Investigation And Evaluation Of Excellent Germplasm Resources Of Zanthoxylum Bungeanum In Dechang County

Zanthoxylum bungeanum is one of the characteristic forestry industries in Decang county.However,the effects of several years of cultivation in some areas are not ideal,and problems such as significant difference in annual output,serious diseases and insect pests exist,which seriously restrict the development of the Zanthoxylum bungeanum industry in Decang county.Therefore,it is urgent to find a suitable Zanthoxylum bungeanum superior trees to improve the local Zanthoxylum bungeanum varieties.So this study taking the germplasm resources of Zanthoxylum bungeanum in Dechang county as the object,the selection indexes of Zanthoxylum bungeanum were selected,the management measures,site conditions,growth habits,bearing habits,yield and fruit quality of the superior trees were investigated and determined,and the comprehensive evaluation and selection of the superior trees of Zanthoxylum bungeanum were carried out by using AHP,membership function and cluster analysis.The selected excellent Zanthoxylum bungeanum superior trees can be used for the improvement of Zanthoxylum bungeanum varieties in Dechang county.At the same time,the stepwise regression analysis of the growth habit index to the 1000-grain weight of dried peel index was carried out.The evaluation index system and mathematical evaluation model of Zanthoxylum bungeanum selection were established,which can provide reference for the selection of pepper trees.The main results are as follows:（1）Dechang county has rich resources of Zanthoxylum bungeanum.The planting area of Zanthoxylum bungeanum in the whole county is about 4,667 hm²,and the distribution of Zanthoxylum bungeanum is found in every township.The planting altitude of Dechang Zanthoxylum armatum DC.is mainly between 1,200 and 2,300 m,while that of Zanthoxylum bungeanum Maxim.is mainly between 1,800 and 2,700 m.（2）The skin color of Zanthoxylum armatum DC.in Dechang county after drying is mostly yellow-green,and that of Zanthoxylum bungeanum Maxim.is jujube red or big red.The average 1000-grain weight of dried peel of Zanthoxylum armatum DC.is19.826g,the average peeling rate is 51.52%,the average volatile oil content is 11.86%,the average nonvolatile ether extract content is 9.78%,and the average numb-taste components content is 11.07 g/kg.The average 1000-grain weight of dried peel of Zanthoxylum bungeanum Maxim.is 11.962 g,the average peeling rate is 51.57%,the average volatile oil content is 9.11%,the average nonvolatile ether extract content is13.06%,and the average numb-taste components content is 9.48 g/kg.Dechang Zanthoxylum bungeanum has excellent quality and good economic value.（3）The phenological period of all selected Zanthoxylum bungeanum superior trees is not exactly the same.The germination,budding,leaf expansion,full-blossom and maturity of Zanthoxylum armatum DC.are earlier than that of Zanthoxylum bungeanum Maxim,while the deciduous period of Zanthoxylum armatum DC.is later than that of Zanthoxylum bungeanum Maxim.（4）Stepwise regression analysis showed that lobular length had the greatest influence on the 1000-grain weight of dried peel among the indicators of growth habit.In order to improve the 1000-grain weight of dried peel,we should pay attention to the selection of lobular length.（5）Among the selected indicators,the weight coefficients were larger,including the 1000-grain weight of dried peel,peeling rate,yielding ability,and stability.The weight coefficients were all 0.0700 and above.These four indicators are the primary indicators of Dechang county Zanthoxylum bungeanum optimization.（6）The comprehensive membership function value of each selected Zanthoxylum armatum DC.tree ranges from 0.46 to 0.70,and the order of the size is WS-001>CD-005>CD-002>KY-001>CD-006>TL-002.The comprehensive membership function value of each selected Zanthoxylum bungeanum Maxim.tree is between 0.51 and 0.75,the order is JS-002>DLC-001>XG-002>XG-004>DLC-004.（7）When the European-style distance is 10,the selected Zanthoxylum bungeanum superior trees is divided into 3 grades,the first grade,which has the best overall performance.The second level,the comprehensive performance is excellent.The other three levels,the comprehensive performance is better.The first grade of Zanthoxylum armatum DC.superior tree WS-001 and Zanthoxylum bungeanum Maxim.superior tree JS-002 were selected as the outstanding Zanthoxylum bungeanum superior tree.（8）Taking the comprehensive membership value（S）as the dependent variable and each selection index as the independent variable,the mathematical evaluation model for selecting the best Zanthoxylum bungeanum was established:S=0.402+5.050C₅+1.818C₈+1.008C₉+0.962C₁₁+2.420C₁₆+0.197C₁₉+1.747C₂₅,R²=0.999.This model can be used to identify and evaluate the superiority of Zanthoxylum bungeanum.To sum up,the germplasm resources of Zanthoxylum bungeanum in Decang county are abundant,with excellent quality and good economic value.In order to increase the 1000-grain weight of the peel of Zanthoxylum bungeanum in Dechang county,the index of lobule length should be selected.Zanthoxylum armatum DC.superior tree WS-001 and Zanthoxylum bungeanum Maxim.superior tree JS-002 can be used as breeding materials of Zanthoxylum bungeanum for further tests.The mathematical evaluation model of Zanthoxylum bungeanum selection can be used to screen Zanthoxylum bungeanum varieties in other counties.