镉胁迫对三个棉花品种(系)产量、纤维品质和生理特性的影响

以抗草甘膦棉花种质系ZD-90和转Bt基因抗虫棉品种s GK3为材料,以陆地棉标准系TM-1为对照,研究了镉(Cd)胁迫下棉花生育期内的植株生长、产量、农艺性状、纤维品质和抗氧化酶系统活性。结果表明,低浓度Cd对棉花植株的生长发育有一定的促进作用;高浓度Cd对植株的生产发育有显著的抑制作用,植株生长量、子棉产量和皮棉产量显著降低。Cd胁迫对棉花单株铃数、铃重和单铃种子数的影响较大,而对衣分无显著影响。不同浓度Cd处理间的棉花纤维品质性状无显著差异。棉花植株体内的抗氧化化物酶(POD、SOD和CAT)活性在棉花生长发育的初期或低浓度胁迫条件下迅速升高,但随着Cd浓度的增大和胁迫时间的延长,酶活性受到抑制。植株体内累积的MDA含量则随着Cd处理浓度的增加和胁迫时间的延长呈逐渐升高趋势。3个品种比较,TM-1对Cd较敏感,ZD-90次之,s GK3受Cd胁迫的为害相对较轻,是一个较耐Cd的棉花品种。

Effects of Cadmium Stress on Yield,Fiber Quality,and Physiological Traits of Three Upland Cotton Cultivars (Lines)

A two-year pot experiment was carried out to study the yield, fiber quality, and physiological traits of two transgenic upland cotton germplasms (ZD-90 and sGK3), using the upland cotton standard line TM-1 as a check, under different levels of cadmium (Cd) stress. The results showed that lower level Cd treatments had increasing effects on the growth and development of cotton plants, while higher levels of Cd greatly inhibited the growth and development of plants, which led to a significant decrease in plant size, seed cotton yield, and lint cotton yield. Among the agronomic traits, boll number per plant, boll weight, and seed number per boll were the most susceptible traits to Cd stress, while lint percentage was the least affected. Cd stress had little effect on fiber quality traits (staple length, fiber strength, and micronaire); differences among the treatments were insignificant. Physiological and biochemical analysis of cotton plants indicated that the activity of antioxidant enzymes such as POD, SOD, and CAT increased greatly to avoid harm from the increase of reactive oxygen species caused by Cd stress at lower levels of Cd treatment. With the increase of Cd level and growth period length, their activities were inhibited greatly, while the MDA content increased gradually. According to the results of our experiments on plant growth, yield, fiber quality, antioxidant enzyme activity, and MDA content, TM-1 was the most susceptible upland cotton germplasm to Cd stress, followed by Zd-90. sGK3 had outstanding Cd tolerance among the materials in the experiment, and could be used as a potential cultivar for cleaning up contaminated soils by phytoremediation.