樱桃番茄苗期对淹水胁迫的响应及其耐涝性评价

为研究樱桃番茄苗期对淹水胁迫天数的响应规律及其耐涝性,选取千禧、立新佳禧、红妃6号、红钻石和台湾赞美5个热带地区常用樱桃番茄品种为试验材料,设置正常水分处理(CK)和淹水处理,对淹水胁迫下不同淹水天数(0、2、4、8和16 d)樱桃番茄苗期功能叶中超氧阴离子自由基(O2·-)含量、丙二醛(MDA)含量、抗氧化酶系统、渗透调节物质和根系活力等生理生化指标及株高、地上部干重、根系干重及根冠比等形态学指标进行了测定。结果表明,淹水前期,樱桃番茄叶片中O2·-和MDA含量多表现为先上升后下降的趋势,而在淹水后期千禧和立新佳禧品种则表现出迅速上升,并在淹水后16 d显著高于CK;叶片超氧化物歧化酶(SOD)活性在淹水后较CK多表现为下降趋势,仅红妃6号在淹水后16 d仍高于CK。过氧化物酶(POD)活性在淹水胁迫下较CK表现出先逐渐上升后下降的趋势,仅红钻石在淹水后期仍略高于CK,过氧化氢酶(CAT)活性仅红妃6号在淹水后2 d显著高于CK,其他品种CAT活性始终低于CK;叶片中可溶性糖和脯氨酸(Pro)的含量在淹水后显著增加。根系活力随着淹水处理时间的延长呈先上升后下降的趋势,且淹水后16 d千禧和立新佳禧品种根系活力较CK显著降低。淹水胁迫下,樱桃番茄株高、地上部干重、根系干重均低于CK;除千禧品种外,其他品种根冠比均高于CK,且红妃6号根冠比与CK间差异达到显著水平。利用主成分分析法对樱桃番茄品种耐涝性进行综合评价,得出各品种耐涝性大小排序:红妃6号>红钻石>台湾赞美>立新佳禧>千禧。本研究结果为热带地区樱桃番茄栽培品种选择及抗涝渍栽培机理研究提供了理论参考。

Responses of Waterlogging Stress and Evaluation of Waterlogging Tolerance in Cherry Tomato at Seedling Stage

The aim of this study is to investigate the response of cherry tomato and its waterlogging tolerance to the number of days under flooding stress at seedling stage. Qianxi, Lixinjiaxi, Hongfei 6, Hongzuanshi and Taiwanzanmei, five common cherry tomato varieties from tropical regions, were selected in this study. Physiological and biochemical indexes such as superoxide anion radical (O2·-) content, malondialdehyde (MDA) content, antioxidant enzyme system, osmotic regulatory substances, root activity and morphological indicators include root activity, plant height, dry weight of shoots, dry weight of roots and root-shoot ratio in functional leaves of cherry tomato seedlings were determined after different flooded days of 0, 2, 4, 8 and 16 d. The results showed that the content of O2·- and MDA in leaves of cherry tomato showed a tendency of first rising and then falling in the early stage, while in the late flooding period, the varieties of Qianxi and Lixinjiaxi showed rapid rise and significantly higher than the control after flooding16 days. The superoxide dismutase was decreased than CK after flooding, and only Hogfei 6 was higher than CK after flooded 16 days. And peroxidase in leaves showed a trend of gradual increase and then decrease and only Hongzuanshi was still higher than CK in the late flooding period, while the catalase activity of Hongfei 6 was significantly higher than the control on the second day of flooding, while others was all lower than the control or on difference form CK. However, during the waterlogging stress it was significant for the content of soluble sugar and proline to increase in the leaves of cherry tomato. As the flooding days went by, the root activity increased first and then decreased, and there was a significant decrease in Qianxi and Lixinjiaxi varieties after flooded 16 days. Under the stress of flooding, plant height, dry weight of aboveground and dry weight of root were lower than that of control. Except for the Qianxi, the root-shoot ratio was higher than that of the control, and hongfei 6 reached a significant level. Using principal component analysis (PCA) to comprehensively evaluate the cultivar’s waterlogging resistance: Hongfei 6 > Hongzuanshi > Taiwanzanmei > Lixinjiaxi > Qianxi. The results of this study provide a theoretical reference for the selection of cherry tomato cultivars and the mechanism of resistance to waterlogging cultivation in the tropics.