三峡库区狗牙根对深淹胁迫的生理响应

选取三峡库区自然消落带野生狗牙根(XC)和非消落带野生狗牙根(FC)为研究对象,采用三重复裂区设计试验,主区为两品种,副区为6个不同深度水淹处理(0,1,2,5,10m和15m),分析了各处理植株几种酶活性和碳水化合物含量的变化情况.结果显示:①不同生境狗牙根受深淹胁迫后,丙二醛(MDA)都呈递增趋势,表明狗牙根在深淹胁迫下受到了不同程度的膜脂过氧化伤害,且随胁迫程度的增加受伤害增大.②超氧化物歧化酶(SOD)、过氧化物酶(POD)、谷胱甘肽还原酶(GR)活性和醇脱氢酶(ADH)活性较对照都有所增加;XC处理POD和SOD的最大值出现在5m深水淹处理,而FC出现在2m深处理,且XC 5米深淹处理GR值较对照和其他处理明显大;各受淹处理地下茎可溶性糖含量和淀粉含量都保持在较高水平.③从抗氧化酶活性和ADH活性的变化规律,以及淹水胁迫下植株的能量代谢情况,初步得出XC与FC都具有一定的耐淹性,且XC较FC具更耐深淹的能力,表明狗牙根作为禾本科植物遗传上具有一定的耐淹性,自然消落带狗牙根因长期生长于水淹胁迫环境,耐淹能力得到了进一步强化.从狗牙根对深淹胁迫的生理响应上,证明狗牙根是宜用于三峡水库消落带植被恢复的物种.

Physiological responses of Bermudagrass (Cynodon dactylon (L.) Pers.)to deep submergence stress in the Three Gorges Reservoir Area

A submergence experiment was conducted on Bermudagrasses originally distributed in the water-level-fluctuation zone (XC) and non-water-level-fluctuation zone (FC) of the Three Gorges Reservoir Area. Six treatments with respective submerged depth of 0, 1, 2, 5, 10, 15m were carried out to investigate the physiological responses of Bermudagrasses. The results indicated that: ①Malondialdehyde (MDA) content increased significantly with the increase of submergence depth,, indicating that Bermudagrass suffered the damage of membrane lipid peroxidation under the submergence condition;. ②The activities of superoxide dismutase (SOD), peroxide (POD), glutathione reductase (GR) and alcohol dehydrogenase (ADH) in the roots of Bermudagrass were higher than that of un-submerged control. The maximum of POD, SOD and GR activities of XC appeared at 5 meters in submergence depth, and FC at 2 meters. There were relative higher soluble sugar and starch contents by the submergence treatment. ③Bermudagrasses originally growing in the natural water-level-fluctuation zone (XC) could endure much deeper submergence than FC by the characteristics of antioxidative enzymatic activities, ADH activity and energy metabolism. The results implies that Bermudagrass has submergence-tolerant instinct, and the submergence-tolerant ability of XC was strengthened by the long-time periodic submergence in its natural habitats. Bermudagrass could be a promising species for revegetation of the water-level-fluctuation zone in the Three Gorges Reservoir Area.