Shree P. Singh

Races of common bean (Phaseolus vulgaris, Fabaceae)

Evidence for genetic diversity in cultivated common bean (Phaseolus vulgaris) is reviewed. Multivariate statistical analyses of morphological, agronomic, and molecular data, as well as other available information on Latin American landraces representing various geographical and ecological regions of their primary centers of domestications in the Americas, reveal the existence of two major groups of germplasm: Middle American and Andean South American, which could be further divided into six races. Three races originated in Middle America (races Durango, Jalisco, and Mesoamerica) and three in Andean South America (races Chile, Nueva Granada, and Peru). Their distinctive characteristics and their relationships with previously reported gene pools are discussed.RésuméSe presenta una revisión sobre la evidencia de variabilidad genética en el fríjol cultivado (Phaseolus vulgaris). De acuerdo con los análisis estadísticos multivariados de datos morfológicos, agronómicos y moleculares y con información adicional disponible sobre variedades criollas de América Latina que representan varias regiones ecológicas y geográficas de sus centros primarios de domesticación en las Américas, se establece la existencia de los dos grupos principales de germoplasma: los de Mesoamérica y de los Andes suramericanos; los cuales pueden ser divididos en seis razas. Tres razas se originaron en Mesoamérica (razas Durango, Jalisco y Mesoamérica) y tres los Andes suramericanos (razas Chile, Nueva Granada y Perú). Se discuten sus características distintivas y sus relaciones con otros acervos de genes reportados anteriormente.

Production and Utilization

Several books, book chapters, symposia proceedings, bulletins, and review articles covering different aspects of this general topic have been published during the last few decades (Adams et al., 1985; Allavena, 1984; Araya & Beck, 1995; Beebe, 1989; CIAT, 1981, 1985, 1989; Gepts, 1988; Graham, 1978; Graham & Ranalli, 1997; Laing et al., 1984; Maiti, 1997; Park & Buzzell, 1995; Robertson & Frazier, 1978; Schoonhoven & Voysest, 1991; Schwartz & Pastor-Corrales, 1989; Singh, 1989, 1992; Singh & Voysest, 1997; Thung & Oliveira, 1998; Vieira, 1967; Vieira et al., 1998; Voysest, 1983, 1998; Wall, 1973; White et al., 1988; Wortmann et al., 1998; Zaumeyer & Meiners, 1975; Zaumeyer & Thomas, 1957; Zimmermann et al., 1988). Readers interested in details may refer to these and other publications. This chapter will provide an overview and supplementary information.

Geographical distribution of the DL1 and DL2 genes causing hybrid dwarfism in Phaseolus vulgaris L., their association with seed size, and their significance to breeding

SummaryDwarlism in F1 hybrids has been observed in over 100 crosses of dry beans (Phaseolus vulgaris L.) at the Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia. In each cross, one parent always had small seeds and the other parent either medium or la ge ones. This apparent incompatibility between the two groups of germplasm was controlled by two complementary, dominant genes: DL1 and DL2. Smallseeded bean lines carried gene DL1 and originated in Brazil, Colombia, Guatemala, and Mexico; medium for large-seeded bean lines carried gene DL2 and were from Bolivia, Brazil, Chile, Colombia, Turkey, The United States, and West Germany. Thes two genes have probably played an important role in the evolution of dry bean forms of different seed sizes by serving as a genetic barrier or isolating mechanism, thus limiting free genetic recombination between the two germplasm groups.Apparent differences in the adaptiveness and yielding ability of the two groups of bean germplasm, smallys, medium- and large-seeded, and some breeding implications for manipulation of the genes causing F1 hybrid dwarfism were also discovered.

Patterns of variation in cultivated common bean (Phaseolus vulgaris, Fabaceae)

More than 18,000 accessions of common bean (Thaseolus vulgaris, Fabaceae) from the Centro Internacional de Agricultura Tropical (CIAT) germplasm bank were examined at two locations in Colombia. A large variation in cultivated dry bean was found among accessions from primary centers of domestication in Middle and South America. For some bean types, such as medium- and large-seeded white, variation was greater among germplasm from western Asia (Turkey) and Europe (Portugal, Spain, Greece, France, Italy, and Bulgaria). Based on growth habit, on seed, pod, and leaf characteristics, and on ecological regions of adaptation, dry-bean germplasm was divided into a total of six gene pools from Middle American and four gene pools from South American centers of domestication. Most of the variation in the snap or stringless bean appears to be of relatively recent origin; it was greatest among cultivars from China, Europe, and the United States. These could be grouped into two additional gene pools. A strategy for breeding and transfer of genes across gene pools is also discussed.

Common bean improvement in the twenty-first century

Contributors. Acknowledgments. Preface. Production and Utilization S.P. Singh. Diversity in Phaseolus Species in Relation to the Common Bean D.G. Debouck. Development of an Integrated Linkage Map P. Gepts. Marker-Assisted Selection J.D. Kelly, P.N. Miklas. Genetic Transformation H.-J. Jacobsen. Integrated Genetic Improvement S.P. Singh. Breeding to Improve Plant Type A. Vandenberg, T. Nleya. Breeding to Improve Yield J.D. Kelly, et al. Improvement of Medium-Seeded Race Durango Cultivars M.A. Brick, K.F. Grafton. Improvement of Small-Seeded Race Mesoamerica Cultivars S.P. Singh. Improvement of Large-Seeded Race Nueva Granada Cultivars J.S. Beaver. Improvement of Snap Bean J.R. Myers, J.R. Baggett. Integrated Management of Abiotic Stresses M. Thung, I.M. Rao. Integrated Pest Management H.F. Schwartz, F.B. Peairs. Appendix. Index.

Novel Phaseolin types in wild and cultivated common bean (Phaseolus vulgaris, Fabaceae)

Forty-one wild types and 41 cultivars of common bean (Phaseolus vulgaris) from Meso-and South America were screened for variability of phaseolin seed protein using one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS/PAGE) and two-dimensional isoelectric focusing SDS/PAGE. Wild accessions from the Andean region showed phaseolin types which had not been previously identified in wild material from that region. Other wild accessions from Argentina exhibited novel phaseolin patterns collectively designated as ‘J’ (‘Jujuy’) phaseolin types, and one accession from northern Peru exhibited a novel phaseolin type, the ‘I’ (‘Inca’) type. The ‘H’ and ‘C’ phaseolins, previously identified only in cultivars, were observed in several wild accessions from Argentina. Among cultivars, two minor variants of the ‘S’ phaseolin type were identified. The ‘Sb’ (‘S Brazil’) was characteristic of a limited number of cultivars from Brazil whereas the ‘Sd’ (‘S Durango 222’) predominated in cultivars of the Mexican central highlands. The distribution of the previously described ‘B’ phaseolin appeared to be larger than formerly known as it extended not only in Colombia but also in Central America. It is possible to correlate the ‘Sb’, ‘Sd’, and ‘B’ phaseolin types with certain agronomic traits.ResumenLa variabilidad de faseolina, la proteina principal de la semilla, fue analizada en una muestra de 41 formas silvestres y 41 formas cultivadas del fríjol común (Phaseolus vulgaris) de Meso- y Suramérica mediante electroforesis a una y dos dimensiones en gelos de poliacrilamida con dodecil sulfato de sodio (SDS/ PAGE). Las formas silvestres de la región andina enseñaron tipos de faseolina que no habían sido identificados anteriormente en material silvestre de esta región. Formas silvestres de Argentina mostraron varios tipos nuevos de faseolina que fueron llamados tipos ‘J’ (‘Jujuy’) y una accesión silvestre del norte de Peru mostró un tipo nuevo que fué llamado el tipo ‘I’ (‘Inca’). Dentro de las formas cultivadas, dos formas variantes de la faseolina ‘S’ fueron identificadas. El tipo ‘Sb’ (‘S Brazil’) fué característico de un núméro limitado de variedades de Brasil, mientras el tipo ‘Sd’ (‘S Durango 222’) predominaba en variedades del altiplano central de México. La distribución de la faseolina ‘B’ descrita previamente parece ser más amplia que lo que se había determinado anteriormente ya que se encuentra no solamente en Colombia pero también en América Central. Es posible correlacionar los tipos de faseolina ‘Sb’, ‘Sd’, y ‘B’ con ciertos rasgos agronómicos.

New sources of resistance to anthracnose and angular leaf spot of beans (Phaseolus vulgaris L.).

Summaryover 13000 CIAT bean accessions were evaluated for their reactions to the anthracnose (Colletotrichum lindemuthianum) and angular leaf spot (Isariopsis griseola) pathogens over a 3 yr period. Among these accessions, 156 were resistant to all races of the anthracnose pathogen collected from Popayán, Colombia. Thirty were resistant to numerous races obtained from other parts of the world, including Europe. Although many of these new resistant sources originated in Mexico and Central America, they are quite diverse for geographic origin, plant type, seed color and seed size. In addition, more than 50 of the 156 lines were also resistant to isolates of I. griseola with diverse sources of origin throughout Colombia.

Pathogenic variation in, sources of, and breeding for resistance to Phaeoisariopsis griseola causing angular leaf spot in common bean

If we are to breed common bean (Phaseolus vulgaris L.) for durable resistance to diseases, we must understand pathogenic variation and find sources of resistance. Our first objective was to determine the patterns of pathogenic variation found among isolates of Phaeoisariopsis griseola (PG), the fungus that causes angular leaf spot (ALS) in common bean. We characterized 433 PG isolates from 11 Latin American and 10 African countries, using differential cultivars, isozymes, and/or random amplified polymorphic DNA (RAPD) markers. We also systematically screened, for ALS resistance, common bean accessions from the world collection held at CIAT, and assessed the progress so far made in breeding for resistance to ALS. Despite their great diversity within and between countries on both continents, the PG isolates were classified into two major groups: Andean, and Middle American. Although each group had internal differences for virulence, and biochemical and molecular characteristics, the ‘Andean’ PG isolates were more virulent on common beans of Andean origin, than on those of Middle American origin, thus, suggesting a host-pathogen co-evolution. The ‘Middle American’ PG isolates, although more virulent on common beans from Middle America, also attacked Andean beans, thus, exhibiting a much broader virulence spectrum. To find sources of resistance, we tested 22,832 common bean accessions against naturally occurring PG isolates in the field at CIATs Experiment Station, Quilichao, Colombia, between 1985 and 1992. The resulting 123 intermediate (scores of 4 to 6) and resistant (scores of 1 to 3) accessions were then tested in the greenhouse against selected 14 PG isolates of diverse origins. Nineteen accessions were intermediate or resistant to at least 13 of 14 PG isolates. Similarly, of 13,219 bred lines tested in the field between 1978 and 1996, 89 were intermediate or resistant. Of these, 33 bred lines proved intermediate or resistant to at least eight of nine PG isolates to which they were challenged in the greenhouse. We suggest that, to breed for durable resistance to ALS, common bean populations should be developed from crosses between Andean and Middle American gene pools. The populations should then be systematically evaluated and selected against the broadest range of the most virulent PG isolates of diverse evolutionary origins.

Interspecific hybridization between common and tepary beans: increased hybrid embryo growth, fertility, and efficiency of hybridization through recurrent and congruity backcrossing.

Cultivated common bean (Phaseolus vulgaris L.) and tepary bean (Phaseolus acutifolius A. Gray) genotypes possessing desirable agronomic traits were hybridized. The F1 hybrids were backcrossed twice with the common bean (i.e., recurrent backcrossing). Also, alternate backcrosses with common and tepary beans (i.e., congruity backcrossing) were carried out. Embryo culture was necessary for all initial interspecific crosses, and its requirement was proportionally lower when the common bean was used as the recurrent parent and as the last parent of congruity backcrosses. Modification of the embryo culture technique was necessary to produce congruity hybrids. Effects of both tepary and common bean genotypes on the success rate of hybridization were observed. Tepary accession G 40001 and common bean cultivar ICA Pijao facilitated interspecies hybridization. Growth of hybrid embryos before rescue, recovery of mature hybrid plants, and the vigor and fertility of F1 hybrids all increased with increased recurrent and congruity backcrosses and intermatings between male-sterile F1 and selected fertile F2 plants of the third and fifth congruity backcrosses. Introgression of tepary genes was verified by means of seed protein electrophoretic analysis and morphological markers. The results suggest that congruity backcrossing can help to gradually reduce or overcome P. vulgaris x P. acutifolius hybridization barriers such as genotype incompatibility, early embryo abortion, hybrid sterility, and lower frequencies of hybridization.

A major QTL for common bacterial blight resistance derives from the common bean great northern landrace cultivar Montana No. 5

Knowledge of the evolutionary origin and sources of pest resistance genes will facilitate gene deployment and development of crop cultivars with durable resistance. Our objective was to determine the source of common bacterial blight (CBB) resistance in the common bean Great Northern Nebraska #1 (GN#1) and GN#1 Selection 27 (GN#1 Sel 27). Several great northern cultivars including GN#1, GN#1 Sel 27, and Montana No.5 (the female parent of the common x tepary bean interspecific population from which GN #1 and GN # 1 Sel 27 were derived) and known susceptible checks were evaluated for CBB reaction in field and greenhouse environments. These genotypes and CBB resistant and susceptible tepary bean including Tepary #4, the male parent and presumed contributor of CBB resistance toGN#1 and GN#1 Sel 27, were assayed for presence or absence of three SCAR markers tightly linked with independent QTLs conditioning CBB resistance. The parents and F2 of Montana No. 5/GN #1 Sel 27 and Montana No.5/Othello(CBB susceptible) were screened for CBB reaction and SCAR markers. CBB resistance in Montana No.5 was comparable to that of GN#1 and GN#1 Sel27. The SAP6 SCAR marker present in GN#1 and GN#1 Sel 27 was also present in Montana No.5, and it co-segregated (R2 =35%) with the CBB resistance in the Montana No.5/Othello F2 population. Although a few CBB resistant and susceptible transgressive segregants were found in the F2 of MontanaNo.5/GN #1 Sel 27 and later confirmed by F3 progeny tests, SAP6 SCAR marker was present in all progenies. None of the tepary bean specific CBB resistance-linked SCAR markers were present in GN#1, GN#1 Sel 27, or Montana No.5. A cluster analysis of 169 polymorphic PCR-based markers across three common bean and Tepary #4 indicated that GN#1, GN#1 Sel 27, and Montana No.5 were closely related, and not related at all with Tepary #4.Thus, these results clearly indicate Montana No.5, not Tepary #4, as the source of CBB resistance in GN#1 and GN#1 Sel 27.