Population structure and combining ability of diverse Medicago sativa germplasms

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 U.S. 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 three-way 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 x 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.

Comparison of phenotypic trait variation and total protein polymorphism in local and exotic germplasms ofMedicago sativain Iran

“…Parallel to our findings, significant variations were observed with respect to morphological, phenological, biological and molecular properties between populations in previous studies (Maureira et al 2004;Jafari & Goodarzi 2007;Tucak et al 2009;Benabderrahim et al 2009Benabderrahim et al , 2011Xavier et al 2011). The reason for this variation detected within populations may be related to genetic structure, which is probably due to heterozygosis of cross-pollination of alfalfa (Prosperi et al 2006).…”

“…The introduction of biochemical and molecular techniques has allowed a more accurate evaluation of genetic relationships of alfalfa: allozyme gene markers (Fayd-Lameche et al 1996;Jenczewski et al 1999), total protein profiles (Krochko & Bewley 2000;Chandra & Panday 2011;Radovic´et al 2012), restriction fragment length polymorphism (RFLP) (Maureira et al 2004), random amplified polymorphic DNA (RAPD) (Tucak et al 2008), simple sequence repeat (SSR) (Falahati-Anbaran et al 2007), sequence related amplified polymorphisms (SRAP) (Vandemark et al 2005) and amplified fragment length polymorphism (AFLP) (Keivani et al 2010). However, the protein profiling of germplasm and the use of genetic markers have been widely and effectively used to determine the taxonomic and evolutionary aspects of several crops (Khan 1990;Murphy et al 1990;Das & Mukharjee 1995;Ghafoor et al 2002;Emre et al 2007;Radovic´et al 2012).…”

Applied Genetics and Genomics in Alfalfa Breeding

“…Hybrids between dormant/semi-dormant and nondormant sativa germplasm could also be expected to show heterosis for yield [21]. The non-dormant Peruvian germplasm may represent a separate heterotic pool from other sativa germplasm [39,40], but otherwise, no clearly defined heterotic pools within sativa germplasm are evident [41,42]. A lack of specific combining ability effects among a large set of genotypes grown in a subtropical environment also point to the general lack of clear pre-existing heterotic groups in alfalfa [43].…”

Genetic Relationships Among Medicago sativa L. Clones Commonly Grown in Central Anatolia

“…This extensive geographical adaptation promotes genetic variation and give breeders possibility of using highly diverse genotypes in breeding programs (Maureira et al 2004). Synthetic variety breeding is most effective and intensive method to improve perennial forage crops like alfalfa through polycross.…”