Recently, grafting has been used to improve abiotic stress resistance in crops. Here, using watermelon ‘Zaojia 8424’ (Citrullus lanatus) as scions, three different gourds (Lagenaria siceraria, 0526, 2505, and 1226) as rootstocks, and non-grafted plants as controls (different plants were abbreviated as 0526, 2505, 1226, and 8424), the effect of cold stress on various physiological and molecular parameters was investigated. The results demonstrate that the improved cold tolerance of gourd-grafted watermelon was associated with higher chlorophyll and proline content, and lower malondialdehyde (MDA) content, compared to 8424 under cold stress. Furthermore, grafted watermelons accumulated fewer reactive oxygen species (ROS), accompanied by enhanced antioxidant activity and a higher expression of enzymes related to the Calvin cycle. In conclusion, watermelons with 2505 and 0526 rootstocks were more resilient compared to 1226 and 8424. These results confirm that using tolerant rootstocks may be an efficient adaptation strategy for improving abiotic stress tolerance in watermelon.

中文翻译：

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冷胁迫对不同葫芦砧木嫁接西瓜苗生长、生理特性及卡尔文循环相关基因表达的影响

最近，嫁接已被用于提高作物的非生物胁迫抗性。这里以西瓜‘枣家8424’（Citrullus lanatus）为接穗，三种不同的葫芦（Lagenaria siceraria、0526、2505 和 1226) 作为砧木，以未嫁接植物作为对照（不同植物缩写为 0526、2505、1226 和 8424），研究了冷胁迫对各种生理和分子参数的影响。结果表明，与冷胁迫下的 8424 相比，葫芦嫁接西瓜的耐寒性提高与较高的叶绿素和脯氨酸含量以及较低的丙二醛 (MDA) 含量有关。此外，嫁接西瓜积累较少的活性氧 (ROS)，伴随着增强的抗氧化活性和与卡尔文循环相关的酶的更高表达。总之，与 1226 和 8424 相比，具有 2505 和 0526 砧木的西瓜更具弹性。