淹水深度对樱桃番茄苗期生理生化特性的影响

以耐涝型‘红妃6号’（HF）和敏感型‘千禧’（QX）2个樱桃番茄品种为材料,以正常水分为对照（CK）,设置6个淹水深度,分别为?10、?5、?2、0、2、5 cm（D10、D5、D2、W0、U2、U5）,测定不同处理下樱桃番茄苗期的生长及生理生化指标,探究樱桃番茄苗期对不同淹水深度的响应。研究结果表明,淹水处理较CK能抑制株高、茎粗、干物质重及根系长度、直径、表面积和体积的增长,但差异显著性不同;随着淹水深度的升高,株高、干物质量及根系长度、直径、表面积和体积受抑制作用越明显,且W0、U2和U5处理显著低于CK,而D10、D5处理下株高、茎粗及根系平均直径与CK无显著差异。丙二醛（MDA）、可溶性糖和脯氨酸含量随淹水深度升高而逐渐增加,超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）活性也表现出随着淹水深度的升高而逐渐升高的趋势,且从淹水后2~6 d均表现D2、W0、U2、U5处理高于CK处理;而在淹水14 d,QX品种W0、U2、U5处理SOD和CAT活性均表现出显著低于CK。从相关性分析也发现,MDA、POD、CAT、可溶性糖和脯氨酸之间存在显著正相关关系。因此,淹水深度是洪涝致害的一个重要因素,淹水深度越高,对樱桃番茄伤害越大;樱桃番茄种植面下5 cm为淹水深度阈值。

Effect of Flooding Depth on Physiological and Biochemical Characteristics of Cherry Tomato at Seedling Stage

In this experiment, two cherry tomato varieties, ‘Hongfei 6’ (HF) of waterlogging tolerance type and ‘Qianxi’ (QX) of sensitive type, were used as the materials, with normal moisture as the control (CK). Six flooding depth, respectively ?10 cm, ?5 cm, ?2 cm, 0 cm, 2 cm, 5 cm (D10, D5, D2, W0, U2, U5) was used to determine the growth, physiological and biochemical indicators of cherry tomato seedlings under different treatment to explore the response of cherry tomato at seedling stage to different flooding depths. Flooding treatment could inhibit the growth of plant height, stem thickness, dry matter weight, root length, root diameter, root surface area and root volume compared with CK. With the increase of flooding depth, plant height, dry matter mass, root length, root diameter, root surface area and root volume were inhibited more obviously, and the effects of W0, U2 and U5 were significantly lower than that of CK, while there was no significant difference in plant height, stem diameter and mean root diameter between D10, D5 and CK. The content of malondialdehyde (MDA), soluble sugar and proline gradually increased with the increase of the flooding depth. The activity of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) also showed a tendency to gradually increase with the increase of flooding depth, and from 2 to 6 days, the effects of D2, W0, U2, and U5 were higher than that of CK. After 14 days of flooding, the activity of SOD and CAT of QX of W0, U2 and U5 were significantly lower than those of CK. Correlation analysis revealed that MDA, POD, CAT, soluble sugar and proline were significantly positively correlated. Therefore, flooding depth was also an important factor for flood damage. Higher flooding depth would lead to greater damage to cherry tomatoes. 5 cm below the cherry tomato planting surface was the flooding depth threshold.