植物激素对海带孢子体发生的影响

采用析因试验设计，对影响海带孢子体发生的主要环境因子进行优化，筛选出温度8℃、光强30umol-m^-2·s^-1、光时12h的最佳环境条件．基于此条件，对吲哚乙酸（IAA）、赤霉素（GA，）、脱落酸（ABA）、激动素（KT）和矮壮素（CCC）等5种植物激素进行了初步筛选，结果表明0．1mg·L^-1IAA、2．0mg·L^-1KT对海带孢子体的发生有显著促进作用，0．5mg·L“IAA及0．1、0．5、1．0mg·L^-1ABA抑制孢子体的发生，GA3、CCC无显著的影响．采用拉丁方区组设计，对具有显著促进作用的KT进行浓度筛选，获得了促进孢子体发生的最佳浓度4mg·L^-1．在此条件下，孢子体于第5天发生，第16天发生率达94．2％±2．0％，孢子体发生显著加快．此外，孢子体发生与细胞增殖呈异速生长关系，并且连续光照斜率高于短光照，表明短光照更适合孢子体的发生．

Effects of Plant Hormones on Sporophyte Occurrence of Laminaria japonica

A three-way factorial experimental design is used to test the effects of major environmental factors on the sporophyte occurrence of Laminaria japonica.The optimum culture condition of 8 ℃,30 μmol photon m-2 s-1 and a 12 h light: 12 h dark photoperiod is obtained.Based on the condition,the effects of five kinds of plant hormones(IAA,GA3,ABA,KT and CCC) on sporophyte occurrence are tested by single factor experimental design.Results show that 0.1 mg·L-1IAA and 2.0 mg·L-1KT have significant promoting effects on the occurrence,0.5 mg·L-1IAA and ABA significantly inhibit the occurrence,and there is no significant influence of GA3 and CCC on the occurrence.Latin square design is used to screen the concentrations of KT which promotes sporophyte occurrence,and the optimal concentration of 4 mg·L-1 is obtained.Under this concentration,sporophytes occur on the 5th day of culture and the incidence reaches 94.2%±2.0% on the 16th day,showing that the occurrence is improved significantly.In addition,the allometry relationship between cell proliferation rate and sporophyte incidence is found.In comparision to continuous illumination,the slope of allometry relationship is lower at short illumination,which suggests short illumination is more suitable for sporophyte occurrence.