... Those nodes supported with bootstrap val-ues great than 700/1000 are noted. Each RGA is desig... more ... Those nodes supported with bootstrap val-ues great than 700/1000 are noted. Each RGA is designated by its species abbreviation followed by the GenBank accession number. ... 27. Shultz. JL, K. Meksem, J. Shetty, CD Town, H. Koo, J. Potter, K. Wakefield. ...
Proceedings of the National Academy of Sciences, 1995
Common bean (Phaseolus vulgaris) consists of two major geographic gene pools, one distributed in ... more Common bean (Phaseolus vulgaris) consists of two major geographic gene pools, one distributed in Mexico, Central America, and Colombia and the other in the southern Andes (southern Peru, Bolivia, and Argentina). Amplification and sequencing of members of the multigene family coding for phaseolin, the major seed storage protein of the common bean, provide evidence for accumulation of tandem direct repeats in both introns and exons during evolution of the multigene family in this species. The presumed ancestral phaseolin sequences, without tandem repeats, were found in recently discovered but nearly extinct wild common bean populations of Ecuador and northern Peru that are intermediate between the two major gene pools of the species based on geographical and molecular arguments. Our results illustrate the usefulness of tandem direct repeats in establishing the polarity of DNA sequence divergence and therefore in proposing phylogenies.
Proceedings of the National Academy of Sciences, 2008
Foraging range, an important component of bee ecology, is of considerable interest for insect-pol... more Foraging range, an important component of bee ecology, is of considerable interest for insect-pollinated plants because it determines the potential for outcrossing among individuals. However, long-distance pollen flow is difficult to assess, especially when the plant also relies on self-pollination. Pollen movement can be estimated indirectly through population genetic data, but complementary data on pollinator flight distances is necessary to validate such estimates. By using radio-tracking of cowpea pollinator return flights, we found that carpenter bees visiting cowpea flowers can forage up to 6 km from their nest. Foraging distances were found to be shorter than the maximum flight range, especially under adverse weather conditions or poor reward levels. From complete flight records in which bees visited wild and domesticated populations, we conclude that bees can mediate gene flow and, in some instances, allow transgene (genetically engineered material) escape over several kilom...
Common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. campestris pv... more Common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans, is one of the most important diseases of common bean (Phaseolus vulgaris) in East Africa and other bean-growing regions. Xanthomonad-like bacteria associated with CBB in Malawi and Tanzania, East Africa, and in Wisconsin, U.S., were characterized based on brown pigment production, pathogenicity on common bean, detection with an X. campestris pv. phaseoli- or X. campestris pv. phaseoli var. fuscans-specific PCR primer pair, and repetitive element polymerase chain reaction (rep-PCR) and restriction fragment length polymorphism (RFLP) analyses. The common bean gene pool (Andean or Middle American) from which each strain was isolated also was determined. In Malawi, X. campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans were isolated predominantly from Andean or Middle American beans, respectively. In Tanzania, X. campestris pv. phaseoli var. fuscans w...
Anthracnose, one of the most important diseases of common bean (Phaseolus vulgaris), is caused by... more Anthracnose, one of the most important diseases of common bean (Phaseolus vulgaris), is caused by the fungus Colletotrichum lindemuthianum. A “candidate gene” approach was used to map anthracnose resistance quantitative trait loci (QTL). Candidate genes included genes for both pathogen recognition (resistance genes and resistance gene analogs [RGAs]) and general plant defense (defense response genes). Two strains of C. lindemuthianum, identified in a world collection of 177 strains, displayed a reproducible and differential aggressiveness toward BAT93 and JaloEEP558, two parental lines of P. vulgaris representing the two major gene pools of this crop. A reliable test was developed to score partial resistance in aerial organs of the plant (stem, leaf, petiole) under controlled growth chamber conditions. BAT93 was more resistant than Jalo-EEP558 regardless of the organ or strain tested. With a recombinant inbred line (RIL) population derived from a cross between these two parental lin...
The germplasm of cultivated common bean exhibits a lower level of genetic diversity within each g... more The germplasm of cultivated common bean exhibits a lower level of genetic diversity within each geographical gene pools (Mesoamerican and Andean) compared to that of the respective wild ancestors. Crosses between these two gene pools potentially provide a source of additional genetic diversity but their progenies have been characterized by phenotypic abnormalities and reduced productivity. In order to gain additional
Most information about the molecular biology of phaseolin, the major seed storage protein in Phas... more Most information about the molecular biology of phaseolin, the major seed storage protein in Phaseolus vulgaris, has been obtained from the T-type phaseolin, which is characteristic of the Andean gene pool of the species. In the work reported here, two cDNA clones for the S-type phaseolin representing the other major, Middle American gene pool were isolated and sequenced. Analysis of the DNA sequences revealed the presence of two subtypes of S phaseolin, α and β, depending on the presence or absence, respectively, of a 27-bp direct repeat. These are similar to the α- and β-phaseolin subtypes found in the Andean, T phaseolin; however, the additional 15-bp direct repeat also found in the T α-phaseolin gene type was apparently absent from the S α-phaseolin genes. The overall sequence identity was greater between the α or β subtypes of different gene pools than between the a or p subtypes within gene pools. This implies that the gene subtypes were formed prior to the formation of the tw...
... Those nodes supported with bootstrap val-ues great than 700/1000 are noted. Each RGA is desig... more ... Those nodes supported with bootstrap val-ues great than 700/1000 are noted. Each RGA is designated by its species abbreviation followed by the GenBank accession number. ... 27. Shultz. JL, K. Meksem, J. Shetty, CD Town, H. Koo, J. Potter, K. Wakefield. ...
Proceedings of the National Academy of Sciences, 1995
Common bean (Phaseolus vulgaris) consists of two major geographic gene pools, one distributed in ... more Common bean (Phaseolus vulgaris) consists of two major geographic gene pools, one distributed in Mexico, Central America, and Colombia and the other in the southern Andes (southern Peru, Bolivia, and Argentina). Amplification and sequencing of members of the multigene family coding for phaseolin, the major seed storage protein of the common bean, provide evidence for accumulation of tandem direct repeats in both introns and exons during evolution of the multigene family in this species. The presumed ancestral phaseolin sequences, without tandem repeats, were found in recently discovered but nearly extinct wild common bean populations of Ecuador and northern Peru that are intermediate between the two major gene pools of the species based on geographical and molecular arguments. Our results illustrate the usefulness of tandem direct repeats in establishing the polarity of DNA sequence divergence and therefore in proposing phylogenies.
Proceedings of the National Academy of Sciences, 2008
Foraging range, an important component of bee ecology, is of considerable interest for insect-pol... more Foraging range, an important component of bee ecology, is of considerable interest for insect-pollinated plants because it determines the potential for outcrossing among individuals. However, long-distance pollen flow is difficult to assess, especially when the plant also relies on self-pollination. Pollen movement can be estimated indirectly through population genetic data, but complementary data on pollinator flight distances is necessary to validate such estimates. By using radio-tracking of cowpea pollinator return flights, we found that carpenter bees visiting cowpea flowers can forage up to 6 km from their nest. Foraging distances were found to be shorter than the maximum flight range, especially under adverse weather conditions or poor reward levels. From complete flight records in which bees visited wild and domesticated populations, we conclude that bees can mediate gene flow and, in some instances, allow transgene (genetically engineered material) escape over several kilom...
Common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. campestris pv... more Common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans, is one of the most important diseases of common bean (Phaseolus vulgaris) in East Africa and other bean-growing regions. Xanthomonad-like bacteria associated with CBB in Malawi and Tanzania, East Africa, and in Wisconsin, U.S., were characterized based on brown pigment production, pathogenicity on common bean, detection with an X. campestris pv. phaseoli- or X. campestris pv. phaseoli var. fuscans-specific PCR primer pair, and repetitive element polymerase chain reaction (rep-PCR) and restriction fragment length polymorphism (RFLP) analyses. The common bean gene pool (Andean or Middle American) from which each strain was isolated also was determined. In Malawi, X. campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans were isolated predominantly from Andean or Middle American beans, respectively. In Tanzania, X. campestris pv. phaseoli var. fuscans w...
Anthracnose, one of the most important diseases of common bean (Phaseolus vulgaris), is caused by... more Anthracnose, one of the most important diseases of common bean (Phaseolus vulgaris), is caused by the fungus Colletotrichum lindemuthianum. A “candidate gene” approach was used to map anthracnose resistance quantitative trait loci (QTL). Candidate genes included genes for both pathogen recognition (resistance genes and resistance gene analogs [RGAs]) and general plant defense (defense response genes). Two strains of C. lindemuthianum, identified in a world collection of 177 strains, displayed a reproducible and differential aggressiveness toward BAT93 and JaloEEP558, two parental lines of P. vulgaris representing the two major gene pools of this crop. A reliable test was developed to score partial resistance in aerial organs of the plant (stem, leaf, petiole) under controlled growth chamber conditions. BAT93 was more resistant than Jalo-EEP558 regardless of the organ or strain tested. With a recombinant inbred line (RIL) population derived from a cross between these two parental lin...
The germplasm of cultivated common bean exhibits a lower level of genetic diversity within each g... more The germplasm of cultivated common bean exhibits a lower level of genetic diversity within each geographical gene pools (Mesoamerican and Andean) compared to that of the respective wild ancestors. Crosses between these two gene pools potentially provide a source of additional genetic diversity but their progenies have been characterized by phenotypic abnormalities and reduced productivity. In order to gain additional
Most information about the molecular biology of phaseolin, the major seed storage protein in Phas... more Most information about the molecular biology of phaseolin, the major seed storage protein in Phaseolus vulgaris, has been obtained from the T-type phaseolin, which is characteristic of the Andean gene pool of the species. In the work reported here, two cDNA clones for the S-type phaseolin representing the other major, Middle American gene pool were isolated and sequenced. Analysis of the DNA sequences revealed the presence of two subtypes of S phaseolin, α and β, depending on the presence or absence, respectively, of a 27-bp direct repeat. These are similar to the α- and β-phaseolin subtypes found in the Andean, T phaseolin; however, the additional 15-bp direct repeat also found in the T α-phaseolin gene type was apparently absent from the S α-phaseolin genes. The overall sequence identity was greater between the α or β subtypes of different gene pools than between the a or p subtypes within gene pools. This implies that the gene subtypes were formed prior to the formation of the tw...
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