激素处理对楸树种子在不同温度下萌发特性的影响

以鄂西南楸树(Catalpa bungei C.A.Meyer)种子为供试材料,用质量浓度为100、200、300、400 mg·L-1的赤霉素(GA3)、吲哚丁酸(IBA)、脱落酸(ABA)对楸树种子进行处理,测试发芽率、发芽势和发芽指数,分析外源激素处理对楸树种子萌发的影响。结果表明:在外源激素质量浓度为100~400 mg·L-1时,随着外源激素质量浓度的增大,GA3处理的种子无论在恒温还是变温条件下,种子的发芽率、发芽势和发芽指数均先增大后减小;IBA处理的种子,在恒温条件下随着外源激素质量浓度的增大发芽率不断增大,而在变温条件下呈先上升后下降趋势;ABA处理的种子,随着外源激素质量浓度的增大,种子的发芽率、发芽势和发芽指数,无论恒温还是变温均呈显著下降趋势。一定质量浓度的GA3、IBA会对楸树种子的萌发起到促进作用,而ABA无论质量浓度高低均对楸树种子的萌发具有抑制作用。

Germination Response of Catalpa bungei Seed to Exogenous Hormones Treatment under Different Temperatures

The seeds of Catalpa bungei C.A.Meyer were taken as the tested materials,and gibberellin(GA3),indole butyric acid(IBA),and abscisic acid(ABA)at mass concentrations of 100,200,300,and 400 mg·L-1 were used to test the germination rate,germination energy and germination index,and the effects of exogenous hormone treatment on the seed germination of Catalpa bungei were analyzed.The results showed that when the mass concentrations of exogenous hormone were 100-400 mg·L-1,with the increase of the mass concentration,the germination rate,germination energy and germination index of seeds treated with GA3 were increased first and then decreased under constant and variable temperature conditions.The germination rate of IBA-treated seeds were increased with the increase of the concentration under constant temperature conditions,but increased first and then decreased under temperature-changing conditions.With the increase of ABA concentrations,the germination rate,germination energy and germination index of seeds presented a significant downward trend regardless of constant temperature or variable temperature.Therefore,GA3 and IBA could promote the seed germination of C.bungei at a certain mass concentration,while ABA would inhibit the seed germination of C.bungei regardless of the mass concentration.