| Tomato is one of the most important vegetable crops and belongs to thermophilic plant. Under high temperature, tomato often leads to loss of production and susceptiple to disease. As the increase of global warming, heat-resistant research in tomato has been a universal focus, and has become a hotspot in the research of tomato.In this paper, each of two tomatoes (heat-resistant and heat-susceptiple tomatoes) were obtained though calculating the fruit set of tomato in all the ten tomatoes. To obtain identification index of heat tolerance in tomato, the four selected different heat-tolerance tomato materials were used to study the change of electrolyte leakage (EC) and chlorophyll fluorescence parameters under heat stress. By cDNA-AFLP technique, heat-resistance related gene has been isolated. This had laid a foundation for study of heat resistant in tomato, and provided a theoretical basis for heat resistant breeding in tomato.The results of this paper are as follows:1. High temperature can cause pollen vigor down, which affect bad pollination, disorder fertilization process, produce deformity fruit, even the fallen petal full-drop.Tomato fruit set is the best method of inspecting heat resistant ability under heat stress.This experiment conduct in the greenhouse trellis of YangDu test site in Zhejiang academy of agricultural sciences from June to August in 2009. Summing up the different periods of 10 tomato materials, it is showed that 'CLN-2413R' and '05-161F2-1-13-0-0-0'have better fruit set, more than 50%. But '9246' and '9185'have poorer fruit set, less than 1%. Fruit set and heat resistant tolerance in tomato have a significant positive correlation. 2. Through the determination of electrolyte permeability (EC) and relative electrolyte permeability (EC%) in tomato under heat stress with heat resistant tomatoes ('CLN-2413R' and '05-161F2-1-13-0-0-0') and heat susceptible tomatoes ('9246' and '9185') at the seedling stage, and anglicizing the correlation of the two electrolyte permeability and fruit set under high temperature stress, it is found that electrolyte permeability (EC) under heat stress and fruit set have a significant negative correlation (|R|>0.95). The electrolyte permeability (EC) under heat stress is suitable for a identification index of heat resistant tolerance in tomato at the seedling stage.3. Using FM-2 portable fluorescence spectrometer to measure the chlorophyll fluorescence parameters (Fv'/Fm',OPSⅡ,qP,Fv/Fm,Fv/F0,ETR) under heat stress in the four selected tomato materials, and analysing the relativity of the chlorophyll fluorescence parameters and fruit set, the results showed:the correlation of the chlorophyll fluorescence parameters (Fv'/Fm',qP,Fv/Fm,Fv/F0,ETR) and fruit set under high temperature is more than 0.9(|R|>0.9), a significantly correlation. It can be used as a identification index of heat resistant in tomato.4. Using the cDNA-AFLP technology to research gene differential expression of 'CLN-2413R' and '9246'at the seeding stage, it has isolated out 12 genes associated with heat-resistance ('CLN-2413R':3;'9246':9). Through the sequence analysis, the results showed that:four genes are related to tomato heat transfer coefficient (HTC); one gene has higher homology with eukaryotic luciferase; one gene is the sequence of tomato's chromosome; two genes are the sequence of tomato malic enzyme; the rest of the four genes are less than all the homology with known sequence in blast. And using the real-time fluorescence quantitative PCR technology to analysis gene differential expression, preliminary results showed that 'CLN-2413R' genes' expression level is higher than '9246' genes' after high temperature stress.It is showed that 'CLN-2413R' heat resistant gene can be lots of expressed after high temperature. |
PDF Full Text Request