毛竹种子萌发和幼苗生长对铝胁迫的反应

为研究毛竹Phyllostachys pubescens耐铝性，以毛竹为材料并对照耐铝性不同的2种水稻Oryza sativa品种（敏感型IR1552和耐受型Azucena），通过不同铝浓度对毛竹及水稻种子发芽率、根长的影响，及对其幼苗根伸长量、丙二醛质量摩尔浓度和植物胁迫保护酶超氧化物歧化酶、过氧化物酶的影响，来确定毛竹耐受性。结果表明，毛竹种子耐铝浓度为200 μmol·L^－1，在达到500 μmol·L^－1时，开始出现显著抑制现象，2 000 μmol·L^－1时达到半致死浓度，种子耐铝程度低于铝敏感型水稻品种IR1552；毛竹幼苗在500 μmol·L^－1浓度铝处理下，1 d即出现根伸长显著被抑制现象，且3 d后抑制加深，而敏感型IR1552则能在第3 天时恢复生长。毛竹幼苗经铝胁迫3 d后超氧化物歧化酶活性变化不显著（P = 0.1531），过氧化物酶活性变化显著（P = 0.018 0），而2个品种水稻均为极显著，且相对于水稻，在对照未加铝处理的毛竹苗根系中过氧化物酶活性和丙二醛质量摩尔浓度均较高。总而言之，毛竹耐铝程度低于水稻敏感型IR1552，在植物界中属于中等耐铝水平。图3表3参29

Aluminum stress with seed germination and seedling growth in Phyllostachys pubescens

Based on the effects of different aluminum （Al） concentrations （0,50,200,500,and 2 000 μmol·L-1） on seed germination,seedling root growth,superoxide dismutase （SOD）,peroxidase （POD）,and malondialdehyde （MDA） in Phyllostachys pubescens （moso bamboo）,this study determined the level of Al tolerance for moso bamboo through comparison with two rice cultivars：Oryza sativa ＇IR1552＇ （Alsensitive） and Oryza sativa ＇Azucena＇（Al-tolerant）.Results showed that an Al concentration of 200 μmol· L-1 did not significantly inhibit seed germination of moso bamboo,whereas with 500 μmol·L-1,germination was inhibited but not significantly.Also,an Al concentration of 2 000 μmol·L-1 resulted in 50% survival.For the 500 μmol·L-1 Al treatment,seedling root growth was inhibited in 1 d,and with continued Al stress growth within 3 d did not recover.However,with continued Al stress,root growth in ＇ IR1552＇ recovered within 3 d.Meanwhile,with Al stress for 3 d,there was no significant increase of SOD activity in the root tips of moso bamboo （P=0.153 1）,but POD activity for moso bamboo （P=0.018 0）,＇IR1552＇ and ＇Azucena＇ （P0.05） were significant.In addition,POD activity and MDA content in the root tips of moso bamboo were higher than in ＇IR1552＇.These results showed that P.pubescens had a lower Al-tolerance than ＇IR1552＇ indicating a moderate Al-tolerance in plants.