亚适宜温光下萘乙酸钠对番茄幼苗生长与生理特性的影响

以番茄“中杂105”为试材，研究亚适宜温光条件下根施10 mg·L^-1萘乙酸钠对番茄幼苗生长与生理特性的影响.结果表明： 亚适宜温光处理番茄幼苗生物量、壮苗指数、根系活力、光合速率、根系和叶片中全氮含量均显著下降，超氧化物歧化酶和过氧化物酶活性升高，过氧化氢酶活性降低，玉米素核苷含量显著下降，而脱落酸含量显著增加.亚适宜温光条件下，与对照相比，根施10 mg·L^-1萘乙酸钠可使番茄幼苗全株干质量、壮苗指数分别提高16.4%、22.9%，并使根、叶中全N含量及光合速率分别增加8.5%、28.5%、37.0%，提高根系活力和保护酶活性，增加吲哚乙酸和玉米素核苷含量，抑制脱落酸含量的增加.亚适宜温光处理下，根施10 mg·L^-1萘乙酸钠可以通过提高番茄幼苗根系活力、保护酶活性和光合速率，调控内源激素水平变化，促进番茄幼苗生长.

Effects of sodium naphthalene acetate on growth and physiological characteristics of tomato seedlings under suboptimal temperature and light condition.

Taking tomato ‘Zhongza 105’ as test material, the influences of sodium naphthalene acetate (SNA) on growth and physiological characteristics of tomato seedlings under suboptimal temperature and light condition were investigated. The results showed that the dry mass, vigorous seedling index, root activity, total nitrogen content, net photosynthesis rate (P_n) of tomato seedlings were significantly decreased by suboptimum temperature and light treatment. In addition, the catalase activity and zeatin riboside (ZR) concentration were also reduced. However, the superoxide dismutase, peroxidase activity and the content of abscisic acid (ABA) were increased. Compared with treatment of the same volume distilled water on tomato seedlings under suboptimum temperature and light condition, the dry mass of whole plant and vigorous seedling index of tomato seedlings were significantly increased by 16.4% and 22.9%, as the total N contents in roots and leaves and P_n were also increased by 8.5%, 28.5%and 37.0%, respectively, with the treatment of root application of 10 mg·L^-1SNA. Besides protective enzyme activity and the root activity were improved, the indole acetic acid (IAA) and ZR concentration of tomato were raised, and ABA concentration was reduced. The results indicated that root application of certain concentration of SNA could promote the growth of tomato seedlings by increasing the tomato root activity, protective enzymes activity, P_n and regulating endogenous hormone concentration under suboptimum temperature and light condition.