Evaluation On Local Pear Germplasm Resources In Sichuan Based On Appearance And Sugar-acid Content

Sichuan is located in 36 biodiversity hotspots in the world.The diverse climate and complex terrain have produced abundant pear germplasm resources.It is an important production area for pears.It has a long history of cultivation and is widely distributed.Basin,Minjiang River and Tuojiang River Basin,Dadu River Basin,Yalong River and Anning River Basin.In this study,75 pear germplasm resources from 17 pear producing areas in the five major pear producing areas of Sichuan Province were collected and evaluated.The main research results are as follows:1.Through the analysis of the genetic diversity of appearance traits and the detection and analysis of soluble sugar,organic acid and the content of the two components,it was found that the genetic diversity of pear germplasm resources in Sichuan is rich,and the variation coefficients of 16 key appearance qualities are in 13%-77%,and the range of genetic diversity index is 5.81-6.60.The range of total sugar content was 251.71-717.14mg/g,the average value was 390.49 mg/g,and 4 sugar components were detected.The content range of total acid was 28.32-138.02 mg/g,the average content was 64.55 mg/g,and 8 acid components were detected.Among the germplasm resources screened in this study,there were 70 germplasm resources with malic acid type and 5 with citric acid type.2.The results of principal component analysis and cluster analysis showed that the five indicators of longitudinal diameter,single fruit weight,transverse diameter,length of fruit stem and relative area of fruit cover color can be used as indicators to evaluate the external quality of pear fruit,sugar-acid ratio,total The three indexes of acid and total sugar can be used as indexes to evaluate the quality of sugar and acid in pear fruit.Through comprehensive score evaluation,20 germplasm resources with relatively high-quality appearance quality and 7 resources with relatively high-quality soluble sugar,organic acid and their components were screened out.Combined with the analysis of the evaluation results of appearance and sugar-acid quality,6 germplasm resources with better comprehensive performance were screened out.3.The results of cluster analysis showed that there are four types of sugar-acid quality.Among them,among the 75 collected resources,there are 67 resources with low sugar and low acid;5 resources with high sugar and high acid;2 resources with low sugar and high acid;and 1 resource with high sugar and low acid.In this study,through the collection,evaluation and research of the germplasm resources and fruits of five major pear producing areas in Sichuan Province,it provides guidance for the production and cultivation of pears,selection of cultivars and suitable cultivars for cultivation areas under the background of geographical environment and ecological climate in Sichuan Province.Provide a reference for performance assessment.At the same time,provide direction for pear variety breeding,sort out key core germplasm resources,and provide basis for pear germplasm resource development and utilization and variety breeding.