Authors: I J Maureira F Ortega H Campos T C Osborn
Publish Date: 2004/08/06
Volume: 109, Issue: 4, Pages: 775-782
Abstract
Although unadapted germplasms have been used to improve disease and insect resistance in alfalfa there has been little effort to use these for improving forage yield We evaluated genetic diversity and combining ability among two unadapted germplasms Medicago sativa ssp sativa Peruvian and M sativa ssp falcata WISFAL and three Northern US adapted alfalfa cultivars Population structure analyses indicated that the WISFAL and Peruvian germplasms were genetically distinct from the cultivars although Peruvian was relatively closer to the cultivars Peruvian and WISFAL germplasms were intermated to generate a novel hybrid population This population was crossed to the three cultivars as testers and the testcross progenies were evaluated for forage yield along with the hybrid population the original germplasms Peruvian WISFAL and cultivars testcrosses of Peruvian and WISFAL to the three cultivars and a threeway hybrid of the cultivars The experiment was carried out in the field in Temuco Chile and Arlington Wisconsin USA and forage was harvested during two seasons Results from these evaluations showed that hybrids between the Peruvian × WISFAL population and the cultivar testers yielded as much as the cultivar testers Heterosis was observed between Peruvian and WISFAL and between these germplasms and the cultivar testers suggesting that each germplasm may contain different favorable alleles If Peruvian and WISFAL populations contain alleles at different loci that complement cultivar testers then combining and enriching these alleles in a single population could result in improved combining ability with alfalfa cultivars
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