不同倍性蜜枚西瓜幼苗在低温胁迫下的生理生化特性

Studies on Physiological and Biochemical Characteristics of Seedlings of Different Ploidy Watermelons under Cold-stress

以蜜枚二倍体及其人工诱导的同源四倍体、三倍体为材料研究了西瓜品种的不同倍性幼苗在冷胁迫下冷害指数、细胞保护酶(SOD、POD)及PRO、MDA的变化。结果表明:在没有冷诱导时M4x、M3x的耐冷性不如M2x。随着冷胁迫时间的延长,SOD、POD活性都有所增加,M2x比M4x、M3x增加幅度大,最后下降。MDA含量变化呈相反的趋势。M2x的体内活性氧积累少,表现出比多倍体耐冷性强。PRO含量变化M2x、M3x先上升,4d后表现下降,M4x的PRO含量从开始就表现下降。

The changes of malondialdehyde(MDA)and soluble protein(PRO)content ,the activity of superoxide dismutase(SOD)and peroxidase (POD)in leaves of different ploidy cultivars of Meimi watermelon(autotetraploid,autotriploid and diploid)under different periods in low temperature were studied.Before cold-treatment ,the seedlings were incubated in the LH-200automatic temperature controlling chamber with the temperature of30℃/20℃,and14h photoperiod (4000lx).The results showed the autotetraploid and triploid had lower cold tolerance than that of diploid cultivars under the condition of(12±1)℃temperature and1000lx.With the increase of stress time ,the SOD and POD activity of3ploidy cultivars were gradually increased.SOD and POD activities of M2x were increased greater than those of M3x and M4x,then decreased.The reverse result of MDA contents were showed.The PRO content of M2x and M3x was increased at first,and then decreased.