Preliminary Screening And Comprehensive Evaluation Of Superior Plants Of Toona Sinensis

Chinese toon (Toona sinensis (A. Juss) Roem) is a perennial hardwood, which is a member of Meliaceae family. The young leaves and shoots can be used as a vegetable called Hsiang Chun Ya (Xiang Chun Ya) and thus Chinese toon is known as a "tree vegetable". The fresh young leaves and shoots are crispy, delicious, aromatic and contain abundant nutritional ingredient. Local varieties, which contain inferior and superior varieties, are mainly cultivated for traditional plucking in many places. The study was carried out on 130 plants of Chinese toon which are from 15 provenances, such as Badong, Zhuxi and Wuhan lion mountain in Hubei in order to select superior individual trees.One key point of this study is sensory analysis. As a tree vegetable, Hsiang Chun Ya is deferent from other vegetables. What distinguished from others vegetables is its unique sensory quality, which is a very important criterion for people to buy Hsiang Chun Ya. According to sensory evaluation of vegetables, 7 indexes, including color, aroma, crispness, sweetness, astringency, toughness and brightness, are determined to assess sensory quality of Hsiang Chun Ya. 5-point rule is introduced according to graded standard of sensory evaluation and 5 standards are made to each index. Every index of all plants is evaluated and vested a score by using expert scoring method. The importance of each index is deferent from others, so AHP (Analytical hierarchy process) is used to decide the index weight.Biological characteristics and phenological observation of 130 plants are recorded. Biological characteristics included characteristics of stem and leaf. The items of stem involved color and texture of trunk stem, color and texture of annual shoots and characteristics of lenticel. The recorded items of leaves are length and angular divergence of compound leaf, color of compound-leaf petiole, amount of leaflets in each compound leaf, color, size and characteristics of leaflet and so on. The items of characteristics of tender shoots are color of tender leaf and sprout, texture of sprout. Phonological periods refer to loosing periods of bud scale, sprouting, leaf expension, hearty leaf expension, shoots growth starting, shoots growth stopping, summer shoot starting, summer shoot stopping, leaf discolour, full leaf discolour, abscission starting, hearty abscission periods and terminal abscission periods.The comprehensive score per plant was given through multiplication by matrix of evaluation and matrix of weight. Five grades are classified by Whole-distance-equal...