干旱荒漠区4种一年生植物种子萌发期耐盐性

采用不同浓度的NaCl溶液对4种一年生草本植物雾冰藜(Bassia dasyphylla)、白茎盐生草(Halogeton arachnoideus)、沙米(Agriophyllum squarrosum)和画眉草(Eragrostis pilosa)种子进行处理,通过测定种子相对发芽率、相对发芽势、发芽指数等指标,分析了种子萌发期耐盐差异性。结果表明:1)随着NaCl溶液浓度的增大,种子发芽率呈逐渐下降的趋势,在蒸馏水中第3天达到了发芽高峰,发芽基本结束,在NaCl溶液中第7天结束发芽。2)随NaCl溶液浓度逐渐增大,4种植物种子发芽率和发芽势均呈先增加后降低的趋势,同一植物种子发芽率和发芽势在不同浓度NaCl溶液中存在显著差异(P <0.05)。NaCl溶液浓度对白茎盐生草种子发芽率和发芽势影响较大,画眉草次之,其余两种较小。3)随NaCl溶液浓度逐渐增大,4种植物种子发芽指数呈下降趋势,雾冰藜活力指数显著高于白茎盐生草、沙米和画眉草种子;盐胁迫对画眉草发芽指数和活力指数影响较大,当NaCl溶液浓度达到2.1%时,幼苗活力指数降到最低。4) 4种植物幼苗长度均随NaCl浓度增...

Experimental study on salt tolerance of seeds of four annual plants during germination

The seeds of four annual herbaceous plants,Bassia dasyphylla,Halogeton arachnoideus,Agriophyllum squarrosum,and Eragrostis pilosa,were selected for treatment in a study of relative germination rate,relative germination potential,germination index,and other indicators to analyze their differing salt tolerance under different concentrations of NaCl solution.The following results were found:1)the germination rate of seeds gradually decreased with increasing NaCl concentration,and peak germination was achieved within 3 days in distilled water,while the germination was basically absent on day 7 in NaCl solution.2)When the concentration of NaCl solution increased gradually,the germination rate and germination potential of the four plant species first increased,then decreased.The germination rate and germination potential of the same plant's seeds varied significantly(P<0.05)in different concentrations of NaCl solution.Salt content had the greatest influence on the germination rate and germination energy of the H.arachnoideus seed,followed by E.pilosa,while the other two species exhibited the smallest change.3)Under the condition of increasing salt stress,the germination index of the four plant species showed a declining trend,with B.dasyphylla activity index being significantly higher than that of the H.arachnoideus,A.squarrosum,and E.pilosa;the salt stress had the greatest detrimental effect on the germination index and vigor index of E.pilosa.When the NaCl solution concentration reached 2.1%,the seedling vigor index was reduced to a minimum.4)The length of seedlings of the 4 plant species first increased with the increase of salt concentration and then decreased rapidly,thus a suitable concentration of salt promoted the growth of seedlings.Low concentration NaCl solution had a strong influence on the length of E.pilosa seedlings,while high concentration NaCl had a greater influence on the length of B.dasyphylla,H.arachnoideus,and A.squarrosum seedlings.According to the analysis of various indicators,the combined salt tolerance of the four annual plant seeds in the germination period and be ordered:A.squarrosum>B.dasyphylla>E.pilosa>H.arachnoideus.Accounting for germination rate,germination energy,seedling length,and other indicators,the optimum concentration of salt solution was 0~0.6% for B.dasyphylla,0~0.6% for H.arachnoideus,0~0.9% for A.squarrosum,and 0~0.6% for E.pilosa.