SANTOS, J. D. L.; SANTOS, JONATHAS D.L.; http://lattes.cnpq.br/5932687440749581; SANTOS, Jonathas Diego Lima.
Resumo:
The Brazilian citrus industry faces serious problems and losses due to the large number of
diseases caused by pathogens. Considering that the genetic resistance is an important
component of integrated strategies to control plant diseases, because it is efficient, low cost to
the producer, beneficia] to man and the environment, the citrus breeding programs seek to
increase productivity by using genetic strategies for disease control. Durante o
desenvolvimento de novas variedades, melhoristas têm incorporado a seleção assistida por
marcadores, na detecção de genes que estejam associados com a resistência a doença. A new
and efficient system of molecular markers, TRAP (Target Region Amplification
Polymorphism) based on PCR, using bioinformatics tools and information database of ESTs
to generate polymorphic markers around the possible sequences of candidate genes. In this
sense, the largest database of expressed genome of citrus in the world, CitEST generated in
Brazil, represents & powerful tool to help the citrus breeding program, since it has all the
genes expressed in citrus species considered (ll species) and genotypes under contrasting
conditions, such as resistant versus susceptible induced versus not induced by pathogens. In
this context, this paper describes the identification of markers amplified by primers TRAPS
fixed, designed from genes associated with resistance to CTV (citrus tristeza virus), using
DNA from individuals of the Fl progeny from the crossing of Poncirus trifoliata with Sunki
(Citrus sunki), parental susceptible and resistant to disease, respectively. Of a total of 08
combinations of primers abritrário / fixed tested 02 combinations showed polymorphism,
generating a total of 04 marks and an average number of markers per pair of primer on the
value of 2. The Chi—square applied to individual markers traps, revealed that 100% of the
identified markers segregate in Mendelian lzl ratio. Therefore, these markers may be placed
on the linkage map of P. trifoliata. These markers may also be used in the genotyping of all
individuals of that population Fl.