Search

Your search keyword '"Boerma H"' showing total 582 results
Start Over Author "Boerma H"
582 results on '"Boerma H"'

106. A novel Phakopsora pachyrhizi resistance allele ( Rpp) contributed by PI 567068A.

Author

King, Zachary, Harris, Donna, Pedley, Kerry, Song, Qijian, Wang, Dechun, Wen, Zixiang, Buck, James, Li, Zenglu, and Roger Boerma, H.

Subjects
PHAKOPSORA pachyrhizi, ALLELES in plants, GENOTYPES, SINGLE nucleotide polymorphisms, HAPLOTYPES
Abstract

Key message: The Rpp6 locus of PI 567102B was mapped from 5,953,237 to 5,998,461 bp (chromosome 18); and a novel allele at the Rpp6 locus or tightly linked gene Rpp[PI567068A] of PI 567068A was mapped from 5,998,461 to 6,160,481 bp. Abstract: Soybean rust (SBR), caused by the obligate, fungal pathogen Phakopsora pachyrhizi is an economic threat to soybean production, especially in the Americas. Host plant resistance is an important management strategy for SBR. The most recently described resistance to P. pachyrhizi ( Rpp) gene is Rpp6 contributed by PI 567102B. Rpp6 was previously mapped to an interval of over four million base pairs on chromosome 18. PI 567068A was recently demonstrated to possess a resistance gene near the Rpp6 locus, yet PI 567068A gave a differential isolate reaction to several international isolates of P. pachyrhizi. The goals of this research were to fine map the Rpp6 locus of PI 567102B and PI 567068A and determine whether or not PI 567068A harbors a novel Rpp6 allele or another allele at a tightly linked resistance locus. Linkage mapping in this study mapped Rpp6 from 5,953,237 to 5,998,461 bp (LOD score of 58.3) and the resistance from PI 567068A from 5,998,461 to 6,160,481 bp (LOD score of 4.4) (Wm82.a1 genome sequence). QTL peaks were 139,033 bp apart from one another as determined by the most significant SNPs in QTL mapping. The results of haplotype analysis demonstrated that PI 567102B and PI 567068A share the same haplotype in the resistance locus containing both Rpp alleles, which was designated as the Rpp6/Rpp[PI567068A] haplotype. The Rpp6/Rpp[PI567068A] haplotype identified in this study can be used as a tool to rapidly screen other genotypes that possess a Rpp gene(s) and detect resistance at the Rpp6 locus in diverse germplasm. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

109. Evaluation of USDA Soybean Germplasm Accessions for Resistance to Soybean Rust in the Southern United States

Author

Walker, D. R., primary, Boerma, H. R., additional, Phillips, D. V., additional, Schneider, R. W., additional, Buckley, J. B., additional, Shipe, E. R., additional, Mueller, J. D., additional, Weaver, D. B., additional, Sikora, E. J., additional, Moore, S. H., additional, Hartman, G. L., additional, Miles, M. R., additional, Harris, D. K., additional, Wright, D. L., additional, Marois, J. J., additional, and Nelson, R. L., additional

Published
2011
Full Text
View/download PDF

115. Breeding Plants for Resistance to Nematodes

Author

Boerma, H. Roger and Hussey, Richard S.

Subjects
fungi, food and beverages, Article
Abstract

Plant breeders and nematologists have developed improved cultivars of important crop species with resistance to plant-parasitic nematodes. The effectiveness of these breeding efforts has depended on the availability of efficient screening procedures, identification of adequate sources of durable resistance, nature of the nematode feeding habit, and knowledge of the inheritance of resistance. These factors determine to a large degree the breeding method and potential success of the research. Systematic searches for nematode resistance have identified resistant germplasm lines within crop species or from related species. When the resistance gene(s) is from related species, incongruity barriers or sterility of the resulting hybrids often must be overcome. In these situations, backcrossing is usually necessary to incorporate the resistance gene(s) and recover the desirable commercial traits of the crop species. If the resistance gene(s) is present within the crop species, the choice of breeding method depends on the inheritance of the resistance, type of screening procedure, and other important breeding objectives for the species. In the future, plant molecular biologists and geneticists will make available novel sources of nematode resistance through incorporation of transgenes from other genera. These efforts will likely require conventional breeding strategies before commercial utilization of an improved resistant cultivar.

Published
1992

123. Penetration and Development of Meloidogyne incognita on Roots of Resistant Soybean Genotypes

Author

Herman, M., Hussey, R. S., and Boerma, H. R.

Subjects
Article
Abstract

Meloidogyne incognita penetration and development were studied in roots of highly resistant (PI 96354, PI 417444), resistant (Forrest), and susceptible (Bossier) soybean genotypes. Although more second-stage juveniles (J2) had penetrated roots of PI 96354 and PI 417444 than roots of Forrest and Bossier by 2 days after inoculation, fewer J2 were present in roots of PI 96354 at 4 days after inoculation. Juvenile development in all genotypes was evident by 6 days after inoculation, with the highest number of swollen J2 present in roots of Bossier. At 16 days after inoculation, roots of PI 96354 had 87%, 74%, and 53% fewer J2 than were present in roots of Bossier, Forrest, and PI 417444, respectively. Differential emigration of J2, not fewer invasion sites, was responsible for the low number of nematodes in roots of the highly resistant PI 96354. Some 72% of the J2 penetrating the roots of this genotype emerged within 5 days after inoculation, whereas 4%, 54%, and 83% emerged from roots of Bossier, Forrest, and PI 417444, respectively. Penetration of roots of PI 96354 decreased the ability of J2 emerging from these roots to infect other soybean roots.

Published
1991

126. Response of Resistant Soybean Plant Introductions to Meloidogyne incognita in Field Microplots

Author

Herman, M., Hussey, R. S., and Boerma, H. R.

Subjects
Article
Abstract

The response of two soybean plant introductions, PI 96354 and PI 417444, highly resistant to Meloidogyne incognita, to increasing initial soil population densities (Pi) (0, 31, 125, and 500 eggs/100 cm³ soil) of M. incognita was studied in field microplots for 2 years. The plant introductions were compared to the cultivars Forrest, moderately resistant, and Bossier, susceptible to M. incognita. Averaged across years, the yield suppressions of Bossier, Forrest, PI 417444, and PI 96354 were 97, 12, 18, and < 1%, respectively, at the highest Pi when compared with uninfested control plots. Penetration of roots by second-stage juveniles (J2) increased linearly with increasing Pi at 14 days after planting. At the highest Pi, 62% fewer J2 were present in roots of PI 96354 than in roots of the other resistant genotypes. Soil population densities of M. incognita were lower on both plant introductions than on Forrest. At 75 and 140 days after planting, PI 96354 had the lowest number of J2 in the soil, with 49% and 56% fewer than Forrest at the highest Pi. The resistance genes in PI 96354 should be useful in a breeding program to improve the level of resistance to M. incognita in soybean cultivars.

Published
1990

132. Evaluation of Soybean Germplasm Accessions for Resistance to Phakopsora pachyrhizi Populations in the Southeastern United States, 2009-2012.

Author

Walker, David R., Harris, Donna K., King, Zachary R., Zenglu Li, Boerma, H. Roger, Buckley, J. Blair, Weaver, David B., Sikora, Edward J., Shipe, Emerson R., Mueller, John D., Buck, James W., Schneider, Raymond W., Marois, James J., Wright, David L., and Nelson, Randall L.

Subjects
PLANT breeding, CROP genetics, SOYBEAN, PLANT germplasm, PLANT introduction, SOYBEAN disease & pest resistance
Abstract

Between 2009 and 2012, 118 soybean [Glycine max (L.) Merr.] accessions from the USDA Soybean Germplasm Collection were screened for resistance to soybean rust (Phakopsora pachyrhizi) at up to five locations in the southeastern United States. In 2009, plant introductions (PIs) from maturity groups III through IX were evaluated for relative disease severity and intensity of sporulation from uredinia compared with 12 susceptible cultivars from the same range of maturity groups. Resistance evaluations were based primarily on disease severity and intensity of sporulation from rust pustules. To assess resistance at several nurseries, a rust index score was calculated from the severity and sporulation ratings. Many of the PIs were moderately to highly resistant at the 2009 locations between Alabama and South Carolina, but the P. pachyrhizi population in Bossier City, LA, was virulent on most of those accessions. The 2011 rating data from Quincy, FL, indicated an increase in the virulence of the pathogen there since 2009, and this trend was observed again in 2012. In contrast, many of the same PIs developed substantially less soybean rust in Attapulgus, GA, in 2012. Despite the comparatively greater disease that many accessions had in Louisiana in 2009 and in Quincy in 2011 and 2012, at least 78 PIs were resistant in Georgia in 2012, and 20 of those were at least moderately resistant in both Florida and Georgia that year. No accessions were immune to rust at all of the nurseries, but PI 200492 (Rpp1), PI 547875 (a backcross line with Rpp1), and PI 567102B (Rpp6) were the most resistant of the accessions with named resistance genes and were among the most resistant accessions overall. Among the most resistant accessions with unknown resistance genes, PI 416826A, PI 417125, PI 567034, and PI 567104B consistently had effective levels of resistance in different locations and years. Information about the most resistant PIs and their reactions to soybean rust infection across years and locations will be useful for the development of rust-resistant soybean cultivars in the United States. [ABSTRACT FROM AUTHOR]

Published
2014
Full Text
View/download PDF

133. An R package for SNP marker-based parentoffspring tests.

Author

Abdel-Haleem, Hussein, Pengsheng Ji, Boerma, H. Roger, and Zenglu Li

Subjects
SOYBEAN, GENETIC polymorphisms, GENOMES, BIOMARKERS, GENE mapping
Abstract

Background With the advancement of genotyping technologies, whole genome and high-density SNP markers have been widely used for genotyping of mapping populations and for characterization of germplasm lines in many crops. Before conducting SNP data analysis, it is necessary to check the individuals to ensure the integrity of lines for further data analysis. Results We have developed an R package to conduct a parent-offspring test of individuals which are genotyped with a fixed set of SNP markers for further genetic studies. The program uses monomorphic SNP loci between parents and their progeny genotypes to calculate the similarity between each offspring and their parents. Based on the similarity of parents and individual offspring, the users can determine the threshold level for the individuals to be included for further data analysis. We used an F5-derived soybean population of '5601T' x PI 157440 that was genotyped with 1,536 SNPs to illustrate the procedure and its application. Conclusions The R package 'ParentOffspring' coupled with the available SNP genotyping platforms could be used to detect the possible variants in a specific cross, as well as the potential errors in sample handling and genotyping processes. It can be used in any crop which is genotyped with a fixed set of SNP markers. [ABSTRACT FROM AUTHOR]

Published
2013
Full Text
View/download PDF

148. Genome Duplication in Soybean (Glycine subgenus soja)

Author

Shoemaker, R C, primary, Polzin, K, additional, Labate, J, additional, Specht, J, additional, Brummer, E C, additional, Olson, T, additional, Young, N, additional, Concibido, V, additional, Wilcox, J, additional, Tamulonis, JP, additional, Kochert, G, additional, and Boerma, H R, additional

Published
1996
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results