seed protein, oil and individual fatty acids in soybean seed. Fifteen soybean genotypes were planted at four environments. There was no effect of year and planting date on lutein content in soybean seed. However, genotype × year, genotype × planting date and genotype × year × planting date were significant for lutein content. Although each genotype showed similar response across environments, lutein content varied significantly across the four growing environments in 14 of the 15 genotypes evaluated. Lutein content was not correlated with seed protein or oil and palmitic or stearic acid concentrations. However, lutein was positively correlated with oleic acid content and negatively correlated with linoleic and linolenic acids content.     

Environmental and genetic variation for protein content in winter wheat (Triticum aestivum L.)

Summary There is a considerable amount of variation in the protein content of wheat kernels. This variation may be induced by environmental factors, but can also be attributed to genetic differences. Within a genotype the correlation between grain yield and grain protein content can be either close to zero, positive, or negative. depending on the fertility level. Between genotypes this correlation is strongly negative. It is argued that the negative inter-genotypic correlation is largely a consequence of the high harvest-index of high yielding varieties. Breeding methods to alleviate the negative yield-protein content relationship are given.     

Variation in the crude protein content of field beans (Vicia faba L.) in relation to the possible improvement of the protein content of the crop

Summary A survey of the protein content of various field bean varieties indicates a range of variation extending over sixteen units of crude protein from 22–38%. Analysis of single plants from within three WPBS varieties Dylan. Danas and Dacre indicates that a similar range exists within commercial varieties. Examination of the progenies of high and low protein single plant selections together with a preliminary estimation of heritability suggest that protein content is highly heritable. No significant correlations were found between protein content and seed yield.     

大豆品种郑97196抗疫霉病基因RpsZheng精细定位

大豆疫霉病是由大豆疫霉引起的一种重要大豆病害,可造成严重的经济损失。种植含有抗疫霉病基因的大豆品种是控制该病害最有效的途径。前人在大豆品种郑97196的3号染色体上鉴定了一个抗疫霉病基因RpsZheng。本研究的目的是验证幵精细定位抗疫霉病基因RpsZheng。以Williams和郑97196杂交衍生的188个F_(2:3)家系为作图群体,用大豆3号染色体上的SSR标记构建RpsZheng遗传连锁图,获得与RpsZheng紧密连锁的侧翼SSR标记SattWM82_39 (2.5 cM)和BARCSOYSSR_03_0269 (1.0 cM)。基于亲本间全基因组重测序数据鉴定和开发多态性InDel标记,进一步将RpsZheng候选区域缩小至105.2 kb,通过检测RpsZheng候选区域内的共分离标记特异性,获得了能够有效检测RpsZheng的分子标记WZInDel11。本研究明确了RpsZheng的候选基因组区间,鉴定出了能够有效用于基因功能研究和辅助选择育种的共分离分子标记。     

Association analysis using SSR markers to find QTL for seed protein content in soybean

Association analysis studies can be used to test for associations between molecular markers and quantitative trait loci (QTL). In this study, a genome-wide scan was performed using 150 simple sequence repeat (SSR) markers to identify QTL associated with seed protein content in soybean. The initial mapping population consisted of two subpopulations of 48 germplasm accessions each, with high or low protein levels based on data from the USDA’s Germplasm Resources Information Network website. Intrachromosomal LD extended up to 50 cM with r ² > 0.1 and 10 cM with r ² > 0.2 across the accessions. An association map consisting of 150 markers was constructed on the basis of differences in allele frequency distributions between the two subpopulations. Eleven putative QTL were identified on the basis of highly significant markers. Nine of these are in regions where protein QTL have been mapped, but the genomic regions containing Satt431 on LG J and Satt551 on LG M have not been reported in previous linkage mapping studies. Furthermore, these new putative protein QTL do not map near any QTL known to affect maturity. Since biased population structure was known to exist in the original association analysis population, association analyses were also conducted on two similar but independent confirmation populations. Satt431 and Satt551 were also significant in those analyses. These results suggest that our association analysis approach could be a useful alternative to linkage mapping for the identification of unreported regions of the soybean genome containing putative QTL.     

Variation in Seed Yield and Quality Characters of Four Spring Oil Rapeseed Cultivars as Influenced by Population Arrangements and Densities

Variations of yield and quality characters of four spring oilseed rape cultivars ( B. napus L.) arranged in 16 or 32 cm between drills and under three population densities (30, 60 and 90 plants/nr) were investigated in a split-plot design with three replications in 1986 and 1987 in West Germany.
Cultivar Callypso gave the highest seed and oil yields per plot and the highest seed index, harvest index and seed yield/main stem, per branches and per plant. Differences due to arrangements were significant in 1986 only, i.e., the value of a special plant distribution was more pronounced under unsuitable weather condition (as in 1986). With respect to the three population densities, most of the characters showed significantly higher values with 30 plants/nr. Only seed yield and oil yield per plot that showed 7.27% and 5.6% increase, respectively, under the highest population density (90 plants/nr) but the differences were insignificant.
The highest oil content was obtained from cultivar Callypso and from the lowest population density. By contrast, higher protein content was obvious under higher population densities and the differences from the lowest density were significant in both years. Differences in fatty acid composition were not significant for the three main effects.     

长柱红山茶种子营养成分的产地差异性研究

长柱红山茶(Camellia longistyla)种子颇具油用价值.以黔东南雷公山区和黔北赤水河谷采集的野生种子为材料,分别测试分析其种子形态特征、内含氨基酸及脂肪酸含量的差异,以探讨环境对种子营养价值的影响.结果表明:1)长柱红山茶种子属大粒种子,千粒重达30383.2 g,脂肪含量达428.6%;不同产地的种子形态达到显著差异、种子千粒重呈极显著差异、可溶性糖含量显著差异、可溶性蛋白含量和脂肪含量不显著差异.2)产于雷公山区和赤水河谷的种子中皆含有7种人体必需氨基酸和6种非必需氨基酸,总氨基酸(TAA)含量分别为193.7,330.1 mg/g,人体必需氨基酸(EAA)含量分别为80.1,132.9mg/g,其中组氨酸含量最高(分别为57.9mg/g和10.14mg/g),亮氨酸次之(分别为20.7mg/g和34.1mg/g),色氨酸最低(分别为01.8mg/g和00.3mg/g);不同产地种子氨基酸含量中除胱氨酸、缬氨酸含量差异显著外,其余11种氨基酸、总氨基酸、人体必需氨基酸、非必需氨基酸的含量差异达到极显著差异.3)2个产地的种子营养评价皆达到WHO/FAO的理想蛋白质标准,可作为贵州特有的油用山茶种质资源开发利用.     

An analysis of seed development in Pisum sativumL. XVI. Assessing variation for fatty-acid content by use of a non-destructive technique for single-seed analysis

Analyses of seeds from a wide range of pea lines have revealed extensive variation for all of the major fatty acids normally found in pisum. Unlike total lipid content, this variation was not affected by the presence of mutant alleles at the r and rb loci. To allow chemically analysed seed to be used in crosses, which is of particular importance for F₂ seed, a method has been developed by which individual seeds can be analysed non-destructively. This system entails drilling a small hole in the seed, away from the embryonic axis. The small quantity of powder produced by this process can be used for the chemical analysis but does not prevent the seed from being grown to produce progeny. Reducing the sample size had no significant effect upon the compositional analysis of the fatty acids.     

Nondestructive assessment of protein content in single seeds of rapeseed (Brassica napus L.) by near-infrared reflectance spectroscopy

The potential of near-infrared reflectance spectroscopy (NIRS) to detectwithin-plant differences for seed protein content was investigated. Fourhundred and fifty-one single seeds were scanned by NIRS using a specialadapter. After non-destructive NIRS scanning, the seeds were analysed forprotein content by the Dumas combustion method and a calibrationequation was developed. A validation set of 117 additional seeds fromthree individual plants from the cultivars Bristol, Lirajet and Maplus wasanalysed for protein content both by NIRS and combustion. The coefficientof determination between NIRS and combustion values in the validation setwas 0.94, with a standard error of performance (SEP) of 0.77% and aratio of the SEP to the standard deviation (SD) of the validation set of0.28. The coefficient of variation (CV) for seed protein content inindividual plants, as determined by the combustion method, was 11.7%for Bristol, 8.9% for Lirajet, and 9.5% for Maplus. The comparison ofsuch variation with the standard error (SE) of NIRS analysis, defined as thecombination of the SE of the combustion method and the SEP of NIRScalibration equation, revealed that the maximum explainable variance withinindividual plants that can be detected using NIRS analysis of proteincontent in single seeds was 0.86 for Bristol, 0.83 for Lirajet, and 0.85 forMaplus. These results demonstrated that NIRS is a powerful tool fornon-destructive assessment of within-plant variation for seed protein contentin rapeseed.     

The effects of climatic variation in Europe on the yield response of spring wheat cv. Minaret to elevated CO2 and O3: an analysis of open-top chamber experiments by means of two crop growth simulation models

In the ESPACE-Wheat programme, 25 open-top chamber experiments were carried out in 1994, 1995 and 1996, on nine locations, divided over eight European countries. In most experiments, spring wheat cv. Minaret was subjected to two levels of atmospheric CO₂ and two levels of ozone. Grain yields in the control treatments (ambient levels of CO₂ and O₃) varied strongly between sites. Also, yield response to elevated CO₂ and O₃ showed great variation. The present study was conducted to determine whether climatic differences between sites could account for the observed variation.

Two simulation models were used for the analysis: AFRCWHEAT2-O3 and LINTULCC. AFRCWHEAT2-O3 simulates phenology, canopy development and photosynthesis in greater detail than LINTULCC. Both models account for the effects of radiation and temperature on crop growth. New algorithms were developed to simulate the effects of CO₂ and O₃. Weather data that were measured in the experiments were used as input, and simulated growth responses to CO₂ and O₃ were compared with measurements. No attempt was made to merge the two models. Thus two independent tools for analysis of data related to climate change were developed and applied.

The average measured grain yield in the control treatment, across all 25 experiments, was 5.9 tons per hectare (t ha⁻¹), with a standard deviation (SD) of 1.9 t  ha⁻¹. The models predicted similar average yields (5.5 and 5.8 t ha⁻¹ for AFRCWHEAT2-O3 and LINTULCC, respectively), but smaller variation (SD for both models: 1.2 t ha⁻¹). Average measured yield increase due to CO₂-doubling was 30% (SD 22%). AFRCWHEAT2-O3 expected a slightly lower value (24%, SD 9%), whereas LINTULCC overestimated the response (42%, SD 11%). The average measured yield decrease due to nearly-doubled O₃ levels was 9% (SD 11%). Both models showed similar results, albeit at lower variation (7% yield decrease at SDs of 6 and 4%). Simulations accounted well for the observation that, at elevated CO₂, the percentage yield loss due to O₃ was lower than at ambient CO₂.

The models predicted lower variation among sites and years than was measured. Yield response to CO₂ and O₃ was predicted to depend on the climate, with a predominant effect of temperature on the response to CO₂. In the measurements, these climatic effects were indeed observed, but a greater part of the variation was not related to light intensity, temperature, CO₂, or O₃. This unexplained variability in the measured dataset was probably caused by factors not accounted for in the models, possibly related to soil characteristics.

We therefore conclude that even perfect information on the climate variables examined in ESPACE-Wheat, i.e. light intensity and temperature, by itself would be insufficient for accurate prediction of the response of spring wheat to future elevated levels of CO₂ and O₃.     

Analysis of protein, starch and oil content of single intact kernels by near infrared reflectance spectroscopy (NIRS) in maize (Zea mays L.)

Maize samples (n = 309) containing 3090 single intact kernels from a broad variety of breeding materials were scanned by Near Infrared Reflectance Spectroscopy (NIRS) to develop non-destructive determination calibrations for crude protein, starch and oil content in kernels. Calibration equations of single kernels were developed by partial least square regression (PLS). Regression parameters between the chemical values, determined by reference methods, and the predicted values, determined by Near Infrared Reflectance Spectroscopy, were verified by cross validation and external validation. It was found that embryo position had a significant influence on the effect of calibrations. Reliable calibrations were developed for the prediction of protein and starch contents with the embryo upwards, whereas the oil content required the embryo to be downwards. The cross validation and external validation coefficients for protein were 0.91 and 0.94, for starch 0.90 and 0.89 and for oil 0.94 and 0.95, respectively. The data suggested that NIRS could be successfully used in breeding programmes, as an accurate and non-destructive tool to predict protein, starch and oil contents at the level of single kernels.