Spinach is one of the leafy vegetables that has high nutritional and economic importance due to its global consumption. This vegetable is very valuable fresh and even processed, and its annual consumption is increasing every year. For this reason, high performance in this plant is very important to meet global needs, but factors such as bolting greatly affect the quality and productivity of this plant. Bolting is a phenomenon caused by the coordinated effects between different environmental variables and internal genetic components, which often limits economic production in plants such as spinach because the increase in stem length along with flower differentiation causes changes in taste and color and lack of marketability. It has been determined that the five paths of photoperiod, age, temperature, vernalization, and autonomous form a complex regulatory network that determines the exact time of flowering due to their interaction with environmental and epigenetic factors. Therefore, to solve this problem, it is necessary to investigate mechanisms involved in this process, especially molecular factors such as the expression level of genes involved in bolting in spinach plants. Therefore, in this study, an experiment was designed to investigate the expression of genes involved in autonomous pathways and circadian rhythm in different stages of spinach growth. To achieve this goal, two genotypes, Virofly and Kashan, were selected as the late-flowering and early-flowering genotypes, respectively, and were cultivated in a completely randomized block design with three biological replications in the growth chamber in the crop year 1400-1401. After preparing leaf samples from different growth stages of the plant including 4, 6, 8, 10, and 12 leaves, and RNA extraction and cDNA synthesis, the expression level of some genes was investigated and eva‎luated using Real-time polymerase chain reaction. Based on the results, it was found that the LHY gene has the lowest expression level at the 4-leaf (vegetative) stage in both investigated cultivars And respectively, at the 8-leaf stage in the Kashan mass and at the 12-leaf stage in the Virofly variety (the stage when the plant is entering the reproductive phase or flowering has started), the highest level of expression is observed. The investigation of this gene shows that a high expression of this gene is observed at the critical point of the beginning of flowering and when entering the reproductive phase. The LD gene in the Kashan genotype showed a significant role in the transition from the vegetative to the reproductive phase. Also, the expression of this gene in the Kashan genotype was higher than in the Virofly genotype in different growth stages. Also, the FLD/RSII gene had a higher expression in both masses in the reproductive stage than in the vegetative stage, and this gene has a high expression level during flower formation. Examining the results of the TOC1 gene shows that the expression of this gene in Kashan mass in the vegetative stages until entering the reproductive phase is higher than that of the Virofly variety, which indicates the role of the stimulus of this gene in entering the reproductive phase and early flowering. The results of this study play an important role in understanding the effect of important genes in regulating flowering time in spinach. Also, by using these results in the improvement programs, it is possible to improve the existing stands from the point of view of flowering time. In addition, these results can be useful in studies related to the regulation of genetic mechanisms related to bolting in other vegetables and even crops.

ابوذر سورني

مجيد طالبي , امير مساح