西藏林芝地区史前遗址古DNA与粟的高原适应研究

粟(Setaria italica)是最早传播到青藏高原的农作物，在大麦传入青藏高原之前，粟一直是高原的主要作物(距今5200-3600年)。但是，青藏高原年均温低、昼夜温差大、生长季短等特点均不利于粟的生长，粟在传入青藏高原的过程中经历了怎样的适应性演化到目前仍没有明确的答案。针对上述问题，本项目拟以西藏林芝地区距今3600-距今3200年的立定遗址中出土的炭化粟种子和相应文化层沉积物为研究对象，利用古DNA宏基因组和DNA探针技术完成古代粟的基因组和功能基因的重建；根据不同时期粟基因组的单核苷酸多态性和系统发育分析确定其系统发育地位；通过对反映粟适应性的抽穗期指示基因SipRR37和光周期敏感性基因Hd1-like的注释和差异位点分析，探究立定遗址古代粟应对高原环境的基因适应性改变。

Foxtail millet (Setaria italica) was the first crop introduced to the Tibetan Plateau. Before the introduction of highland barley, foxtail millet had been the main crop of Tibetan Plateau during 5200-3600 Before Present (BP). However, environmental conditions such as low annual average temperature, pronounced diurnal temperature, and short growing season on the Tibetan Plateau pose negative effects on the growth of foxtail millet. Along with the introduction of foxtail millet into the Tibetan Plateau, whether the species has undergone genetic variation and adaptive evolution is still not well understood. In order to address these knowledge gaps, this project is planned to study the carbonized seeds of foxtail millet and the cultural sediments in different periods ranging from 3,200 BP to 3,600 BP at the Klu lding site in the Nyingchi Region. The main aims: reconstructing the genome and functional gene of ancient foxtail millet using ancient DNA metagenomic and target genome enrichment; determining the evolutionary history of foxtail millet by single nucleotide polymorphisms (SNPs) and phylogenetic analysis of the ancient and modern foxtail millet genomes; revealing the adaptive genetic variation of foxtail millet in response to the alpine environment through the SNPs analysis of heading date indicator gene (SiPRR37) and photoperiod sensitive gene (HD1-like) of foxtail millet in Klu lding site.