Postgraduate Program in Seed Science and Technology, Eliseu Maciel Faculty of Agronomy, Federal University of Pelotas, Pelotas, Rio Grande do Sul, 96010-900, Brazil.
Postgraduate Program in Plant Physiology, Department of Botany, Institute of Biology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, 96010-900, Brazil.
Sci Rep. 2021 May 26;11(1):11038. doi: 10.1038/s41598-021-90487-x.
Rice is a crop that presents sensitivity to cold, especially in the germination phase, which leads to high economic losses. Alternative management forms are essential to increase tolerance to low temperatures, and seed priming represents a promising tool. The objective of this study was to investigate the priming effect of the aqueous extract of carrot roots on rice seeds to increase tolerance to low temperatures during germination. Seeds from cultivars BRS Querência (cold-susceptible) and Brilhante (cold-tolerant) were soaked for 24 h in concentrations of 0, 25, 50, and 100% carrot extract, sown on germitest paper and conditioned in BOD for 21 days at 15 °C. As a control, the seeds soaked in water were also germinated at 25 °C. They were evaluated for germination, first germination count, and germination speed index to calculate the stress indices: tolerance index, susceptibility index, and harmonic mean. They were also evaluated for the length and dry mass of shoot and root. The results showed that the rice seeds conditioning in carrot extract effectively reduces the damage caused by cold, significantly increasing the germination speed and the percentage of final germination and the growth evaluations, more expressive at 100% concentration. The stress indexes are efficient in estimating the tolerance of the cultivars and the effect of the different conditions in low-temperature conditions, highlighting the superiority of the Brilhante cultivar.
水稻对低温敏感，尤其是在发芽阶段，这会导致严重的经济损失。因此，需要采取替代管理方式来提高水稻的低温耐受性，而种子引发则是一种很有前途的方法。本研究旨在探讨胡萝卜根水提物对水稻种子引发处理，以提高其在发芽阶段对低温的耐受性。选用对低温敏感的品种 BRS Querência 和对低温耐受的品种 Brilhante 的种子，分别用浓度为 0、25、50 和 100%的胡萝卜提取液浸泡 24 小时，播种在 germitest 纸上，在 15°C、BOD 条件下培养 21 天。以水浸泡的种子作为对照，在 25°C 下进行发芽。评估种子的发芽率、首次发芽计数和发芽速度指数，以计算胁迫指数：耐胁迫指数、敏感性指数和调和平均值。同时还评估了芽和根的长度和干重。结果表明，用胡萝卜提取物处理水稻种子能有效减轻低温造成的损伤，显著提高发芽速度和最终发芽率以及生长评价，在 100%浓度下效果更为明显。胁迫指数能够有效地估计品种的耐胁迫性和不同低温条件下的处理效果，突出了 Brilhante 品种的优势。
