烟草耐盐愈伤组织变异体对盐渍的适应性

用组织培养及逐步增加,NaCl浓度的方法,筛选出烟草耐盐愈伤组织变异体。能耐盐(2％ NaCl)的愈伤组织在2％ NaCl中继代29次,再移入无盐培养基中培养11和20代后不能保持提高的耐盐性,分别退化到只耐1.5％与1.0％ NaCl的水平。耐2％ NaCl愈伤组织产生的再生植株自交后代,其萌发种子、幼苗及成长植株均未能表现出耐盐性,说明用选择胁迫方法所筛选出的耐盐细胞系,其耐盐性的提高属于生理适应性。

Salinity Adaptation of Tobacco Salt-Tolerant Callus Variant

By increasing the salt concentra-tion gradually, a cell line tolerant to2% NaC1 was established. The 2%NaC1-tolerant variant callus was sub-sultured through 52 passages in a modi-fied MS medium containing 2% NaC1,then transferred to a medium contain-ing 0.5%, 1.0%, 1.5%, or 2.0%NaC1 respectively with original type,its fresh wt, dry wt., relative growthrate and proline content were all supe-rior to original type (Table 1, Fig.2). The callus line possessed NaC1--tol-erance thoroughly and the NaC1--toler-ance was positively correlative withproline content. But when the 2% Na-C1--tolerant variant callus was subeul-tured though 29 passages in a mediumcontaining 2% NaC1, then transferredto NaC1--free for 11 and 20 pasaages, itdid not maintain the tolerance. Astable 2, 3 showed, they could onlytolerated NaC1 levels of 1.5% or1.0%. Self--pollinated progenies of regen-erated plant from the salt--tolerant vari-ant were obtained. The germinatingseeds (Fig. 3), seedlings (Fig. 4, 5)and adult plants of the progenies wereall not salt tolerant. The results showed that the in-creased tolerance to salt of tobacco cal-lus variant obtained as reported in thispaper was only a physiological adapta-tion.