Abstract

Augustine Antwi-Boasiako, Benjamin Karikari and Obed Amponsah Abrokwah

ABSTRACT

Soybean rust, caused by Phakopsora pachyrhizi (H. Sydow and Sydow), is one of the most important foliar diseases affecting soybean worldwide. Yield losses due to rust under excessive infestation could be up to 75 % in unprotected fields. The tread of soybean research in Africa is towards developing soybean varieties resistant to rust disease. Molecular screening for rust resistance gene in soybean genotypes was conducted at Council for Scientific and Industrial Research (CSIR) – Crops Research Institute (CRI) Molecular Biology Laboratory, Fumesua in Kumasi. Field screening of soybean genotypes for resistance was conducted at a “hot spot” at Tampola, Navrongo in the Kassena Nankana District of the Upper East Region of Ghana. The study was conducted to determine the presence of rust resistance gene(s) in 34 soybean genotypes and to evaluate the genotypes resistant to P. pachyrhizi. Simple Sequence Repeat (SSR) markers revealed genotypes SIT-E TGx1990-3F, SIT-M TGx1987-91F and SIT-M TGx1989-45F have multiple resistance genes (Rpp1, Rpp2 and Rpp3), however, genotype TGx1909-3F was identified not to have resistance gene. Out of the 34 soybean genotypes, SIT-M TGx1989-45F, SIT-M TGx1987-40F, SIT-E TGx1990-3F and SIT-M TGx1987-91F were found to be highly resistant to rust disease during a phenotypic screening at the disease hot spot. Genotypes observed to have resistance gene(s) (Rpp1, Rpp2, Rpp3, Rpp4, and Rpp5) to soybean rust could further be exploited and used in the breeding programme.