大麦耐铝毒机理及遗传改良研究进展

Advance in Studies on AIuminum Toxicity and Inheritance Improvement in Barley

综述了大麦酸铝毒害及其遗传改良研究进展。大麦铝毒害的首要症状是根系的生长发育受阻 ,根系微观结构改变 ,其机制可能包括 :铝引起细胞死亡、缺乏细胞壁合成底物、铝影响DNA合成以及矿质元素吸收等几个方面。大麦可以通过增加根际分泌物如有机酸、多肽等螯合根际铝 ,也可提高根际 pH使铝沉淀 ,减弱铝毒性 ,对进入细胞内的铝也可通过与铝形成无毒的复合物 ,或将铝主动运入液泡中 ,解除内部铝毒。对大麦的遗传研究表明 ,大麦耐铝性是由单基因控制 ,耐铝性不同的品种分别是由多基因座控制。利用苏木精染色等方法已鉴定出一些耐铝材料 ,通过突变体筛选已获得了一些抗铝的大麦品种。运用分子生物学技术 ,有望将小麦耐铝基因导入大麦 。

In this paper the current advances in the studies on aluminum toxicity and inheritance improvement in barley are reviewed.Aluminum induced changes in root growth and microstructure.The mechanism of aluminum toxicity may include cell death,lack of substrate for synthesizing cell wall,inhibiting DNA synthesis and limiting nutrition acquisition.Barley may become tolerant aluminum through secretion organic acid,polypeptide to chelating aluminum,takng up H +to alkalize rhzosphere to reduce the apoplastic Al +activity,or by formation of nonphytotxicitic complexes to reduce thesyplastic Al +activity.Aluminum tolerant barley also can detoxify auminum by chelating Al +,or transferring then into vacuoe when aluminum enters into cytoplasm.Tolerance to aluminum in barey may be mediated by a single dormant gene with many locus.Many barley genotypes tolerant to aluminum had been screened by staining roots with haematoxylin.It is hopeful that transfer aluminum tolerant gene in wheat to barley by using modern molecular biology technology.