Bibliographic citations
Chavarry, B., (2014). Caracterización morfológica de una muestra de accesiones de maíces peruanos del Banco de Germoplasma de Maíz (Zea mays L.) de la UNALM [Universidad Nacional Agraria La Molina] [Tesis, Universidad Nacional Agraria La Molina]. https://hdl.handle.net/20.500.12996/2341
Chavarry, B., Caracterización morfológica de una muestra de accesiones de maíces peruanos del Banco de Germoplasma de Maíz (Zea mays L.) de la UNALM [Universidad Nacional Agraria La Molina] [Tesis]. : Universidad Nacional Agraria La Molina; 2014. https://hdl.handle.net/20.500.12996/2341
@mastersthesis{renati/245945,
title = "Caracterización morfológica de una muestra de accesiones de maíces peruanos del Banco de Germoplasma de Maíz (Zea mays L.) de la UNALM [Universidad Nacional Agraria La Molina]",
author = "Chavarry Gómez, Belmar",
publisher = "Universidad Nacional Agraria La Molina",
year = "2014"
}
The present research was carried out in the Universidad Nacional Agraria La Molina (UNALM), located in the Rímac river valley at an altitude of 255 meters. The biological material consists of a sample of 118 peruvian maize accessions collected in different departments and maintained in the UNALM Germplasm Bank. The installation of the experiment was carried out on June 10, 2011; each accession was planted on a plot of 40m2 without repetition with a population of 260 plants per plot.The objectives of this research are: to characterize a sample of Peruvian maize accessions conserved in the UNALM genebank using plant and ear descriptors; to determine the most efficient variables for cluster analysis and to determine the race of corn for each accession according to data collected by morphological descriptors. The 18 descriptors for morphological characterization of the maize plants were selected from the morphological descriptors manual FAOIBPGR. The morphological descriptors were plant and ear height, ear insertion knot, total number of leaves, number of leaves on the cob, leaf area, panicle length, color of stem, ear length, top, medium and bottom diameter of ear, ear taper rate, number of rows per ear, number of kernels per row, disposition of rows, days to male and female flowering. Statistical analysis includes the formation of a basic matrix of data, calculation of the variation coefficients for each descriptor, correlation analysis, principal component analysis and cluster analysis; using for that purpose the statistical program NTSYSpc22N of the microsoft Excel 2010. The data of basic matrix are averages of ten corn plants in case of quantitative descriptors and modas in case of qualitative descriptors. Most of the evaluated morphological descriptors are correlated each other, then the number of original variables or descriptors was reduced from 18 to four variables or principal components where the first component has an eigen-value of 8.82, the second component has an eigen-value of 2.68, the third and fourth component have an eigen-value of 1.44 and 1.07 respectively; these first four principal components concentrate the 77.79% of the total data variation. According to principal component analysis only descriptors panicle length, taper rate and row arrangement proved less efficient variables for grouping accessions to present a low coefficient of contribution in each major component. Morphological characterization of a sample of accessions of Maize Germplasm Bank UNALM; allowed to discriminate accessions in groups, but the groups formed not match the racial classification. The mismatch is due to the race to which belongs each accession was determined using few data cob and corn used other characters are used to describe the races but not to classify. Morphological characterization can be used to improve the original racial classification, but must be based only on the most efficient characters to group accessions in races Racial classification in Peru as well as morphological criteria included ecological and cultural criteria, in addition to data cob and grain that were decisive. Therefore concluded that cluster analysis and the construction of phenograms are not decisive for racial classification, but may be part of a holistic approach that considers criteria other than morphological.
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