High temperatures (>30°C day and/or >20°C night) in tropical lowlands and production areas in temperate zones reduce yield and quality in common bean (Phaseolus vulgaris L.). Tepary bean (P. acutifolius A. Gray) is a crop adapted to hot arid climates and is grown in the American Southwest and parts of Mexico under temperatures that are too high for pod formation in common bean. Interspecific hybridization may enable transfer of heat tolerance traits from tepary bean to common bean. Twenty-five tepary bean plant introductions (PI) with the ability to set seed under controlled-environment conditions were evaluated under high (35 °C day/32 °C night) and control (27 °C day/24 °C night) temperature treatments during reproductive development. Four accessions (PI 200902, PI 312637, PI 440788, and PI 440789) exhibited normal pod formation and comparatively high yield when exposed to high temperature, while common bean controls displayed zero pod and seed set. These four PIs showed a mean decrease in seed yield of 72.9% from control to high temperature treatment, as compared to 90.3% among all tepary beans. These accessions were hybridized with the dry bean cultivar `ICA Pijao', and the heat-tolerant bean cultivars `Carson' and `CELRK' and breeding line `Cornell 503'. Immature embryos were cultured to obtain interspecific hybrids. Fertility of F1 hybrids and generation of backcrosses are discussed.
Katy M. Rainey* and Phillip D. Griffiths
N. Guner and J.R. Myers
Plant breeders are interested in developing upright common beans (Phaseolus vulgaris L.) to reduce diseases and permit mechanical harvest, and improve seed quality. Morphological and genetic characteristics of an architectural mutant in common beans were studied. The mutant had shiny, dark green leaves, overlapping leaflets, and short petioles. Branching was nearly absent, resulting in single stemmed plants. Although mutant plants carried Fin for indeterminacy, and plants progressed in flowering from lower to higher nodes, the terminal node was reproductive. This represents a new form of determinacy in common bean. Inheritance studies demonstrated that the mutant syndrome was controlled by a single recessive gene. Allelism tests between the mutant and overlapping leaflets (ol), and dark green savoy leaf (dgs) showed that the mutant was not allelic to either locus. The trait was designated as Topiary with the gene symbol top, describing its compact and neat appearance. Linkage was tested between top and growth habit (fin), shiny leaves, cross-sectional shape of pods, striped pod (C prpst), and pod suture strings. All genes segregated independently. The genetic merit of the Topiary mutant for improving common beans needs to be investigated, especially the value of single stem growth habit combined with an upright plant habit.
F.A. Bliss, J.C. Rosas, and P.A.A. Pereira.
The discovery of bruchid resistance in wild beans and the demonstration that theArcelin protein is responsible for the resistance, provide an opportunity to develop resistant cultivars of common bean, Phaseolus vulgaris L. Arcelin expression is controlled by multiple alleles, which impart different levels of insect resistance. In field tests in Honduras and Brazil, backcross-derived lines with the Arl-1 allele were most resistant, especially to Mexican bean weevil. Seed mixtures of 0.80 Arl-1:0.20 susceptible and equal amounts of Arl-1,Arl-2, and Arl-3, and Arl-4 containing seeds showed resistanc elevels and seed yields similar to lines homogeneous for Arl-1. Breeding lines uniform for appearance and agronomic performance, but heterogenous for resistance genes are being tested as potential new dry bean cultivars having stable insect resistance.
Maria G. Janssen and Albert H. Markhart III
Tepary beans (Phaseolus acutifolius Gray) are more drought tolerant and have stomata that are more sensitive to low leaf water potentials (ψ w) than common beans (P. vulgaris L.). This study was designed to examine the role of ABA in controlling stomatal behaviour in these species. Comparison of the bulk leaf ABA content does not explain why tepary stomata are more sensitive to low leaf ψ w compared to common bean (at -1.4 MPa ABA content increased 40-fold in common bean and 25-fold in tepary). We hypothesize that the greater sensitivity of tepary stomata to low leaf ψ w is related to a higher concentration of ABA in the xylem sap, and/or to a greater sensitivity of tepary stomata to ABA. Xylem sap of well-watered and water stressed plants is analyzed to determine the concentration of ABA, and whether ABA is a putative candidate serving as a chemical root signal in response to water stress in Phaseolus. To test stomatal sensitivity to ABA, epidermal strips and detached leaves are exposed to a range of ABA concentrations. The relationship between stomatal aperture and different ABA concentrations is discussed.
C.A. Strausbaugh, J.R. Myers, R.L. Forster, and P.E. McClean
ELISA samples. We also acknowledge Jeff Prischman for technical assistance and M. Silbernagel and P. Berger for critical review of this manuscript. This research contributed to W-150 regional project objectives and was supported by the Idaho Bean
A. Dursun, D.P. Coyne, M.F. Mohamed, and G. Jung
Common bacterial blight, incited by the bacterium Xanthomonas campestris pv. phaseoli (Xcp), is a serious disease of common beans [Phaseolus vulgaris (P. v.)]. Some tepary beans (P. acutifolius) are resistant (R) to Xcp and used to breed P. v. with R to Xcp. The objective was to determine the inheritance of the reaction to different strains of Xcp in crosses between susceptible (S) and R tepary lines. The parents, F2, and F3 populations from six tepary crosses involving 3 R × S, 1 R × moderately (M) R, and 2 R × R were inoculated with Xcp strains EK-11, LB-2, and SC-4A. Different single dominant genes controlled the reaction to different Xcp isolates in R × S crosses. Coupling linkage was detected between the genes controlling the reactions to each of the Xcp strains in the crosses NE #4B(s) × NE #19(R) and NE #4B(S) × CIAT-640005(R), except for NE #8A(MR) × NE #4B(S) with strains EK-11 and LB-2 and EK-11 and SC-4A. Transgressive segregation for S was observed in the F2 and F3 NE #8A × NE #8B(R), indicating that the parents possessed different genes for R. No segregation for reactions occurred n the F2 NE #8B × NE #19 and NE #19 × CIAT-640005, indicating that these parents possessed the same genes for R to the three strains.
Bean common mosaic necrosis virus (BCMNV) includes four African strains, BCMNV-NL3, -NL-5, -NL8, and -TN1, previously considered to be members of the bean common mosaic virus (BCMV) group. Many bean cultivars resistant to BCMNV-NL8 were found to be susceptible to the other strains of the virus. `California Light Red Kidney' (CLRK) and `Carbon', resistant to BCMNV-NL8, were crossed with the susceptible cultivars Sanilac or Black Turtle 2 (BT-2). In plants of F1, F2, and reciprocal backcross populations involving CLRK × `Sanilac' or BT-2 × `Carbon', the resistance to BCMVN-NL8 was determined to be conferred by a single dominant factor. The same factor was detected in BCMNV-NL8-resistant `Great Northern 1140' and `IVT-7214, when crossed with the susceptible cultivar Stringless Refugee or BT-2.
Geunhwa Jung, Paul W. Skroch, Dermot P. Coyne, James Nienhuis, E. Arnaud-Santana, H.M. Ariyarathne, Shawn M. Kaeppler, and Mark J. Bassett
Published as Nebraska Agricultural Research Division journal series paper no. 11460. Research was conducted under projects 20-036 and 20-042. We acknowledge financial support from the Title XII Bean/Cowpea CRSP (AID contract no. DNA-1310-G-SS-6008
H.M. Ariyarathne, D.P. Coyne, G. Jung, P.W. Skroch, A.K. Vidaver, J.R. Steadman, P.N. Miklas, and M.J. Bassett
, Lincoln, Agricultural Research Division, journal series paper no. 12205. Research was conducted under Title XII Bean/Cowpea CRSP Project, Univ. of Nebraska, Lincoln, Univ. of Puerto Rico, Mayaguez, Ministry of Agriculture, and Dominican Republic under AID
Mark J. Bassett and Mathias J. Silbernagel
Dry seed of the common bean (Phaseolus vulgaris L.) breeding line S-593 was treated with 200 Gy of gamma radiation, and M2 seed was produced. The seed was planted at Prosser, Wash., and selection was made for plants with greatly reduced seed set. The inheritance of one of the selections for possible male sterility mutation was studied in F2, F3, and backcross generations. This character is controlled by a single recessive gene, for which the symbol ms-1 is proposed. Plants carrying ms-l/ms-1 produce well-filled pods after manual pollination with pollen from normal plants, but produce no seed when protected from insect pollination in greenhouse and field environments. Uses for this mutant are discussed.