வேளாண் அறிவியல் மற்றும் உணவு ஆராய்ச்சி இதழ்
திறந்த அணுகல்

சுருக்கம்

Resistance Sources to Bean Anthracnose Disease in Uganda and Brazil

Awori E1,2, Kiryowa M2, Souza TLPO3, Vieira, AF 4, Nkalubo ST2, Kassim S2 and Tusiime G1

Bean anthracnose caused by the fungus Colletotrichum lindemuthianum is among the most destructive diseases of common bean in Uganda, Brazil and worldwide, especially in the high altitude and low temperature areas. This study was conducted to identify sources of effective resistance for use in bean breeding program in both Uganda and Brazil. Through mutual germplasm exchange, 11 bean cultivars were obtained from Embrapa, Brazil; and 13 cultivars were sent from Uganda to Embrapa, Brazil. The exchanged materials together with 12 differential cultivars and susceptible checks were evaluated in the field for two seasons in Uganda and Brazil. The germplasm was further evaluated in Uganda under controlled conditions using three C. lindemuthianum races 336, 375, and 381. The experiments were laid in a randomized complete block design with 3 replicates and disease severity data was scored using a 1-9 scale: 1=no symptoms and 9=dead plants. The results showed the cultivars G2333 (Co-42+Co-52+Co-7), TU(Co-5), AB136 (Co-6+co-8), Kaboon (Co-12), K10 (Co-42+Co-34+Co-5+Co-6), K13 (Co-42), SEL 1308 (Co-42) and BRS Cometa to be the most effective against C. lindemuthianum among the germplasm screened in both Uganda and Brazil. The lines BRS Ametista, BRS Horizonte as well as BRS Pontal, whose resistance genes are not yet characterized, also showed good resistance in both countries. Breeding programs in Uganda and Brazil should make use of the resistance genes Co-42 (G2333, SEL1308), Co-5 (G2333, Tu), Co-34 (K10), Co-6, Co-8 (AB136) and Co-1 (Kaboon) through either single gene deployment or in gene pyramid combinations for effective control of diverse C. lindemuthianum pathotypes. The resistance in the cultivars K10, BRS Ametista, BRS Horizonte and BRS Pontal should be characterized to identify the genes responsible for the observed resistance.