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- Author or Editor: M. L. Schuster x
- Journal of the American Society for Horticultural Science x
Abstract
Reaction to Xanthomonas phaseoli (E.F. Smith) Dowson, cause of common blight disease in beans, Phaseolus vulgaris L., was inherited quantitatively in the cross early flowering susceptible cv. Great Northern (GN) 1140 × late flowering tolerant line ‘GN Nebr. #1, sel. 27’. F1 populations showed partial dominance for susceptibility at 25 days and nearly complete dominance at 43 days after inoculation. Genes controlling delayed flowering, under long photoperiod and high temp, and tolerant reaction were linked. Early, blight tolerant advanced lines were not obtained by pedigree selection. They were obtained, however, by the backcross method, using ‘GN Nebr. #1, sel. 27’ as the recurrent parent. Different photoperiod × temp regimes in growth chambers induced flowering at the same or different times in nearly-isogenic lines of the same age. Vegetative plants exhibited higher levels of tolerance and lower bacterial populations than did plants in the pod stage. The bacterial population in susceptible ‘GN 1140’ was higher than in early and late tolerant lines.
Abstract
‘Great Northern (GN) Nebraska #1, sel. 27’ and PI 150414 dry bean lines were highly tolerant to races 1 and 2 of halo blight bacterium (Pseudomonas phaseolicola) when inoculated with 5 × 106 and 2 × 108 cells per ml. The tolerant reactions to both races was completely dominant in the F1 ‘Gallatin 50’ (susceptible) crossed with both tolerant parents when inoculated with the low cell concn. However, tolerant and susceptible plants occurred in F1’s when inoculated with the high cell concn. In the F2 generation derived from the above crosses, the tolerant inoculated leaf, pod, and plant non-systemic chlorosis reactions to race 1, were each controlled by a different major dominant gene designated by the symbols LHB-1, PD HB-1, SC HB-1, respectively. Coupling linkage was detected between the genes controlling the leaf and systemic chlorosis reactions. This is the first report of 3 different genes, each separately controlling the expression of the halo blight reaction in different plant parts, namely, susceptible water-soaked reaction in inoculated pods and leaves, and systemic chlorosis reaction of leaves.
The leaf tolerant reaction to race 1 in ‘GN Nebraska #1, sel. 27’ and PI 150414 was controlled by the same allele. The same dominant allele in PI 150414 controlled the tolerant reactions to races 1 and 2.
Abstract
A new method of inoculation of bean seedlings with urediospores of Uromyces phaseoli typica Arth. produced an even distribution of numerous pustules on the leaves. A suspension of urediospores in Freon-113 was sprayed on both surfaces of the primary leaves. The plants were then placed in a moist chamber for 18 hr under a low light intensity of 2 × 10-5µ einsteins cm2 sec-1, before being transferred to the greenhouse. In screening tests the cvs. Great Northern 1140 and Kentucky Wonder Wax No. 765 were resistant to Brazilian race B11; ‘GN 1140’ showed the highest grade of resistance. Segregation for the reaction to rust race B11 in the F2 generation in crosses between the resistant cv. GN 1140 and 4 susceptible lines indicated that a major gene controlled the reaction with the resistant reaction dominant. The symbol RB11 was assigned to the dominant allele. Linkage was not detected between genes controlling plant habit and disease reaction.
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.