玉米(Zea mays)幼苗对风吹的生理响应

Physiological Response of Corn Seedlings to Wind Blowing

在中国东北半干旱风沙区,春季玉米(Zea mays)幼苗经常受到大风危害。为了解玉米幼苗受到大风吹袭危害时逆境生理特征的变化,2012年在内蒙古东部科尔沁沙地研究了在0(CK)、6、9、12、15、18m·s^(-1)等6个风速、10min风吹对其幼苗相对含水量、丙二醛、膜透性、保护酶活性和渗透调节物质含量的变化。结果表明:(1)风吹后玉米幼苗相对含水量均显著高于CK,增加幅度10.10%~26.52%,说明风吹未造成水分胁迫;(2)各风吹处理丙二醛含量均高于CK,膜透性均低于CK,但与CK的差异均未达到显著水平,说明风吹后玉米幼苗膜脂过氧化程度并不严重;(3)随着风速的增加,过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性均先增加后下降,CAT含量在9m·s^(-1)达到最大,较CK显著增加了35.53%,在15 m·s^(-1)、18 m·s^(-1)处理时分别较CK显著下降了40.98%和52.46%,SOD含量在6~15m·s^(-1)呈显著上升趋势,较CK增加了40.49%~140.61%,过氧化物酶(POD)含量在6m·s^(-1)和18m·s^(-1)时较CK分别显著增加了97.69%和106.41%;(4)风吹后可溶性糖和脯氨酸含量分别只在6m·s^(-1)和18m·s^(-1)时较CK显著增加了26.58%和35.08%,起到渗透调节作用,其余各处理可溶性糖和脯氨酸均未发挥渗透调节作用。

The seedlings of corn are often damaged by strong wind in the spring in semi-arid wind-eroded area of the Northeast,China.In order to understand physiological responses of the corn seedlings to wind blowing,a field wind-blowing experiment using a wind speed gradient of 0（CK）,6,9,12,15,and 18 m·s^（-1）and 10 min of wind blowing times was conducted and changes of relative water content（RWC）,malondialdehyde（MDA）,membrane permeability,protective enzymes activities and osmotic regulation substances contents of corn seedlings were investigated in 2012 in the Horqin Sandy Land of Inner Mongolia.The results showed that：（1）RWC was significantly higher in the wind treatments than that in the CK,with an increased magnitude of 10.10%-26.52%,which suggested no water stress occurred in the wind blowing process;（2）compared to the CK,MDA contents were higher and membrane permeability were lower in the all wind treatments,but the differences among them and the CK were not significant,which suggested that membrane lipid peroxidation under wind blowing stress was not serious;（3）with increase of wind speed,activities of the CAT and SOD increased firstly and then decreased.CAT activity increased by 35.53% with the highest value in the 9 m·s^（-1） treatment,and decreased by 40.98%in 15 m·s^（-1） and 52.46%in the 18 m·s^（-1） treatments,respectively,compared to CK.SOD activity showed a significantly increased trend from6m·s^（-1） to 15 m·s^（-1） treatments,with an increased magnitude of 40.49%^（-1）40.61% compared to CK.POD activity increased by 97.69% and 106.41%in the 6 m·s^（-1） and 18 m·s^（-1） treatments compared to CK,respectively;（4）Proline and soluble sugar contents increased by 32.15% and 35.08%in the 6 and 18 m·s^（-1）treatments compared to the CK,which played osmotic adjustment role under wind blowing stress.Proline and soluble sugar did not play role in osmotic adjustment in the other wind treatments.