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Open access

Nicolas E. Valladares-Sanchez, Dermot P. Coyne, and M. L. Schuster

Abstract

The leaf and pod reactions of greenhouse-grown plants of reportedly tolerant lines of P. vulgaris L.: Plant Introduction (PI) 169727, PI 197687, PI 163117, PI 207262, PI 325684, PI 325691, ‘Great Northern Nebr. #1 sel. 27’; P. coccineus: PI 165421 and P. acutifolius: Tepary (Nebr. Acc. 10) to Xanthomonas phaseoli (E. F. Smith) Dowson isolates [Xp-S and Xp 816 (Nebr.), Xp-15 (Michigan), Xp-Br (Brazil)], and X.p. fuscans (Burkh.) Starr & Burk. [Xpf-UI (Uganda)], were studied. The multiple needle method was used to inoculate leaves and a dissecting needle was used to inoculate pods of these plants. A differential reaction of lines to isolates was observed for each of the reactions on leaves and pods. All P. vulgaris lines were susceptible or moderately susceptible to the new virulent Xp-Br strain. Leaves and pods of P. acutifolius were highly tolerant to all isolates while P. coccineus PI-165421 showed a differential reaction to all isolates: leaves were highly tolerant and pods highly susceptible. The internal reaction for pods was more severe than the external reaction. P. vulgaris PI 207262 showed a uniform tolerance of leaf and pod to the USA isolates, while ‘GN Nebr. #1 sel. 27’ had a tolerant leaf and susceptible pod. These results suggested differential genetic control of pod and leaf reactions. Transgressive segregation for a high level of leaf tolerance to the virulent Xp-Br strain (water soaking method of inoculation) was observed in field-grown P. vulgaris F2 plants from the crosses ‘GN Nebr. #1 sel. 27’ × PI 163117 and ‘GN Nebr. #1 sel. 27’ × ‘Guali’. Transgressive segregation was confirmed in greenhouse-grown selected F3 families. High leaf tolerance was not associated with pod tolerance. Linkage was detected among the major genes controlling late maturity and indeterminate plant habit, and the polygenes controlling common blight tolerance.

Open access

Safi S. Korban, Dermot P. Coyne, and John L. Weihing

Abstract

A Hunter Color Difference meter and a white-paint color chart were used to determine the degree of whiteness among 8 white-seeded Great Northern (GN) cultivars of Phaseolus vulgaris. A correlation coefficient of +0.84 was found between the 2 methods. The former method provided better separation of cultivars for degrees of whiteness than the latter method. Two genetic studies were conducted, with seed-coat whiteness determined by use of the white-paint color strip. ‘GN Emerson’ had the whitest seed-coat. The inheritance of seed-coat whiteness was investigated in 1978 using parents, F2s of the crosses Plant Introduction (PI) 165078 (bright white) with ‘GN Emerson’ (moderately bright white), ‘GN Valley’ (dull white) and ‘GN UI 59’ (dull white) and in the reciprocal cross ‘Bulgarian White’ (brightest white) × ‘GN UI 59’ (dull white). A quantitative pattern of inheritance was observed. Broad sense heritability estimates for this trait ranged from 46 to 57%. The Gardner and Eberhart model, Analysis II, was used in 1979 to estimate genetic effects for the trait in a 6 parent diallel cross involving ‘GN Emerson’, ‘GN UI 59’, ‘Bulgarian White’, ‘GN Star’ (dull white), ‘GN 1140’ (dull white) and ‘GN D-88’ (dull white). Additive genetic effects were predominant; but heterosis effects were also important, including significant effects for specific combining ability, and reciprocal crosses. ‘Bulgarian White’ showed high combining ability for brighter whiteness. The genetic data indicate that improvement of seed-coat whiteness in dry beans should be relatively easy to accomplish.

Free access

Oğuz Top, Cantuğ Bar, Bilal Ökmen, Duygu Yüce Özer, Dane Rusçuklu, Nilüfer Tamer, Anne Frary, and Sami Doğanlar

WAOX activity than S. lycopersicum. Moreover, 20% of the population had significantly higher activity than both parents indicating substantial transgressive segregation for this trait. WAOX activity of fruit from the S. pimpinellifolium accession

Free access

Samuel F. Hutton, Jay W. Scott, and Jeffrey B. Jones

the resistant breeding lines used in this study was crossed with each other to determine the potential for pyramiding their resistance genes and to estimate whether these lines had QTL in common. In general, transgressive segregation was not clearly

Open access

Rachel A. Itle, Eileen A. Kabelka, and James W. Olmstead

. Transgressive segregation was examined using Tukey’s test for the fruit with the lowest average replicate measurements for L* color space values and its corresponding chroma and hue values for each plant of F 2 and BC 1P1 populations of all three families

Free access

Joseph Tychonievich and Ryan M. Warner

interspecific hybrids. The S. nemorosa × S. transsylvanica F 2 population exhibited transgressive segregation for a wide range of phenotypic traits ( Fig. 2 ). For example, time to flower varied from 13 to 29 weeks compared with 15 and 19 weeks to flower

Free access

Travis L. Stegmeir, Chad E. Finn, Ryan M. Warner, and James F. Hancock

of remontant (RM) and non-remontant (NRM) genotypes for the FVC11 population evaluated at Benton Harbor, MI. Many progeny displayed transgressive segregation with their trait values being higher than those of their parental genotypes. Only for

Open access

Cindy Rouet, Joseph O’Neill, Travis Banks, Karen Tanino, Elodie Derivry, Daryl Somers, and Elizabeth A. Lee

transgressive segregation ( Table 3 ). Three QTL associated with electrolyte leakage were identified ( Table 4 , Supplemental Figs. 3 and 4 ). A QTL for electrolyte leakage at −10 °C explaining 22% of the phenotypic variance mapped to LG3.H1 at 15 cM in the

Open access

Iyiola Fawole, W. H. Gabelman, and G. C. Gerloff

Abstract

Genetic control of root development in beans was investigated in the parents, F1, backcrosses and F2 obtained from 6 crosses made among 6 lines obtained from an earlier study of efficiency in P utilization. One line produced significantly larger and more vigorous roots and a narrower shoot/root ratio than the other 5 lines, both at stress and at adequate levels of P. Quantitative inheritance patterns and transgressive segregation for root dry weights were observed and high broad sense heritability estimates were obtained. Dominance variance was more important than additive variance in 4 families.

Open access

J. N. Moore, Catherine Lundergan, and Elvin D. Brown

Abstract

Nine seedling populations involving small-, intermediate-, and large-seeded parental clones of tetraploid blackberries (Rubus sp., subgenus Eubatus) were evaluated for seed-size inheritance. All seedling progenies exhibited a wide range of seed sizes with high frequencies of transgressive segregation especially for small seed size The frequency distribution curves were skewed in the direction of small seed size. The data support a model for quantitative inheritance with partial dominance for small seed size. Calculations of heritabihty show an average maximum estimate of 97%, supporting previous observations of the lack of environmental effects on the expression of seed size in blackberries.