Variation Of Xanthoceras Sorbifolium Bunge Seed Characteristics And Selection Of Superior Rootstock Provenance

Xanthoceras sorbifolium Bunge is a unique rare woody oil plant,medicinal plant,edible and nectar source tree species in China.It is also an excellent tree species for combating desertification,greening barren mountains and beautifying cities.It is widely distributed in the"Three North"areas of China.But at present,most of X.sorbifolium are still in wild and semi wild state,with extremely mixed types,unclear seed source,slow growth,low yield and low ecological and economic benefits.Therefore,in this thesis,26geographical provenances of X.sorbifolium were selected as the research object.The characteristics of X.sorbifolium seeds,the growth characteristics of multi-point seedlings and the applicability of afforestation as rootstock were comprehensively and systematically evaluated by the methods of field investigation and indoor analysis,which provided a theoretical basis for the selection of improved varieties and the rational utilization of germplasm resources of X.sorbifolium.The main results are as follows:(1)The oil content of X.sorbifolium varied greatly among different provenances,ranging from 56.54%to 76.27%.There were 18 kinds of fatty acids with the highest content of linoleic acid and oleic acid,and the content of monounsaturated fatty acid>polyunsaturated fatty acid>total saturated fatty acid.The characteristics of biodiesel oil were in line with ASTM D6751-2010,International standards such as en EN 14214-2008and GB/T 20828-200.There are 17 kinds of amino acids and 8 kinds of essential mineral elements in seeds.The average contents of V_B1,V_B2 and V_E are higher.Among the 26provenances,Ganqika,Zhalute,Naiman,Kulun and Dongying are the best sources for edible oil and biodiesel production.(2)The best seed source of X.sorbifolium is toubuxin,Inner Mongolia.The seed vigor and moisture content are 93.29%and 13.28%.The water absorption characteristics can be divided into three periods:rapid water absorption period,gentle water absorption period and growth water absorption period.The morphological and quality indexes were rich in genetic diversity among and within groups,and the overall repeatability was also high.Treatments,provenances and their interactions had significant effects on the germination rate,germination index and germination time of X.sorbifolium seeds.The best way of seed treatment is B-shacang+5%peg soaking for 24 hours,and the best provenance for germination is Horqin,Inner Mongolia.The results showed that the morphological quality and germination index of seeds showed a trend of geographic variation gradually increasing from west to east,which was similar to the variation pattern of seed quality characteristics.Inner Mongolia Horqin,Inner Mongolia tubuxin,Inner Mongolia Zhalute,Inner Mongolia shebotu and Heilongjiang Mudanjiang were the best provenances of X.sorbifolium.(3)The high quality provenances of the high quality X.sorbifolium in the test points of Zhangwu(Northeast China)in Liaoning Province are Neiman,zarut and Haicheng of Liaoning Province.The high quality provenances of the experimental points in Anqiu(East China)of Shandong Province are Dongying,Anqiu and Kulun in Inner Mongolia.The high quality Provenances of Jingbian(northwest)test points in Shaanxi Province are Horqin,Naiman and Fangshan in Beijing.These provenances can be found in Liaoning The site environment in Shandong and Shaanxi provinces or similar to the experimental sites in this thesis is promoted.The quality provenance of different test points is not identical,and the seedling preservation rate,seedling height,ground diameter,leaf dry quality and branch quality will vary with the different test sites.Considering the average plant height and the diameter of the ground,the average breeding value of Kulun and Dongying provenances in Inner Mongolia is the highest,which has a great breeding potential.(4)Two year old X.sorbifolium from 26 provenances were used as Rootstocks to graft new Xanthoceras sorbifolia varieties'Zhongshi 4'and'Zhongshi 9'.The overall compatibility of'Zhongshi 9'was higher than that of'Zhongshi 4'.The grafting survival rates of Neiman,Dongying and Kulun stock provenances in Inner Mongolia were the highest,and Zhangjiakou in Hebei was the lowest;The fruit yield of Neiman rootstock grafted with'Zhongshi 4'was the highest,while that of Horqin rootstock grafted with'Zhongshi 9'was the highest.Based on the growth,physiological characteristics and fruit yield,the results showed that the high-quality rootstock provenances of'Zhongshi 4'were Neiman,Horqin,Kulun,Fangshan and Linyi in Inner Mongolia,and the high-quality rootstock provenances of'Zhongshi 9'were Jingbian,Horqin,Kulun,Neiman,Fangshan in Beijing and Guanshan in Liaoning.