关键词: 白芥, Na₂SO₄胁迫, 生理指标, 主成分分析, 隶属函数法

Abstract:

In order to investigate germination, the morphological and physiological characteristics of Sinapis alba L. in response to Na₂SO₄ stress at different growth stages, and to screen out white mustard of strong salt tolerance, the filter paper bed germination method was adopted. Treatments were carried out with 0, 30, 60, 90, 120, 150, 180, 210 mmol/L of Na₂SO₄, and the germination rate, radical length, hypocotyl length, salt-tolerance critical value and salt-tolerance limit value were determined. In addition, the pot cultivation method was employed. The white mustard strains were stressed with 90, 120, 150 mmol/L of Na₂SO₄, and malondialdehyde, proline, photosynthetic pigment, water content and plant height were determined. Both principal component analysis and fuzzy mathematical membership function method were used for comprehensive evaluation. The results showed that 90 mmol/L Na₂SO₄ stress was suitable for screening white mustard germplasm, the threshold value of salt tolerance was 97-118 mmol/L, and the limit value of salt tolerance was 239-251 mmol/L. There were little correlation among the salt tolerance at the germination stage, seedling stage and flowering stage, the strongest salt tolerance was 11 baijie 3-1 line at germination stage and 12 baijie 15-7 line at flowering stage. The content of leaf proline, water content and chlorophyll a could be used as the reliable indexes to identify salt tolerance of white mustard.

Key words: White mustard (Sinapis alba), Na₂SO₄ stress, Physilogical index, Principal component analysis, Membership function method