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Genetics of and breeding for resistance to Xanthomonas campestris pv. phaseoli (Smith) dye in beans (Phaseolus vulgaris L.)
Abstract
Four bean varieties (RK Charlevoix, GN Harris, GN 1140, and GN Emerson) were inoculated using three methods: leaf water soaking (WS), multiple needle-florists frog (MN), and a razor blade (RB), with three strains of the bacteria at two concentrations of 10$\sp6$ and 10$\sp8$ cfu/ml. The strains were similar in virulence. There was a significant interaction between methods of inoculation (M) x concentration of inoculation (C) x genotype (G). A second experiment was conducted to determine the amount of bacteria deposited into the leaves using the three inoculation methods. There were fewer bacteria in the leaves at time of inoculation and at 24 hr with the RB method than with the other methods in both varieties; the latter difference was not significant. The dry seeds, flower buds, small pods, and green seeds of the individual plants of four dry bean cultivars/line (Bac-6, Venezuela 44, Pompadour Checa, and GN Tara) were examined for possible internal bacterial infection after inoculating the plants at different sites. Inoculation of the pedicels of the flower buds and small pods resulted in transmission of the bacteria through the vascular tissue of the pod to the seeds. Planting infected seeds did not result in a systemic transmission of the bacteria in the vascular tissue of the plant to the seeds. The infected leaves were likely to be the main source for the external infection of the pods. Leaf and pod disease reactions to strains of X c pv p were inherited quantitatively in crosses among five Phaseolus vulgaris cultivars/lines: Bac-6 (mod. res.) x NE-EPl (mod. res.), Bat-862 (mod. res.) x Pompadour Checa (sus.), Pompadour Checa (sus.) x Bac-6 (mod. res.) and Venezuela 44 (sus.) x Bat-862 (mod. res.). Transgressive segregations for resistance or susceptibility were observed. Pod disease reaction was not correlated with leaf disease reaction at any growth stage. Low or no correlations were detected between disease reactions of leaves at the seedling and flowering stages. Low negative or no correlations were observed between leaf disease reaction and number of days to first flower. Intermediate to low narrow-sense heritability estimates for leaf and pod disease reaction were found in the different crosses. Two recessive genes were found to control two foliar abnormality traits: crippled growth and variegated leaves.
Subject Area
Plant pathology
Recommended Citation
Aggour, Ahmed Reda Abd El-Mohsen, "Genetics of and breeding for resistance to Xanthomonas campestris pv. phaseoli (Smith) dye in beans (Phaseolus vulgaris L.)" (1987). ETD collection for University of Nebraska-Lincoln. AAI8806140.
https://digitalcommons.unl.edu/dissertations/AAI8806140