Wohlfeiler Josefina, Alessandro María Soledad, Morales Andrés, Cavagnaro Pablo Federico, Galmarini Claudio Rómulo
Estación Experimental Agropecuaria La Consulta, Instituto Nacional de Tecnología Agropecuaria (INTA), ex Ruta 40 Km 96, La Consulta 5567, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires 1425, Argentina.
Plants (Basel). 2022 Apr 15;11(8):1075. doi: 10.3390/plants11081075.
Carrots require a certain number of cold hours to become vernalized and proceed to the reproductive stage, and this phenomenon is genotype-dependent. Annual carrots require less cold than biennials to flower; however, quantitative variation within annuals and biennials also exists, defining a gradient for vernalization requirement (VR). The flowering response of carrots to day length, after vernalization has occurred, is controversial. This vegetable has been described both as a long-day and a neutral-day species. The objective of this study was to evaluate flowering time and frequency in response to different cold treatments and photoperiod regimes in various carrot genotypes. To this end, three annual genotypes from India, Brazil, and Pakistan, and a biennial carrot from Japan, were exposed to 7.5 °C during 30, 60, 90, or 120 days, and then transferred to either long day (LD) or short day (SD) conditions. Significant variation (p < 0.05) among the carrot genotypes and among cold treatments were found, with increased flowering rates and earlier onset of flowering being associated with longer cold exposures. No significant differences in response to photoperiod were found, suggesting that post-vernalization day length does not influence carrot flowering. These findings will likely impact carrot breeding and production of both root and seed, helping in the selection of adequate genotypes and sowing dates to manage cold exposure and day-length for different production purposes.
胡萝卜需要一定时长的低温才能通过春化作用进入生殖阶段，且这种现象因基因型而异。一年生胡萝卜比两年生胡萝卜开花所需的低温时间少；然而，一年生和两年生胡萝卜品种内部也存在数量上的差异，这就定义了一个春化需求梯度（VR）。胡萝卜在春化作用发生后对日照长度的开花反应存在争议。这种蔬菜既被描述为长日照植物，也被描述为中性日照植物。本研究的目的是评估不同胡萝卜基因型在不同低温处理和光周期条件下的开花时间和频率。为此，将来自印度、巴西和巴基斯坦的三个一年生基因型以及一个来自日本的两年生胡萝卜品种，分别在7.5°C下处理30、60、90或120天，然后转移到长日照（LD）或短日照（SD）条件下。结果发现，胡萝卜基因型之间以及低温处理之间存在显著差异（p < 0.05），开花率的提高和开花时间的提前与更长时间的低温处理相关。在对光周期的反应上未发现显著差异，这表明春化作用后的日照长度不会影响胡萝卜开花。这些研究结果可能会对胡萝卜的育种以及根和种子的生产产生影响，有助于为不同的生产目的选择合适的基因型和播种日期，以控制低温处理时长和日照长度。
