Paraffin dissections of the structural and morphological changes during somatic embryogenesis were studied using callus tissue from Ananas comosus ＇Shenwan＇ as material. Results showed the pineapple somatic embryogenesis can be divided into 5 phases, proembryo, globular embryo, pear embryo, bamboo shoot embryo and mature embryo. Proembryo is the multicellular structure formed by differentiation and division of embryogenic cells, club or spindle shaped, with the diameter of 50 - 200 μtm, grey, uniform, no structural differentiation. Globular embryo is similar to a sphere with a diameter of 200- 500 μ, differentiation starts at this phase and some vascular tissue were observed at the end stage of globular phase. Pyriform embryo is about 600 - 1 000 μtm long, with different diameters between upperand lower ends, which resembles the shape of a pear, it has the largest diameter in the middle lower section （400 - 800 μxrn）, and bipolarity is already showed in this phase. Bamboo shoot embryo has a resemblance to the bamboo shoot, with a length of 1 000 - 2 000 Ixrn, the largest diameter is about 600 - 1 Q00 grn in the lower section. The cotyledon primordium, coleoptile primordium and plumule primordium are already visible at the later stage of bamboo shoot embryo. Mature embryo is about 2 000 - 4 000μtm long, the largest diameter is about 1 000 - 1 500 grn in the lower section. Cotyledon, coleoptile, leaf primordium and cotyledon growing point are shown in plumule, however, the differentiation of radical is slow, with a layer of coleorhizae tissues covering it. Both plumule and radical are endogenous, with collarshaped cotyled6n and the sheath like first leaf （coleoptiles）, short hypocotyls, rosetteshaped leaf primordium on the top of hypocotyls are demonstrated as the characteristics of pineapple somatic embryo.

Pineapple (Ananas comosus) callus was infected by the Agrobacterium tumefaciens (LBA4404 strain),containing a plant expression recombinant plasmid (pUHA1-CYP1A1). After infection,the callus was co-cultivated with agrobacteria for 3 d on medium(MS+3.0 mg/L BA+2.0 mg/L NAA+100 μmol/L AS+8 g/L agar) then transferred to selection medium(MS+3.0 mg/L BA+2.0 mg/L NAA+20 mg/L Km+400 mg/L Carb+8 g/L agar). Adventitious shoots were initiated after 10 d of culture; 28 d later,the green Km-resistant shoots were transferred to selection medium (MS+2.0 mg/L NAA+30 mg/L Km+300 mg/L Carb+8 g/L agar) for the second successive selections,then were transferred to mediun (MS+1.0 mg/L IBA+30 mg/L Km+8 g/L agar)for rooting,as a result,a total of 95 Km-resistant plants were obtained,its transformation rate is 0.12%─2.69%. PCR assays were performed to some of the Km resistant plants and its positive rate is 64.29%. The results of southern hybridization further confirmed that CYP1A1 has been integrated into the genome of pineapple. Taking the agar as medium coagulant,adding AS to co-culture medium,increasing selection times,gradually increasing the concentration of Km in the new round of selection medium etc are the important conditions of obtaining transformants by Agrobacterium tumefaciens-mediated genetic transformation in pineapple callus.

The histological and cytological methods were applied on the study of the characteristics of multiplication and differentiation and principles of regeneration of pineapple[Ananas comosus (L.) Merr.] in vitro tissue culture, using non-embryogenic tissue as material. A certain morphologic difference of non-embryogenic callus was displayed gradually after 3 cultures on multiplication media. Globular nodular structure, parenchyma clumps, compact interior callus and surface loose callus were classified from non-embryogenic callus based on their morphology, differentiation capacity as well as histological and cytological characteristics. One type of non-embryogenic callus will generally give rise to the same type of non-embryogenic callus on multiplication medium of MS +3.0 mg/L BA + 2.0 mg/L NAA, however, types of callus can be convertible by manipulating the formulation of media. In the meantime, organogenesis during multiplication was common, typically by parenchyma cells from the surface of callus differentiating into meristematic cells, thereby leading to adventitious buds differentiation. 4 types of non-embryogenic callus could go through organogensis by ways of protocorm-like-bodies, multishoots and adventitious buds, plant regeneration through somatic embryogenesis could also be induced, in which protocorm-like-bodies had the highest potential to generate somatic embryos, followed by multishoots. Auxin and cytokinin had great impacts on the morphology, differentiation pathways and multiplication capacity on non-embryogenic callus.

10～60 days old embryos of the three wampee cultivars, Yunan Seedless Wampee,Chicken Heart and Sweet, were used as materials for in vitro culture of immature embryos. Cultured in WPM medium supplemented with CH 0.50 g/L + PVP1 g/L (or AC 0.3%) + AgNO3 10 mg/L+ GA3 0.25 mg/L+ BA 1.5 mg/L+ NAA0.5 mg/L, 10～23 days old embryos only formed callus. However, the highest callus formation was obtained from 20 days old embryos, with the lowest browning rate and good growth. There were 11%～26% of 30 days old embryos developed seedlings and the survival rate of the seedlings rose with embryo age. The seedling survival rate was between 50% and 73% for 60 day old embryos. Chicken Heart had the highest callus induction rate, followed by Sweet, and the lowest was Yunan Seedless Wampee;however, Sweet had the lowest callus browning rate, and Yunan Seedless Wampee had the highest. Cultured in WPM medium supplemented with CH 0.50 g/L+ AC 0.3% + AgNO3 10 mg/L+GA3 0.25 mg/L+ BA 1.5 mg/L+ NAA or IBA 1 mg/L, the callus could be subcultured and proliferated. The key factor for proliferation was plant growth regulators. The most difficult problem for wampee tissue culture was browning, slowly growing and difficult in differentiation.

介绍了植物基因工程技术在监测和净化难分解性有机污染物质方面的研究进展.生物中存在着能降解难分解性有机污染物质的酶及其编码基因,具有识别和除去难分解性有机污染物质的免疫系统、受体和响应元件.这方面的研究工作多以哺乳动物为材料,植物的相关研究还处于起步阶段.创造环境监测和环境污染净化为目标的新型植物将成为转基因植物研究的极其重要的研究方向之一.