| As one of the most widely cultivated vegetables,tomato(Solanum lycopersicum)is essential to people's life and is an important food processing material.Tomato is also an important model plant.Mutant is a good material for new variety breeding and functional genomics study,while the current tomato mutant library is still relatively small.Therefore,in this paper,seeds of the sequencing tomato varieties 'Heinz 1706' were treatment with different concentration EMS,then mutagens were screened from offspring and obtain stable mutant lines,a mutant strain of leaf color was analyzed after tomato mutant library was established.The main results of this research are as follows:1.The seeds of tomato varieties 'Heinz 1706,were treated with different concentrations of EMS(0.3%,0.5%,0.7%,0.9%,1.00%,1.3%,1.5%,2.0%)for 8h and 12h,the results showed that the seed germination rate decreased with the increase of EMS concentrations and the prolongation of treatment time.High concentration of treatment significantly reduced the seed setting rate,affecting the normal growth and development of plants.We finally confirmed using 1%concentration of EMS treatment 12h is a suitable treatment method for seed mutagenesis through comprehensive consideration of the mutation rate and growth and development status.2.There were 553 mutant strains 1160 plants with variation of leaf shape,leaf color,flower morphology,fruit size,plant type and other characters were obtained by counting the growth and development characteristics from 7864 individuals of M2 population.The total individual variable is 7.0%,among which 324 had multiple mutated phenotypes and 229 had only a single mutant phenotype.Leaf,flower,fruit and plant muutant strains were 375,183,196 and 460,respectively,the variation frequencies were 4.77%,2.33%,2.49%and 5.85%,respectively.The seeds of mutant plants of the tomato 'Heinz 1706' were hoarded and the library of mutants was constructed.3.A leaf-colored yellowing mutant(Y55)was obtained from the M2 population and showed a significant yellow leaf phenotype during the whole plant growth.It's growth potential was weaker than that of the wild type,but can normally blossom and fruit.The content of chlorophyll a,chlorophyll b,carotenoid,total chlorophyll and chlorophyll a/b of Y55 were significantly lower than that of wild type.At the same time,the content of precursor substance of Chlorophyll synthesis of Y55 was significantly lower than that of wild type.The results showed that the decrease of chlorophyll content of Y55 was likely due to the decrease of the synthesis ability of chlorophyll biosynthetic pathway.According to the observation of scanning electron microscopy and transmission electron microscopy,we found that the area of lower epidermis under guard cells,stomatal area and fuzzy number of Y55 are significantly lower than the wild type,the structure of chloroplast was damaged.The analysis results of photosynthetic and fluorescence parameters showed that photosynthetic rate of Y55 were significantly lower than those of wild type,the photosynthetic efficiency and photosensitivity of Y55 were lower than that of wild type.Genetic analysis showed that the yellow leaf phenotype was controlled by a single stealth gene.In conclusion,the EMS mutagenesis treatment system of 'Heinz 1706' and the mutant library were established in our research.The morphological characters,physiological parameters and genetic traits of leaf color of Y55 were analyzed.These researched have laid a solid foundation for further study of related gene functions. |
PDF Full Text Request