NaCl胁迫对3种饲草种子萌发的影响

Effects of NaCl Stress on Seed Germination of Three Varieties of Forage

【目的】研究新引进饲草品种的耐盐能力,分析其耐盐浓度范围,筛选耐盐能力强的品种,提高饲草产量和盐碱地利用率。【方法】以引进的饲料油菜、饲用甜高粱、紫花苜蓿新品种为研究对象,分别用不同浓度NaCl溶液0%、0.4%、0.8%、1.2%、1.6%胁迫处理,测定7 d内的发芽率、发芽势、相对盐害率、发芽势盐害率、萌发指数。【结果】与对照0%处理相比,在NaCl浓度为0~0.4%时,3种饲草种子的发芽率、发芽势均无显著变化。饲用甜高粱在低盐胁迫时较敏感,NaCl浓度为0.4%时,相对盐害率为53.41%,萌发指数为28;NaCl浓度为0.8%,紫花苜蓿的发芽率最高,为96.67%。饲料油菜的发芽率次之,为93.33%。饲用甜高粱的发芽率最低,为75.33%,发芽势盐害率最高,为18.57%,盐胁迫抑制较明显,萌发指数最低,为20.89;NaCl浓度为1.2%时,饲料油菜的的发芽率最高,为83.33%,相对盐害率达100%,饲用甜高粱和紫花苜蓿的相对盐害率分别为93.4%和67.68%。NaCl浓度为1.6%时,紫花苜蓿的发芽率最高,为74.67%,盐害率最低,为81.61%。【结论】饲用甜高粱对低盐胁迫较敏感,饲料油菜在中、高浓度盐胁迫时的萌发抑制明显,紫花苜蓿对盐害的耐受最强,高盐胁迫下仍能保持最高的发芽率、发芽势。3种饲草对NaCl盐胁迫的耐受程度为紫花苜蓿>饲料油菜>饲用甜高粱。

【Objective】To study the salt tolerance of newly introduced forage varieties,the range of salt tolerance concentration,and screen out the varieties with strong salt tolerance,which is very important to improve salinized soil and land efficiency.【Methods】The new varieties of forage rape,sweet sorghum and alfalfa were taken as the research objects,different concentrations of NaCl solution(0%,0.4%,0.8%,1.2%,1.6%)were used for stress treatment to determine the germination rate,germination potential,relative salt damage rate,salt damage rate of germination potential and germination index within 7 days.【Result】Compared with the control 0%treatment,when the concentration of NaCl was 0-0.4%,there was no significant difference in germination rate and germination potential among the three forages.Sweet sorghum was more sensitive to low salt stress,when the concentration of NaCl was 0.4%,the relative salt damage rate was 53.41%,and the germination index was 28;When the concentration of NaCl was 0.8%,the germination rate of alfalfa was the highest,which was 96.67%.The germination rate of forage rape was 93.33%.The germination rate of forage sweet sorghum was the lowest,which was 75.33%.Otherwise,the salt damage rate of germination potential was the highest,which was 18.57%.The inhibition of salt stress was obvious,the germination index was the lowest(20.89);When the concentration of NaCl was 1.2%,the germination rate of forage rape was the highest,which was 83.33%and the relative salt damage rate was 100%.The relative salt damage rates of sweet sorghum and alfalfa were 93.4%and 67.68%respectively.When the concentration of NaCl was 1.6%,the germination rate of alfalfa was the highest(74.67%),and the salt damage rate was the lowest(81.61%).【Conclusion】In general,forage sweet sorghum is sensitive to low salt stress.The germination of feed rape is obviously inhibited under medium and high concentration salt stress.Alfalfa has the strongest tolerance to salt stress,and maintained the highest germination rate and germination potential under high salt stress.The tolerance order of the three forages to NaCl stress is alfalfa>forage rape>forage sweet sorghum.