Common bacterial blight (CBB), incited by Xanthomonas campestris pv. phaseoli (Xcp), is an important disease of common bean (Phaseolus vulgaris L.). Tepary bean (P. acutifolius A. Gray) is of interest to bean breeders because of resistance to CBB. The objective was to identify RAPD markers linked to major dominant genes for CBB resistance and purple flower color using bulked segregant analysis in an F2 population from a tepary bean cross Nebr#19 [resistant (R) to CBB and white flower color] × Nebr#4B [susceptible (S) to CBB and purple flower color]. Ten RAPD primers (600 RAPD primers screened) showed polymorphisms between bulked DNA derived from R and S plants. All markers showed coupling linkage with CBB resistance. The RAPD marker of G-14 primer was 5.2 cM distant from the gene for resistance to Xcp strain LB-2. The RAPD marker of L-18 primer was 6.8 cM distant from the gene for resistance to Xcp strain SC-4A. The RAPD marker of G-14 primer was 26.2 cM distant from the gene for resistance to Xcp strain EK-11. Seven RAPD primers showed polymorphisms between bulked DNA derived from purple and white flower plants. All markers showed coupling linkage with the gene for purple flower color. The RAPD marker of Y-6 primer was 3.6 cM distant from the gene for purple flower color.
S.O. Park, A. Dursun, and D.P. Coyne
D. P. Coyne, E. Arnaud-Santana, J. Beaver, and H. Zaiter
Some dry bean lines (L) Phaseolus vulgaris resistant (R) (compatible reaction) to Xanthomonas campestris var. phaseoli (Xpc) developed in the temperate zone express susceptibility (S) in the field in the tropics and tropical lines (S) express moderate R in the temperate zone. There is only limited information on the influence of P on Xpc reaction in dry beans. Experiments were conducted in growth chambers (GC) and in the field (NE, Dominican Republic, Puerto Rico) to investigate the influence of P and P × temperature (T) on the reaction of L to Xpc. A split-plot design was used with T as the main-plots and P and L as sub-plots in the GC experiment and with P as main-plots and L as sub-plots in the field experiments. The disease reactions were more severe on L under short P and under higher T than under shorter P and lower T. No interactions were detected among these treatments. PC-50 showed moderate R, delayed flowering, flower bud abortion, and increased branching under long P (field, NE). These results have implications for breeders in the evaluation of field R of L from different latitudes and for their value in breeding.
D.P. Coyne, J.M. Reiser, Lisa Sutton, and Alice Graham
J.W. Gonzales, D.P. Coyne, D.T. Lindgren, D. Schaaf, and K. M. Eskridge
The potato leafhopper (PLH), Empoasca fabae Harris is the most important Empoasca species attacking dry beans (Phaseolus vulgaris L.) in North America. The objective of this study was to determine the heritability (h2) of PLH injury based on parent-offspring regression analysis of F3 means on individual F2 plants derived from crosses of pinto `Sierra' (resistant) × great northern `Starlight' (susceptible), and black bean `Tacarigua' (resistant) × `Starlight' (susceptible). Low narrow-sense heritability values of 0.29 ± 0.06 and 0.28 ± 0.10, respectively, were obtained for the above crosses. The low narrow-sense heritability estimates indicated large environmental effects on the expression of PLH injury in dry beans. An allelic test showed that both resistant parents possessed the same genes for resistance.
D. S. Nuland, D. T. Lindgren, D. P. Coyne, and J. R. Steadman
The objective of this cooperative system is to establish reaction of both private and public developed dry beans to common blight, rust, and white mold as well as to document performance in the absence of disease constraints. All commercially available Great Northerns and Pintos plus entries from the Cooperative Dry Bean Nursery and selected entries from public and private breeding programs are included. Entry number ranges from 70 to 80 each year. Annual results are published in “Biological and Cultural Tests for Control of Plant Diseases”.
D.P. Coyne, J.R. Steadman, D.T. Lindgren, and D.S. Nuland
D.P. Coyne, D.S. Nuland, D.T. Lindgren, and J.R. Steadman
J.M. Bokosi, D.P. Coyne, J.R. Steadman, D. O'Keefe, and J. Reiser
The inheritance of specific resistance (SR) and foliar abnormalities (FA) were studied in the F2 and F3 progeny of the following crosses; `PC-50' × Chichara 83-10, `PC-50' × `EZ Pick', A-10-2 × GN `Beryl', and A-10-2 × P114. A single dominant gene controlled SR to rust strain US85NP10-1 in `PC-50' × Chichara 83-10. Duplicate recessive genes determined foliar crippling (FC) in `PC-50' × Chichara 83-10 and A-10-2 × P114. The inheritance of hybrid plant abnormality in `PC-50' × `EZ Pick' and A-10-2 × GN `Beryl' differed from previously reported complementary dominant genes or duplicate recessive genes. Foliar variegation (FV) was controlled by duplicate recessive genes in `PC-50' × Chichara 83-10 and by triplicate recessive genes in `PC-50' × `EZ Pick', A-10-2 × GN `Beryl', and A-10-2 × P114. No associations were detected between SR and FC, SR and FV, or FC and FV.
J.M. Bokosi, D.P. Coyne, E. Arnaud-Santana, J.R. Steadman, and D. O'Keefe
An association between abaxial leaf pubescence (ALP) and adult plant resistance (APR) on trifoliolate leaves was reported previously. Recombinant inbred (RI) lines from crosses PC-50 (P1) with XAN-159 (P2) and BAC-6 (P3), and P3 with HT7719 (P4) were used to study the inheritance of specific resistance (SR), APR and ALP. P1 is resistant to A88TI-4b and has abaxial hairs on the trifoliolate leaves while P2, P3, and P4 are all susceptible (S) and have glabrous (G) leaves. P3 is resistant to D85C1-1. SR to A88TI-4b on primary leaves (PL) was determined by a single dominant gene with an additional dominant gene for APR on the 4th trifoliolate leaves in P1 × P2. ALP was governed by a single dominant gene with no association with APR. SR to A88TI-4b on PL in P1 × P3 was controlled by a single dominant gene. SR to DC85C1-1 on the PL was determined by a single dominant gene in P3 × P4.
J. M. Bokosi, D. P. Coyne, J. R. Steadman, and D. O'Keefe
Twenty-four diverse bean (Phaseolus vulgaris L.) lines (Malawi) derived from single plant selections from landraces were evaluated for bean rust (Uromyces appendiculatus) resistance and leaf pubescence in the greenhouse (NE). A randomized complete block design was used. Each line was inoculated on the primary leaf (35-60% leaf expansion) 7 days after planting and on the 4th trifoliolate leaf (10-20% leaf expansion) with two rust strains, D82VC74fh(Dominican Republic) and A88TI-20a (Tanzania). Rust uredinia size was recorded on the 14th day after inoculation. Three lines, `Nasaka', 16-6, and `Kamtsilo' had specific resistance (SR) to one or the other of the strains but none to both strains. Many lines were susceptible on the primary leaves but had moderate to highly resistant reactions on the 4th trifoliolate leaves indicating adult plant resistance (APR). APR was the main type of rust resistance for most of these 24 lines. Many of these APR lines were glabrous. No association was observed between APR and pubescence.