Studies On The Inheritance Of Resistance To Leaf Mould In Tomatoes (Lycopersicon Esculentum Mill.)

Tomato(Lycopersicon esculentum Mill.)is one of the most important vegetables all over the world,and has a very significant position in the people's everyday life of production and consumption.However,leaf mould(Fulvia fulva)is one of the multitude factors limited the tomato production,especially with the rapid development of the protected culture.Fulvia fulva has become the one of the most sever diseases in tomato production under greenhouse condition.To breed resistant cultivar is the most economically and effectively way to solve the detriment of Fulvia fulva.In this experiment,seedlings of six progenies,i.e.,sensitive to Fulvia fulva parent '010712" (P₁),resistant to Fulvia fulva parent '021217-3'(P₂),F₁(P₁×P₂),F₂,and BC_1P1(F₁×P₁). BC_1P2were used to study the inheritance of resistance to Fulvia fulva.And in order to study the relationship between resistance to Fulvia fulva and some related enzymes,SOD.G-POD. CAT,PPO and PAL,changes of these enzymes activities of P₁,P₂ and their hybrid(F-1) seedling were assayed both in inoculated population and none inoculated population. Meanwhile,MDA,the peroxide product of membrane lipid,was tested as well.The main results were as follow:1.It was found that symptom of leaf mould of sensitive population was appeared 2 weeks after inoculation.Investigated data showed that the resistant parent,F₁ and BC_1P2had no symptoms of invasion even 25 days after inoculation,while all seedlings of sensitive parent were infested by leaf mould,F₂ and BC_1P1progenies were separated in resistant and invasion. Chi-square test showed that the ratio of seedling numbers of resistant and invasion in F₂ progeny accorded with 3 to 1 ratio,while the ratio was 1 to 1 in BC_1P1progeny.Based on the result,the character of resistant to Fulvia fulva was determined by one dominant gene.2.It was found that there was little difference among the resistant parent,sensitive parent and their hybrid in the G-POD,CAT,PPO and PAL activities before inoculated,but the SOD activities of the resistant parent P₂ and F₁ were higher than that of the sensitive parent.On the other hand,obviously differences were found in SOD,G-POD,CAT,PPO and PAL activities among these three tomato populations when seedlings were inoculated with the pathogen of Fulvia fulua(race 1.2.3).Moreover.the relative activities of SOD,G-POD.CAT.PPO and PAL in the resistant parent and F₁ were much higher than that of the sensitive parent.It probably means SOD.G-POD,CAT.PPO and PAL act an important role in resistant to Fulvia fulva in tomatoes.There was closed relationship between the resistant to Fulvia fulva and the content of MDA which was the product of peroxide product of membrane lipid in tomatoes.It was found that the MDA contents were in lower level,either in the resistant populations,P₂ and F₁,or the sensitive population,P₁,and no significant differences were tested among the three tomato populations which were not inoculated with the pathogen of leaf mould.MDA contents were increased after inoculation,but it was the sensitive parent that the MDA content was much higher than that of the resistant parent and F₁,and this difference was more obvious 10 days after inoculation,which was just the period that the leaf mould symptom was being appeared.