Souza, A.A. and Boscariol, R.L. and Moon, D.H. and et al, . (2000) Effects of Phaseolus vulgaris QTL in controlling host-bacteria interactions under two levels of nitrogen fertilization. Genetics and Molecular Biology, 23 (1). pp. 155-161.
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Abstract
Molecular markers were used to estimate the effect of mineral nitrogen on the phenotypic expression of quantitative trait loci (QTL) controlling the number of Rhizobium nodules (NN) and resistance to Xanthomonas axonopodis pv. phaseoli in the common bean. Recombinant inbred lines derived from a BAT-93 x Jalo EEP558 cross were grown in a greenhouse in the absence or presence (5 mM NH4NO3) of nitrogen. Resistance to Xanthomonas was assessed as diseased leaf area (DLA) and the number of nodules was obtained by direct counting. Analyses of variance were used to detect significant associations between 85 marker loci from 12 linkage groups (LG) and quantitative traits. In the absence of nitrogen, 15 and 11 markers, distributed over 7 and 5 LG, showed a significant association with NN and DLA, respectively. The combined percentage of phenotypic variance explained by the marker-loci and QTL associations was 34% for NN and 42% for DLA. In the presence of nitrogen, there were only five significant associations for NN and eight for DLA, which explained 28 and 26% of the total phenotypic variance, respectively. The effects of some QTL were detected only at a certain level of nitrogen. The contribution of parental alleles at two NN QTL was dependent on the level of nitrogen. Four QTL were associated with both the number of Rhizobium nodules and resistance to Xanthomonas, suggesting a common genetic control of responses to bacterial infections in the common bean. Despite the dramatic environmental interactions noted with some QTL, in other cases the phenotypic effects were not affected by the amount of nitrogen. The stability of the latter QTL may be relevant when breeding cultivars adapted to variable soil fertility.
| Item Type: | Article |
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| Additional Information: | We thank Dr. Paul Gepts for genotypic information of the recombinant inbred lines and M. Bizetto, F. Montrazzi and C. Malvas for their technical assistance. This project was supported by PADCT/ CNPq and FAPESP through grants No. 62.0263/92-0 and 92/ 3792-7. A.A.S. and R.L.B. were the recipients of fellowships from CAPES and FAPESP, respectively. S.M.T. and L.E.A.C. were the recipients of fellowships from CNPq. Publication supported by FAPESP. |
| Author Affiliation: | Centro de Citricultura “Sylvio Moreira”, IAC, SP, Brasil |
| Subjects: | Plant Protection Plant Physiology and Biochemistry > Plant Physiology |
| Divisions: | Common Bean |
| Depositing User: | Mr Arbind Seth |
| Date Deposited: | 23 Aug 2013 10:52 |
| Last Modified: | 23 Aug 2013 10:52 |
| Official URL: | http://dx.doi.org/10.1590/S1415-47572000000100029 |
| URI: | http://eprints.icrisat.ac.in/id/eprint/11464 |
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