芦苇Phragmites communis Trin. 耐盐变异体的生物学鉴定和快速繁殖以及在海水生态养殖中的应用示范

本文以芦苇野生亲本和耐盐变异体为材料，比较了两者在形态、生理生化以及分子生物学特性上的差异，对耐盐变异体抗盐能力提高的机理作了初步的探讨。为了适应推广芦苇耐盐变异体的需要，进行了耐盐变异体快速繁殖的研究，建立了两种诱导丛生芽的技术系统。对耐盐变异体芦苇在滩涂上的利用作了有益的尝试。结果总结如下： 1．通过对芦苇野生亲本和耐盐变异体的基因组DNA用随机引物扩增分析，发现两者的基因组DNA在序列上存在着一定的差异，并克隆测序了几个对变异体而言是特异的标记序列。 2．生化分析发现，在盐胁迫下，两者在可溶性蛋白上存在着差异，芦苇耐盐变异体在胁迫下分别在20～30 kD和43～66．2 kD之间各有一条特异的蛋白带表达。而且变异体盐胁迫下在同工酶的表达上也与野生亲本有着显著的区别。 3．生理测定发现，芦苇耐盐变异体在200 mmol/L NaCl盐胁迫下光合作用要比野生亲本强，叶绿素测定的结果与此相吻合，在此浓度的胁迫下，变异体叶绿素含量受影响较小，而野生亲本的叶绿素含量明显降低。对两者胁迫前后的离子含量测定发现，虽然K+含量最多，但是植株内离子含量变化最大且增加最多的离子是Na+，而且变异体内Na~+增加的量比野生亲本高得多。另一个变化较大的是游离脯氨酸的含量，其变化情况类似于Na~+，在胁迫后脯氨酸含量增加明显，而且变异体内的增加量比野生亲本高。对变异体进一步的胁迫反应证实了Na+和脯氨酸含量变化与胁迫反应的密切联系。推测它们的这些变化与变异体抗盐能力提高密切相关。 4．将芦苇耐盐变异体的种子苗切去种壳和种子根，以此作为外植体，通过筛选大量的激素组合，最终建立了两种快繁技术系统（MP－A和MP－B）进行丛生芽诱导。两个系统都包含预处理和诱导两个主要步骤，其中预处理培养基激素组合是相同的（NAA 2～5 mg/L + 2,4-D 0.05 ～ 0.1 mg + BA 1mg/L）,而诱导处理的培养基激素组合不同，分别为：MP－A的诱导处理的激素组合是将预处理的激素组合中的2，4－D去除即可;MP－B诱导处理的激素组合为1mg/L NAA + 0.05 ～0.1mg/L 2,4-D + 2～5mg/L BA. 两个系统都获得显著的丛生芽诱导效果。 5．在滩涂水产养殖中引入芦苇种植、发现耐盐芦苇能有效地降低水体污染和病害，实验了两种模式的种养殖方式：围隔模式和混合模式，初步结果表明混合模式效果较好。这一初中初步验证了芦苇对海水养殖的价值，对开发滩涂具有很大的意义，具有创新性。

Flower color chimera and abnormal leaf mutants induced by C-12(6+) heavy ions in Salvia splendens Ker-Gawl.

The effect of C-12(6+) heavy ions bombardment on mutagenesis in Salvia splendens Ker-Gawl. was studied. Dose-response studies indicated that there was a peak of malformation frequency of S. splendens at 200 Gy. Abnormal leaf mutants of the bileaf, trileaf and tetraleaf conglutination were selected. Meanwhile, a bicolor flower chimera with dark red and fresh red flower was isolated in M1 generation of S. splendens. Random amplified polymorphic DNA (RAPD) analysis demonstrated that DNA variations existed among the wild-type, fresh and dark red flower shoots of the chimera. The dark red flower shoots of the chimera were conserved and cultivated at a large-scale through micropropagation. MS supplemented with 2.0 mg/L BA and 0.3 mg/L NAA was the optimal medium in which the maximum proliferation ratio (5.2-fold) and rooting rate (88%) were achieved after 6 weeks. Our findings provide an important method to improve the ornamental quality of S. splendens.

An efficient in vitro method for mass propagation of Potentilla potaninii wolf

This study reports a method for high-frequency shoot organogenesis and plant establishment of Potentilla potaninii Wolf. Hypocotyl and cotyledon explants of P. potaninii were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of benzyladenine (BA) and alpha-naphthaleneacetic acid (NAA) to induce adventitious shoot formation for micropropagation. The highest frequency of adventitious shoot regeneration was achieved from hypocotyl and cotyledon explants grown on MS medium supplemented with 5.0 mg l(-1) BA and 1.0 mg l(-1) NAA. The regenerated shoots rooted most efficiently on half-strength MS medium supplemented with 1.0 mg l(-1) NAA and 0.5 mg l(-1) indole-3-acetic acid or indole-3-butyric acid. The acclimatized plants with normal morphology and growth characters flowered and set seeds in the following year.