NaCl胁迫对不同辣椒品种种子萌发的影响

以河西走廊3个日光温室主栽辣椒（Capsicum frutescens）品种（陇椒2号、陇椒3号和陇椒5号）为材料，研究不同浓度(0、30、60、90、120、180 mmol·L-1)的中性盐NaCl溶液对3个品种的辣椒种子萌发的影响。结果表明，随着盐浓度的增加，3个辣椒品种的种子发芽率、发芽势和发芽指数均不同程度下降，而相对盐害率则逐渐升高，并以陇椒3号的耐盐性最好，当盐浓度为180 mmol·L-1时仍有60.64%的发芽率。盐胁迫对发芽起始时间并无影响，但当盐浓度超过90 mmol·L-1时，发芽高峰期会随着盐浓度的增大而推迟。辣椒叶片内的POD、SOD和CAT的活性均随着浓度升高呈先上升后降低的趋势，以陇椒3号的酶活性升高幅度最大，陇椒2号的上升幅度最小。3个品种辣椒叶片内的MDA含量均随着盐浓度增大逐渐增加，陇椒2号的增加幅度最大，陇椒3号的最小。以上结果反映出3个辣椒品种的萌发和苗期的耐盐能力由强到弱依次为陇椒3号、陇椒5号、陇椒2号。

Effects of NaCl stress on seed germination of different varieties of pepper

Taking 3 widely cultured pepper(Capsicum frutescens) varieties including Longjiao 2, Longjiao 3 and Longjiao 5 as study objects, the effects of different concentration of NaCl solution treatments(0, 30, 60, 90, 120, 180 mmol·L-1 on seed germination of these 3 pepper varieties were studied. The results indicated that, with the increasing of concentration of NaCl solutions, the germination rate, germination energy and germination index of 3 pepper varieties decreased, while the salt injury index decreased. Longjiao 3 had the strongest salt tolerance since the germination rate of Longjiao 3 was 60.64% when the concentration of NaCl solution was 180 mmol·L-1. Salty stress had no effect on the time needed before germination of 3 pepper varieties, but the germination peak delayed with the increasing of concentration of NaCl solution, when the concentration of NaCl was higher than 90 mmol·L-1. With the increasing of concentration of NaCl solution, the activities of POD, SOD and CAT in leaves of 3 pepper varieties appeared a trend of firstly increased and then descended. The steepest rise was observed in Longjiao 3, while Longjiao 2 had a minimum rise. The MDA content in leaves of 3 pepper varieties were all increased with the increasing of concentration of NaCl solution. Longjiao 2 had a maximum rise on MDA, while Longjiao 3 had a minimum rise on MDA. All of above results indicated that, the capability of germination and salt tolerance of these 3 pepper were Longjiao 3>Longjiao 5>Longjiao 2.