Geographical Patterns Of Variations In Main Chemical Components Of Oil-tea Camellia Seeds

The oil plants have higher oil contents and are the main sources of vegetable oils.Vegetable oil is closely related to the national economy.It is not only an important part of daily food,but also a raw material with wide industrial uses.Encouragingthe research,exploration and utilization of abundant oil plants resources in China is an important way to cope with the growing demand for vegetable oil.Understanding the geographical pattern of changes in the main chemical components of oil plant seeds is the basis for the exploration and utilization of oil plant resources.Camellia oleifera,known as “Oriental Olive Oil”,is the woody oil plant with the largest cultivation area and the highest total oil production in China.Wild C.oleifera is a valuable genetic resource for C.oleifera breeding.Understanding the geographical pattern of the main chemical componentsin wild C.oleifera seeds and its correlation with environmental factors,can help to explore and utilize valuable wild C.oleifera genetic resources,and promote the breeding of good varieties of C.oleifera.In this study,a large number of research literatures on seed fatty acids in Chinese seed plants have been collected,mainly based on the data of seed oil content and fatty acid composition in 112 families,386 genera and 718 species.The geographical patterns of seed oil content and fatty acid composition in Chinese seed plants were analyzed,and the key environmental factors were discovered.Using wild C.oleifera seeds from different latitudes as materials,the geographic patterns of main chemical componentsin wild C.oleifera seeds,including oil content,fatty acid,alpha-tocopherol,squalene,camellia saponin,beta-sitosterol and flavor substances,were studied.The correlations were analyzed between the main chemical components inC.oleifera seeds and environmental factors.The main conclusions of this study are as follows:1.The seed oil contentin Chinese seed plants demonstrated an obvious geographical pattern,showing significant downward trends with increasing latitude and altitude.The driest monthly precipitation may affect seed oil content.The seed oilcontent of woody plants was significantly higher than that of herbaceous plants.2.The seed unsaturated fatty acid content in Chinese seed plants increased significantly with the increase of latitude.It may be mainly affected by the annual mean temperature and the precipitation of driest month,and decreased significantly with the increase of the two factors.The seed oil melting point decreased significantly with the increase of latitude,and it was significantly negatively correlated with theunsaturated fatty acid content.It was also mainly affected by the annual mean temperature and theprecipitation of driest month,and increased significantly with the increase of the two factors.There was a significantly negative correlation between the seed unsaturated fatty acid content and oil content.3.The oil content of wild Camellia oleifera seeds was negatively correlated with latitude and monthly mean of diurnal temperature difference.The oil content of wild Camellia oleifera seeds was the highest(56%)in Nanling region of Ruyuan,Guangdong Province.The content of unsaturated fatty acids in wild Camellia oleifera seeds was not significantly correlated with altitude,latitude and most meteorological factors,but positively correlated with monthly mean temperature in January and December.4.The content of alpha-tocopherol in wild Camellia oleifera seeds varies greatly from place to place,but the correlation with latitude and meteorological factors is not significant.The squalene content of wild Camellia oleifera seed oil was positively correlated with the monthly mean of diurnal temperature difference.The content of tea saponin in wild Camellia oleifera seeds was negatively correlated with latitude,and decreased with the increase of August precipitation.The content of beta-sitosterol in wild Camellia oleifera seeds varied slightly,and the correlation between beta-sitosterol and latitude and meteorological factors was not significant.5.The quantity of flavor substances in small fruit Camellia oleifera is the largest,Jiangxi Academy of Forestry Science in the cultivation of common Camellia oleifera Ganwu 1 is in the second place,followed by Hainan in the cultivation of Vietnamese Camellia.The amount of flavor substances in cultivated Camellia oleifera seed oil was significantly higher than that in wild Camellia oleifera seed oil.This study provides an important reference for exploiting and utilizing thegenetic resources of Camellia oleifera.