Karnal bunt resistance in Synthetic Hexaploid wheats (SH) derived from durum wheat × Aegilops tauschii combinations and in some SH × bread wheat derivatives
Bridge crosses utilizing the D genome synthetic hexaploids (SH), Triticum turgidum / Aegilops tauschii (2n = 6x = 42, AABBDD), are a potent means of improving bread wheat (T. aestivum) for biotic and abiotic stresses. The synthetic germplasm enables incorporation of the genetic diversity of T. turgidum cultivars together with the attributes of the Ae. tauschii accessions. In this research, SH wheats were screened for karnal bunt in Obregon, Mexico over six crop cycles and several SHs were earlier identified with an immune response. These SHs have unique Ae. tauschii accessions as parents. Phenologically descriptors and additional trait evaluations led us to develop a sub-set of the most desirable combinations for wheat breeding. The SH wheats are generally tall, late to mature, have good agronomic type, and are non-free threshing with a high 1000 kernel weight. All have a spring growth habit with several possessing multiple stress resistances. The resistance exhibited by SH wheats has been transferred into elite but KB susceptible bread wheat cultivars thus generating a new and unique genetic resource that can be readily exploited by conventional breeding programs.
Key WordsD genome interspecific hybridization karnal bunt resistance Aegilops tauschii
Unable to display preview. Download preview PDF.
- Brennan, J.P., E.J. Warham, J. Heranadez, D. Byerlee, and F. Coronel. 1990. Economic losses from KB of wheat in Mexico. CIMMYT Economics Working Paper 90/02. CIMMYT, Mexico, D.F., Mexico.Google Scholar
- Mujeeb-Kazi, A., V. Rosas and S. Roldan. 1996. Conservation of the genetic variation of Triticum tauschii (Coss.) Schmal. (Aegilops squarrosa auct. Non L.), in synthetic hexaploid wheats (T. turgidum L. s. lat. X. T. tauschii; 2n=6x=42, AABBDD), and its potential utilization for wheat improvement. Genetic Resources and Crop Evolution. 43: 129–134.CrossRefGoogle Scholar
- Mujeeb-Kazi, A., A. Cortes, R. Delgado, and V. Rosas. 2001. Cytogenetics of bread wheat/Thinopyrum bessarabicum derivatives based upon Ph and ph influence. Agronomy Abstracts. American Society of Agronomy, CD-ROM.Google Scholar
- Munjal, R. L. 1975. Status of Karnal bunt (Neovossia indica) of wheat in northern India during 1968–69 and 1969–70. Indian J. Mycol. Plant Pathology. 5: 185–187.Google Scholar
- Warham, E.J. 1984. A comparison of inoculation methods for Karnal bunt (Neovossia indica). Phytopathology. 74: 856–857.Google Scholar