Metabolism Of Sugar And Organic Acids In Different Varieties Of Tomato Fruits And The Hybrid Seed Purity Identification Of ’Zhe Fen702’ By SSR Marker

Tomato,catched great attention from consumers, is one of the most important vegetables around theworld.Currently,consumers focus on the flavor quality of tomato fruits, which is ralated to differentcultivars. Since the ratio of sugar to organic acid plays an important role in flavor quality, it isimportant to study the metabolism of sugar and organic acid in fruits. Tomato belongs toself-pollinated plants, so the hybrid seeds may be easily mixtured by female inbred seeds during theproduction process. Meanwhile, it is crucialt to identificate the seed purity by molecular markers. Inthe present study, we have determined the composition and content of sugars and organic acids, aswell as activities of sugar metabolism related enzymes in4cultivars of tomato fruits (‘ZJ4’,‘Zhezhen’,‘Micro-Tom’,‘Zheza809’) Besides, the polymorphism of tomato (‘zhefen702’) and itsparental lines are analyzed by SSR marker system. The main results are as follows:(1) Both the contents of glucose and fructose are minimum in mature green stage and reach thehighest level during Yellow stage. The Fructose content is slightly higher than glucose in red stage.The citric acid and malic acid are the main organic acids in tomato fruit. The citric acid increasesduring red stage, while the malic acid reduces.(2) The acid invertase and the neutral invertase increase during growing development in tomato. Theinvertase reaches the highest level during red stage in ’ZJ4’,’Zhezhen’ and ’Micro-Tom’ tomato, whilethose in ’Zheza809’ tomato reaches the highest level during yellow stage.(3) The sugar and orange acid ratios decreased during growing development. In red stage, the contentof sugar: Zhezhen’>’Zheza809’>’ZJ4’>’Micro-Tom’, the content of orange acid:’Micro-Tom’>’Zhezhen’>’Zheza809’>’ZJ4’, The sugar and organic acid ratio:’ZJ4’>’Zhezhen’>’Zheza809’>’Micro-Tom’.(4) Over100SSR primers are used in present study, in which14primers show stable andpolymorphic amplification profiles in hybrids and their parents. The bands of hybrid tomato arecomplementary types of their parents,and thus these primers are adapt to examine the purity of hybridtomato seed. Then, Primer LEag001one of the14primers, is selected for SSR identification with100single seeds of‘Zhefen702’. The purity is100%and this results was in accordance with filedperformance.