Phylogenetic Implications of a Unique 5.8S nrDNA Insertion in Cyperaceae

The purpose of this study was to assess the phylogenetic utility of a large insertion (3 bp) in the 5.8S gene of nuclear ribosomal DNA (nrDNA) in Cyperaceae and selected Juncaceae. This was done by reconstructing the character evolution of the insertion on a phylogeny derived from rbcL sequences. Results suggest that the insertion was gained once at the base of Cyperaceae followed by multiple losses in its most-derived taxa. Despite several homoplastic losses (CI = 0.20), the pattern of insertion loss (RI = 0.88), and base pair variation within the insertion were useful for defining sedge clades at various taxonomic levels. For example, whereas a loss of the insertion appeared to characterize a major terminal clade within Cyperaceae, both an insertion loss and sequence variation were consistent with infrageneric clades previously discovered in an ITS phylogeny of Eleocharis. The presence/absence of the insertion also supported previous conclusions based on morphological and molecular data that tribe Scirpeae and Scirpus s.l. are polyphyletic. In the context of our current understanding of Cyperaceae relationships, evolutionary patterns related to this insertion provide additional support for groups defined in prior phylogenetic analyses. The present analysis also suggests that the controversial position of Oxychloe andina (Juncaceae) in previous rbcL analyses, as sister to Cyperaceae (Y12978) or as nested within Cyperaceae (U49222), is due to the fact that Y12978 is a Juncaceae/Cyperaceae chimera, whereas U49222 is the sequence of a Cyperaceae contaminant. When U49222 is excluded from analyses and the Cyperaceae portion of Y12978 is removed, Juncaceae and Cyperaceae are monophyletic with Oxychloe positioned within a Juncaceae clade of single-flowered genera

Sorghum Landraces Production Practices in Nyanza, Coast and Eastern Regions, Kenya

Sorghum Sorghum bicolar L. is an important cereal crop grown in the semi-arid areas. It is rank as the fifth key cereal crop worldwide. The ability of sorghum to adapt to drought, salinity, infertile soils, and high temperatures makes it a critical crop in the dry regions. However, farmers grow many landraces some of which do not perform well since the majority cannot afford nitrogenous fertilizers to boost their harvest. Therefore, a baseline survey was conducted in Eastern, Nyanza and Coastal regions to assess the production systems for sorghum. Structured questionnaires were used to gather information from a total of 76 randomly selected farmers in the study regions. Data on socio-economic characteristics, sorghum varieties, use of farm inputs, and source of seeds, farming systems, traits preference, farm sizes, yields and constraints in production of the crop was collected. Parameters studied were analyzed using Statistical Programmes for Social Sciences (SPSS) (IBM SPSS Statistics 20). Results showed that majority of respondents in Eastern (99%), 80% in Nyanza and all respondents in the coastal region cultivated landraces. Most of the respondents had farm sizes between 0.5-5acres. A larger proportion of respondents in the three regions reported low harvests from their farms, recording below 5 bags every season. Most of the farmers across the three regions intercrop sorghum with other crops with all respondents in Eastern, 80% in Coast and 68% in Nyanza. Some farmers plant sorghum without fertilizers, others used either inorganic or organic fertilizers while the rest use both organic and inorganic. The traits desired by farmers in the region included high yields, early maturity, resistance to pest and diseases, sweetness and tolerance to drought. Farmers cited pests and diseases, weeds such as striga, and drought as the key constraints to sorghum production in the regions. Key words: drought, landraces, sorghum, tolerance, traits DOI: 10.7176/JESD/10-10-16 Publication date:May 31st 201

Revision of the Afro-Madagascan genus Costularia (Schoeneae, Cyperaceae) : infrageneric relationships and species delimitation

A recent molecular phylogenetic study revealed four distinct evolutionary lineages in the genus Costularia s.l. (Schoeneae, Cyperaceae, Poales). Two lineages are part of the Oreobolus Glade of tribe Schoeneae: the first being a much-reduced genus Costularia s.s., and the second a lineage endemic to New Caledonia for which a new genus Chamaedendron was erected. The other two lineages were shown to be part of the Tricostularia Glade of tribe Schoeneae. Based on morphological and molecular data, the genus Costularia is here redelimited to represent a monophyletic entity including 15 species, which is restricted in distribution to southeastern Africa (Malawi, Mozambique, South Africa, Swaziland, Zimbabwe), Madagascar, the Mascarenes (La Reunion, Mauritius), and the Seychelles (Mahe). Molecular phylogenetic data based on two nuclear markers (ETS, ITS) and a chloroplast marker (trnL-F) resolve the studied taxa as monophyletic where multiple accessions could be included (except for Costularia laxa and Costularia purpurea, which are now considered conspecific), and indicate that the genus dispersed once to Africa, twice to the Mascarenes, and once to the Seychelles. Two endemic species from Madagascar are here described and illustrated as new to science, as is one additional species endemic to La Reunion. Two taxa previously accepted as varieties of Costularia pantopoda are here recognised at species level (Costularia baronii and Costularia robusta). We provide a taxonomic revision including an identification key, species descriptions and illustrations, distribution maps and assessments of conservation status for all species

Mapania multiflora, a distinctive new species of Cyperaceae (Mapanioideae) from Borneo

Mapania multiflora is described and illustrated. It is vegetatively similar to taxa with broad leaves and pseudopetioles, such as M. cuspidata. However, it is reproductively similar to sect. Thoractostachyum with a paniculate inflorescence and furrowed fruit. The DNA is similar to M. bancana in sect. Thoractostachyum, in the three sampled cpDNA regions: atpH-F, trnL-F and psbA-trnH. However, it is identical to none of these due to its unique combination of vegetative, reproductive and molecular characteristics