Contents Of Flavonoids And Caffeoyl Quinic Acid And The Anitoxidant Capacity And Investigation Of Late Blight Resistance In Different Tomato Varieties

Among different tomato varieties the mutrition they contain are obvious distinct.Specifically, the content of flavonoid and caffeoyl quinic acid （CQA）, two important nutrients,is extremely different in diverse varieties of tomato. In this study, we got23tomato varietiesfor quantitative detection of flavonoid and CQA in the pulps and peels. The rutin andkaempferol rutinoside are selected for substance flavonoid, and three typical CQA containingchlorogenic acid,1,5-dicaffeoyl quinic acid （diCQA） and3,4,5-Tricaffeoyl quinic acid（triCQA） are also detected in the experiment.Firstly we detected the content of rutin and kaempferol rutinoside in the selectedvarieties. According to the results of HPLC, the respective average content of the rutin andkaempferol rutinoside is2.016mg.g^-1and0.468mg.g^-1. In particular, the content of rutin inthe peel of TaiwanQiaomeiren could reach15.770mg.g^-1at the highest level, and kaempferolrutinoside in the peel of JinhuangYidianhong reached2.820mg.g^-1. In addition, both of theflavonoid mentioned above had a distinct difference content between pulp and peel from thesame cultivar. As a result, with an average content of0.235mg.g^-1and0.200mg.g^-1in the allstudied pulps for rutin and kaempferol rutinoside respectively, the mean amount in the peels is3.797mg.g^-1and0.737mg.g^-1.Then, we also analyzed the statistics result about CQAs from these cultivated tomatovarieties with the average amount of0.812mg.g^-1、0.256mg.g^-1and0.297mg.g^-1forchlorogenic acid、diCQA and triCQA respectively. The highest content of the three kinds ofCQA is2.24mg.g^-1、1.60mg.g^-1and6.13mg.g^-1separately from the peel ofJinhuangYidianhong、ZiyiXiannv and TaiwanQiaomeiren. Similar to flavonoid, due tovariance between pulp and peel from the same fruit, chlorogenic acid、diCQA and triCQAhave an average content of0.90mg.g^-1、0.39mg.g^-1and0.52mg.g^-1separately in all the peels,which are1.3、3.3and6.3times the content in pulps.As we know, contents of the five substances are different from each other, but whatinterests us is the relationship between each of the five ingredients and antioxidant capacity ofthe whole fruit. It is amazing that rutin components from peels and pulps are both highlycorrelated with the antioxidant capacity, with the correlation coefficient reaching1.000. Giventhe extremely significant correlation, we carried on linear regression analysis of the datameasured and obtained an equation to describe the relations which were showed below:Antioxidant capacity=3.320*rutin content+1.630E-10. Unlike rutin, other ingredients have a different degree in pertinence relation withantioxidant capacity. Kaempferol rutinoside and diCQA in the pulps are moderately correlatedwith the whole fruit’s antioxidant capacity. However, as with the results of kaempferolrutinoside and diCQA in the peels, chlorogenic acid and triCQA have no correlation withantioxidant capacity in the peels and pulps. Meanwhile, we also analyzed the relation betweenantioxidant capacity and the whole amount of flavonoid, as well as CQAs in peels and pulps.As we tested in this research, antioxidant capacity is mediumly correlated with the wholecontent of rutin and kaempferol rutinoside in all studied pulps, but we didn’t find thisrelationship in the peels.Another important research in this article is about breeding for disease resistance onpotatoes. Potato late blight, which is caused by Phytophthora infestans de Bary and leads todramatically decrease in potato production, is a destructive disease. Considering severelyeconomic losses caused by this disease, screening effective resistance genes which conferbroad-spectrum resistance and durable resistance becomes more and more important forbreeding today.Tomato, another cash crop, belongs to Solanaceae as good as potato and they have a veryclose genetic relationship. Though many different physiological races of Phytophthorainfestans have been differentiated, they can not infect tomatoes as easily as potatoes.Therefore, it is of great significance for us to screen resistance genes from different tomatovarieties. In this research, we put38cultivated tomato varieties as the object and obtained7resistant varieties and5susceptible ones via inoculating race90128and JL-5of blightpathogen on leaves in vitro. The results of the study laid the foundation for preliminarylocation of the effective resistance genes and made molecular breeding for potato-diseaseresistance possible.