|Kyetere, D - NAARI KAMPALA, UGANDA|
|Pratt, R - OHIO STATE U-OARDC|
Submitted to: African Crop Science Journal
Publication Type: Proceedings
Publication Acceptance Date: January 13, 1997
Publication Date: N/A
Technical Abstract: Three experiments to evaluate the response of 87 recombinant inbred lines (RILs) to maize streak virus (MSV) were carried out at two different locations in Africa. Two field experiments were planted at the Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) Station, Harare, Zimbabwe, and one glasshouse experiment at NAARI, Kampala, Uganda. At each hlocation infestation of RILs was carried out using viruliferous leafhopper (Cicadulina mbila) populations raised on plants, collected from that location, showing very severe streak symptoms. The screening was thus, in each case, carried out with viruliferous local natural MSV isolate inoculum. A semi-quantitative rating scale of 1 (tolerant) to 5 (susceptible) was used. Virus symptoms were rated four times fortnightly. Analysis of variance of MSV data showed significant differences among RILs. The performance of the parents, F1 and RILs for the four dates was consistent across locations. Those genotypes that were tolerant or susceptible were tolerant or susceptible, respectively, when rated early or late in the two locations. Genetic analysis of the RILs using restriction fragment length polymorphisms (RFLPs) was carried out. The association of these molecular genetic markers and MSV tolerance was determined using single factor analysis of variance (SFAOV) and two interval mapping procedures. Results from these three approaches identified the same gene accounting for the variation in MSV tolerance in the two locations.