在贯叶金丝桃组织培养物中贯叶金丝桃素和断贯叶金丝桃素的不同累积

贯叶金丝桃素（1）是贯叶金丝桃中的抗抑郁活性成分。从该植物体外培养物中发现了贯叶金丝桃素及3个相似的异戊烯基问苯三酚衍生物。这些化合物的累积与其植株再生有关。通过在线LC—DAD、LC—MS、LC—NMR法鉴定了贯叶金丝桃素同系物断贯叶金丝桃素（3）的结构。研究了植物激素和诱导剂对贯叶金丝桃组织培养物中化合物1与3比例的影响。

Direct Regeneration of Plants Derived from in vitro Cultured Shoot Tips and Leaves of Poplar （Populus×euramericana ＇Neva＇）

The purpose of the present study was to establish a regeneration procedure for Populus × euramericana ＇Neva＇ by using in vitro shoots tips and leaves. For sterilization, 0.1% （w/v） mercuric chloride （HgCl2） solution for 8 to 10 min was the optimal treatment for this poplar cultivation. The effects of benzyladenine （BA） and α-naphthaleneacetic acid （NAA） added to Murashige and Skoog （MS） medium were tested on organogenesis. The highest regeneration rate and numbers of shoots/explant from shoot tips （96.7%, 9.8） and leaves （90.0%, 8.7） were obtained on the half-strength MS medium supplemented with 0.5 mg/L BA and 0.1 mg/L NAA. The optimal medium for in vitro rooting of shoots was on a half-strength MS medium containing 1 mg/L indolebutyric acid （IBA） with the highest rooting frequency （93.3%） and numbers of roots/explant （8.2）. For acclimatization, in vitro rooted plantlets were transferred to plastic cups containing vermiculite and peat （1： 1）. After acclimatization, transplanted plantlets grew well in a shade house. Therefore, we believe that this efficient plant regeneration protocol especially by leaf explants is very important for in vitro clonal propagation of Populus×euramericana ＇Neva＇.

Establishment of Plant Acceptor System for Hyperosmosis Transformation

Calli and adventitious buds induced from different explants such as young stems and leaves of tomato variety Moneymaker,and mature embryos and young spikelets of rice variety TP309 were used to establish hyperosmotic transformation system at various osmotica treatments.The results revealed that the calli induced from tomato young leaves and rice young spikelets were the ideal transfomation acceptor.The cells of calli were still vigorous when treated with 0.75 mol/L hyperosmotic solution for 4 hours.The differentiation rates of calli varied from 7.5% to 93.3% in different media.The bud differentiation was apparently inhibited by hyperosmotic treatments.0.75mol/L sucrose hypertonic solution and 0.2mol/L CaCl2 solution were favorable hyperosmoticum and hypcosmoticum respectively.

In vitro Culture of Early Rabbit Embryos Injected with Foreign Gene and Its Retention

Fertilized rabbit eggs injected with SMTPGH gene were cultured in vitro and retention of theinjected gene was studied using PCR technique and nonradioactive labelling methed. In a mediumof TC199 + 10% FCS, three quarters of the fertilized eggs developed to the blastocyst stage. Noapparent change of the injected gene was found before the 8-cell stage, after which it was eitherintegrated into the chromosome of the host or lost gradually. But finally, the retention rate of theinjected gene should be equal to its integration rate.

A Review on the Regeneration of Balsam Pear （Momordica Charantia L.）

An efficient protocol was developed for direct plant regeneration, multiplication and rooting of Balsam pear in vitro. The key factors influencing regeneration such as genotypes, explants type, seedling age, plant hormones and additives were summarized. The paper also discussed the problems existing on balsam pear tissue culture and prospected the future development of this system.

A Review of Somatic Embryogenesis in Cucurbitaceae

Somatic embryo is widely used in genetic engineering and cell engineering. This paper reviewed the recent research results of somatic embryogenesis in Cucurbitaceae plants. Somatic embryogenesis is controlled by many factors such as genotype, explant type, seedling age, basal culture medium, carbohydrate, nitrogen, growth regulators, additives and illumination et al.. Abnormality, desynchrony and browning are the main problem existing in Cucurbitaceae somatic embryogenesis. Then some ideas on how to obtain high quality somatic embryo are given. At last, we forecast the application of somatic embryo in breeding of Cucurbitaceae plants.

Biocompatibility of nano-hydroxyapatite/Mg-Zn-Ca alloy composite scaffolds to human umbilical cord mesenchymal stem cells from Wharton's jelly in vitro

Seeding cells and scaffolds play pivotal roles in bone tissue engineering and regenerative medicine.Wharton’s jelly-derived mesenchymal stem cells(WJCs)from human umbilical cord represent attractive and promising seeding cells in tissue regeneration and engineering for treatment applications.This study was carried out to explore the biocompatibility of scaffolds to seeding cells in vitro.Rod-like nano-hydroxyapatite(RN-HA)and flake-like micro-hydroxyapatite(FM-HA)coatings were prepared on Mg-Zn-Ca alloy substrates using micro-arc oxidation and electrochemical deposition.WJCs were utilized to investigate the cellular biocompatibility of Mg-Zn-Ca alloys after different surface modifications by observing the cell adhesion,morphology,proliferation,and osteoblastic differentiation.The in vitro results indicated that the RN-HA coating group was more suitable for cell proliferation and cell osteoblastic differentiation than the FM-HA group,demonstrating better biocompatibility.Our results suggested that the RN-HA coating on Mg-Zn-Ca alloy substrates might be of great potential in bone tissue engineering.

The day after the 7th day of the Creation:Breakthrough of human embryo in vitro culture

Since the creation of intelligent creatures,we are no longer the puppets of the creator.For thousands of years,people have been thinking about the nature and the future of ourselves,and reconstruction of the process of life has become the ultimate dream for us.In 1951,William Harvey,a British scientist,elaborated the theory of the structure and function of embryos for the first time in his book'the reproduction of animals',which established the foundation for people to explore the process and the mechanism of embryonic development.