The Cultivar Introduction And Analysis Of Multi-traits Variation Of Seedling In Tilia

Tilia plants are deciduous tree with rich species,full of vitality and lush in spring,and dense and aromatic flowers in summer.In Europe and America,they are not only honeyed plant,but also widely used as important garden tree species.Therefore,many new cultivars of Tilia plants with high quality have been cultivated abroad,which have great advantages in ornamental,growth and stress resistance.However,Tilia has just begun to be applied in gardens in China in recent years and there are no cultivars of independent intellectual property rights that can be popularized at present.Therefore,garden enterprises have started to introduce a large number of foreign cultivars,without systematic,comprehensive and scientific evaluation.Tilia cordata ‘Greenspire’ was an excellent horticulture cultivar of Tilia cordata,which was widely used in urban area of the world,but there is no research on its scientific layout and application in China.In addition,although China has rich resources of Tilia with great potential for development,the research on new cultivars of Tilia in China is not systematic compared with foreign countries.Analytic hierarchy process(AHP)was used in this study in four aspects: ornamental index,growth index,photosynthetic traits index and stress resistance index.A comparative experiment was conducted in the coastal areas of Shandong province was provided on eight foreign introduced and high-quality cultivars: Tilia cordata ‘Greenspire’,Tilia cordata ‘Shamrock’,Tilia cordata ‘Corinthian’,Tilia europaea ‘Euchlora’,Tilia platyphyllos ‘Fastigiata’,Tilia platyphyllos ‘Zelzate’,Tilia americana ‘Sentry’ and Tilia americana ‘Redmond’.Through systematic and comprehensive scientific comparison and evaluation of these cultivars,the recommended basis for the application of these cultivars in the coastal areas of Shandong province was provided.Regional experiments were conducted to provide an important basis for the scientific layout and application of the cultivated variety T.cordata ‘Greenspire’ in North China.Moreover,the variation of several growth traits of Tilia Americana,Tilia miqueliana,Tilia platyphyllos and Tilia tomentosa were analyzed to screen out high-quality individual plants,which provided theoretical basis for the development of new cultivars of Tilia in China,and also provided high-quality parent materials and gene resources for cross breeding.Through the above research,the main conclusions are as follows:(1)T.cordata ‘Greenspire’,T.platyphyllos ‘Fastigiata’,T.cordata ‘Shamrock’ and T.americana ‘Sentry’ were high-quality Tilia cultivars with excellent ornamental,strong growth and adaptability,which were suitable for wide application in the coastal areas of Shandong province.The comprehensive qualities of T.americana ‘Redmond’ and T.platyphyllos ‘Zelzate’were average,which can be used selectively in the coastal areas of Shandong province according to the situation.The comprehensive qualities of T.cordata ‘Corinthian’ and T.cordata ‘Shamrock’ were poor,so they were not recommended to be used in the coastal areas of Shandong province.T.americana ‘Sentry’ was the best cold-resistant species,which can be prefered in the places with very low winter temperature.(2)The growth of T.cordata ‘Greenspire’ performed better than the local commonly used Tilia plant T.cordata ‘Corinthian’ in Cangzhou.The growth of the local commonly used Tilia plant T.Americana performed better than T.cordata ‘Greenspire’ in Pizhou.While in Qingdao,T.cordata ‘Greenspire’ and the local commonly used Tilia plant Tilia mandshurica had their own advantages in growth,which can be selected according to the actual demand.(3)Variation is the material basis of new variety breeding.T.Americana,T.platyphyllos,T.miqueliana and T.tomentosa had great variations in the 9 most representative growth traits,such as leaf length,leaf width,petiole length,internode length,ground diameter,seedling height,root number,root diameter and root length,which would be helpful to the selection of excellent provenance of Tilia,and provided scientific basis and breeding materials for genetic improvement of Tilia in the future.In addition,the morphological indexes of these Tilia seedlings are closely related,which can be used to identify and select their seedling or underground traits in the future.Finally,we selected a batch of excellent individual plants for further observation,determination and reproduction.