薇甘菊组织培养及体细胞胚胎发生的研究

研究了4种外植体、10种不同浓度激素组合对薇甘菊(Mikania micrantha H.B.K.)离体再生的影响,并对胚性愈伤组织中的体细胞胚发生发育过程进行了组织细胞学观察.结果表明,所用不同浓度激素组合的培养基均能诱导薇甘菊外植体产生愈伤,培养基以MS+6BA 1 mg/L为最宜;不同种类的愈伤组织再分化结果有明显差异,生长良好的胚性愈伤组织转入分化培养基后可诱导体细胞胚的发生.薇甘菊体细胞胚胎发生的形式为单细胞内起源.体细胞胚起源于胚性愈伤组织的胚性细胞,胚性细胞经过一次不均等分裂产生两个细胞,即胚细胞和胚柄细胞.然后依次经过具胚柄的多细胞原胚,再经过球形胚、心形胚、鱼雷胚阶段,发育成具有子叶的成熟胚状体,然后长成为再生植株.     

PLBs induction and clonal plantlet regeneration from leaf segment of commercial hybrids of Phalaenopsis

Induction of Protocorm-like bodies (PLBs) from leaf segments is a clonally propagation technology that used somatic embryogenesis regeneration from in vitro buds of floral stalks, and is a potential alternative for replacement actual low-yield and high-cost clonal propagation of Phalaenopsis orchids. The objective of this work was to evaluate induction of PLBs in leaf segments of two commercial hybrids of Phalaenopsis, arranged in culture media with different combinations of plant growth regulators. The leaf segments (0.4–0.5 cm²) used for PLBs inductions were obtained from young in vitro-induced shoots from inflorescence stalks. They are cultivated in NDM culture media, supplemented with combinations of plant growth regulators Naphthaleneacetic Acid, Thidiazuron and Benzyladenine. The flasks were kept for 60-d in darkness and then for cold white light with photon flux density of 35–40 μmol m^?2 s^?1. The cultivar ‘Ph908’ showed a higher percentage of leaf segments with PLBs (45%) and number of PLBs (25 per leaf segment), in medium containing 0.25 mg L^?1 of TDZ, whereas ‘RP3’ showed only 10% containing PLBs and 2 PLBs per leaf segment in NDM with 1.0 mg L^?1 NAA, 20 mg L^?1 BA and 0.125 mg L^?1 TDZ.     

Monitoring genetic stability inQuercus serrata Thunb. somatic embryogenesis using RAPD markers

Genetic stability of propagules regeneratedvia somatic embryogenesis is of paramount importance for its application to clonal forestry. Random amplified polymorphic DNA (RAPD) markers were used to determine the genetic stability in somatic embryogenesis ofQuercus serrata Thunb. (Japanese white oak). Forty samples from an embryogenic line, consisting of regenerated plantlets, somatic embryos, and embryogenic calli, were examined using 54 decanucleotide primers. A total of 6520 clear reproducible bands obtained from these studies exhibited no aberration in RAPD banding pattern among the tested samples. Our results show that somaclonal variation is absent in our plant propagation system. The genetic stability is discussed in terms of the origin of somatic embryos.     

Yolk mobilization in perch, Perca fluviatilis L., embryos

During embryogenesis of the perch, Perca fluviatilis L., a gradual proteolysis of yolk proteins was revealed by SDS-PAGE and immunoblotting and was comparable to other teleosts. A 118 kDa polypeptide was processed in two 96 and 18 kDa descendants; further proteolysis produced two peptides of 64 and 31 kDa. Ultrastructure and immunocytochemistry were used to compare electrophoresis patterns with morphological changes in the developing embryo and to localise yolk proteins in embryonic cell layers. In contrast to most other freshwater teleost, in spawned eggs of the perch yolk spheres fused together forming a homogenous yolk mass; lipid droplets formed a single oil drop on top of the egg. Combination of electrophoresis data and light and electron microscopical observations suggested a specific and parallel mobilization of yolk and lipid. In addition, yolk absorption by the yolk syncytial layer was observed. Numerous yolk platelets were found in the yolk syncytial layer and, in later stages of embryogenesis, also in the inner cell mass, but never in the cells of the enveloping layer.     

玉米小孢子胚胎发生的细胞形态学观察

通过观察玉米小孢子胚胎发生的细胞形态学特征,发现：离体培养条件下单核后期的花粉可以通过均等分裂和不均等分裂两条途径形成胚状体,与前人的研究结果一致。淀粉的积累,多核小孢子的液泡化以及花药壁的衰退都可影响雄核发育。将诱导培养3周的花药转移到降低蔗糖浓度、去除TZBA并附加KT的分化培养基上,有利于球形胚和梨形胚的极性分化和成熟,而发育较迟的胚状体则停止发育,趋向退化。因此胚状体之间出现明显的两极分化。     

花生组织培养研究进展

花生组织培养对于品种改良、新品种繁殖、遗传转化和种质保存等具有重要意义．本文概述了花生苗的再生培养、体细胞胚的诱导培养、花药培养、远缘杂种胚营救培养、原生质体培养和遗传转化的研究进展,并展望了花生组织培养未来的发展     

糖源对棉花花药培养的影响──Ⅱ 糖源对棉花花药愈伤组织增殖和分化的影响

不同糖源诱导产生的愈伤组织具有一定的后效应,一般在诱导阶段生长较慢的愈伤组织当转入同一培养基上培养时则表现出优势。以可溶性淀粉、蔗糖和麦芽糖为糖源的培养基上均可诱导棉花花药愈伤组织获得了胚胎发生和胚状体;葡萄糖虽有利于棉花花药愈伤组织生长,但却没能诱导胚胎发生和胚状体的形成。乳糖即不利于愈伤组织的生长,又不利于胚状体的形成。半乳糖作为糖源,愈伤组织虽能增殖,但生长速度极慢。山梨糖不能被棉花花药愈伤组织吸收,故以山梨糖为糖源时愈伤组织极易褐化死亡。甘露醇的添加促进了葡萄糖诱导形成胚性愈伤组织和胚状体。     

Towards genetic transformation in the monocot Alstroemeria L.

The successful application of plant biotechnology to Alstroemeria improvement will largely depend on the availability of an efficient regeneration/transformation system. Regeneration in Alstroemeria is accomplished from nodular embryogenic callus initiated from zygotic embryos. Histological studies of embryogenic callus initiation from 4-weeks old cultured ovules revealed that the outermost layers of the protoderm of the embryogenic nodules divided to form either a new nodule or aproembryo. Transient gene expression after particle bombardment of nodular embryogenic callus was optimized using DNA of pAHC25. The highest β-glucuronidase expression was found when the GUS gene was under control of the maize ubiquitin promoter, the target tissue was placed 5 cm below the microcarrier launch assembly and when the rupture disc-breakage point was between 650–900 psi. Kanamycin blocked regeneration of somatic embryos, however, did not block growth of nodular embryogenic callus. With phosphinothricin both callus growth and regeneration were blocked. Bombardment of nodular embryogenic callus with DNA of pAHC25 combined with selection on medium containing phosphinothricin resulted in putative transgenic chimeric. Friable calli were selected from nodular embryogenic callus and used to initiate suspensions. These cell suspensions were subjected to transformation by particle bombardment using DNA of pAHC25 and resulted in a stable transformed friable callus line after selection based on luciferase activity. Even after 2 years of maintenance this callus line was luciferase positive and the Polymerase Chain Reaction analysis demonstrated the presence of the introduced gene in this friable callus line. This revised version was published online in July 2006 with corrections to the Cover Date.     

豆科牧草沙打旺抗乙硫氨酸变异系筛选

以NaN3诱变处理的沙打旺胚性愈伤组织为材料,用甲硫氨酸类似物—乙硫 氨酸为选择剂,筛选到1株抗性稳定且能再生植株的抗0.6 mmol L－1乙硫氨酸 变异系。该变异系细胞对乙硫氨酸的抗性是野生型细胞的8倍。当把变异系愈伤组织传入 体细胞 胚胎诱导培养基上,平均体细胞胚胎发生频率为13.9%,平均每g鲜重愈伤组织可产生21 个体