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Abstract Lolium multiflorum is a crosspollinated plant, there must have the mixtures in hybridizations. The discrimination of true and false hybrids is necessary. The study aimed to select excellent hybrid combinations and progenies, and provided the essential data for the subsequent cross breeding. Parental cultivars we choose were the international good varieties and the leading varieties in southwestern Sichuan. Five parental cultivars of Lolium multiflorum and five cross combinations were used to identify their true hybrids by SSR molecular markers. The SPSS computer software was used to analyze the data to differentiate the differences between parents and progenies on morphological characteristics. The results were as followed:(1) 20 primer pairs produced 426 polymorphic bands with average percentage of polymorphism of 82.41%, each pair of primers amplified 25.9 bands on average, and 21.3 bands had polymorphism on average. Samples had relatively high molecular genetic polymorphisms so it was feasible to identify the parents and hybrids.(2) The hybrid progenies could be divided into two types, including the progenies with paternal characteristic bands and without, the progenies with paternal characteristic were considered as the true, 108 true F1 hybrid individuals were identified as the true hybrids using SSR molecular markers from the 150 hybrid individuals through several pairs of primer. There were 24 true hybrids both in combinations from ChangjiangNo.2×GanxuanNo.1 and GanxuanNo.1×ChangjiangNo.2 which produced the most amount of true hybrids and 19 true hybrids in combinations of Barspectra×GanxuanNo.1 which produced the least amount of hybrids. (3) Significant heterobeltiosis were found in the F1 progenies from the cross combination of ChangjiangNo.2×GanxuanNo.1. The differences in vegetative organ and reproductive organs among the five cross combinations were significant. The coefficient of variance in cross combination of Major×GanxuanNo.1 was the highest while cross combination of Barspectra×GanxuanNo.1 had the lowest coefficient of variance. The phenotypic traits performances of F1 hybrids from ChangjiangNo.2×GanxuanNo.1 was significantly better than the rest of the F1 hybrids produced from other combinations. We finally got the optimal hybrid combinations ChangjiangNo.2×GanxuanNo.1 and its good hybrids in morphological character through SSR molecular markers and analyzing the data to differentiate the differences between parents and progenies on morphological characteristics. This study showed that identifying the true hybrids of five different hybrid combinations by SSR molecular markers indicated the feasibility for Lolium Multiflorum in the assistant identification of SSR molecular. It plays a significant meaningful role in accelerating breeding progress, constructing genetic linkage maps and QTL analysis. The results can provide theoretical basis for cross breeding in Lolium multiflorum and the hybrid progenies can offer potential breeding materials in future.
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Received: 07 December 2012
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