One hundred and thirty SSR markers from wheat, maize and sorghum were screened for the transferability to Paspalum. The transfer rate was 67.5, 49.0 and 66.8% respectively. This would be a very efficient approach for DNA marker development for species which are not well studied molecularly. The polymorphism level for transferred SSR markers was 51.5% within species (Paspalum vaginatum) and 87.1% among Paspalum species. The high level of polymorphism is directly related to the high degree of heterozygosity maintained by its way of reproduction, i.e. self-incompatibility. Forty transferred polymorphic SSR markers were selected and used for characterization and evaluation of seventy-three Paspalum accessions. In total, 209 polymorphic bands were detected from these 40 SSR markers, with an average of five polymorphic bands per marker. The Paspalum accessions clustered into three major groups. Two very similar dendrograms can be generated from either 109 or 209 polymorphic bands. This led us to determine that 18 of the transferred SSR markers were sufficient for genetically differentiating the investigated germplasm accessions. The number of SSR markers required for germplasm characterization and evaluation is discussed. This is the first report of the transfer of SSR markers from major field crops to newly emerged environmental turfgrasses.

Within the cultivated peanut species (Arachis hypogaea L.), there are two subspecies comprising six botanical varieties, and the effect of botanical taxon on oil content and fatty acid composition variability is unclear. To gauge the variability, 83 peanut accessions were analyzed for oil content (expressed at 0% moisture) and fatty acid composition. We found that within the subsp. hypogaea, var. hypogaea contained a much higher amount of oil in seeds than did the var. hirsuta Köhler (520 vs. 473 g/kg, P < 0.05); within the subsp. fastigiata Waldron, the vars. aequatoriana Krapov. & W.C. Gregory and vulgaris Harz contained a similar amount of oil in seeds (491 g/kg), not significantly different from other botanical varieties, but var. fastigiata contained a higher amount of oil (500 g/kg) than the var. peruviana Krapov. & W.C. Gregory (483 g/kg). In terms of the fatty acid composition, oil from seeds of var. hypogaea contained much more oleic acid than did var. hirsuta (491 vs. 377 g/kg, P < 0.05), but much less palmitic acid (97 vs. 138 g/kg, P < 0.05%) and linoleic acid (308 vs. 402 g/kg, P < 0.05). Oil from seeds of var. vulgaris contained much more oleic acid than did var. aequatoriana (437 vs. 402 g/kg, P < 0.05), but much less linoleic acid (346 vs. 380 g/kg, P < 0.05). Significant negative correlations of oleic with palmitic and linoleic acids were detected. The information on the oil content and fatty acid composition variability among botanical varieties would be useful for peanut breeders seeking germplasm containing both high oil content and proper fatty acid composition.

The genetic diversity of the genus Lespedeza is not well known and the phylogenetic relationship of Lespedeza with the genus Kummerowia is unclear. We report the first study in which polymorphic expressed sequence tag-simple sequence repeat (EST-SSR) markers derived from Medicago, cowpea and soybean were used to assess the genetic diversity of the USDA Lespedeza germplasm collection and clarify its phylogenetic relationship with the genus Kummerowia. Phylogenetic analysis partitioned 44 Lespedeza accessions into three main groups some of which were species-specific and eight subgroups. This data set revealed some misidentified accessions, and indicated that the two species in the genus Kummerowia are closely related to the genus Lespedeza. Morphological reexamination was used to correct the misidentified accessions within the genus Lespedeza. Our results demonstrated that phylogenetic analysis with morphological reexamination provides a more complete approach to classify accessions in plant germplasm collection and conservation.

Barkley, N. A., Pinnow, D. L., Wang, M. L.. Ling. K. S.. and Jarret. R. L. 2011. Detection and classification of SPLCV isolates in the U.S. sweetpotato germplastn collection via a real-time PCR assay and phylogenetic analysis. Plant Dis. 95:1385-1391.The United States Department of Agriculture-Agricultural Research Service sweetpotato (Ipomoea batatas) germplasm collection contains accessions that were initially collected from various countries worldwide. These materials have been maintained and distributed as in vitro plantlets since the mid-1980s. The status of viral infection by the emerging Sweet potato leaf curl virus (SPLCV) and other Begomovirus spp. in this germplasm has yet to be determined. In order to minimize the potential distribution of virus-infected clones, all accessions in the collection were tested for SPLCV using a real-time polymerase chain reaction assay. In total. 47 of 701 accessions of in vitro plantlets tested positive for SPLCV. The presence of SPLCV detected in these materials was confirmed via biological indexing using the indicator plants /. nil and /. murkata. Symptoms appeared more rapidly on /. muricata than on /. nil. Nucleotide polymorphisms among the isolates were evaluated by sequencing the AVI coat protein gene from 24 SPLCVinfected accessions. The results revealed that the SPLCV isolates shared high sequence identity. Ten nucleotide substitutions were identified, most of which were synonymous changes. Phylogenetic analysis was conducted on those 2^ SPLCV isolates in combination with six described SPLCV species and various SPLCV strains from GenBank to evaluate the relationships among viral species or strains. The results from this analysis indicated that most of the AVI genes derived from previously classified SPLCV species clustered together, some of which formed well-supported monophyletic clades. further supporting the current taxonomy. Overall, identification of SPLCV-infected germplasm will allow approaches to be employed to eliminate the virus from the collection and limit the distribution of infected materials.