Variabilidade genética em teca quanto a resistência a murcha de Ceratocystis : uma abordagem baseada em estudos fenotípicos e genômicos

Abstract

Teak is among the most important forest species in the world, however, the cultivation of this species has been facing problems with Ceratocystis wilt disease. The main problem is the symptoms that can cause economic losses, since the main symptom of the disease are stains on the bole that compromise the quality of the bole and make the wood unusable for sale. For teak cultivation, there are no resistant cultivars and due to the long cycle of this crop, genetic improvement programs need to adopt strategies to collect more accurate and rapid information. Therefore, the objective of this study is to help the UNEMAT teak genetic improvement program to establish protocols for inoculating Ceratocystis fimbriata in teak and evaluate them in terms of their ability to discriminate teak genotypes in terms of resistance to the fungus C. fimbriata. This thesis also aimed to verify the existence of genetic variability considering different isolates of C. fimbriata through phenotypic and genomic studies. According to the methodologies tested, it was possible to identify sources of resistance of T. grandis to Ceratocystis wilt through a protocol that allows discriminating resistant and susceptible genotypes in a shorter time. Reducing the plant evaluation period was essential to achieve the objectives proposed for this thesis, allowing the entire germplasm bank to be evaluated for resistance to Ceratocystis wilt to six isolates of C. fimbriata. GWAS studies were promising, and it was possible to identify SNP variants linked to resistance for three of the six trained isolates.