不同基因型玉米品种对Pb的富集特征

为了研究不同基因型玉米品种对Pb的富集特征,选用2个Pb低富集玉米品种(曲辰11号、曲辰3号)和2个Pb高富集玉米品种(靖丰8号、旭玉1446),开展Pb胁迫(2 000 mg·kg-1)下的大田试验,研究了玉米植株生物量的变化、各部位Pb含量、Pb总吸收量、富集与转运规律、土壤p H值及有效态Pb含量。结果表明:(1)与对照相比,Pb胁迫导致4个玉米品种根、茎、叶和籽粒生物量不同程度的下降,总生物量下降9.65%~20.46%,但低富集玉米品种生物量的下降程度小于高富集玉米品种;(2)玉米各部位的Pb含量分配规律为根叶茎籽粒,分别为95.39~121.02、25.56~43.21、14.06~25.41、2.52~5.38 mg·kg-1;低富集玉米品种根的Pb含量高于高富集玉米品种,而茎、叶和籽粒的Pb含量低于高富集玉米品种;玉米植株对Pb的总吸收量为4.46~7.94 mg·株-1,低富集玉米品种植株的Pb总吸收量显著低于高富集玉米品种;(3)不同基因型玉米品种对Pb的富集系数和转运系数均小于1,表现为低富集玉米品种低于高富集玉米品种;(4)不同基因型玉米品种土壤p H值为6.60~6.82,且低富集玉米品种显著高于高富集玉米品种,土壤有效态Pb含量范围为969.86~1 116.15 mg·kg-1。

Accumulation Characteristics of Pb by Zea Mays of Different Genotyoes

To determine the characteristics of lead(Pb)accumulation by different maize genotypes, two low accumulation genotypes(Quchen11, Quchen 3)and two high accumulation maize genotypes(Jingfeng 8, Xuyu 1446)were used in a field experiment under Pb stress(2000 mg·kg-1). The following parameters were measured including the change of plant biomass , Pb contents in different plant parts, totalPb uptake,Pb accumulation and translocation of different maize varieties,soil pH value and available Pb contents in soils. The results showedthat:(1)Compared with the control, the Pb stress caused a decrease at differnet levels on the biomass of roots, stems, leaves and grains of thefour maize genotypes. The plant biomass decreased by 9.65%~20.46%. And the decrease level on the plant biomass of the low accumulationmaize genotypes was less than the high accumulation maize genotypes.(2)The Pb contents were found highest in the roots(95.39~121.02mg·kg-1), followed by the leaves(25.56~43.21 mg·kg-1)and stems(14.06~25.41 mg·kg-1), and lest in the grains(2.52~5.38 mg·kg-1).Moreover, the Pb contents in roots were higher of low accumulation maize genotypes than high accumulation maize genotypes. In contrast, thePb contents in the stems, leaves and grains were less of the low accumulation maize genotypes than the high accumulation maize genotypes.The total Pb accumulation of maize was 4.46~7.94 mg per plant, and which was significant less of the low accumulation maize genotypes thanthe high accumulation maize genotypes.(3)For the four maize genotypes, both the accumulation factor and translocation factor of Pb wereless than 1, and were smaller of the low accumulation maize genotypes than the high accumulation maize genotypes.(4)The pH values insoils were 6.60~6.82, which were significant higher of the low accumulation maize genotypes than the high accumulation maize genotypes, theavailable Pb contents in soils were 969.86~1116.15 mg·kg-1.