Ecogeographical distribution of wild, weedy and cultivated Sorghum bicolor (L.) Moench in Kenya: implications for conservation and crop-to-wild gene flow

Abstract

The potential gene flow between a crop and its wild relatives is largely determined by the overlaps in their ecological and geographical distributions. Ecogeographical databases are therefore indispensable tools for the sustainable management of genetic resources. In order to expand our knowledge of Sorghum bicolor distribution in Kenya, we conducted in situ collections of wild, weedy and cultivated sorghum. Qualitative and quantitative morphological traits were measured for each sampled wild sorghum plant. Farmers' knowledge relating to the management of sorghum varieties and autecology of wild sorghum was also obtained. Cluster analysis supports the existence of several wild sorghum morphotypes that might correspond to at least three of the five ecotypes recognized in Africa. Intermediate forms between wild and cultivated sorghum belonging to the S. bicolor ssp. drummondii are frequently found in predominantly sorghum growing areas. Crop-wild gene flow in sorghum is likely to occur in many agroecosystems of Kenya.

Potentials of tropical starches as pharmaceutical excipients: A review

“…Most varieties are drought and heat tolerant, and of relatively low cost. It is used for food (as grain and in sorghum syrup or ''sorghum molasses''), fodder, production of alcoholic beverages and biofuels [108]. Starch is the major component of sorghum grain, and comprises $70% of dry grain weight [109].…”

Genetic structure and relationships within and between cultivated and wild sorghum (Sorghum bicolor (L.) Moench) in Kenya as revealed by microsatellite markers

“…Detailed description of the collection, including the ecogeographical variation across the country is published elsewhere (Mutegi et al 2010).…”

“…It is an important food crop and dietary staple in the country's arid and semi-arid lands which account for over 80 percent of the total land area. A wide diversity of sorghum landraces is cultivated under equally diverse agro-climatic conditions and practices by subsistence farmers in different communities of Kenya (Mutegi et al 2010). …”

“…Moreover, morphologically and geographically diverse wild relatives of domesticated sorghum in the primary and tertiary gene pools are known to occur in the country (Clayton and Renvoize 1982;Mutegi et al 2010). Wild relatives of sorghum are recognised as broad genetic base reservoirs and potential sources for resistance and adaptation traits in breeding programs (Gurney et al 2002;Kamala et al 2002;Reed et al 2002;Rao Kameswara et al 2003;Rich et al 2004) and deserve special conservation attention.…”

“…drummondii) (Harlan and De Wet 1972;Dogget 1988). All subspecies of S. bicolor are inter-fertile under sympatric conditions, leading to a continuum of wild-weedy-domesticate complex forms that have been documented to occur in many sorghum growing parts of Africa (Dogget and Majisu 1968;Dogget 1988;Tesso et al 2008;Mutegi et al 2010). Moreover, cultivated and wild sorghum occupy diverse ecological landscapes and have over the years been subjected to diverse biotic and abiotic selection pressures across their geographic range.…”