用~（32）P示踪法研究腐植酸对小麦吸收及转移磷的增效作用

以春小麦京红８号、冬小麦冀麦２４为材料，研究了腐植酸对小麦发芽率和幼苗生长的影响，用３２Ｐ中示踪法研究了不同浓度腐植酸与０．１％Ｎａ２Ｈ３２ＰＯ４在小麦４叶期，７叶期，始穗期和抽穗期深叶，３２Ｐ中的吸收率，转移率及分布的影响。不同浓度的腐植酸浸种，在２５℃条件下对发芽没有明显的促进作用。但在水分不足或补水情况下，０．０１ｇ·Ｌ－１腐植酸浸种的幼苗生长快，干、鲜重增加，为壮苗打下良好基础，０．０３ｇ／Ｌ有抑制作用。０．０１ｇ·Ｌ－１腐植酸加０．１％Ｎａ２Ｈ３２ＰＯ４在不同生育期涂抹叶片，对磷的吸收和转移有促进作用，０．０３ｇ·Ｌ－１加０．１％Ｎａ２Ｈ３２ＰＯ４表现抑制作用。从而０．０１ｇ·Ｌ－１腐植酸对小麦吸收磷及其转移有增效作用。

Study on the Effect of Humic Acid on Absorption and Transportation of Phosphate in Wheat By Using 32P Tracer Method

The effect of humic acid on seed germiniation rate and seedling growth was studied,'the absorption rate, transportation of rate and distribution of 32P were studied simultaneously with the developing process of wheat seedlings. The results showed that by soaking seeds in different concentration of humic acid solution, no apparent effect of humic acid on seed germination was found, but the seedlings whose seeds were soaked in 100 ug/mL humic acid solution growed quickly and its dry weight increased greatly under condition of water dificit.The inhibition of the seedling growth and increase of seedling dry weight were found in seedlings whose seeds were soaked in 300μg/ml humic acid solution. The promotion of absorption and transportation of phospthate either in the leaves smeared with 100ug/μL humic acid soltion including 0. 1 % Na2HPO2 or in adjacent leaves in the different developing stages and the inhibition of absorption and transportation of phosphate was found by smearing leaves with 300 humic acid solution including 0. 1% Na2HPO4 which indicated that 100ug/ mL humic acid solution promoted the absorption and transportation of phosphate in the wheat.