| Sapium sebiferum is a native tree species in China,it has beautiful autumn leaves and high garden application value.Based on the investigation of Sapium sebiferum natural forest and artificial forest in different areas of Anhui province,the selection standard of superior Sapium sebiferum was formulated.Through first selection,second selection and last selection,one excellent single plant of yellow,red and purple Sapium sebiferum was finally selected;The asexual breeding system of superior Sapium sebiferum plants was explored,and the discoloration mechanism of Sapium sebiferum leaves was tentatively analyzed.The main results are as follows:According to the color types of Sapium sebiferum in autumn,Sapium sebiferum is divided into yellow system,red system and purple system,which are selected among the same color systems,and the lab color model is introduced at the same time.The selection criteria of Sapium sebiferum were formulated: strong growth,beautiful crown shape,the best viewing period of leaves > 20 d,discoloration rate > 80%,high brightness and color saturation of leaves,consistent and stable color of leaves in discoloration period for three consecutive years,etc.Through the public’s application for excellence,inspection,first selection,second selection and last selection,the Yellow superior Sapium sebiferum plant ’Jinhuang No.4’,the red superior Sapium sebiferum plant ’Hehong No.6’,and the purple superior Sapium sebiferum plant ’chuzi No.1’ were finally selected‘ The characteristics of "Jinhuang 4" are as follows: the leaf color is golden yellow in autumn,the discoloration rate of leaves is close to 100%,and the best viewing period of leaves is 23 days‘ ’Hehong 6’ is characterized by early discoloration.In the late and late discoloration stage,the whole plant leaves are red,yellow and orange,one plant is multicolor,and the whole plant leaves are Chinese red in the complete discoloration stage.The best ornamental period of leaves was 25 days‘ Chuzi 1 ’is characterized by: after the leaves completely change color,the autumn leaves are jujube purple,the color change process is rich(green→peach red→jujube purple),and the best viewing period of the leaves is 28 days.The results of Sapium sebiferum tissue culture experiment showed that: the biggest impact on the qualified rate of Sapium sebiferum tissue culture seedlings was the disinfection time of explants,followed by the shoot tip of exosomes,and then the ratio of hormones in the culture medium.The superior clones had the lowest impact on the qualified rate of tissue culture seedlings.In order to effectively improve the qualified rate of tissue culture seedlings,the optimal scheme is the upper part of stem tip + explant disinfection time of 12 min + culture medium of MS + 0.6mg/L6-BA +0.3mg/L NAA(6-BA:NAA=2:1);The biggest influence on the bud induction rate of Sapium sebiferum tissue culture seedlings is the stem tip of explants,followed by the hormone ratio in the culture medium,and then the disinfection time of explants.The excellent clone has the lowest influence on the bud induction rate of tissue culture seedlings.In order to effectively improve the bud induction rate of tissue culture seedlings,the optimal scheme is the upper part of shoot tip + explant disinfection time of 12 min + culture medium of MS+ 1.0mg/L 6-BA + 0.3mg/L NAA(6-BA: NAA=3:1).The results of Sapium sebiferum cutting experiment showed that the cutting part had the greatest impact on the rooting rate of Sapium sebiferum cutting seedlings,followed by the concentration of cutting hormone(IBA),and then the cutting matrix.The superior clone had the lowest impact on the rooting rate of Sapium sebiferum cutting seedlings.In order to effectively improve the rooting rate of Sapium sebiferum cutting seedlings,the optimal scheme is that the upper part of cuttings + cutting matrix is Vvermiculite:Vperlite= 1:1+3500 mg/L IBA.The comparison of physiological and biochemical indexes of Sapium sebiferum leaves in the color process of three color systems shows that: the contents of chlorophyll a and chlorophyll b in the leaves are lower in the complete color change period,the ratio of carotenoid / total chlorophyll in the leaves is higher in the complete color change period,and the content of N in the leaves is higher in the end color change period and complete color change period,which may be the key factors for the yellow color of Sapium sebiferum in autumn;The content of chlorophyll b in leaves was higher at the end of discoloration and complete discoloration stage,the content of carotenoid in leaves tended to be stable after discoloration and higher at complete discoloration stage The middle level of carotene / total chlorophyll ratio in leaves(significantly lower than that of yellow Sapium sebiferum and significantly higher than that of red Sapium sebiferum)and the middle level of N element content in leaves(significantly lower than that of yellow Sapium sebiferum and significantly higher than that of red Sapium sebiferum)may be the key factors for the purple color of Sapium sebiferum in autumn;The anthocyanin content in leaves was higher in the complete discoloration period,and the anthocyanin content increased more than that in the early discoloration period,the ratio of carotene / total chlorophyll in leaves was lower in the complete discoloration period and the content of N element in leaves was lower in the complete discoloration period.may be the key factors for the red color of Sapium sebiferum in autumn. |
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