Commercial pea (Pisum sativum L.) cultivars, plant introduction (PI) lines, and Oregon State Univ. (OSU) breeding lines were tested for resistance to pathotype P2 (lentil strain) and pathotype P1 (type strain) of pea seedborne mosaic virus (PSbMV) and to bean yellow mosaic virus (BYMV) to assess the relative proportion of resistant and susceptible pea genotypes. Of the 161 commercial cultivars tested, 117 (73%) were resistant and 44 were susceptible to PSbMV-P2. Of these PSbMV-P2-resistant cultivars, 115 were tested for resistance to BYMV and all were resistant. Of the 44 PSbMV-P2-susceptible cultivars, 43 were tested for BYMV susceptibility and all were infected except two, `Quincy' and `Avon', both of which were susceptible to a BYMV isolate in another laboratory. Of 138 commercial cultivars inoculated with PSbMV-P1, all were susceptible. All PI lines and OSU breeding lines that were resistant to PSbMV-P1 were resistant also to PSbMV-P2. The high percentage of commercial cultivars resistant to PSbMV-P2 was probably attributable to the close linkage of genes sbm-2 and mo and the widespread use by breeders of BYMV-resistant `Perfection' and `Dark Skin Perfection' in developing new pea cultivars. Segregation ratios in progenies of three separate crosses between PSbMV-P2-resistant and PSbMV-P2-susceptible cultivars closely fit the expected 3 susceptible: 1 resistant ratio expected for resistance conferred by a single recessive gene.
K. Kasimor, J.R. Baggett, and R.O. Hampton
Adrienne E. Kleintop, James R. Myers, Dimas Echeverria, Henry J. Thompson, and Mark A. Brick
, 2009 ). The identification of snap bean cultivars with high levels of TPC may be useful for breeding cultivars with high antioxidant potential. Different strategies to develop high TPC cultivars would have to be pursued for processed vs. fresh market
Rie Sadohara, James D. Kelly, and Karen A. Cichy
are extensively studied for breeding this market class ( Kato, 2000 ; Komiyama and Kato, 2004 ; Komiyama, 2013 ). Important bean paste qualities include paste yield, whiteness, stickiness, smoothness, and flavor, described in detail by Sadohara
Mark J. Bassett
Common bean (Phaseolus vulgaris L.) seedcoats can have partly colored patterns such as the new two-points pattern, which has an unknown genotype. The gene t cf (derived from PI 507984) expresses partly colored seedcoat pattern with colored flowers. A genetic tester stock t cf two-points BC3 5-593 was derived from PI 507984 by backcrossing to the recurrent parent, Florida dry bean breeding line 5-593, which has black self-colored seeds and purple flowers due to the genotype T P V. A series of test crosses were made between t cf two-points BC3 5-593 and three genetic tester stocks: t z j ers white BC3 5-593, t z bip bipunctata BC3 5-593, and t z virgarcus BC3 5-593. All three test crosses were studied in F1 and F2 populations, and the latter test cross in F3 progenies derived from 80 randomly selected F2 plants. The two-points pattern was never observed with white flower plants expressed by t/t, supporting the hypothesis that tcf is necessary for two-points expression. The complete genotype for two-points was found to be t cf z j ers. The t cf gene expresses more extensive colored zones in partly colored seedcoats than t. For example, t cf z J expresses self-colored seedcoats, whereas t cf/t z J expresses white ends pattern and t z J expresses virgarcus. Similarly, the t cf z j ers genotype expresses two-points pattern, whereas t z j ers expresses white seedcoat; and t cf/-z J/j ers expresses PI type pattern, whereas t z J/j ers expresses weak virgarcus pattern.
Soon O. Park, Dermot P. Coyne, Nedim Mutlu, Geunhwa Jung, and James R. Steadman
Agricultural Research Division journal series paper 12097. Research was conducted under Projects 20-036 and 20-042. We acknowledge financial support from the Title XII Bean/Cowpea CRSP (AID contract DNA-1310-G-SS-6008-00). We also appreciate Anne K. Vidaver
Mark J. Bassett, Rian Lee, Tim Symanietz, and Phillip E. McClean
Two common bean (Phaseolus vulgaris L.) genes, J (modifies seedcoat color and pattern) and L (modifies partly colored seedcoat pattern), were tested for allelism using genetic tester stocks. Those stocks have a common genetic background by backcrossing to the recurrent parent, Florida dry bean breeding line 5-593, that has black self-colored seeds and purple flowers due to the genotype T P [C r] Z J G B V Rk. Specifically, the L gene from `Thuringia' and the lers gene from `Early Wax' were tested for allelism with the j gene from various genetic tester stocks. L was found to be identical with j, but l ers was a different allele at J. We propose the gene symbols J (formerly l), j (formerly L), and j ers (formerly l ers). The seedcoat genotype of `Thuringia' was found to be t P C z j g b v lae rk d. A new seedcoat pattern called reverse margo was found to be determined by the genotype T/t z/z j/j ers in a P C G B V genetic background. A randomly amplified polymorphic DNA marker was developed for the j gene (formerly L) from `Thuringia' using bulk segregant analysis in an F2 population segregating for j vs. J in a t z genetic background, i.e., from the cross t z j × t z J in BC1 to 5-593. The linkage distance between marker OL4525 and j was determined to be 1.2 cM. In a population segregating for J and j ers, the distance between the marker and j ers was determined to be 4.7 cM. The utility of marker OL4525 is limited primarily to the Middle American gene pool.
Mark J. Bassett, Lee Brady, and Phil E. McClean
Common bean (Phaseolus vulgaris L.) plants with partly colored seeds and colored flowers were derived from PI 507984 in two genetic tester stocks, `2-points t cf BC1 5-593' and `2-points t cf BC2 5-593'. These stocks were produced by backcrossing to the recurrent parent, Florida dry bean breeding line 5-593, which has black self-colored seeds and purple flowers due to the genotype T P V. The crosses `2-points t cf BC1 5-593' × 5-593 and `2-points t cf BC2 5-593' × 5-593 produced F2 populations in which all plants had colored flowers. Those results, when considered with previously published work, do not support the previously reported hypothesis that the genes t Fcr Fcr-2 produce partly colored seedcoats and flower color restoration with t. The crosses `2-points t cf BC1 5-593' × `self-colored t BC2 5-593' and `2-points t cf BC2 5-593' × `minimus t BC3 5-593' produced F2 populations that segregated 3:1 for colored:white flowers, respectively. Those results are consistent with the revised hypothesis that t cf can produce partly colored seedcoats without affecting flower color. The RAPD marker OM19400, which is linked in repulsion to T, was used with the F2 populations from the crosses `2-points t cf BC2 5-593' × 5-593 and `2-points t cf BC2 5-593' × `minimus t BC3 5-593' and established that the t cf gene from PI 507984 is either an allele at T or tightly linked to T. F3 data from the cross `2-points t cf BC2 5-593 × 5-593 also support the t cf hypothesis. On the basis of the above experiments, the gene symbol t cf is proposed for an allele at T that pleiotropically produces partly colored seeds and colored flowers.
Mark J. Bassett and Phillip N. Miklas
Among light red and dark red kidney common bean (Phaseolus vulgaris L.) varieties, pink seedcoat color (light red kidney) is dominant to dark red, but when Red Mexican varieties (with dark red seedcoats) are crossed with dark red kidney varieties, dark red seedcoat is dominant to the pink segregants observed in an F2 population. A genetic investigation of this reversal of dominance was performed by making crosses in all combinations among standard varieties of the four recessive-red market classes—Light Red Kidney `California Early Light Red Kidney', Pink `Sutter Pink', Red Mexican `NW 63', and Dark Red Kidney `Montcalm'—and observing segregation for seedcoat colors in F2 and F3 progenies. The data were consistent with the hypothesis that `NW 63' carries a new allele at Rk, viz., rk cd, where cd stands for convertible dark red kidney. Thus, C rk cd expresses dark red kidney seedcoats and c u rk cd expresses pink seedcoats. Also, C B rk cd expresses garnet brown seedcoats, whereas C B rk d expresses liver brown seedcoat color. Thus, we propose the gene symbol rk cd for the Rk locus gene in `NW 63'. The rk gene from Light Red Kidney `Redkloud' and `Sutter Pink' was backcrossed (with c u b v) into the recurrent parent 5-593, a Florida dry bean breeding line with seedcoat genotype P [C r] J G B V Rk. In the F2 progenies of BC2 to 5-593, the c u b v rk segregants from `Redkloud' gave true pink seedcoats, whereas those derived from `Sutter Pink' gave consistently very weak pink color under humid Florida growing conditions. We propose the gene symbol rk p, where p stands for pale pink, for the distinctive rk allele in `Sutter Pink'. The more general implications of the above findings were discussed.
Mark J. Bassett
Plant Introduction (PI) accession 507984 of common bean (Phaseolus vulgaris L.) has partly colored seed coats and either pure white flowers or light laelia flowers. Crosses were made with white-flowered plants of PI 507984: white-flowered plant #1 × the genetic stock t ers ers2 BC2 5-593 and white-flowered plant #2 × recurrent parent dry bean breeding line 5-593. Inheritance was studied in the F1, F2, and F3 of the former cross and the F1 and F2 of the latter cross. PI 507984 (white flower, plant #1) × t ers ers2 BC2 5-593 gave F1 plants with colored flowers and partly colored seeds. The F2 gave a 9:7 segregation ratio (colored flowers to white flowers), and the genetic model proposed is that flower color is restored in the presence of t/t by two complementary genes, Fcr and Fcr-2. That model was confirmed by F3 progeny tests of 21 F2 parents with colored flowers. The cross PI 507984 (white flower, plant #2) × 5-593 gave an F2 segregation ratio of 9:3:4 (bishops-violet: light laelia: white flowers), indicating that the white-flowered PI 507984 has v lae masked by t. Analysis of all the data suggests that PI 507984 is heterogeneous at Fcr and Fcr-2, having all three possible homozygous genotypes, viz., either light laelia flowers from v lae t Fcr Fcr-2 or white flowers from v lae t Fcr fcr-2 or v lae t fcr Fcr-2. The flower color restoration gene in 5-593 is arbitrarily assigned the symbol Fcr. Great variability occurs in partly colored seeds of PI 507984 due to the environment in which the seed was produced.
James D. Kelly and Veronica A. Vallejo
constructive comments during the preparation of this manuscript. Support from the USAID Bean/Cowpea Collaborative Research Support Program grant DAN 1310-G-SS-6008-00 and the Michigan Agricultural Experiment Station is recognized.