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- Author or Editor: Mark J. Bassett x
Linkage between the Fin locus controlling plant habit and the Z locus controlling partly colored seedcoats in common bean (Phaseolus vulgaris L.) was studied in the F2 and F3 progenies from the cross `t virgarcus BC3 5-593' (determinate habit, virgarcus pattern of partly colored seeds, fin tz) × `Steuben Yellow Eye' (indeterminate habit, sellatus pattern of partly colored seeds, Fin t z sel). The heterozygous genotype z sel/z produces the piebald pattern of partly colored seeds, whereas Fin is completely dominate to fin. Selection was made in the F2 for crossover phenotypes: indeterminate habit with virgarcus seeds or determinate habit with piebald seeds. Linkage calculations were based on crossover genotypes confirmed by F3 progeny tests grown in the greenhouse. The recombination percentage between Fin and Z was 1.032±0.33 map units. The gene symbol z sel is proposed, where t Z gives the expansa partly colored seedcoat pattern, t z sel gives sellatus, and t z gives virgarcus.
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.
The inheritance of hilum ring color in common bean (Phaseolus vulgaris L.) was investigated using various genetic tester stocks developed by backcrossing recessive alleles into a recurrent parent stock 5-593 with seedcoat genotype P [C r] D J G B V Rk, viz., mar BC2 5-593, mar BC3 5-593, mar v BC2 5-593, mar d BC2 5-593, and mar d BC3 5-593. The current hypothesis is that the margo character is controlled by mar and hilum ring color is controlled by d but expresses only with mar. The V locus controls flower and seedcoat color. The allelism test crosses `Citroen' (P C d j g b v lae) × mar BC3 5-593 and `Citroen' × mar d BC3 5-593 demonstrated that mar is allelic with j and that the putative d in mar d BC3 5-593 is allelic with the d in `Citroen'. Thus, the former genetic tester stocks mar BC3 5-593 and mar d BC3 5-593 are reclassified as j BC3 5-593 and d j BC3 5-593, respectively, because mar is a synonym for j. Similarly, the former genetic tester stock mar v BC2 5-593 is reclassified as j v BC2 5-593. The interaction of j with d expresses as loss of color in the hilum ring. The development of the white-seeded genetic tester stock P c u d j BC3 5-593 was described in detail, where the all-recessive tester `Prakken 75' was used as the source of the recessive alleles. The previously reported work showing that the partly colored seedcoat gene t interacts with mar to control seedcoat pattern is now interpreted to mean that the joker (J) locus interacts with t to produce partly colored seedcoat patterns. The genetic loci D and V were found to segregate independently. The common gene for dull seedcoats (asper, asp) is discussed and contrasted with j.
In strain gauge tests of sieve size 4 pods of snap bean (Phaseolus vulgaris L.), ‘Idelight’ and ‘Green Isle’ required the lowest pod detachment force (PDF) of 13 genotypes tested.
Common bean (Phaseolus vulgaris L.) genotype, MITA 10597, has small seeds (
The inheritance of novel flower and seedcoat patterns was studied in three parental materials: PI 390775 and `Springwater Half Runner' (SHR), which have patterned flower and seedcoat colors, and 5-593, a Florida dry bean breeding line with unpatterned purple flowers and seeds. Using crosses between 5-593 and the other two parents, an analysis of F1, F2, backcross F2, and backcross F3 data demonstrated that a single recessive allele in each of the patterned parents controlled flower and seedcoat pattern. Genetic tester stocks were used to demonstrate that the recessive gene for patterning in PI 390775 was nonallelic with C, T, and Mar, the three genes previously known to control seedcoat pattern in common bean. An allelism test between the recessive pattern genes from PI 390775 and SHR demonstrated that they were allelic and that the gene from SHR was dominant. The gene symbols stp (for the gene from PI 390775) and stp hbw (for the dominant gene from SHR) are proposed, where stp stands for stippled seedcoat pattern and the superscript letters hbw stand for half banner white.
A mutation for blue (methyl-violet) flower color was induced by gamma irradiation of dry seed in common bean (Phaseolus vulgaris L.). Inheritance and allelism tests demonstrated that the mutation is controlled by a single recessive gene that is not allelic with Sal or V. The gene symbol blu is proposed for this mutant. Linkage was detected between blu and Fin, which controls the change from indeterminate to determinate plant habit. Three linkage estimates ranged from 19 to 35 cM, but the large variability (homogeneity x 2 = 45.32) precludes making a conclusive combined estimate of linkage. The tentative combined estimate of linkage is 27 cM.
The P locus in common bean (Phaseolus vulgaris L.) can express complete absence of color (white) in seedcoats and flowers with p (with B V) or a pale grayish white seedcoat and nearly white flower with p gri, but P has never been considered a seedcoat pattern locus. Genes controlling seedcoat colors and patterns have been backcrossed into the recurrent parent 5-593 with black seedcoats and violet flowers. The cross, p BC3 5-593 × t stp mic BC3 5-593 (black seeds with a long white micropyle stripe and fibula arcs), failed to show evidence of genetic complementation in either F1 or F2 progeny, leading to the hypothesis that P and Stp are allelic. Five cross combinations between two recessive P alleles (p BC3 5-593 and p gri BC3 5-593) and three recessive alleles at the stippled seedcoat gene Stp (stp BC3 5-593, stp hbw BC3 5-593, and stp mic BC3 5-593) expressed no genetic complementation in seedcoats and flowers of F1 progeny and confirmed the allelism hypothesis. New gene symbols are proposed for the recessive alleles at Stp, viz., p stp for stp, p hbw for stp hbw and p mic for stp mic. The dominance order at P is P > p mic > p hbw > p stp > p gri > p. Crosses were made between t self-colored BC3 5-593 and three other parents—p stp BC3 5-593, p hbw BC3 5-593, and p mic BC3 5-593—to explore interactions between the pattern genes T and P; and segregation for seedcoat patterns in F2 was discussed. The hypothesis was proposed that the T locus regulates expression at P, or the biosynthetic step regulated by P.
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.
The inheritance of intensified anthocyanin expression (IAE) in a syndrome of plant organs of common bean (Phaseolus vulgaris L.) was investigated. A selection from accession line G07262, having white flowers with blue veins on the wing petals and a long, white micropyle stripe on black seedcoats, was used as the source of IAE syndrome. G07262 was crossed with three genetic tester stocks based on Florida dry bean line 5-593, which has the flower and seedcoat genotype T P [C r] Z J G B V Rk. The tester stocks were 5-593 (black seed and bishops violet flowers), t z bip bipunctata BC1 5-593 (a partly colored seedcoat), and v BC2 5-593 (mineral brown seedcoat and white flowers). Analysis of the F1 and F2 data from the test cross G07262 × t z bip bipunctata BC1 5-593 demonstrated that 1) G07262 has genotype t p mic V; 2) genotype t/t prevents expression of IAE syndrome by a dominant gene (Prp i -2) carried cryptically by G07262, i.e., T/-is required for expression of the gene; and 3) Prp i -2 may (preliminary data) express blue veins on white flowers with t V. From the cross with v BC2 5-593, an F4 selection for white flowers with red banner back and mineral brown seedcoats (due to v) was made. When the F4 selection was crossed with 5-593, analysis of the F2 progeny demonstrated that G07262 carries a dominant gene for IAE syndrome, which expresses with V/- but not with v/v. From the test cross 5-593 × G07262, a series of additional cycles of selection and test crosses (including the dark red kidney tester c u b v rk d BC1 5-593) were made, and two new two-colored seedcoat patterns were developed that have never been previously reported. In a test cross with one of them, F2 data demonstrated that the dominant gene for IAE syndrome from G07262 is independent of the C locus, and the gene symbol Prp i -2 is proposed for this IAE syndrome gene to distinguish it from the previously reported IAE syndrome gene [c u Prp i]. A gene symbol reconciliation was made for all previous work with inheritance of IAE syndrome and purple pod genes without the syndrome.