Prediction of industrial tomato hybrids from agronomic traits and ISSR molecular markers.
Heterosis is a highly relevant phenomenon in plant breeding. This condition is usually established in hybrids derived from crosses of highly divergent parents. The success of a breeder in obtaining heterosis is directly related to the correct identification of genetically contrasting parents. Currently, the diallel cross is the most commonly used methodology to detect contrasting parents; however, it is a time- and cost-consuming procedure. Therefore, new tools capable of performing this task quickly and accurately are required. Thus, the purpose of this study was to estimate the genetic divergence in industrial tomato lines, based on agronomic traits, and to compare with estimates obtained using inter-simple sequence repeat (ISSR) molecular markers. The genetic divergence among 10 industrial tomato lines, based on nine morphological characters and 12 ISSR primers was analyzed. For data analysis, Pearson and Spearman correlation coefficients were calculated between the genetic dissimilarity measures estimated by Mahalanobis distance and Jaccard's coefficient of genetic dissimilarity from the heterosis estimates, combining ability, and means of important traits of industrial tomato. The ISSR markers efficiently detected contrasting parents for hybrid production in tomato. Parent RVTD-08 was indicated as the most divergent, both by molecular and morphological markers, that positively contributed to increased heterosis and by the specific combining ability in the crosses in which it participated. The genetic dissimilarity estimated by ISSR molecular markers aided the identification of the best hybrids of the experiment in terms of total fruit yield, pulp yield, and soluble solids content.
Departamento de Pesquisa em Melhoramento de Hortaliças, Estação de Pesquisa e Desenvolvimento Sakata, Bragança Paulista, SP, Brasil.
A S T
AS
Figueiredo
Departamento de Agronomia, Campus Universitário Cedeteg, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brasil.
J T V
JT
Resende
Departamento de Agronomia, Campus Universitário Cedeteg, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brasil.
M V
MV
Faria
Departamento de Biologia, Campus Universitário Cedeteg, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brasil.
P R
PR
Da-Silva
Departamento de Ciências Biológicas, Universidade Estadual do Centro-Oeste, Guarapuava, PR, Brasil.
B S
BS
Fagundes
Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina, Estação Experimental de Itajaí, Itajaí, SC, Brasil.
R G F
RG
Morales
D018556:Crops, Agricultural / Q000235:genetics; D003433:Crosses, Genetic; D005638:Fruit / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D014644:Genetic Variation; D006823:Hybrid Vigor; D006824:Hybridization, Genetic; D018551:Solanum lycopersicum / Q000235:genetics*; D018895:Microsatellite Repeats; D010641:Phenotype; D000069600:Plant Breeding / Q000379:methods*; D019105:Random Amplified Polymorphic DNA Technique
D005819:Genetic Markers