Inheritance of Resistance to Phytophthora sojae in the Soybean PI 567574A
Authors:
R. A. Leitz, C. D. Nickell, and G. L. Hartman
Abstract:
Phytophthora root rot of soybean can cause heavy crop losses. Monogenic race-specific resistance to the causal organism, Phytophthora sojae, is controlled by 13 dominant alleles at seven loci in soybean. Soybean germplasm lines have been identified with new race resistance patterns. These lines need to be characterized to determine the inheritance of that resistance and compared to known sources of resistance. The objective of this study was to characterize the inheritance of resistance to P. sojae in PI 567574A. Results indicate that there are two alleles at independent loci that control resistance in this PI. Allelism studies indicated that the two alleles are Rps1c and Rps3a.
Animation and Image Analysis for Evaluation of Soybean (Glycine max L. Merrill.) Somatic Embryo Growth
Authors:
Marco T. Buenrostro-Nava1,3, Holly M. Frantz1, Peter P. Ling2 and John J. Finer1,4
Abstract:
Recent advances in machine vision technology have resulted in an increase in the use of image analysis in different areas of cell biology. Image analysis has been used to study in vitro-grown animal cells using light microscopy (Gauthier et al., 1992) and the movement and compartmentalization of proteins in plant cells using confocal microscopy (Haseloff and Siemering, 1998). In the area of plant developmental biology, image analysis has been utilized with tissue culture systems to collect information on tissue growth and development. Smith et al. (1989) were the first to use image analysis as a non-invasive method to evaluate growth of in vitro cultures of some woody, vegetables and grass plants. Computer vision techniques were later used to follow the kinetics of somatic embryo formation in suspension cultures of carrot (Cazzulino et al., 1990; Ibaraki et al., 1996). In order to select coffee somatic embryos with high germination efficiency, Ling et al. (1996) used machine vision to first establish the relationship between the elongation coefficient and the growth aspect ratio of mature embryos and then determine the ability of those embryos to germinate. Using computer analysis to evaluate size, shape and color-related measurements from images of sweet potato somatic embryos (during torpedo and cotyledonary-stage), Padmanabhan et al. (1998a) identified germination-competent and non-competent embryo types and then compared these characteristics with the embryo anatomy using histological analysis (Padmanabhan et al.,1998b). These reports demonstrated the potential of image analysis for embryo growth studies. However, to our knowledge, there are no reports on the use of image analysis to evaluate growth of somatic embryos from their earliest developmental stage or using computer animation to better understand embryo development and growth over time. For most analysis of plant biological systems, evaluations are still based on human vision and results can often be highly variable and very subjective. This makes comparisons difficult with qualitative data from different laboratories. The objective of this work was to demonstrate the capability of characterizing somatic embryo development using image analysis and animation techniques.
Segregation for Stem Canker resistance in Southern Soybean crosses
Authors:
J. Tyler
Abstract:
Stem Canker caused by Diaporthe phaseolorum (Cooke & Ellis) Sacc. f. sp. meridionalis Morgan-Jones (Dpm) can cause significant yield losses in soybean [Glycine max (L.) Merr.] in the southern USA. Some cultivars are resistant. The parental donor of resistance is unknown for many cultivars, therefore it is not known which genes are the most common in the elite germplasm base. Progeny from 44 resistant X resistant soybean genetic populations were evaluated for their reaction to the fungus causing stem canker disease. Susceptible progeny were identified in only 8 populations. The frequency of susceptible plants in those was low. This indicates that few loci are represented in the current elite breeding gene pool. An implication from the study is that breeders can delay testing for stem canker resistance until very late phases of development if both parents are resistant.
RAPD Markers Associated with Salt Tolerance In Wild Soybean Populations
Authors:
Q. Zhang, H. Wang, and Z. Hu
Abstract:
Salinity is a major environmental constraint to crop production in the arid and semi-arid regions of the world (Greenway and Munns 1980). Most crop plants including wild soybeans are sensitive to salt stress. Sources of salt tolerance have been identified among some related wild species. These genetic resources could potentially be used to improve salt tolerance of soybean cultivars. One approach to facilitate the selection and breeding for complex traits such as salt tolerance is the identification and utilization of simply inherited genetic markers that are genetically associated with the trait of interest (Tanksley 1993; Foolad et al., 1995). In previous study, we employed isozymes and RAPDs as genetic markers to identify the relationship between the markers and salt-tolerance. Little correlation was found (Wang et al., 1997). The present investigation was conducted to further examine randomly amplified polymorphism DNA (RAPD) markers associated with salt tolerance and therefore to study the molecular mechanisms of adaptation of wild soybean to changing saline conditions.
Amberger et al., (1992) reported that the Chinese cultivar Jilin 3 (PI 427099 [GRIN]) was very conducive to generate variants from tissue culture. Among the progeny of a chimeric foliage plant (LA55-1) identified in the R3 generation, were plants with green foliage, chimeric foliage, and yellow viable, and yellow lethal plants. The yellow viable mutant was allelic to y20 [Soybase] and the yellow lethal mutant was allelic to y18 [Soybase]. These data will be reported elsewhere. Our objective was to determine linkage relationships of these two mutants with morphological and isoenzyme mutants in soybean.
In March 1981 A. Williams of Williams, IN sent seed to me harvested from a number of chlorophyll-deficient plants. His mutant in cultivar Williams [GRIN] (78-2-80) was allelic to y9 [Soybase] and was linked to pb (pubescence tip [Soybase]) (Thorson et al., 1989). His mutant in cultivar Williams (78-3-80) was cytoplasmically inherited and was designated cyt-Y5 (T315 [GRIN]) (Cianzio and Palmer, 1992). His mutant in cultivar Williams (80-7) was designated y23 [Soybase] (T288 [GRIN]) and was placed on classical genetic linkage group 8 [Soybase] (Palmer et al. 1990). Our objective was to determine the inheritance and linkage relationships of chlorophyll-deficient Williams (77-2-80) obtained from A. Williams.
Genetic Study on Resistance to Soybean Cyst Nematode (Heterodera glycines) Race 14 in Huibuzhi Black Bean from Xing County in Shanxi Province
Authors:
Yantong Wang1, Peng Deliang2, and Chen Shouyi3
Abstract:
Heterodera glycines is a serious disease in world soybean (Glycine max) production. Huibuzhi black bean from Xing county in Shanxi province, China is one of the most important sources of resistance. It is resistant to all investigated races, 1, 3, 4, 5 and 14 of SCN. It is also widely used in Chinese breeding programs as a resistant donor. The objective of this research is to determine SCN race type at the Experiment station, Plant Protection Institute, Chinese Academy of Agricultural Sciences in Beijing and to investigate the inheritance of resistance of the identified SCN race in Huibuzhi black bean.
The Amino Acid Sequence Determination of a New Variant of Kunitz Soybean Trypsin Inhibitor (SBTi-A2)
Authors:
Xin Hua, Xie Kefang, Dong Aiwu, Yan Qingyan, and Gu Qimin
Abstract:
A substantial amount of Kunitz trypsin inhibitor (SBTi-A2) exists in soybean seeds. Three codominant alleles, Ti-a[Soybase], Ti-b[Soybase] and Ti-c[Soybase] were identified and their protein sequences have been determined. Ti-d was reported by Zhao Shuwen (1992), as a new variant of SBTi-A2 discovered in the Gansu province of China. The amino acid sequence of Ti protein was deduced from its DNA sequence which is obtained by PCR and determined by DNA sequence analysis in our laboratory.
Effect of Different Mutagenic Treatments on Morphological Traits of M2 Generation of Soybean
Authors:
Martin Hajduch*2, Frantisek Debre3, Blanka Böhmová1, and Anna Pretová2
Abstract:
Despite the richness of the soybean germplasm collection the genetic base of the present day collection remains poor (Delannay et al., 1983). Present investigation was, therefore, undertaken to obtain information on effect of g-irradiation and sodium azide as well as their combination on morphological traits of the M2 generation of two soybean cultivars Tolena and Toping.
Inheritance of Partial Resistance to Sclerotinia sclerotiorum in Soybean Cultivars Asgrow A2506 and Novartis S19-90
Authors:
D. D. Hoffman1, A. D. Nickell2, C. D. Nickell1, B.W. Diers1, and G. L. Hartman1
Abstract:
Partial resistance to Sclerotinia stem rot (SSR), [Sclerotinia sclerotiorum (Lib.) de Bary] has been identified in soybean [Glycine max (L.) Merr.] accessions and cultivars in the United States. There have been no reports of the inheritance of partial resistance to S. sclerotiorum in soybean. The objectives of this study were to: (i) estimate the number of genes contributing to resistance to S. sclerotiorum in the soybean cultivars Asgrow A2506 and Novartis S19-90 and (ii) estimate broad and narrow sense heritabilities. Data from greenhouse evaluations of three crosses, Asgrow WR2347 x Asgrow A2506, Novartis S19-90 x Asgrow A2506, and Novartis S19-90 x Asgrow WR2347, were used to estimate goodness of fit for theoretical inheritance models in F2 and F3 generations and to estimate heritabilities. We found significant results indicating partial resistance to S. sclerotiorum is caused by multiple genes and some may be recessive. Estimates of heritabilities indicated more dominance occurred when Novartis S19-90 was used as a parental line compared with Asgrow A2506. All heritability estimates based on F2:3 family means (>0.86) were higher than the heritability estimates based on F2 plant basis. This presages selection for partial resistance to S. sclerotiorum in soybean based on F2:3 family means evaluation would be more efficient than selecting on a single F2 plant basis. The high heritability estimates in our greenhouse evaluations are valuable to soybean breeders selecting for partial resistance to S. sclerotiorum.
Influence of wp on Pod Characteristics and Agronomic Traits of Soybean Lines
Authors:
D. C. Gay, J. M. Hegstad, P. A. Stephens, and C. D. Nickell
Abstract:
Homozygous recessive wp alleles produce pink flower color in soybean when in the presence of the non-allelic gene W1[Soybase] by modifying the expression of purple pigmentation (Stephens and Nickell, 1992). Stephens et al. (1993) found no differences between pink and near-isogenic purple-flowered soybean lines for the agronomic traits yield, maturity, height, lodging, and seed quality. Pink flower soybeans differ from magenta flowered soybeans, which have the genotype W1_wmwm[Soybase]. Magenta flower color lines were associated with a 3% reduction in yield, attributed to a lower photosynthetic rate and earlier leaf senescence compared with purple-flowered Harosoy[GRIN] (Buzzell et al., 1977). Stephens et al. (1993) observed that two-seeded pods were more prevalent in pink flowered lines, while purple-flowered lines produced proportionally more three-seeded pods. However, seeds per pod or pods per plant were not counted to determine the possible effect of wp upon pod characteristics. In petunia and maize, it was determined that flavonols are required in the pollen grain to initiate pollen tube growth and ensure successful fertilization (Taylor, 1995). The most diverse group of flavonol compounds is the anthocyanins, which generate pigmentation in floral tissues. In soybean, the wp locus is thought to modify anthocyanin production to generate pink flowers instead of purple flowers, however it is unknown if there is a relationship between anthocyanin modification and seeds per pod, or pods per plant. Other studies have found a relationship between leaflet shape and seeds per pod (Bernard and Weiss, 1973). The recessive gene ln[Soybase] is responsible for both narrow leaflet shape and a predominance of four-seeded pods. Another gene for leaflet shape, lo[Soybase], is associated with few-seeded pods (Domingo, 1945). In the literature, there are no reports relating flower color with seeds per pod or loculi per pod. The objective of this study was to describe the influence of wp upon pod characteristics and agronomic traits when crossed into a different genetic background.
The Effect of Selection Method on the Association of Yield and Seed Protein with Agronomic Characters in an Interspecific Cross of Soybean
Authors:
Li Xinhai1, Wang Jinling1,Yang Qingkai1, Jiao Shaojie2, and Wang Liming2
Abstract:
Correlations of seed yield and protein percentage of soybeans (Glycine max) were variable. Seed protein content was both positively and negatively associated with maturity (Kwon and Torrie 1964; Weiss et al. 1952). Close relationships between protein content and either plant height or lodging were not reported (Johnson et al. 1955a). In general, high seed yield was associated with low protein percentage (Byth et al. 1969; Hartwig 1969; Hymowitz et al. 1972; Johnson et al. 1955b), although positive correlations between those two traits were also observed among progenies of some crosses (Kwon and Torrie 1964; Weiss et al. 1952). With respect to components of yield, protein content has been positively and negatively associated with number of fruiting nodes per plant and with number of seeds per pod, and has been positively associated with seed size (Fehr and Weber 1968). In two populations, an inverse relationship was reported between protein content and resistance to shattering (Johnson et al. 1955b).
The Effects of Daylength on the Growth of Soybean and the Creation of Wide-adaptation Germplasm
Authors:
Guiru Zhang and Weiguang Du
Abstract:
There are plenty of reports about the photoperiodic response of soybean. The early studies were mainly focused on the effect of daylength on blooming stage. Further studies showed that daylength influences, not only the development of soybean before flowering, but also the development between flowering and maturity (Major 1975, Akhanda et al. 1981, Liu et al. 1983). He et al. (1993) and Han et al. (1995) investigated the post-flowering photoperiodic responses of soybean by treating soybean with different daylengths before and after flowering. These studies together proved that photoperiod affects the whole growth and development period, but few studies have associated photoperiod with yield characters and creation of wide-adaptation lines of soybean. The goal of this study was to understand the response of cultivars to different daylengths and to create daylength insensitive germplasm. These will provide knowledge and material for high-yield breeding and photoperiodic breeding of soybean.
Genetic Analysis of Phytophthora Rot Resistance in the Soybean PI 567.496
Authors:
A. D. Jenks, R. A. Leitz, and C. D. Nickell
Abstract:
Phytophthora root rot, caused by Phytophthora sojae, has been a very harmful disease in soybeans for many years. Recent crop loss estimates have ranked Phytophthora root rot as the second or third most destructive disease for soybeans (Doupnik, 1993). Resistance to Phytophthora in soybeans is controlled by thirteen dominant genes. There are fifty-three known races of the pathogen (Ryley et al., 1998). The pathogen may attack plants in all stages of growth with disease development favored by poorly drained soils and cool wet weather (Moots, et al., 1988).
Genetic Analysis of Phytophthora Rot Resistance in the Soybean PI 567.504
Authors:
D.J. Weber, R.A. Leitz, and C.D. Nickell
Abstract:
The soilborn fungus Phytophthora sojae causes the disease Phytophthora root rot. The disease can attack soybeans at any stage of development. Seed rot and pre-emergence damping-off can occur in flooded areas or ponded soils. Post-emergence damping-off and seedling stem rot cause wilting and plant death (Schmitthenner, 1985). Plant Introduction (PI) 567.504 is resistant to hypocotyl inoculation of races 1, 4, 7, 13, and 25 and susceptible to races 3, 5, 12, and 20. Hegstad et al. (1998) suggested on the basis of RFLP analysis that PI 567.504 carries the Rps3a gene for resistance to P. sojae. The objective of this study was to determine the genetic control of resistance to P. sojae race 25 in PI 567.504.