Genetic stability analysis of the temporary immersion bioreactors-derived sugarcane seedlings with simple sequence repeat (SSR)markers

The utilization of temporary immersion system-bioreactors (TIB)has shown promise for sugarcane micropropagation due to its capacity for high-yield seedlings production. However, the temporary immersion system also carries the risk of somaclonal variations (SV)in regenerated plants. SV, encompassing phenotypic changes resulting from genetic or epigenetic alterations, and it presents challenges in preserving the genetic uniformity of the seedlings, a crucial factor for sugarcane productivity. A molecular marker like Simple Sequence Repeats (SSR)offers a reliable means to assess the genetic stability of TIB-derived sugarcane seedlings, ensurinng that the temporary immersion system-based micropropagation produces true-to-type planting materials. In this study, SSR analysis was conducted to determine the relative genetic stability of TIB-derived sugarcanes, using 15 SSR markers, generating over 200 DNA fragments ranging from 150 to 4,000 bp in size. The genetic stability was calculated as the Jaccard's similarity index of the SSR patterns of TIB-derived sugarcanes compared to their mother plants. The genetic stability varied between 92 and 96 percent in three Indonesian sugarcane varieties (PSKA 942, PS 094, and PS 091)which is relatively high considering the high cell mass multiplication in TIB (up to 30 multiplies). Morphological observations in the field also revealed no differences between TIB-derived sugarcane and their mother plants, convincing the true-to-type of micropropagation products. This study demonstrated the high relative genetic stability of TIB-derived sugarcanes, paving the way for large-scale commercial application in plantations.