ARS | Publication request: Screening of a broad range of rice (Oryza sativa L.) germplasm for in vitro rapid plant regeneration and development of an early prediction system

Submitted to: In Vitro Cellular and Developmental Biology - Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 23, 2008
Publication Date: August 1, 2009
Citation: Dabul, A., Miller, H.B., Roychowdhury, M., Hubstenberger, J.F., Lorence, A., Phillips, G.C. 2009. Screening of a broad range of rice (Oryza sativa L.) germplasm for in vitro rapid plant regeneration and development of an early prediction system. In Vitro Cellular and Developmental Biology - Plants. 45 (4):414-420.

Interpretive Summary: Rice has emerged as the model system for studying the grasses, which include the major food crops such as corn, wheat, and barley. Tissue culturing is a technique used to grow plant cells or parts of plants in a sterile environment or medium. For tissue culture to be useful, it is important to be able to regenerate whole plants from the culture so the selection of rice cultivars which have a high frequency of regeneration is essential. Thirty-three rice cultivars with agricultural and biotechnological characteristics of interest were screened with the aim of selecting the best regenerators. The cultivars that showed at least 85% frequency of partial regeneration by 15 and 30 days had a high frequency of producing whole plants by 45 days; those entries not reaching the 85% threshold of partial regeneration by 15 or 30 days had only a moderate to low frequency of whole plant regeneration. This suggests that the occurrence of early partial regeneration by a cultivar could be a useful predictor of its ability to regenerate a whole plant. These earlier measurements can be used to speed up the time and lower the cost of comparing the regeneration ability across multiple cultivars.

Technical Abstract: Rice has emerged as a model monocot for studies in agriculture and biotechnology, due to its relatively small genome and ready access to plant material. Tissue culture is one of the tools required for genetic transformation, for some breeding programs, and selection of high frequency regenerator types is essential for success in these technologies. Thirty-three rice entries with agricultural and biotechnological characteristics of interest were screened with the aim of selecting the best regenerators. Entries that exhibited between 50% and 90% regeneration frequencies included ‘Taipei-309’, ‘Super Dwarf’, ‘Norin’ (japonicas); PI 312777, ‘Ali Combo’ (indicas); ‘STG-S’ and ‘LA3’ (weedy red rices). Those entries showing at least 85% frequency of greening or somatic embryo formation at 15 d or 30 d on regeneration medium, ultimately produced whole plants after 45 d on regeneration medium at high frequency; those entries not reaching the 85% threshold of greening at 15 or 30 d exhibited moderate to low frequency of whole plant regeneration. This suggests an early prediction system for useful rice regenerator types, which would be beneficial for high throughput screening of germplasm as well as decreasing time and cost of in vitro culture.