马铃薯试管块茎形成的分子机理及调控

通过对马铃薯块茎主要贮藏蛋白patatin基因表达和内源激素变化的研究揭示试管块茎形成讨衟atatin基因表达水平与块茎形成的关系，patatin基因在块茎分化形成中的作用机理

Use of microtubers in seed potato system has been considered as a revolutionary improvement in potato production, which is based on a technical prerequisite of high efficiency in microtuber induction. Through research on the patterns of patatin gene expression and variation of the endogenous growth substances during tuberization, main factors influencing tuber initiation have been further clarified and a technical system of mass production of potato microtubers has been developed. The results showed that the expression of patatin gene was in advance to the mophogenesis of tubers and tubers formed or tuber-like swelling occurred only in the treatments that patatin expression was detectable, suggesting a direct involvement of patatin gene in regulation of microtuber initiation. Furthermore, the expression of patatin gene was induced by high concentration of sucrose and its strength was correlated to photoperiods. Meanwhile, increase in JA, GA3 and ABA with different levels were observed during tuberization, but increase in JA was the highest among the substances assayed and it was positively related to tuber formation. These increases were also found variable with potato genotypes and number of tubers formed seemed not to be depended on the absolute contents of each growth substances but the balance among them especially the ratio of GA3/JA. Within the treatments of the present research, 8% of sucrose and 8h/d photoperiod favoured patatin gene expression and JA accumulation which enhanced tuberization. The results reinforced that potato varieties responsed differently to the tuber inducing conditions when they were opposed to 20℃ and 8% sucrose, indicating a genotype-dependent accumulative response to tuber induction. Therefore, the technique based mainly on photoperiod regulation as the key component for tuberization has been established.