Shanlan upland rice (Oryza sativa L.) is a unique upland rice variety cultivated by the Li nationality for a long time, which has good drought resistance and high utilization value in drought resistance breeding. To explore the origin of Shanlan upland rice and its genetic relationship with upland rice from other geographical sources, 214 upland rice cultivars from Southeast Asia and five provinces (regions) in southern China were used to study genetic diversity by using SSR markers. Twelve SSR primers were screened and 164 alleles (Na) were detected, with the minimum number of alleles being 8 and the maximum number of alleles being 23, with an average of 13.667. The analysis of genetic diversity and analysis of molecular variance (AMOVA) showed that the differences among the materials mainly came from the individuals of upland rice. The results of gene flow and genetic differentiation revealed the relationship between the upland rice populations, and Hainan Shanlan upland rice presumably originated from upland rice in Guangdong province, and some of them were genetically differentiated from Hunan upland rice. It can be indirectly proved that the Li nationality in Hainan is a descendant of the ancient Baiyue ethnic group, which provides circumstantial evidence for the migration history of the Li nationality in Hainan, and also provides basic data for the advanced protection of Shanlan upland rice, and the innovative utilization of germplasm resources.

Shanlan upland rice is a kind of upland rice and is suitable for planting in the mountains and in hilly terrain. It is mainly found in China’s Hainan province. To discover the drought-resistant genes in Shanlan upland rice, two representative varieties—Baishanuo (BSN) and Dongfang Manpoxiang (MPX)—were selected for transcriptome sequencing, after which gene expression analysis was used to confirm their gene expression patterns. The results demonstrated that 2791 and 829 differentially expressed genes (DEGs) were identified for each variety, including 184 and 58 transcriptional factors, respectively. Expression analysis demonstrated that some genes with unknown functions, such as Os10g0505900, were highly expressed under drought stress treatment. The transcriptomic data and digital gene expression profiling data obtained in this study provide a basis for studying the drought-resistant mechanism in Shanlan upland rice.