低氧胁迫对油菜幼苗不定根生长的影响

摘要

为了解低氧胁迫对甘蓝型油菜(Brassica napus L.)幼苗的影响,采用营养液琼脂培养通氮气系统模拟低氧环境(氧气浓度小于1mg/L),测定低氧胁迫下油菜不定根的变化.结果表明,低氧胁迫处理6d,油菜品系GAC 的干重下降了45.3％,品种中双10号下降了22.3％.低氧胁迫明显诱导油菜不定根的生长,在低氧条件下处理6d时,GAC和中双10号的不定根数量达到21和36条/株,比对照分别增加了88.6％和137.3％.人工切除不定根明显降低油菜·重,GAC和中双10号的·重与对照相比分别下降了24.9％和35％.0.5％琼脂营养液低氧预处理6d和好氧锻炼能增加中双10号生物量和不定根数,但对GAC影响不大.相关分析表明,低氧胁迫时油菜不定根数量与干重的相关系数明显大于对照时的相关系数.上述结果表明,油菜不定根大量形成可能是油菜适应低氧胁迫的一种重要生理机制.%To understand the effects of low oxygen stress on rapeseed seedlings,Brassica napus L.inbred line GAC and cultivar Zhongshuang 10 were used to investigate adventitious rooting in liquid medium with 1 mg/L oxygen.Results indicated that 6d of low oxygen stress significantly decreased seedling dry weight by 45.3％ in GAC and 22.3％ in Zhongshuang 10 respectively.Adventitious root growth was significantly induced.The 6d low oxygen treatment increased the adventitious roots by 88.6％ in GAC and 137.3％ in Zhongshuang 10.Excision of adventitious roots led to decrease of seedling dry weight by 24.9％ of GAC and 35％ of Zhongshuang 10 respectively.Pretreatment of low oxygen (6d-low oxygen treatment in liquid medium with 0.5％ agar) and aeration exercise increased the dry weight and the number of adventitious roots of Zhongshuang 10,but had no obvious effect on GAC.Results indicated that correlation between adventitious roots and dry weight was larger under low oxygen stress than normal condition.It indicated that adventitious root formation is one of the important physiological mechanisms for rape seedlings to adapt to low oxygen stress.