纳米氧化锌浸种对铅胁迫下水稻种子萌发生理的影响

Effects of Seed Soaking with Zinc Oxide Nanoparticle on the Germinationand Anti-physiology of Fragrant Rice Seeds under Pb Stress

以香稻品种象牙香占和玉香油占为试验材料,设置4个纳米氧化锌(ZnO NPs)浸种浓度水平[ck、T_(1)(25 mg/L)、T_(2)(50 mg/L)和T_(3)(100 mg/L)]和2个铅浓度水平[Pb 0(0 mg/L)和Pb 300(300 mg/L)],共16个处理,测定2个香稻品种的发芽率、根长、芽长及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量。结果表明,在Pb 0处理下,与ck处理相比,T_(1)、T_(2)和T_(3)处理影响2个香稻品种的前期发芽率(1~2 d),但后期的发芽率无显著影响(p>0.05)。T_(1)、T_(2)、T_(3)处理对2个香稻品种的根长和芽长无显著影响。同时,T_(1)、T_(2)、T_(3)处理降低了2个香稻品种的SOD、POD和CAT活性,而玉香油占根和芽的MDA含量则较ck高。在Pb 300处理下,与ck处理相比,T_(1)、T_(2)、T_(3)处理影响了2个香稻品种前期发芽率(1~2 d),对后期的发芽率无显著影响(p>0.05)。且在T_(1)、T_(2)和T_(3)处理下,象牙香占的芽长和玉香油占的根长高于ck处理,而象牙香占根的POD活性、芽的SOD活性、根和芽的CAT活性以及玉香油占芽的CAT活性均较ck低,同时2个香稻品种的MDA含量也低于ck处理。综合分析认为,铅胁迫下进行纳米氧化锌浸种处理对香稻种子发芽率无影响,但能在一定程度上缓解铅胁迫对香稻种子发芽、形态特征及抗逆生理的影响,主要表现为对根、芽长的影响和降低MDA含量,而不同品种不同部位的生理响应有一定的差异。

Two fragrant rice cultivars,Xiangyaxiangzhan and Yuxiangyouzhan were used as materials under four concentrations of seed soaking with ZnO NPs,ck,T_(1):25 mg/L,T_(2):50 mg/L and T_(3):100 mg/L and two concentrations of Pb,Pb 0:0 mg/L and Pb 300:300 mg/L to determine the seed germination rate,root length,shoot length,superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activities and malondialdehyde(MDA)contents of two fragrant rice cultivars.The results showed that under Pb 0 treatment,T_(1),T_(2) and T_(3) treatments affected the early germination rate(1-2 days),but had no significant effect on the late germination rate(p>0.05),compared with ck.T_(1),T_(2) and T_(3) treatments had no significant effects on root and shoot length of two fragrant rice cultivars.Meanwhile,T_(1),T_(2) and T_(3) treatments decreased the SOD activities,POD activities and CAT activities of two fragrant rice cultivars,but increased MDA contents of root and shoot in Yuxiangyouzhan.under Pb 300 treatment,T_(1),T_(2) and T_(3) treatments affected the early germination rate(1-2 days),but had no significant effect on the late germination rate(p>0.05),compared with ck.Moreover,compared to ck,under T_(1),T_(2) and T_(3) treatments the shoot length of Xiangyaxiangzhan and the root length of Yuxiangyouzhan increased,but the POD activity of root,the SOD activity of shoot and the CAT activities of root and shoot in Xiangyaxiangzhan and the CAT activity of shoot in Yuxiangyouzhan decreased,while the MDA content of two fragrant rice cultivars decreased.Comprehensive analysis showed that soaking seeds with ZnO NPs under Pb stress had no effect on germination rate of fragrant rice,but could alleviate the Pb stress on germination,morphological characteristics and anti-physiology of fragrant rice to a certain extent,mainly manifested as the effect of root and shoot length and reduced the MDA content,and there were differences in the physiological responses of different cultivars of different parts.