African Journal of Crop Science

ISSN 2375-1231

African Journal of Crop Science ISSN: 2375-1231 Vol. 12 (6), pp. 001-006, June, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Combating Puccinia graminis f. sp. tritici in Kenyan Wheat: Insights on Ug99 Resistance

P. N. Njau1*, R. Wanyera1, G. K. Macharia1, J. Macharia2, R. Singh3 and B. Keller4

1Kenya Agricultural Research Institute (KARI) Njoro, Kenya.
2Egerton University Njoro. P. O. Box 536 Njoro, Kenya.
3CIMMYT Mexico. Apdo - Postal 6-641, 06000 Mexico, DF.
4Institute of Plant Biology, University of Zurich, Switzerland

Accepted 31 March, 2023

Abstract

Stem or black rust, caused by Puccinia graminis, has historically caused severe losses to wheat (Triticum aestivum) production worldwide. The causal race, commonly known as Ug99 and designated as TTKS based on the North American nomenclature, carries virulence for several genes commonly present in wheat germplasm. All Kenyan germplasm are known to be susceptible or partially susceptible to Ug99 although no proper documentation has been done. This study was aimed at evaluating the Kenyan bread wheat varieties on their response to Ug99. The varieties were screened for resistance at seedling stage and adult plant resistance stage. None of the varieties apart from Bonny were resistant at seedling stage. Some old Kenyan varieties were found to have adult plant resistance probably due to the presence of non-race specific gene Sr2 complex which among others can be exploited in breeding for resistance in Kenyan wheat.

Key words: Race specific resistance, adult plant resistance, genetic erosion.