Mndolwa, Eninka John2026-08-282026-08-282008https://www.suaire.sua.ac.tz/handle/20.500.14820/7929DissertationAngular leaf spot (ALS) incited by Phaeoisariopsis griseola is wide spread in all bean growing areas in Tanzania. It is of great concern in wet bean growing areas of the country, yet little information is available in Tanzania on cultivars resistant to the disease. The objective of this work was to incorporate angular leaf spot (ALS) resistance in adapted common bean lines through backcrossing procedure, determine inheritance of ALS in the crosses and screen advanced backcross lines for ALS resistance. Backcrossing was done in the screen house at SUA where G5686 x C/wonder, Amendoim x Rojo and Mexico54 x Soya were crossed to their respective parents. The backcrossed lines obtained together with the advanced bean lines from Prosser USDA-ARS Washington were evaluated for resistance to ALS. Completely randomized design (CRD) was used in screen house and Randomized Completely Block Design (RCBD) was used for field trials. For F2, F3, BC m and BC1.2 there was no randomization nor replication as this has no effect in early generations of bean improvement. For the advanced lines there were three replications in each of the two different locations i.e. SUA-Morogoro and Madira, Arusha. An appreciable amount of genetic variation (P < 0.05) for ALS resistance, pods per plant and seed yield was observed. The following advanced lines were found resistant to ALS in both locations PSO4・336Ab・7, PSO4-126Aa-8, PSO4-335B-1, PSO4-139Ba-l, PSO4- 139Bb-5, PSO4-139Bb-l, PSO4-106Ba-2, PSO4-139Bb-4, PSO4-126Ab-8, PSO4- 139Ba-7, PSO4-139Ab-10 and PSO4-126Aa-6. Both lines showed intermediate or resistant reaction to ALS disease, moreover, some of these did not develop any disease symptoms and thus could be immune to the disease or have escaped the disease. Significant and positive correlation between number of pods per plant and yield was observed in advanced lines where r = 0.751, (P < 0.001) fbr Morogoro trial where r = 0.509 and (P < 0.001) for Arusha trial. Heritability estimates were low 0.190 to medium 0.228 for disease resistance and moderate 0.30 to high 0.73 fbr number of pods per plant. It is recommended that further studies be conducted among the lines evaluated and the best performing lines to be selected then advanced and later be evaluated for other characteristics such as size, cooking time and protein concentration.enBean growingPhaeoisariopsis griseolaAngular leaf spot (als)TanzaniaThesis