30 POSTER SESSION 4 (Abstr. 460-484) Breeding/Genetics/Molecular Markers
J. R. Baggett and D. Kean
P.N. Miklas, K.F. Grafton, and B.D. Nelson
grants from The Quaker Oats Co. M.H. Dickson, H.F. Schwartz, M.A. Brick, and D. P Coyne contributed bean genotypes. J.R. Steadman contribute disolates of S. sclerotionon. J .R. Venette reviewed the manuscript. W.L. Albus and J. Vander Wal provided
Phillip N. Miklas, Richard Delorme, Valerie Stone, Mark J. Daly, J. Rennie Stavely, James R. Steadman, Mark J. Bassett, and James S. Beaver
Understanding the genomic associations among disease resistance loci will facilitate breeding of multiple disease resistant cultivars. We constructed a genetic linkage map in common bean (Phaseolus vulgaris L.) containing six genes and nine quantitative trait loci (QTL) comprising resistance to one bacterial, three fungal, and two viral pathogens of bean. The mapping population consisted of 79 F5:7 recombinant inbred lines (RILs) derived from a `Dorado'/XAN 176 hybridization. There were 147 randomly amplified polymorphic DNA (RAPD) markers, two sequence characterized amplified region (SCAR) markers, one intersimple sequence repeat (ISSR) marker, two seedcoat color genes R and V, the Asp gene conditioning seed brilliance, and two rust [Uromyces appendiculatus var. appendiculatus (Pers.:Pers) Unger] resistance genes: one conditioning resistance to Races 53 and 54 and the other conditioning resistance to Race 108. These markers mapped across eleven linkage groups, one linked triad, and seven linked pairs for an overall map length of 930 cM (Kosambi). Genes conditioning resistance to anthracnose (Co-2) [Colletotrichum lindemuthianum (Sacc. and Magnus) Lams.-Scrib.], bean rust (Ur-5), and bean common mosaic virus (I and bc-3) (BCMV) did not segregate in this population, but were mapped by inference using linked RAPD and SCAR markers identified in other populations. Nine previously reported quantitative trait loci (QTL) conditioning resistance to a variety of pathogens including common bacterial blight [Xanthomonas campestris pv. phaseoli (Smith) Dye], ashy stem blight [Macrophomina phaseolina (Tassi) Goid.], and bean golden mosaic virus (BGMV), were located across four linkage groups. Linkage among QTL for resistance to ashy stem blight, BGMV, and common bacterial blight on linkage group B7 and ashy stem blight, BGMV, and rust resistance loci on B4 will complicate breeding for combined resistance to all four pathogens in this population.
Katy M. Rainey and Phillip D. Griffiths
The genetic basis for heat tolerance during reproductive development in snap bean was investigated in a heat-tolerant × heat-sensitive common bean cross. Parental, F1, F2, and backcross generations of a cross between the heat-tolerant snap bean breeding line `Cornell 503' and the heat-sensitive wax bean cultivar Majestic were grown in a high-temperature controlled environment (32 °C day/28 °C night), initiated prior to anthesis and continued through plant senescence. During flowering, individual plants of all generations were visually rated and scored for extent of abscission of reproductive organs. The distribution of abscission scores in segregating generations (F2 and backcrosses) indicated that a high rate of abscission in response to heat stress was controlled by a single recessive gene from `Majestic'. Abscission of reproductive organs is the primary determinant of yield under heat stress in many annual grain legumes; this is the first known report of single gene control of this reaction in common bean or similar legumes. Generation means analysis indicated that genetic variation among generations for pod number under heat stress was best explained by a six-parameter model that includes nonallelic interaction terms, perhaps the result of the hypothetical abscission gene interacting with other genes for pod number in the populations. A simple additive/dominance model accounted for genetic variance for seeds per pod. Dominance [h] and epistatic dominance × dominance [l] genetic parameters for yield components under high temperatures were the largest in magnitude. Results suggest `Cornell 503' can improve heat tolerance in sensitive cultivars, and heat tolerance in common bean may be influenced by major genes.
Dyremple B. Marsh, Wayne McLaughlin, and James S. Beaver
Methods to improve the grain yield of red kidney bean without the addition of commercially fixed nitrogen will have significant benefits to farmers in Jamaica and other tropical regions. Red kidney beans provide a major portion of the dietary protein for most families in these regions. Our experimental objective was to evaluate the nitrogen fixing capabilities of several breeding lines of Phaseolus vulgaris when inoculated with Rhizobium strains isolated from Jamaican soils. Surface sterilized seeds of 11 Phaseolus lines were inoculated with inoculum prepared from 5 day old Rhizobium YEM mixture. Rhizobium used were T2 and B17 from Jamaica and UMR 1889. The greenhouse study was arranged as a completely randomized design. Bean lines 9056-101, 9056-98B, 8954-5 and 8954-4 showed improved nodulation and N2 fixation when inoculated with UMR 1899. The combination of breeding line 8954-5 and Rhizobium strain B17 produced the highest nodule number and shoot dry weight of 193 and 0.72 g, respectively. The Rhizobium strain B17showed some ability to compete successfully for nodule sites against known effective strains.
J.M. Quintana, H.C. Harrison, J. Nienhuis, J.P. Palta, K. Kmiecik, and E. Miglioranza
To understand the genetics that control pod Ca concentration in snap beans, two snap bean (Phaseolus vulgaris L.) populations consisting of 60 genotypes, plus 4 commercial cultivars used as checks, were evaluated during Summers 1995 and 1996 at Hancock, Wis. These populations were CA2 (`Evergreen' × `Top Crop') and CA3 (`Evergreen' × `Slimgreen'). The experimental design was an 8×8 double lattice repeated each year. No Ca was added to the plants grown in a sandy loam soil with 1% organic matter and an average of 540 ppm Ca. To ensure proper comparison for pod Ca concentration among cultivars, only commercial sieve size no. 4 pods (a premium grade, 8.3 to 9.5 mm in diameter) were sampled and used for Ca extractions. After Ca was extracted, readings for Ca concentration were done via atomic absorption spectrophotometry. In both populations, genotypes and years differed for pod Ca concentration (P = 0.001). Several snap bean genotypes showed pod Ca concentrations higher than the best of the checks. Overall mean pod Ca concentration ranged from a low of 3.82 to a high of 6.80 mg·g-1 dry weight. No differences were detected between the populations. Significant year×genotype interaction was observed in CA2 (P = 0.1), but was not present in CA3. Population variances proved to be homogeneous. Heritability for pod Ca concentration ranged from 0.48 (CA2) to 0.50 (CA3). Evidently enhancement of pod Ca concentration in beans can successfully be accomplished through plant breeding.
Edison Miglioranza, Phillip Barak, Kenneth Kmiecik, and James Nienhuis
Soils were fertilized with gypsum (CaSO4·2H2O) at rates up to 4 t·ha-1, and Ca2+ concentrations in pods of 12 snap bean (Phaseolus vulgaris L.) cultivars were determined, with the intention of improving snap beans as a source of Ca2+ for human nutrition. The addition of gypsum to the soil did not affect the Ca2+ concentration of pods, even though Ca2+ in the soil solution increased from 4 to 15 mmol·L-1. Calcium concentrations of pods of the various snap bean cultivars ranged from 4.1 to 5.7 mg·g-1 dry mass. `Top Crop', `Astrel', `Tenderlake', and `True Blue' had the highest Ca2+ concentration in the pods and `Labrador' and `Roma II' had the lowest. The results suggest that factors other than Ca2+ supply influenced the Ca2+ concentration of the snap bean pod. Therefore, increased Ca2+ concentration of pods may be better achieved through breeding and selection rather than Ca2+ fertilization when Ca2+ levels in soil are sufficient.
Muharrem Ergun, Ellen T. Paparozzi, Dermot P. Coyne, Durward Smith, Stephen Kachman, and David S. Nuland
Seedcoat color is an important trait, as it affects marketing and consumer acceptance of pinto beans (Phaseolus vulgaris L.). Pinto breeding line NE 94-4 showed seedcoat yellowing in on-farm field trials in Nebraska in 1996 and 1997. Hail, sprinkler irrigation, and fall rainfall appeared to be involved in increasing seedcoat yellowing, based on analysis of field and weather data of on-farm trial sites. The objective of this study was to determine the effect of moisture on seedcoat yellowing of pinto line NE 94-4 (susceptible) and pinto `UI-114' (highly resistant). Two greenhouse experiments were conducted involving misting of bean plants near maturity and injecting water into maturing bean pods. Another experiment evaluated the response of seeds of these two bean entries to moisture by placing them on moist filter paper in petri dishes in the laboratory. Results showed that both genotype and moisture content are involved in seedcoat yellowing. This simple, cheap, and effective filter paper test was then used to evaluate seedcoat yellowing of nine pinto genotypes in response to moisture. Pinto NE 94-4 and `Kodiak' showed the greatest change, while `Bill Z' showed the least change, in seedcoat color.
Scott D. Haley, Phillip N. Miklas, Lucia Afanador, and James D. Kelly
the grant DAN 1310-G-SS-6008-00 from the USAID Bean/Cowpea Collaborative Research Support Program, the Michigan Agricultural Experiment Station, and the USDA-ARS. Mention of a trademark or a proprietary product does not constitute a guarantee or
Mark J. Bassett
Linkage relationships between the locus for shiny pods (ace) and the loci for reclining foliage (rf) and pink (v lae) or white (v) flower color were studied in several crosses among common bean (Phaseolus vulgaris L.) parents. Florida dry bean breeding line 5-593 (Ace Rf V.) was crossed with F3 ace/ace Rf/rf V/v lae, and data were taken in F2. Selections from the previously mentioned F2, viz., F3 ace Rf V, F3 ace rf v lae plant no. 1 and F3 ace rf v lae plant no. 2, were backcrossed to 5-593. Data were taken in F2 on segregation for pod, foliage, and flower characters. Linkage between Ace and V was 37 map units (cM), and linkage between Ace and Rf was 31 cM. A revised estimate for the linkage between Rf and V was 11 cM. The map orientation for linkage group VII is ace -31-rf-11-V.