Reação de acessos de Capsicum e de progênies de cruzamentos interespecíficos a isolados de Colletotrichum acutatum

Abstract

The anthracnose (caused by a complex of Colletotrichum species) is one of the most important diseases of Capsicum in tropical and subtropical regions. Distinct breeding programs around the world have identified some sources of resistance. However, there is a scarce amount of information about the resistance spectrum and stability of these sources to isolates of the Colletotrichum species. In the present work, the reaction to five C. acutatum isolates was characterized in a Capsicum germplasm collection comprising 129 accessions and also in backcross progenies derived from the interspecific cross C. annuum x C. chinense PBC 932 (resistant). Studies aiming to identify correlation between seedling and fruit resistance were also carried out. Cluster analysis indicated one C. annuum, one C. baccatum and two C. chinense accessions with the highest levels of resistance. No significant correlation was observed between resistance at seedling and fruit stage. A large variability was observed for anthracnose reaction in progenies derived from the interspecific cross C. annuum x C. chinense PBC 932, ranging from high levels of susceptibility (55%) to quasi-immune responses (10%). The results suggest that C. chinense PBC 932 is, apparently, a source of stable and wide spectrum resistance to distinct C. acutatum isolates. Therefore, anthracnose resistance genes from PBC 932 are feasible of being incorporated into elite lines via conventional breeding strategies.