MOLECULAR CHARACTERIZATION OF ELITE LINES OF PAPAYA (Carica papaya L.) VIA SSR MARKERS
Palabras clave:
Carica papaya L., germplasm bank, SSR markersResumen
This study aimed to analyze the genetic variability and to estimate diversity parameters of 23 elite papaya lines based on microsatellite molecular markers. The plant material was composed of elite lines, 18 from the 'Formosa' and five from the 'Solo' group. The expected heterozygosity (HE), observed heterozygosity (HO), and the coefficient of inbreeding (ƒ) for each genotype were estimated. The weighted index obtained the dissimilarity matrix, and the estimated genetic distance was presented graphically through the cluster analysis by the Ward method, as well as by the principal coordinates analysis (PCoA). The genotypes were also analyzed for genetic structure, using the Bayesian clustering method. Genetic variability was observed among the analyzed genotypes, mainly among the lines from the Formosa group. As for HO, four elite lines from the ‘Solo’ group had values equal to zero. However, the elite lines from the ‘Formosa’ group showed higher segregation in the loci with values ranging from 0.05 to 0.14. About ƒ, from the five lines in the 'Solo' group, four exhibited maximum fixation indexes for the analyzed loci, with the variation observed from 0.90 to 1.0, while the lines from the 'Formosa' group had a variation from 0.61 to 1.00. These results indicate the need for greater care in the process of obtaining inbreeding seeds to avoid pollen contamination, as well as the need to advance generations of self-fertilization with the lines from the 'Formosa' group to increase the level of inbreeding and ensure greater stability to hybrids that are developed from them
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Referencias
BADILLO, V.M. 2000. Carica L. vs Vasconcellea St. Hil. (Caricaceae) con La rehabilitación de este último. Ernstia, 10(2):74-79.
BARBOSA, C.D.; VIANA, A.P.; QUINTAL, S.S.R.; PEREIRA, M.G. 2011. Artificial neural network analysis of genetic diversity in Carica papaya L. Crop Breeding and Applied Biotechnology, 11(3):224-231. https://doi.org/10.1590/S1984-70332011000300004
BARROS, G.B.A.; AREDES, F.A.S.; RAMOS, H.C.C.; SANTA-CATARINA, R.; PEREIRA, M.G. 2017. Combining ability of recombinant lines of papaya from backcrossing for sexual conversion. Revista Ciência Agronômica, 48(1):166-174. https://doi.org/10.5935/1806-6690.20170019
BLAS, A.L.; YU, Q.; VEATCH, O.J.; PAULL, R.E.; MOORE, P.H.; MING, R. 2012. Genetic mapping of quantitative trait loci controlling fruit size and shape in papaya. Molecular Breeding, 29(2):457–466. https://doi.org/10.1007/s11032-011-9562-1
CARDOSO, D.L.; VIVAS, M.; PINTO, F.O.; VIANA, A.P.; AMARAL JÚNIOR, A.T. DO.; PEREIRA, M.G. 2017. Diallel mixed-model analysis of papaya fruit deformities. Ciência Rural, 47(5):1–4. https://doi.org/10.1590/0103-8478cr20151553
CHARLESWORTH, D. 2003. Effects of inbreeding on the genetic diversity of populations. Philosophical Transactions of the Royal Society B: Biological Sciences, 358(1434):1051–1070. https://doi.org/10.1098/rstb.2003.1296
CHEN, C.; YU, Q.; HOU, S.; LI, Y.; EUSTICE, M.; SKELTON, R.L.; VEATCH, O.; HERDES, R.E.; DIEBOLD, L., SAW, J.; FENG, Y.; QIAN, W.; BYNUM, L.; WANG, L.; MOORE, P.H.; PAULL, R.E.; ALAM, M.; MING, R. 2007. Construction of a sequence-tagged high-density genetic map of papaya for comparative structural and evolutionary genomics in Brassicales. Genetics, 177(4):2481–2491. https://doi.org/10.1534/genetics.107.081463
