Studies On The Inheritance And Fruit Storability In Anti-decayed Tomato Fruit(Lycopersicon Esculentum Mill.)

Common tomatoes which are able to reach red-matured stage, when ripe, will be quickly softened, difficult to be stored and transported in selling season. Thus a lot of tomatoes become decayed, which results in great loss. Tomato with late maturity gene has great advantages in fruit hardness and storability, compared with common tomatoes. In this study we explore the dynamic of the storage property with some special tomato materials, to explore the fruit storage characteristics and inheritance, and to provide a theoretical basis for the utilization of these special tomato materials.1. It was found that with the fruit development, fruit soluble pectin content increased steadily, either in the common ripened parent (Nong-da J46, P₁), or in the ripen mutant parent (Nong-da J45, P₂) and their hybrid (F₁). The fruit PG activity and soluble pectin content of P₂ were much lower than that of the P₁, while the fruit PG activity and soluble pectin content of F₁ was higher than that of P₂ but lower than that of P₁. Experimental data showed that the PG activity did not increase significantly before fruit ripened.2. Fruits of common ripened parent (Nong-da J45, P₁), ripen mutant parent (Nong-da J45, P₂), and F₁, F₂, BC_1P1, BC_1P2 populations were harvested in green-matured stage to investigate the fruit storability and its inheritance. Results showed that fruit decayed index varied with the different tomato populations. Fruit decayed index of P₁ population was higher than and BC_1P1 were able to reach common red-matured stage, and had a relative higher percentage of decay in population level, while the fruit of P₂, fruits of ripen mutant parent did not decay even 47 days after storage, though the fruits of F₁ were able to reach the red-matured stage, the percentage of decayed fruit was lower than that of the common tomato parent, the percentage of decayed fruit in F₂ population was near to that of the F₁ population, but some fruits kept in green-matured stage, and BC_1P2 were good in storage property. Numbers of plant which were able to and not able to turn to red-matured was fit the ratio of 3 to 1 and 1 to 1 in F₂ and BC_1P2 populations, respectively. Same result was obtained in the character of fruit decay. It could be concluded that either the unable to turn red-matured fruit character or the un-decayed fruit character was controlled by one recessive gene each.3. Fruits of normal ripened tomato parent (G1-7-4, P₁), ripe mutant parent (F12-3-6, P₂) and their hybrid (F₁) were harvested at green-matured stage, and fruits were treated with ethephon (1000 mg/1) or with water (CK) for 1 min, and then were storage at 21-25℃. It was found that the contents of sucrose, reduced sugar, total soluble sugar, soluble solid, titratable acid and vitamin C of fruit of P₁, P₂ and F₁ had the similar tendency, i.e, with the storage the contents of the above quality factors were increased firstly, and then decreased, similar tendency was observed both in treated and untreated fruit. On the other hand, the content of above quality factors in F₁ fruit was lower than that of P₁ but higher than that of P₂. During the fruit storage period, the highest content of sugar and titratable acid in ethephon treated fruits was 12 days earlier than that of untreated fruit, and the content of above fruit quality factors were lower than that of the untreated fruit, it suggest that ethephon treatment was able to promote fruit ripe. Result showed that with the fruit storage, lycopene content, PG activities and soluble pectin content of P₁ and F₁ fruits increased, but lycopene content and PG activities of P₂ were at very low level. Ethephon treatment promoted the increase of lycopene content, PG activities and soluble pectin content in P₁ and F₁ fruit, but had no influence to P₂ fruit. It was also found that with the fruit storage, fruit firmness decreased steadily except for the P₂ fruit which was decreased only in the beginning storage stage. Ethephon promoted the decrease of fruit firmness, even for the fruit of P₂, which kept at a relative high level during 12 to 48 days after storage with no ethephon treatment.