Genetic Characterization of Proso Millet (Panicum miliaceum L.) Germplasm.

Proso millet (Panicum miliaceum L.), a short-season summer crop with shallow root system,  is a low cost-of-production alternative crop for winter wheat based dryland cropping system in the western central region of the United States, which covers substantial parts of western NE, KS, SD and eastern CO, WY. The region is characterized by high elevation semi-arid climate and agronomically, proso millet is an ideal for diversifying and intensifying dryland/rainfed production systems. There are only six proso varieties commonly grown.  Because the germplasm base of these cultivars is very narrow, there is a dire need to introduce diversity into proso breeding programs.  There is wide genetic diversity available in proso millet germplasm. The objective of this report is to characterize proso millet core germplasm for morpho-agronomic traits and molecular markers. A total of 95 proso germplasm lines obtained from USDA-ARS NCRPIS, Ames were grown in the field for evaluation of various agronomic traits (plant height, flowering time, panicle length, seed weight and seed color). These lines were also genotyped for various molecular markers (RAPD, ISSR, and SSR). There was significant variation in the morpho-agronomic traits among the germplasm set tested in this report. Plant height ranged from 25 to 100 cm although majority of the lines were about 60 cm in height. Flowering times of the lines varied from 35 days after planting (DAP) to 50 DAP. There were several lines which were never flowered and seed characteristics were not recorded for these lines. Panicle length ranged from 10-30 cm. Thousands seed weight ranged from 1 to 8g although majority of the lines fall between 4-6g. Seed color ranged from cream, yellow, brown, and red with different intensity. This set of proso millet germplasm also was equally diverse with respect to molecular marker profiles. Genetic relationships were reported among these set of proso germplasm based on morpho-agronomic traits and molecular markers. The morpho-agronomic traits reported here were based on 1-2 years data at one location. Further evaluation of the selected lines with desirable traits (early flowering, large seed, longer and thinker panicle with large number of seeds) will be necessary at multiple locations to test stability of these traits. These set of germplasm will serve as source of desirable traits in proso millet variety development.