DNA fingerprinting in soybean (Glycine max (L.) Merrill) with oligonucleotide probes for simple repetitive sequences

Summary Soybean DNA fingerprints were analyzed by digoxigenin-labeled oligonucleotide probes complementary to simple repetitive sequences. The clearest and most polymorphic patterns were obtained with (AAT)₆ as a probe, with which all 47 soybean cultivars tested could be distinguished. However, DNA fingerprints of individuals within cultivars showed the same pattern. Using (CT)₈, (GAA)₅ or (AAGG)₄ as probes, clear polymorphic patterns among cultivars and accessions in the subgenus Soja (Glycine max and Glycine soja) were not observed, while quite different patterns were found in accessions in the subgenus Glycine. The results suggest that G. max and G. soja are closer in their genome structure. DNA fingerprints of reciprocal crosses between cultivars and accessions in the subgenus Soja were similar, and contained bands of both parents. In an F₂ population from these crosses, such bands segregated in a Mendelian fashion.     

Variation in the photoperiodic response on several characters in soybean,Glycine max (L.) Merrill

Summary The photoperiodic response on 12 characters in 40 soybean, Glycine max (L.) Merrill, cultivars were investigated using 10-hour (short day) and 16-hour (long day) photoperiods. Seventeen cultivars showed no significant difference between photoperiods for all 12 characters. Seven cultivars showed significant difference for only one trait. Phenotypic changes in 17 cultivars may be due to factors other than photoperiod. Number of pods per plant, days to maturity, and number of nodes per plant were highly correlated with yield per plant in both photoperiods. Invariably, the cultivars which had significant differences in the numbers of flowers produced per plant between the two photoperiods also had significant differences in the numbers of pods per plant and yield. First node to flower, plant height at flowering, days to flowering, nodes at flowering, and the 100-seed weight were least influenced by the photoperiods in most of the cultivars, while the height at maturity, number of nodes at maturity, number of days to maturity, and yield were most influenced.AVRDC Journal paper 46 (78–88).     

Inheritance of long juvenile period under short day conditions for the BR80-6778 soybean (Glycine max (L.) Merrill) line

The long juvenile period characteristic (LJP), which delays flowering under short day conditions, has been identified in soybean cultivars (Glycine max L. Merrill). This characteristic may be especially important as it increases the range of adaptation of soybean in low latitudes and gives greater flexibility for sowing periods within the same latitude. The inheritance of the long juvenile period was studied in the BR80-6778 soybean line to provide knowledge to support the development of cultivars adapted to short day conditions. Cultivars with classic flowering, Paraná, Bossier, Bragg and Davis, which flower early under short day conditions, were also used as parents in single crosses. They were crossed among themselves and with the genotypes with LJP, BR80-6778 and MG/BR 22 (Garimpo). The study was carried out under short day conditions (early sowings) in greenhouses and in the field at Embrapa National Soybean Research Center, Londrina, PR. Flowering was assessed daily. The results indicated that the BR89-6778 line shares a pair of alleles with the Paraná cultivar, and when associated with the cc allele retards flowering under short day conditions. The following genotype constitutions were attributed to the cultivars: Paraná (aaBBCC), Bossier (AabbCC), and BR80-6778 (aaBBcc). The combination of the genes aabb and aabbcc has a pronounced effect on the manifestation of the trait. This revised version was published online in July 2006 with corrections to the Cover Date.     

Transgenic fertile plants of soybean [Glycine max (L.) Merrill] obtained from bombarded embryogenic tissue

This work describes the production of transgenic, fertile plants of soybean [Glycine max (L.) Merrill]. The transformation method combines the advantages of somatic embryo genesis with the efficiency of particle bombardment of tissues that have a great capacity for in vitro proliferation and regeneration. The results described here represent the first report of transformation of soybean cultivars recommended for commercial growing in South Brazil using somatic embryogenesis, and may open the field for the improvement of this crop in this country by genetic engineering. This revised version was published online in August 2006 with corrections to the Cover Date.     

Genetic differentiation between summer and autumn maturing cultivars of soybean (Glycine max (L.) Merrill) in Kyushy district of Japan

Summary 135 soybean landraces and pure line selections from Kyushu district fo Japan were assayed for isozyme and seed protein loci in order to determine the genetic structure groups of summer and autumn maturing cultivars. Out of the 16 tested loci, Dial, Enp, Estl, and Ti exhibited a marked difference in allelic frequency between both groups. The summer cultuvar groups had a high frequency for Dial-b, Enp-b, Estl-a and Ti-b, whereas Dial-a, Enp-a, Estl-b, and Ti-a were predominant in the autumn groups. The analysis of multi-locus genotypes revealed that both groups mostly consisted of different multi-locus genotypes. The allelic combination Dial-b Enp-b Estl-a Ti-b was most frequently observed in the summer cultivars, whereas four genootypes, Dial-a Enp-a Estl-a Ti-a, Dial-a Enp-a Estl-b Ti-a, Dial-a Enp-b Estl-b and Dial-a Enp-a Estl-b Ti-b, occupied most of the autumn cultivars. These results indicated that both groups were appreciably differentiated from each other. The summer cultivar groups also included a few accessions having the multi-locus genotypes observed predominantly in the autumn groups or Acol-b charcteristic of the landraces native to northern Japan. It seems likely that the summer cultivar groups was not phyletically derived from a single common ancestor, but partly involves the landraces with early maturity derived from northern Japan. Dial, Enp, Estl and Ti are useful genetic markers ot trace the origin and dissemination paths of Japanse soybean landraces.     

大豆突变体ygl2黄绿叶基因的精细定位

叶片是大豆进行光合碳同化的主要器官,其颜色与光能的捕获力和转化效率有关,也与大豆的产量密切相关。因此,大豆叶色相关基因的挖掘对从光合碳同化途径解析大豆产量问题具有重要意义。黄绿叶是区别于大豆普通绿色叶片的突变类型,是研究大豆叶色相关基因的重要遗传材料。本研究发现了一个黄绿叶突变体ygl2(yellow-green leaf 2),该突变体是由大豆品系GL11自然突变而来,其黄绿叶表型可以稳定遗传。与绿叶野生型GL11相比较,突变体ygl2叶片中叶绿素含量极显著降低,株高、百粒重、蛋白含量均存在显著差异。利用GL11和ygl2构建分离群体,遗传分析表明, ygl2的黄绿叶表型受1对隐性核基因控制,利用分离群体将黄绿叶基因ygl2定位于2号染色体末端SSR标记02₁04到02₁07之间,区间物理距离为56.1 kb,包含9个基因。本研究结果为大豆黄绿叶基因图位克隆及分子标记辅助育种奠定了基础。     

QTL mapping of phosphorus deficiency tolerance in soybean (Glycine max L. Merr.)

Phosphorus (P) deficiency is a major abiotic stress that limits plant growth and crop productivity throughout the world. In the present study, 184 recombinant inbred line (RIL) families developed from soybean varieties Kefeng No. 1 and Nanong 1138-2 were used to identify quantitative trait loci (QTL) associated with P deficiency tolerance. Seven traits of plant height (HT), weight of fresh shoot (FSW), weight of fresh root (FRW), weight of dry root (DRW), length of main root (RL), phosphorus content in leaf (LP), phosphorus content in root (RP), were used as parameters to assess the phosphorus deficiency tolerance. The QTL mapping for the seven traits was performed using the program WinQTLCart. Seven QTLs were detected and mapped on two linkage groups for three traits of weight of fresh shoot, phosphorus contents in leaf and in root. The QTLs that had LOD scores more than three were detected for all of the three traits above. Most of the QTLs explained more than 10% of the total variation. The two QTLs for phosphorus content in leaf explained more than 20% of the total variation, respectively. Five QTLs were mapped on linkage group F2, and two on linkage F1. It was suggested that the genes related to phosphorus deficiency tolerance located on linkage group F in soybean.Contributed equally to this work.     

Selecting Soybean ( Glycine max L. Merrill) tolerant to low-calcium stress in short term hydroponics experiment

Soybean cultivation in the acid soils of low latitude Brazilian Savannahs (Cerrados) has become a reality since the 1970's. Soil fertility management and crop breeding have made major contributions to high standard performance of this crop. There are, however, factors that limit the prospect to sustainable production, such as levels of calcium in the soil, below the ploughed zone. This may prevent root elongation and exposes the crop to drought stress. Genetic variability for tolerance has been identified in locally selected cultivars, although it has indirectly been acquired. Experimental data have shown variability for low-Ca tolerance among and within cultivar. Progeny tests with selected individuals were carried out to assess whether these differences were inheritable. The results indicated the method shall be efficiently used to select superior individuals from a recurrent crossing scheme to breed soybeans for more stable yields. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of Seed Coating on Yield Attributes and Yield of Soybean (Glycine max L.)

Investigations were carried out during March to June 1991 to evaluate the effect of seed coating with organic, inorganic nutrients and biofertilizers on yield attributes and yield of soybean under three environments with different soil types viz., clay loam, sandy clay loam and sandy loam. Seed coating with bio-digested slurry 50 per cent, superphosphate 2 per cent, Bradyrhizobium 2 per cent, and Phosphobacteria 2 per cent (w/w of seed) increased the number of filled pods and grain yield by 29.6 and 37.2 per cent, respectively over the uncoated. There was a significant increase in the test weight of grains due to seed coating with Phosphobacteria. Environment with clay loam soil was found to be highly responsive to seed coatings.     

Mapping quantitative trait loci for yield-related traits in soybean (Glycine max L.)

Development of soybean cultivars with high seed yield is a major focus in soybean breeding programs. This study was conducted to identify genetic loci associated with seed yield-related traits in soybean and also to clarify consistency of the detected QTLs with QTLs found by previous researchers. A population of 135 F_2:3 lines was developed from a cross between a vegetable soybean line (MJ0004-6) and a landrace cultivar from Myanmar ({"type":"entrez-nucleotide","attrs":{"text":"R18500","term_id":"772110","term_text":"R18500"}}R18500). They were evaluated in the experimental field of Kasetsart University, Kamphaeng Saen, Nakhon Pathom, Thailand in a randomized complete block design with two replications each in 2011 and 2012 growing seasons. The two parents exhibited contrasting characteristics for most of the traits that were mapped. Analysis of variance showed that the main effects of genotype and environment (year) were significant for all studied traits. Genotype by environment interaction was also highly significant for all the traits. The population was genotyped by 149 polymorphic SSR markers and the genetic map consisted of 129 SSR loci which converged into 38 linkage groups covering 1156 cM of soybean genome. There were 10 QTLs significantly associated with seed yield-related traits across two seasons with single QTLs explaining between 5.0% to 21.9% of the phenotypic variation. Three of these QTLs were detected in both years for days to flowering, days to maturity and 100 seed weight. Most of the detected QTLs in our research were consistent with earlier QTLs reported by previous researchers. However, four novel QTLs including SF1, SF2 and SF3 on linkage groups L and N for seed filling period and PN1 on linkage group D1b for pod number were identified in the present study.     

Insect-mediated cross-pollination in soybean [Glycine max (L.) Merrill]: II. Phenotypic recurrent selection

Recurrent selection is a method for population improvement which has been used in soybean [Glycine max (L.) Merrill] to modify traits such as grain yield, seed-protein content, seed-oil content, tolerance to iron-deficiency chlorosis, and seed size. Nuclear male-sterility with insect-mediated cross-pollination has been successfully used in recurrent selection schemes in soybean. However, little attention has been given to selection to increase the agronomic performance of male-sterile plants per se. The objective of this study was to evaluate the response of male-sterile lines segregating for male-sterile alleles ms2, ms3, ms6, ms8, and ms9 to phenotypic recurrent selection for increased seed-set after 3 cycles, using a selected group of male parents. Bees halictidae, anthophoridae, andrenidae, and megachilidae were utilized as the pollinator vector. The results indicated that recurrent selection in a favorable environment was successful to increase the number of seeds per male-sterile plant. Although a differential response was observed among populations, the seed-set observed would justify the use of some specific male-sterile selections as female parents in a hybrid soybean seed production system.     

基于BSA-Seq技术挖掘大豆中黄622的多小叶基因

The leaves of cultivated soybean (Glycine max L.) are comprising of three leaflets in general, but there are also individual varieties or mutants which have a high frequency of compound leaves with 4-7 leaflets, named multifoliolate leaves. Compound leaf formation enhances the plant's ability to adapt to the external environment. Study of related genes to multifoliolate leaves might contribute to the improvement yield level of and soybean agronomic traits. In this study, a multifoliolate leaf mutant Zhonghuang 622 was identified from the mutant library of soybean cultivar Zhongpin 661, which had 4-9 leaflets in each compound leaf. The compound leaf phenotypes of F₂ and F_2:3 population from a cross between Zhongpin 661 and Zhonghuang 622 were investigated in Beijing and Hainan, respectively. Analysis of phenotypic data from F₂ and F_2:3 population revealed that the multifoliolate leaf trait was controlled by an incomplete dominant gene. BSA-Seq method was used for gene mapping. The two bulks of normal trifoliate and multifoliolate individuals in F₂ population were constructed and sequenced for an average depth of 32.75×, which covered 99.22% genome compared to the reference genome. Through correlation analysis of mixed pool sequencing results by ED method, two regions were located on chromosome 11, with a total length of 5.29 Mb and a total length of 1103 genes. Three regions were identified on chromosome 11 at confidence of 0.99, with a total length of 3.42 Mb and a total of 701 genes by the association analysis of SNP-index method. There were 690 genes located simultaneously and six SNP genes between parents by the two association analysis methods. These results lay the foundation for map-based cloning of the genes related to compound leaf development.     

Genetic variation in soybean (Glycine max (L.) Merril) for cookability and water absorption during cooking

Summary Improvement of cookability is an important objective in breeding of food legumes. The present study was undertaken to investigate variation in cookability in soybean. Genetic variation was observed among lines from two crosses. Absence of associations between cookability and protein content, oil content and grain yield indicate that selection for cookability can be achieved without adversely affecting the expression of these characters.     

Genetic analysis and identification of two soybean mosaic virus resistance genes in soybean [Glycine max (L.) Merr]

Soybean mosaic virus (SMV) commonly affects soybean production worldwide, and the SC18 strain has been widespread in China. This study aimed to characterize and map the SC18 resistance genes present in soybean cultivars ‘Kefeng No. 1’ and ‘Qihuang 22’. Inheritance analysis revealed that two independent single dominant genes in Kefeng No. 1 and Qihuang 22 confer resistance to SC18. Using simple sequence repeat (SSR) markers and bulked segregant analysis, the Kefeng No. 1 and Qihuang 22 resistance genes were located on soybean chromosomes 2 and 13, respectively. We further screened two populations of recombinant inbred lines with 32 SSR markers in the target region, where the resistance gene in Kefeng No. 1 was fine mapped to an 80‐kb region containing six putative genes. Sequence and expression analyses of these genes revealed that SMV resistance in Kefeng No. 1 was probably attributable to three of the candidate genes (i.e. Glyma.02G127800, Glyma.02G128200 and Glyma.02G128300). Collectively, the results of this study will greatly facilitate the cloning of SC18 resistance genes and marker‐assisted breeding of SMV‐resistant soybean cultivars.     

Field screening of soya bean (Glycine max (L.) Merrill) germplasm for aluminium tolerance by the use of augmented design

Summary Selection for aluminium tolerance is necessary to adapt the soya bean crop to vast areas of acid soil in the tropics such as the Brazilian Savannas (Cerrados). The breeding programmes include field testing of large numbers of varieties. The tests are laborious, time consuming and need to be repeated to minimize effects of uncontrolled environmental factors. The present results show that augmented designs are efficient in the identification of Al-tolerant genotypes. These designs (i) allow elimination of soil differences as common causes for error in comparison of entries, and (ii) can be successfully employed in genetic studies and breeding programmes for crop improvement, being more cost effective than fully replicated trials.     

The Interaction of Sowing Date and Water Availability in Determining Plant Architecture, Fruiting Pattern and Yield Components of Soybean (Glycine max L. Merr.)

A 2-year trial has been carried out in northern Italy on soybean (cv. Hodgson) grown in lysimeters, comparing three soil water regimes (well-watered conditions and water stress during vegetative and reproductive stages) at two sowing dates. Plant evapotranspiration and water uptake depth were calculated from volumes of water independently supplied to eight lysimeter layers; at harvest, plant architecture, yield components and fruit distribution along the main stem and lateral branches were evaluated.
Although water stress intensity was not severe, crop evapotranspiration and water uptake depth were severely restricted by water shortage. Both low water-availability and late sowing significantly modified the architecture of plants, decreasing total height, number and length of internodes and lateral branches. Seed allocation along the stem was shifted downwards both by delaying the sowing date and by reducing the water supply; the component most responsible for yield decrease was the number of pods per plant, while unit seed weight was only slightly affected by water stress. Grain yield reduction was higher when water availability was inadequate during the reproductive phase in the early-sown crop and during the vegetative stage in the late-sown crop. This suggests that the intensity of the water shortage, plant phenological stage of stress application, as well as the date of stress application within the growing season determine the yield response of soybean.     

Mega‐environment identification for soybean (Glycine max) breeding and production in Brazilian Midwest region

Mega‐environment (ME) identification is the first step for evaluating, selecting and recommending genotypes within a target region (TR). The present study aimed to (a) identify MEs, using GGE biplot methods, in Brazilian edaphoclimatic region (ECR) 402 of soybean cultivation, located in the Mato Grosso State (the TR) and (b) compare the performance of genotypes within the TR and in each ME using fixed and mixed models. Data from three years of soybean yield trials, 19 genotypes and 22 environments were used. The biplots GGE, GGL + GGE and GGS + GGE were implemented to identify the MEs. Two MEs were identified in the TR. ME1 presents a higher altitude, farms which use a higher level of fertilizer inputs and a higher occurrence of the soybean cyst nematode (SCN) than ME2. When selection and recommendation are made based on MEs, genotypes with both broadly and specific adaptation can be selected. This action can improve grain yield in the entire target region.     

Major QTLs associated with green stem disorder insensitivity of soybean (Glycine max (L.) Merr.)

Green stem disorder (GSD) is one of the most serious syndromes affecting soybean (Glycine max) cultivation in Japan. In GSD, stems remain green even when pods mature. When soybean plants develop GSD, seed surfaces are soiled by tissue fluid and seed quality is deteriorated during machine harvesting. We performed quantitative trait locus (QTL) analyses for GSD insensitivity using recombinant inbred lines (RILs; n = 154) derived from a cross between an insensitive line (‘Touhoku 129’) and a sensitive leading cultivar (‘Tachinagaha’) during a 6-year evaluation. Three effective QTLs were detected. The influences of these QTLs were in the following order: qGSD1 (LG_H) > qGSD2 (LG_F) > qGSD3 (LG_L). At these three QTLs, ‘Touhoku 129’ genotypes exhibited more GSD insensitivity than ‘Tachinagaha’ genotypes. The lower incidence of GSD for ‘Touhoku129’ was attributable primarily to these three QTLs because RILs harboring a ‘Touhoku 129’ genotype at the three QTLs exhibited a GSD incidence similar to that of ‘Touhoku 129.’ Although a limitation of this study is that only one mapping population was evaluated, this QTL information and the flanking markers of these QTLs would be effective tools for resolving GSD in soybean breeding programs.     

Genotype x Bradyrhizobium japonicum strain interactions in dinitrogen fixation and agronomic traits of soybean (Glycine max L. Merr.)

Summary Bradyrhizobium japonicum strain G49 has been the only inoculum used in French soils. Soybean (Glycine max L. Merr.) cultivars were selected and tested according to their performances with this rhizobial strain. The aim of the present study was to determine the consequences of strain substitution on N₂ fixation abilities of various genotypes. Three genotypes and cultivar Weber, in combination with B. japonicum strain G49 or SMGS1, were cultivated in pots and tested for nitrogenase activity under differing nitrogen nutrition conditions. The reliability of ARA (acetylene reduction activity) measurement for assessing symbiotic nitrogen fixation under the experimental conditions used was checked. Genotypic variability for symbiotic fixation activity was observed with each strain under soil culture conditions; important genotype x strain interactions were also involved. These results were corroborated for the protein yield and other yield component performances of the various genotype-strain associations. Thus, in France, the replacement of strain G49 with another one might result in the alteration of the relative agronomic performances of the soybean cultivars, since N₂ fixation is considered as a major factor of soybean productivity.     

Yield stability in common bean (Phaseolus vulgaris L.) genotypes

An experiment was undertaken to determine the stability of seed yield in 21 common bean genotypes representing three growth habits. Seven genotypes in each growth habit (determinate bush, indeterminate bush and indeterminate prostrate) were evaluated in replicated trials at three locations for three years under rain fed conditions in Ethiopia. A combined analysis of variance, stability statistics and rank correlations among stability statistics and yield-stability statistic were determined. The genotypes differed significantly for seed yield and genotype × environment (year by location) interaction (GE). The different stability statistics namely Type1, Type 2 and Type 3 measured the different aspects of stability. This was substantiated by rank correlation coefficient. There were strong rank correlations among S_i ²d, W_i ²,σ_i ² and S_i ², where as there was weak correlation between b_iand R_i ², S_i ²d, W_i ², σ_i ² and S_i ². R² was significantly and negatively correlated with W_i ², σ_i ² and S_i ². σ_i ² is significantly correlated with W_i ².Yield is significantly correlated with b_i and R_i ².None of the statistics per se was useful for selecting high yielding and stable genotypes except the YS(yield-stability statistic). Most of the high yielding genotypes were relatively stable. Of the 21 genotypes, only 11genotypes were selected for their high yielding and stable performance. Genotypes with growth habit III and I (in determinate prostrate and determinate bush) were generally more stable than in determinate bush. This revised version was published online in July 2006 with corrections to the Cover Date.