Rodriguez N.N.,Institute for the Research of Tropical Fruits |
Valdes J.,Institute for the Research of Tropical Fruits |
Rodriguez J.A.,Institute for the Research of Tropical Fruits |
Velasquez J.B.,Institute for the Research of Tropical Fruits |
And 6 more authors.
In this document, research on genetic resources and breeding in guava during the last 50 years in Cuba is included. The morph-agronomic characterization of 395 accessions and a catalogue with 18 of them, together with a new illustrated descriptor with more than 70 descriptors are offered. The discrimination power and information on morph-agronomic characters and AFLP and SSR as dominant and co-dominant molecular markers respectively were compared. The use of discrimination power (D) for morph-agronomic characters facilitated the key elaboration to distinguish among genotypes. Also, the effectiveness of AFLP for discrimination (Dj= 0.991) and SSR for diversity estimation (H ep = 0.60) was determined. The selection of "Enana Roja Cubana", (Red Cuban Dwarf) and EEA 1-23 cultivars due to their low size and high yield is documented. The combination of morph-agronomic characterization and diversity analysis was effective to design conservation strategies, to establish a crossing program, to increase the current cultivar composition and to develop genetic linkage maps. An integrated map from "Enana Roja Cubana" x N6 cross was constructed using AFLP and SSR molecular markers. The eleven linkage groups and 50 quantitative trait loci (QTLs) detected constituted the starting point for gene cloning and the future implementation of marker assisted selection in guava. Moreover, the 176 candidate sequences identified for resistance (RGL) and plant development (MADS-box and HOMEO-box) genes could contribute to linkage map saturation. All these results, along with the use of tissue culture techniques for germplasm conservation and propagation have permitted to propose a methodology to develop a guava breeding program in Cuba. Source