不同种类盐胁迫对水稻种子萌发和幼苗生长的影响

Effects of Different Salt Stress on Seed Germination and Seedling of Rice

采用水培法研究比较了Na_(2)CO_(3)和NaHCO_(3)两种碱性盐,NaCl和Na_(2)SO_(4)两种中性盐和混合盐对水稻种子萌发和幼苗生长的影响。结果表明,盐碱处理下水稻种子的发芽率、发芽势、发芽指数、苗高、根长、侧根数和根系细胞质膜透性等均较CK极显著降低(P<0.01)。其中,Na_(2)CO_(3)和NaHCO_(3)以及混合盐胁迫处理水稻种子的发芽指标和生长指标均极显著低于NaCl和Na_(2)SO_(4)处理(P<0.01)。其中,以Na_(2)CO_(3)处理对水稻种子发芽的抑制作用最大,其发芽率仅8.0%,发芽势为0,发芽指数仅3.0。NaHCO_(3)处理其次,发芽率为14.5%,发芽势为1.7%,发芽指数为6.9。Na_(2)CO_(3)和NaHCO_(3)以及混合盐胁迫处理水稻幼苗的苗高,主根长和侧根数等均极显著低于NaCl和Na_(2)SO_(4)处理(P<0.01)。3个处理均无侧根萌发。不同种类盐处理水稻幼苗根系细胞质膜透性均极显著高于CK(P<0.01),以Na_(2)CO_(3)细胞质膜透性最高,极显著高于其他盐处理(P<0.01)。所有盐处理幼苗和根系K^(+)/Na^(+)比值均极显著低于CK(P<0.01),其中Na_(2)CO_(3)、NaHCO_(3)和混合盐处理根系K^(+)/Na^(+)比值分别仅为0.05,0.07和0.13,均显著低于CK、NaCl和Na_(2)SO_(4)处理(P<0.05)。可见,Na_(2)CO_(3)和NaHCO_(3)加重了伤害与其对水稻根系细胞膜的伤害和K^(+)吸收受到抑制有关。碱性盐主要通过影响水稻侧根萌发来影响水稻幼苗生长。

Effects of Na_(2)CO_(3)and NaHCO_(3),NaCl and Na_(2)SO_(4)on seed germination and seedling growth of rice were studied by hydroponics.The results showed that the germination rate,germination potential,germination index,seedling height,root length,number of lateral roots and cell membrane permeability of roots were significantly lower than CK(P<0.01).The germination and growth indexes of Na_(2)CO_(3),NaHCO_(3)and mixed salt stress were significantly lower than those of NaCl and Na_(2)SO_(4)(P<0.01).Among them,Na_(2)CO_(3)treatment had the greatest inhibitory effect on rice seed germination,the germination rate was only 8.0%,the germination potential was 0,and the germination index was only 3.0.NaHCO_(3)was the second,the germination rate was 14.5%,the germination potential was 1.7%,and the germination index was 6.9.The seedling height,main root length and lateral root number of rice seedlings under Na_(2)CO_(3),NaHCO_(3)and mixed salt stress were significantly lower than those under NaCl and Na_(2)SO_(4)treatments(P<0.01).There was no lateral root germination in all three treatments.The plasma membrane permeability of root cells under different salt treatments was significantly higher than that of CK(P<0.01).The plasma membrane permeability of root cells in different salt treatments was significantly higher than that of CK(P<0.01),and the plasma membrane permeability of Na_(2)CO_(3)cells was the highest,which was significantly higher than that of other salt treatments(P<0.01).The K^(+)/Na^(+)ratios of seedlings and roots of all salt treatments were significantly lower than those of CK(P<0.01),and the K^(+)/Na^(+)ratios of roots in Na_(2)CO_(3),NaHCO_(3)and mixed salt treatments were only 0.05,0.07 and 0.13,which were significantly lower than those of CK,NaCl and Na_(2)SO_(4)treatments(P<0.05).So Na_(2)CO_(3)and NaHCO_(3)aggravated the damage,which was related to the damage to cell membrane of rice root and inhibition of K^(+)absorption.Alkaline salts mainly affect the growth of rice seedlings by affecting the germination of lateral roots.