不同药剂引发处理对干旱胁迫下烟草种子发芽和幼苗生长的影响

Effects of seed priming with different agents on seed germination and seedling growth in tobacco(Nicotiana tabacum L.) under drought stress

采用不同浓度的外源多效唑、氯化钙、脯氨酸和水杨酸引发处理不同耐旱力的烟草品种‘红花大金元'和‘MS K326'种子,用15%聚乙二醇(PEG-6000)溶液模拟干旱条件,测定干旱胁迫下不同烟草品种种子发芽及幼苗生长和生理生化指标变化。结果表明:多效唑(PP333)引发处理对干旱胁迫下‘红花大金元'和‘MS K326'种子发芽和幼苗生长有一定抑制作用,但是能提高干旱胁迫下幼苗抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性,并且降低丙二醛(MDA)含量。氯化钙、脯氨酸和水杨酸3种药剂引发能显著促进‘红花大金元'和‘MS K326'种子发芽,提高干旱胁迫下幼苗根长、全苗长、幼苗干鲜重以及APX,CAT,POD和SOD活性,并且降低MDA含量。其中80 mg·L-1水杨酸引发处理效果最好,可以作为提高烟草种子及幼苗抗旱性的处理方法。

The effects of different agents on seed germination and growth characteristics of tobacco varieties with dif- ferent drought tolerance were studied in this paper. Seeds of two tobacco v.arieties with different drought tolerance were primed indifferent concentration solutions of paclobutrazol, calcium chloride, proline and salicylic acid. Then, the germination, seedling growth and physiological changes under drought stress （simulating with 15% polyethylene glycol 6000） were measured. The resuhs showed that the germination and seedling growth were inhibited, however, the activities of ascorbate peroxidase （ APX）, catalase （ CAT）, peroxidase （ POD ） and superoxide dismutase （SOD） in tobacco seedlings were enhanced and the malondialdehyde （MDA） concentration were decreased after treated with paclobutrazol （PP333）. The germination parameters, root length, seedling length, seedling fresh and dry weight were improved, the activities of APX, CAT, POD and SOD were enhanced and the MDA concentration were decreased in two tobacco varieties after treated with calcium chloride, proline and salicylic acid. The treatmentof 80 mg. L-1 salicylic acid had the best effects among all treatments, suggesting that this treatment can be used to improve drought tolerance of tobacco seeds and seedlings.