| Potatoes are an important economic and food crop.Developing the potato industry according to local conditions is of great significance for promoting rural revitalization in alpine mountainous areas.In Butuo County,Liangshan Yi Autonomous Prefecture,Sichuan Province,the potato industry has become the main pillar industry due to its unique geographical environment and cultural characteristics.The local "Butuo purple potato" is widely praised for its good taste and excellent storage properties.In 2014,"Butuo purple potato" became a national geographic indication agricultural product,with great market development potential.Currently,as an excellent local germplasm resource material,systematic studies on field biological characters,yield characters,and quality characters of "Butuo purple potato" are rarely reported.Different strains of "Butuo purple potato" resources have varying biological characteristics,and the differences in yield and quality are unclear.To explore the yield,quality formation characteristics,and variety specificity of "Butuo purple potato" and analyze the differences between its strains,this study set up a comparison experiment of resource materials between different main varieties and "Butuo purple potato" and a comparison experiment between different germplasm resources of "Butuo purple potato." Different main varieties included ’Mila,’ ’V7,’ ’Xisen 6,’ and other eight varieties,and they were compared with "Butuo purple potato 1"(a typical strain of Butuo purple potato).The comparative experiment of germplasm resources of "Butuo purple potato" evaluated the biological characters,yield,quality,and other characters of the six different strains collected,screened the specific indexes,and selected the optimal strains of "Butuo purple potato." The main results are as follows:1.Phenological and developmental characteristics of "Butuo purple potato"The "Butuo purple potato No.1" variety shows significant or notable differences in phenological development compared to other varieties,with a longer growth period for "Butuo purple potato." The growth period of "Butuo purple potato No.1" is 42-54 days longer than other varieties.The growth period of the six "Butuo purple potato" germplasm lines ranges from 132 to 144 days,with a dormancy period of 108 to 132 days.The sprouting period is concentrated between April 23 rd and April 30 th,the budding period between May 31 st and June 7th,the flowering period between June 26 th and June 30 th,and the maturation period between September 8th and September 14 th.2.Biological characteristics of "Butuo purple potato"The "Butuo purple potato" plant has an upright growth habit,with green or light green leaves,purple flowers,shallow or fairly shallow eyes,neat tubers,smooth or moderately smooth skin,round shape,light purple skin color,and light yellow flesh with a purple ring inside.3.Growth and material accumulation characteristics of "Butuo purple potato"The correlation analysis between the agronomic traits and single-plant yield of different varieties showed that plant height and stem thickness were both extremely significantly positively correlated with single-plant yield.The correlation analysis between the growth habit traits of "Butuo purple potato" resources and single-plant yield showed that plant height,stem thickness,drooping angle,and leaf angle were all extremely significantly positively correlated with single-plant yield,while internode distance,leaf area index,and chlorophyll content were significantly positively correlated with single-plant yield.The main stem number was negatively correlated with single-plant yield.The largest contributor to the yield of "Butuo purple potato" agronomic traits was plant height.The largest contributors to the yield of "Butuo purple potato" growth habit traits were the 4th leaf angle at the base,the 7th internode distance at the base,and the 6th internode distance at the base.The largest contributor to the yield of "Butuo purple potato" yield traits was the number of marketable tubers per plant.4.Yield and quality characteristics of "Butuo purple potato"The dry matter content of different potato varieties(lines)ranges from 11.10 % to29.68 %,starch content ranges from 11.03 % to 28.35 %,soluble sugar content ranges from 0.18 % to 0.82%,reducing sugar content ranges from 0.08% to 0.69 %,total dietary fiber content ranges from 4.52 g to 8.53 g per 100 g,vitamin C content ranges from 0.67 mg to 1.44 mg per gram,and soluble protein content ranges from 0.26 mg to 1.21 mg per gram.Mg ion content ranges from 7.42 mg to 228.33 mg per kg,Ca ion content ranges from 9.56 mg to 82.33 mg per kg,and total amino acid content ranges from 20430.80 μg to46737.39 μg per gram.Among them,"Butuo purple potato No.1" has a vitamin C content of >0.3 mg/g,reducing sugar content of less than 0.4 %,starch content of >22.00 %,and light yellow flesh with a purple ring inside.In addition,it has high dry matter,starch,soluble protein,and total dietary fiber contents,low heavy metal content,and high yield.The dry matter content of the six "Butuo purple potato" germplasm lines ranges from21.38 % to 27.91 %,starch content ranges from 7.74 % to 28.35 %,soluble sugar content ranges from 0.26 % to 0.50 %,reducing sugar content ranges from 0.04 % to 0.16 %,total anthocyanin content ranges from 0.073 mg to 0.118 mg per gram,and total dietary fiber content ranges from 6.1529 g to 8.3504 g per 100 g."Butuo purple potato No.5" has the highest total amino acid content.A comprehensive evaluation of the agronomic traits,quality traits,and yield indicators of Butuo purple potato resources using the DTOPSIS method shows that "Butuo purple potato No.5" has the best overall performance and can be used as a major resource for local development.In summary,the "Butuo purple potato" has an upright growth habit,high vitamin C content,low reducing sugar content,high starch content,and light yellow flesh with a purple ring inside."Butuo purple potato No.5" has the best overall performance.This study has guiding significance for the development and utilization of potato resources in Butuo County. |
