Genetic characterization of a collection of chayote, Sechium edule (Jacq.) Swartz, in Costa Rica by using isozyme markers

Abstract

We established protocols for the analysis of genetic diversity in chayote (Sechium edule) by using isozyme markers, thereby determining the level of genetic diversity present in 42 accessions of chayote from Costa Rica. We obtained clear and reproducible zymograms for eight enzyme staining systems: PGM, 6-PGD, PGI, IDH, MDH, SOD, SKD, and EST, and were able to score 14 putative loci. Eight of the 14 loci examined were polymorphic. We found 35 distinct multilocus genotypes among these accessions. Five of these multilocus genotypes were homozygous for all loci. In addition, our data also revealed that most of the multilocus genotypes (24) were heterozygous for only one of the eight loci, and the rest were heterozygous for two or three loci (9 and 4 accessions, respectively). Seven multilocus genotypes were found in two different accessions. Dice similarity coefficient was used to study the relationship between accessions. This analysis, based on the presence and absence of alleles, revealed that accessions collected in the same location seldom shared the same multilocus genotype. The value of isozyme polymorphisms as tools to continue studies on the characterization of chayote is discussed.

Variación genética en el complejo infraespecífico de chayote evaluada mediante sistemas isoenzimáticos

“…En las accesiones de chayote mexicano, el polimorfismo es muy similar a lo reportado por Abdelnour & Rocha (2008) con base en un estudio con diez sistemas isoenzimáticos, en 42 accesiones de chayote de Costa Rica, en las que encontraron 57,14% de polimorfismo. El porcentaje relativamente alto de polimorfismo puede ser el reflejo de la manipulación por el hombre, sobre todo por la dispersión a que ha sido sometido el chayote (Gottlieb, 1981).…”

Comportamiento postcosecha de Sechium edule y expresión de ACS4, ETR1 y MAPK4 en frutos de diferentes etapas de desarrollo

“…El chayote posee importantes propiedades nutracéuticas, antimicrobianas y medicinales (Ordoñez et al, 2003;Ordoñez et al, 2006;Salazar-Aguilar et al, 2017;Sulaiman et al, 2013). En México existen diversos grupos varietales que presentan diversidad fenotípica y molecular (Abdelnour & Rocha, 2008;Avendaño-Arrazate et al, 2012;Machida-Hirano et al, 2015); lo que representa una rica fuente de recursos genéticos que necesita ser caracterizada para conocer las potencialidades de cada grupo varietal. Durante la vida de anaquel de los frutos se pueden presentar diversos fenómenos que afectan su calidad, ocasionando su rechazo y pérdidas económicas para los productores.…”

Lipoxygenase activity associated to fruit ripening and senescence in chayote (Sechium eduleJacq. Sw. cv. “virens levis”)

“…Chayote fruits are produced a wide range of forms, colors, flavors, and other physiological and morphogenetic variations (Avendaño et al, ; Cadena et al, ). The whole plant is nutritionally relevant in the human diet and for its many traditional medicinal uses (Lim, ; Lombardo et al, ); however, only the fruit has economic importance in several countries, including México, Costa Rica, Brazil, Puerto Rico, and United States, where it is marketed and exported, and represents a significant source of revenue (Abdelnour & Rocha, ; Olguín, Valdovinos, Cadena, & Arevalo, ). It is also produced and traded at small‐scale in countries like England, France, and Spain (Jiménez, Salazar, & Ramos, ).…”