Evaluation Of Walnut Cultivars In Dechang County

For the mixture and differences of walnut cultivars of Dechang County,Sichuan province,with the introduction of the county walnut cultivars and local clones for research materials,first of all,we determine its cultivation environment adaptability and resistance to disease,according to walnut cultivars and clones,ground diameter,tree height,crown breadth,tree potential and incidence of natural fruit growth characteristics,and to evaluate its yield and fruit quality research,using analysis of variance,multiple comparison,making a comprehensive comparative analysis methods such as principal component analysis,in order to breed the appropriate popularization and application of the Dechang’s walnut varieties,and to promote the healthy and high-quality development of Dechang’s walnut industry.The main research conclusions are as follows:(1)15 testing cultivars and clones grow in Dechang under significant differences(p < 0.05),diameter range in 12.04 cm(Y3)～ 22.96 cm(B7),tree height range in 4.06 m(B3)～ 7.13 m(B7),the crown breadth range 11.77 m2(Y3)～ 32.74 m2(Y1),Y1 and Y3 tree grows weak,B3 and Y5 are on general level,the rest are up to the strong level,the fruit of ZY1,ZY2,B4,B5 and B7 all are with no obvious symptoms,The incidence of B3,Y1 and Y4 are serious,and the incidence of the other varieties(clones)are slight.After the investigation and evaluation of 15varieties(clones)’s growth characters and fruit incidence rate,the good v cultivars and clones ZY1,ZY2,B4,B5 and B7 with strong adaptability and high disease resistance are selected through comprehensive evaluation.(2)We evaluated the average yield per plant of 15 cultivars and clones,and the results showed that the average yield per plant of different cultivars and clones was significantly different(p < 0.05).The average yield per plant of Y5 was 34.16 kg,and ZY2 and B7 were slightly lower than that of Y5,showing strong fruit bearing.The average yield per plant of Y1 was the lowest at 12.14 kg,and there was little difference between B1,B3 and Y1.(3)The inner seed coat thickness,peeling difficulty,color,taste and kernel taste of fresh fruit of 15 cultivars and clones were determined.The results showed that the whole kernel of B4,B5 and B7 fresh fruit were easy to take,the inner seed coat was relatively thin,the skin was easy to remove,the inner seed coat had no obvious astringency,the kernel was sweet,suitable for the development of fresh walnut.ZY1 and ZY2 inner coat are purple,may have special phenolic substances,can be developed as characteristic cultivars.(4)The appearance and nutritional quality of dried fruit of 15 cultivars and clones were determined and evaluated.The results showed that the shells of B4,B5 and B6 were relatively thin,and the shell thickness was less than 1.00 mm.The single fruit weight and three-diameters of ZY2,B7 and Y5 were significantly higher than those of other clones.The yield of B4,B5 and B6 are high,close to 65%,while that of B2,the lowest,is only 41%.The highest B8 content was20.27%,and the lowest Y2 content was 12.41%.All cultivars and clones had high crude fat content,ranging from 67.29% to 73.82,with an average level of 71.57%.The average content of mineral elements of all the cultivars and clones was from high to low,which was K >P>Mg>Ca > Mn > Fe> Zn > Cu.(5)on the of evaluating the adaptability,disease resistance and yield of 15 cultivars and clones,the principal component analysis method was used to evaluate the appearance quality and nutritional quality.The comprehensive evaluation results show that the comprehensive characters of B5,ZY2,Y5 and B7 are excellent and of good quality,which is worthy of promotion.