Full length mRNA sequences of Ac-β-actin and Ac-gapdh , and partial mRNA sequences of Ac-18SrRNA and Ac-ubiquitin were cloned from pineapple in this study. The four genes were tested as housekeeping genes in three experimental sets. GeNorm and NormFinder analysis revealed that β-actin was the most appropriate reference gene for qPCR analysis of callus under induction conditions and in different tissue types, meanwhile, 18SrRNA was the most stable reference gene during organ development. Gapdh was the most unstable gene in all tested experimental sets. Transcript level analysis result of AcSERK 1 in stressed callus normalized by β-actin and 18SrRNA further confirmed that reference genes selected in this study were suitable for transcript level analysis of pineapple. The expression pattern of AcSERK 1 during somatic embryogenesis normalized by β-actin coincided with the cytological features of calluses during somatic embryogenesis. These results will enable more accurate and reliable normalization of qPCR results for transcription analysis in pineapple. Keywords: Reference genes, qPCR, pineapple, geNorm, NormFinder African Journal of Biotechnology Vol. 11(29), pp. 7424-7433, 10 April, 2012

介绍了日本的菠萝生产与研究。伴随着罐头加工业发展,日本菠萝生产逐渐壮大,建立起了相应的施肥、花芽诱导等栽培技术。罐头输入自由化后,加工果生产逐渐减少,鲜食果生产比率逐渐增加,研究重点为培育优良鲜食品种、开发高品质栽培和设施栽培技术等方面。近年来,采取推动产区认证和品牌认证、发展网上销售、开发菠萝观光产业等措施,应对市场变化。

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.

Eight conventional DNA extraction methods,i.e.CTAB,improved CTAB,SDS,improved SDS,improved Chen-daming method,high salt low pH,SDS-CTAB and Benzyl Chloride method,were used and slightly modified by adding some purification steps,such as two times of precipitation with isopropanol and ethanol and increasing centrifugation force,to extract genomic DNA from Sanhua plum leaves.Extraction results were analyzed and compared.It was shown that the best DNA extraction result was obtained by using CTAB,followed by improved CTAB and high salt low pH.The other 5 methods were not good for the extraction of Sanhua plum genomic DNA.CTAB method was not only good for the extraction of genomic DNA from Sanhua plum leaves of different seasons(April,August,December) and different maturations(unexpanded,expanded,mature,old) but also good for the extraction of genomic DNA from tender leaves of other 11 tested plum varieties.

Histocytology study was done by paraffin section method on the globular embryogenesis in pineapple(Ananas comosus).The results showed that the non-embryonic callus were cultured on the MS medium contained 4.0 mg · L-1 2,4-D and 0.5 mg · L-1 6-BA,embryogenic cells appeared in it.Then the single embryogenic cells formed a proembryo composed of many cells through cell division.The cells of proembryo had strong division ability,and there were distinct difference in shape and obvious boundary between them/it and the surrounding tissues.A suspensor-like structure was formed on the bottom of the proembryo.Along with the constant growth of the proembryo,its shape converted from long-ellipse to obovate,at last it evolved as a globular embryo with smooth surface,and there were absciss layer in the joint of the bottom of suspensor and matrix tissue.At the same time,cell differentiation appeared in the globular embryo.Pineapple somatic embryogenesis has two original modes,endogenous origin and exogenous origin.Additionally,there were ubiquitous uneven,desynchronization and secondary embryos phenomenon during somatic embryogenesis in pineapple callus.

Bromeliad belongs to Bromeliaceae,origin from Caribbean coast of North American to South America.Only one(Pitcairnia Feliciana) distributes in the west coast of Africa.Bromeliaceae can be divided into three subfamilies: Pitcairnioideae,Bromelioideae and Tillandsioideae.It includes 56 genus,2 656 species and 342 variations.According to its life style in provenance,Bromeliad can be divided into epiphyte,terrestrial and lithophyte.According to ecological characteristics,Bromeliad can be divided into terrestrial Bromeliads,tank Bromeliads and atmospheric Bromeliads.According to purpose,Bromeliad can be divided into edible Bromeliads and ornamental Bromeliads.There are great differences in the cultural pattern of different types of Bromeliads.Except Ananas comosus,which is regarded as fruiter,other species have ornamental value.For example,the tank Bromeliads and silver-leaf tillandsia have already become new species in the international market.

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.

枣树(Ziziphus jujuba)枝条扦插极难生根,树体上能作接穗的枣头又少,加快枣树繁殖一直是枣树生产中一项亟待解决的问题.近年来,以枣树茎段培养进行苗木快速繁殖(张福泉,1983;刘仁贵,1988;罗晓芳等,1996; 刘翠云等,1997)和苗木脱毒(田砚亭等,1993)的研究报道较多,但枣树茎段培养时极易产生不具繁殖作用的枣吊,增殖系数低.

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.