玉米高产种质抗旱性鉴定及生理机理研究

Study on Identification of Drought-Resistant and Physiological Mechanism of High-Yield Maize Germplasm

将玉米种子萌发期、苗期及整个生育期相结合,研究了玉米种子耐旱指数(GSI)、不同生理性状和抗旱指数(DRI)及其相互关系。结果发现:正常条件下叶片水势值较高、胁迫后降低幅度较大以及渗透势较高、胁迫后降低幅度较小的品种,抗旱指数较大;正常条件下水势低、胁迫后降低幅度中等以及胁迫前后渗透势降低幅度较大的品种抗旱指数较低;正常条件下植株POD活性较低、而胁迫后酶活升高幅度较大的品种,抗旱指数较大,而本身酶活较高,胁迫后升高幅度较小的品种,抗旱指数较低;胁迫下升高幅度较小、而本身脯氨酸含量较高的品种,抗旱指数较大;胁迫下升高幅度较大且本身脯氨酸含量较低的品种,抗旱指数一般较小;正常条件下丙二醛(MDA)含量较低的品种,抗旱指数也较大。种子耐旱指数低的品种,抗旱指数也低。综合认为,萌发期种子耐旱指数、苗期叶片水势、渗透势、POD活性与抗旱指数的一致性较高,脯氨酸和丙二醛含量次之,从机理上解释了玉米抗旱性差异。

Fourteen maize cross lines were selected in order to study the index of drought-resisrance indentification and the mechanism in germinating, seedling and maturity period. The seed germination index（GSI）, physiological traits and drought resistance index（DRI） and their ralationship were analyzed. The results showed that the cuhivars had high DRI which the water potential and osmotic potential were high in normal condition, and the decreasing rate were high in water potential and low in osmotic potential under osmotic stress. To cuhivars which had low POD activities and high proline content in normal condition, and increasing rate were high in POD activities and low in proline content, their DRI were high too. In generally, if some cuhivars had lower MDA in normal condition, their DRI were higher. In conclusion, it＇s consistent among GSI, water potential, osmotic potential, POD activity and DRI. These explained the difference of drought-resistance of maize cuhivars in machanism.