| Sapindus mukorossi Gaertn.(Soapberry)regard as one of important bioenergy feedstock species in the development of “Forestry-oil integration” industry,which have a multiple function with bioenergy,chemical industry,medicine,afforestation and beautification together.At present,Fujian,Zhejiang,Guizhou Province and other places in China has developed nearly 26680 hectares of artificial feedstock plantation.Much more serious question aroused,such as low and unstable production and yields,tall tree canopy,fruits and flowers abscission seriously and so on,the main reason is lack of intensive cultivation technique system of orchards gardening.Based on the study of Soapberry cultivation is a blank,this study is aimed at the high light efficiency canopy architecture and flower-fruit nutrition regulation research located in the Jianing Fujian,solving the problem of unclear flowers and fruits development,unclear principle of canopy light efficiency and source-sink nutrition regulation pathway,which can set up highefficiency standard cultivation technique system.The main methods,results and conclusions as follows:1.Based on the methods of tracking and measure the inflorescence and infructescence,in order to investigate the phenological,blossom-fruiting characteristics,branch classifications.The results indicated that the phenology of soapberry contained dormancy stage,budding stage,initial bloom stage,full-bloom stage,terminal stage,primary fruit stage,fruit expanding stage and early ripe stage.In spring of Fujian Jianning,the budding period of soapberry was 8～10 days after the temperature higher than 10℃,and the inflorescence started to grow after the temperature higher than 18°C,then the Initial bloom stage started after the temperature higher than 22°C.From the late blossom period to the early fruit period,the blossom dropping rate of fertile flowers reached to 49.02%.After bear fruit,the dropping rate of the fruits reaches to 72.74% from the Primary fruit stage to the Fruit expanding stage,before the rate remains stable.The fresh weight of fruit increase quickly to the top during 70 days after initial fruiting,then turn stable during 70-110 days,after 110 days,the weight decrease because of lose water content in this stage.Pulp accounts for 60% ～ 65% of the whole fruit weight,seeds weight accounts for 34% ～ 39%,kernel accounted for 6% ～ 7% of the whole fruit.The branches of soapberry could be divided into short fruiting branches(length in 10～33cm),middle and long fruiting branches(length in 35～56cm),and long fruit branches(length in 58～82cm).The yield increased gradually when the last-year branches’ diameters>15mm.The ability of source-sink transfer nutriotion is related to the length of inflorescence and infructescence,shorter is better,and the main section control the transferring is seeds(R2=0.61).2.Based on the research of light distribution on nature tree canopy,the method of setting different number of scaffold branch number(N3,N4,N5,and SC),branch angle(A30°,A45°,A60°,and A90°)and thinning out of fruiting-shoot per projection area(8-20),then combine the branch number and branch angle as a two-factor interaction.The Win SCAOPY,digital lux meter and Li-6400 was used to measure the canopy characteristics(LAI and CGfr),light characteristics(light ratio and PPFD)and photosynthetic characteristics(Pn,Tr,Gs and Ci)in different soapberry tree architectures.The 3D visible photos were used to build trees’ ideotype and analyze the leaves distribution.The results indicate,(1)The light intensity of naturally growing trees are unreasonable— interior canopy’s is only 10 to 15% of the space’s.(2)After trimming and pruning,exterior canopy’s light rate is 40 ～ 54%,central canopy’s is 32～35%,and interior canopy’s is 27 ～ 31%.The treatment of 16-18 fruiting branches contributed to the highest yield of 347 g/m2.(3)Controlling the scaffold branch angle influenced light distribution,and branch angles of 60° and 90° increased light absorbance by 2-3 times in the vertical layers.A90°N3 canopy architecture,which had 16% higher light interception ability than the other treatments and maintained the highest cumulative LAI(19.57)during the growing season,was the most suitable for preserving leaves in August and October,the leaves amount in the middle layer arrive 7000,which can take advantage of canopy space,the fractal dimension arrives 1.988.A60°N3architectures provided 1-2 times higher photosynthetic ability than did the other architectures.(4)Light interception ability was positively correlated(R2=0.785)with LAI from May to October.The number of inflorescences was not directly correlated with yield,but yield in November was positively correlated(R2=0.5)with the photosynthetic rate*LAI in August.Overall,high light interception ability could solve the problem of leaf abscission which have the correlation with LAI,and high photosynthetic ability could decrease fruit abscission in soapberry trees.A60°N3 and A90°N3 are the current ideotypes.3.Carbohydrate,endogenous hormone,mineral element and 13 C analysis was used in this research based on exogenous plants regulator supply.The results indicate,(1)spraying 100 ppm GA3 can make yield 6 times higher.Spraying 2,4-D 10-20 ppm,which significantly increase the fruit-set number 1-2 times.Supplying plant growth regulator which mix with 0.3% Ca2+-20 ppm 2,4-D have highest yield,which is 75% more than CK.(2)After exogenous sucrose supply,1.5% and 3% can increase fruit-setting rate and yield 3-5 times,before blooming spraying 3% 3 times,the carbongydrate content in inflorescence is 3-4 times higher than CK,which give 3 times increasing for the sink allocate and transfer ability.At the same time,GA3 also increase,the ABA is in a opposite trend,decrease from16μg/g to 4μg/g,reduce the stimulate for flower abscission layer.Before physiological fruit drop stage,spraying 1.5% treatment can increase the fruit carbohydrate content 1.5-2.0 times of CK.Significantly reduced ABA content of leaf and fruit to 50% of CK,which guarantee the source-sink increase nearly 2 times of potential.Spraying the high concentration of sucrose can improve the content of N,P,K.(3)Nutrition transfer pathway showed that leaf total sugar and fruit total sugar established relation by P,the fruit sugar and fruit growth hormone(gibberellin,cytokinin and auxin)has a positive correlation,leaf total sugar and leaf cytokinin,leaf nitrogen content and the fruits’ abscisic acid has a positive correlation,the fruits sucrose has the direct relationship with fruit endogenous hormones,leaf N,fruit endogenous hormone and leaf total sugar all have direct correlation.Pruning is an outside method regulate light and leaves distribution,and balance the relation of vegetative growth and reproductive growth.Nutrition supplements is an internal method for regulating the photosynthesis product distribution,increase transfer ability form source to sink.The purpose is to provide technical support to high yield research,and laid a theoretical foundation for the tree nutrition migration and absorb feedback mechanism. |
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