Appraisal With DUS Test Of 5 New Tea Plant Strain Including ’Beichuan 1’

Although Sichuan is a large province of tea resources and tea production,it still needs to strengthen the selection and promotion of new varieties with high quality and characteristics.In this experiment,5 new tea tree strains cultivated by the tea tree breeding team of Sichuan Agricultural University through single plant selection and systematic selection were taken as the research object,and the national-level elite‘Fuding Dabaicha’was used as a control(referred to as‘Fuding’for short).The DUS test was conducted,and its biological characteristics,fresh leaf yield and biochemical quality content were tested,and its adaptability(cold resistance,drought resistance and resistance to diseases and insects)and tea suitability were initially identified.SSR molecular marker technology has carried out variety identification and genetic diversity research,aiming to provide some theoretical basis for breeding new tea varieties with high yield,high quality or high resistance,and applying for the registration of new varieties of tea and protection of new varieties.The research results are as follows:1.From 2018 to 2019,five new strains were tested for DUS for two consecutive years.The results showed that there were significant differences between some of the traits of the five new strains tested and the control’Fuding’and among the strains,that is,they showed specificity,of which the new strains Chuancha 10,Chuancha 9,Hongya 1,Beichuan 1 and Chuanhuang 3 have 10,9,10,9 and 12 traits(leaves,flowers,branches,whole plant)different from the control,respectively,and the results of the determination of the biological traits of the tested strains have been maintained for two consecutive years,indicating that the each traits have consistency and stability.Therefore,judging from the DUS test results,the tested strains have the basic conditions for the registration of new varieties.2.The two-year phenological observation results of each new strain show that:Chuancha 10 is a middle-growing variety,and the germination period is 4～7 days later than the control‘Fuding’;Hongya 1 and Chuanhuang 3 are extremely early-growing varieties,which are more than the control‘Fuding’was 2～9d,3～9d earlier;Chuancha 9 and Beichuan 1 were early-growing varieties,which was close to the control‘Fuding’phenology.From the perspective of fresh leaf output,the average yield of fresh leaves of the five new lines in two years is Hongya 1(391.56 kg/667m~2)>Chuancha 10(352.03 kg/667m~2)>‘Fuding’(311.32 kg/667m~2)>Chuancha 9(303.64 kg/667m~2)>Beichuan 1(291.94kg/667m~2)>Chuanhuang 3(206.64kg/667m~2).Among them,Hongya 1 had the highest output,25.77%higher than the control;followed by Chuancha 10,which was 13.08%higher than the control;Chuancha 9 and Beichuan 1 were close to the control;while Chuanhuang3 had a higher output than the control 33.62%lower.This shows that the growth potential and growth amount of the new shoots of the 5 test strains are greatly different.Hongya 1 and Chuancha 10 have strong growth vigor and high output potential,while Chuanhuang 3 has the weakest growth potential and low production level.3.The field resistance of each new strain was directly identified,and the physiological indexes(MAD,Pro,soluble sugar,REC,POD,SOD,CAT)of leaves of each strain related to resistance were tested,and indirectly compare the resistance of each strain through these physiological indicators.The identification results show that the resistance-related physiological indicators and cold resistance(drought)of each new strain are different.Overall,Chuancha 10 and Chuancha 9 have excellent cold resistance and drought resistance,while Beichuan 1 and Chuanhuang 3 have weaker resistance than control.The identification results of resistance to tea plant diseases and insect pests showed Hongya 1,Beichuan 1 were high resistance,but Chuancha 10,Chuancha 9 and Chuanhuang 3 were medium resistance to tea anthracnose;there are Beichuan 1 and Chuanhuang 3 were high resistance,medium resistance is Hongya 1,and Chuancha 9 is susceptible.Chuanhuang 3 is high resistance to tea lesser leafhopper,and the other strains are all susceptible.4.The main biochemical composition test results of the new strains indicate that the spring extracts of the new strains range from 43.17%to 48.67%;the total free amino acids range from 4.73%to 5.22%;the caffeine ranges from 3.17%to 3.89%;the tea polyphenols ranges from 17.14%to 20.21%;the total amount of catechins ranges from 14.31%to 18.26%;the P/A of various strains in spring ranges from 3.14 to 4.14,the P/A of various strains in summer ranges from 8.40 to 11.11,all are green&black tea is also produced.Among the spring shoots of various strains,Hongya 1 has higher caffeine(3.66%),amino acid content(5.22%),and the highest water extract content(48.67%)and catechins quality index(1364.90),with the biochemical substances for making famous tea basic;Chuancha 9 has higher caffeine(3.98%),tea polyphenols(20.21%)and amino acids(5.04%);Beichuan 1has higher content of catechins(18.26%),amino acids(5.02%)and water extracts(47.20%),and has a strong material basis for making black tea;Chuancha 10 has higher tea polyphenol content(20.07%).The sensory quality evaluation results of the green and black tea samples of various strains showed that the evaluation scores of Hongya 1 black and green tea are significantly higher than that of‘Fuding’.The quality of tea making is excellent:the green tea has a tender and long fragrance,the soup color is green and bright,and the taste is mellow and fresh;the black tea has a floral and fruity fragrance,the soup is red and bright,and the taste is sweet with strong.The quality of black and green tea of Chuancha 10 is close to that of the control.The quality of Chuanhuang 3 is average.5.The SSR molecular labeling results of the new strains showed that after PCR reaction amplification by 10 pairs of primers such as Cs FM1058,Cs A18,Cs TM056,these markers obtained a total of 60 data points,showing that each strain has different genotypes and there are differences at the molecular level;a genetic diversity analysis was conducted.The genetic diversity analysis of the experiment yielded an average genotype No.of 4,allele No.of 4,gene diversity of 0.62,heterozygosis of 0.68,and PIC of 0.56.It shows that each line has rich genetic diversity.To sum up,the DUS test results show that the 5 new strains tested have different traits,so they have specificity,stability and consistency,and the SSR molecular marker results indicate that each strain has different genotypes and rich genetic diversity.A comprehensive comparison of the test and identification results of the yield,resistance,content of main biochemical components,tea making suitability and tea quality of the five new strains.The yield,stress resistance and tea leaves of the varieties Chuancha 10 and Hongya 1 is better than the control to a certain extent,which have the advantage and potential of breeding high-yield and high-quality varieties.Chuanhuang 3 has the lowest yield,and the rest of the indicators are weaker than the control,so it does not have the conditions for breeding and registration of new varieties.