海南岛十倍体油茶资源分布及评价OA北大核心CSTPCD

As a traditional oleaginous resource on Hainan Island,the camellia species predominantly exist as evergreen trees of small to medium stature.The large-fruit camellia with white flowers is widely distributed across various regions of Hainan Island.This study conducted a survey and sampling of camellia populations aged 30 years and above across all municipalities and counties of Hainan Island.Ploidy identification was carried out using flow cytometry and chro-mosome squashing techniques.The research revealed that among the 23 populations surveyed,16 were identified as decaploid and 7 as octoploid,covering 16 municipalities and counties across the island.Decaploid camellia populations were found in 12 counties and cities(Danzhou,Lingshui,Qionghai,Wuzhishan,Ding'an,Chengmai,Tunchang,Lingao,Changjiang,Ledong,Qiongzhong,Baoting),including ancient trees over 100 years old and wild camellia populations in tropical rainforests,all of which were identified as decaploid.In contrast,the octoploid populations were generally un-der 60 years of age and traced back to artificial cultivation,with no other ploidy camellia resources found in the sur-veyed populations.It is evident that the camellia resources on Hainan Island are primarily composed of decaploids and octoploids,with the decaploids being indigenous to the island and the octoploids,not exceeding 60 years of age,being introduced from regions such as Guangdong and Vietnam during the 1960s to 1970s.Both types of camellia have dem-onstrated good adaptability to the growth conditions.Given that decaploid camellia trees have not been found in other camellia distribution areas,the widespread distribution of decaploid camellias on Hainan Island and the discovery of decaploid wild camellia populations in tropical rainforests suggest that the decaploid camellia species are indigenous regional species of Hainan Island,evolved due to unique ecological factors such as the island's tropical monsoon cli-mate.The distribution range of the resources spans from 18°38′42"N to 19°49′53"N and from 108°51′0"E to 110°29′46"E,at altitudes ranging from 4.17 m to 1090 m.