Biology subjects

Joshi, S. V.

Publications and source records attributed to Joshi, S. V..

2 recordsLinked to original sources

bioRxiv2020

On the Validity of the Saccharum Complex and the Saccharinae Subtribe: A Re-assessment

The Saccharum Complex represents an hypothetical collective of species that were supposedly responsible, through interbreeding, for the origins of sugarcane. Though recent phylogenetic studies have cast doubt on the veracity of this hypothesis, it has cast a long shadow over the taxonomics of the Andropogoneae and the Saccharinae subtribe. Though evidence suggests that Saccharum s.s. is comprised of only three true species, according to Kews GrassBase there are as many as 34 species in Saccharum s.l. Our recent work has shown that many of these species are millions of years divergent from Saccharum. As the Saccharum complex represents the species that sugarcane breeders attempt to introgress into sugarcane, and as the Saccharinae, in its current form, covers almst 12 million years of Andropogoneae evolution an update on the extents of the Taxonomic and customary groupings is much needed. Based on the latest sequence based phylogenies and the inclusion of traditional taxonomics we develop an integrated view of the Saccharinae + Saccharum complex species in the context of the major groupings within the Andropogoneae. We use this phylogeny to re-circumscribe the limits of both the Saccharinae subtribe and the Saccharum complex group of interbreeding species.

evolutionary biology↗

bioRxiv2020

Origins, History and Molecular Characterization ofCreole Cane

Since it was first introduced to Europe in 711 CE and planted in the Americas in 1506, a single type of cane dominated sugar production for 1100 years, until it was finally ousted by Tahitian cane c. 1790. This cane became known as Creolea[A][Z] and is present in the ancestry of many sugarcane hybrids, even today. Whether there was only a single variety of Creole cane or multiple varieties has been a matter of debate for decades. Creole cane remains relevant today, as a Creole cane from Jamaica is the currently chosen lecotype for Saccharum officinarum. In this study we identify 18 historical images of Creole cane, many not previously published. We employ image analyses to characterize the internodes and demonstrate evidence for only a single type of Creole in the new world. Chloroplasts and 45s ribosomal RNA sequences from the cultivar BH10/12 (known to have a Creole female parent) were determined that Java ribbon cane is the historical New World sugarcane known as Creole. We demonstrate that Creole cane is an hybrid and not a single species. Thus S. officinarum has no type specimen. We also sequence a ribbon cane (also known as Guinguam) that appeared in the Caribbean between 1790 and 1810 and demonstrate that this cane was a Sinense type from Java that links back to the work of Rumphinus (1660s).

genomics↗