Initiation of morphogenic cell-suspension and protoplast cultures of barley (Hordeum vulgare L.)

Cell-suspension cultures were initiated from embryogenic calli of various barley cultivars. Seven fast-growing suspension lines were obtained from four different cultivars (cvs. Dissa, Emir, Golden Promise and Igri). Two of these cell suspensions showed morphogenic capacity. From a cell suspension of cv. Dissa, albino plantlets were regenerated when aggregates were cultured on solid medium. Aggregates of cv. Igri usually stopped differentiation at the globular stage, but occasionally formed scutellum-like structures. Five suspension lines were used for protoplast isolation and culture. Dividing protoplasts were obtained from all lines, but with cv. Igri a few divisions only and no further development were observed. Protoplasts from the various lines differed in the time of first division (2–14 d), division frequency (0.09–70.9%) and efficiency of colony formation (0.09–7.3%). Protoplasts isolated from the morphogenic cell suspension of cv. Dissa developed compact calli which sporadically regenerated albino plantlets.Abbreviations CC, MS, N6, SH, Kao8p culture media; see Material and methods - cv chltivar - dicamba 3,6-dichloro-o-anisic acid - 2,4-D 2,4-dichlorophenoxyacetic acid - picloram 4-amino-3,5,6-trichloropicolinic acid     

The production of haploid wheat plants from wheat x maize crosses

Summary Hybrid embryos from hexaploid wheat x maize crosses rapidly lose the maize chromosomes to produce haploid wheat embryos. Such embryos almost always aborted when left to develop on the plant, and only 1 was recovered from 2440 florets (0.17% of the expected number). Embryos had greater viability in spikelet culture, 47 (26.5% of the expected number) being recovered from 706 ovaries. Thirty-two of these embryos germinated to give green plants, 31 of which were haploid (21 wheat chromosomes) and 1 of which was euploid (42 wheat chromosomes). Spikelet culture enabled 17.1% of the expected number of embryos to be recovered as haploid plants, a 100-fold improvement on allowing embryos to develop in vivo. Ten haploid plants of Chinese Spring (kr1, kr2), 13 plants of Chinese Spring (Hope 5A) (kr1, Kr2), and 8 of Hope (Kr1, Kr2) were recovered. The potential of wheat x maize crosses for wheat haploid production and for gene transfer from maize to wheat is discussed.     

从“湖北光敏感核不育水稻”的未受精子房和花药培养出单倍体植株

采用10种诱导培养基,培养湖北光敏感核不育水稻农垦58品种的未受精子房和花药。共培养未受精子房2790个,获得胚囊愈伤组织17块,最高诱导频率达3.33%,其中2块分化出绿苗。培养花药16740个,获得花药愈伤组织15块,最高诱导频率为0.92%,其中3块分化出苗,2丛白苗,1株绿苗。胚囊植株和花粉植株经根尖染色体检查为单倍体,2n=x=12。实验证明,液体培养、2,4-D0.2-0.5 mg/1、低温预处理对诱导胚囊愈伤组织及花粉愈伤组织的形成具良好效果。     

虫生真菌双生座壳孢的研究

双生座壳孢(Aschersonia duplex Berk.)系日本卷毛蚧的病原真菌。此菌在人工培养基和自然基物上生长好,并能产生大量分生孢子。对 C 源中的蔗糖、葡萄糖、甘露醇、山梨糖;N 源中的蛋白胨,天冬素、L-酪氨酸、KNO_3利用好。生长适温22—26℃。病原流行季节相对湿度在80％以上。田间接种,对寄主致病性强,有应用潜力。     

马铃薯未传粉子房离体培养诱导双单倍体植株

以MS为基本培养基,附加不同水平的生长素,培养未传粉马铃薯子房,经三年试验,从两个品种中获得了双单倍体的绿色小植株,(2n=2x=24);从分化绿苗力很强的球状愈伤组织中,又不断地分化出许多绿色小植株。绝大多数品种,都可以诱导出愈伤组织,一般诱导率为70％左右。品种的基因型和培养基中的生长素种类与水平在愈伤组织分化绿苗中起着重要作用。通过扦插和试管微型薯培养,可以大量繁殖试管苗,这为马铃薯单倍体育种提供了较有利的条件。     

诱导小麦-天兰偃麦草-黑麦三属杂种花粉植株的研究

以法国六倍体小黑麦为母本,分别与普通小麦(Triticum aestivum)和天兰偃麦草(Elytrigia intermedia of Agropyron glaucum)的杂交后代中的中间类型3号和5号杂交。由此获得的三属杂种F_1性状介于亲本之间,兼有三属亲本类型的特征,呈中间类型。用马铃薯-Ⅱ培养基培养三属杂种F_1的花药,诱导花粉愈伤组织。将所获得的愈伤组织转入190-2培养基进行分化,已成功地诱导出一批三属间杂种花粉植株,并用Giemsa显带技术鉴定花粉植株的染色体组组成。     

The BULT Melanoma: A Spontaneous Transplantable Tumor in Mice

The BULT melanoma originated at Brown University as a spontaneous, small black nodule on the tail of an adult female mouse of the LT/Ch strain. Histological examination of a portion of the tumor indicated that it was intradermal and consisted predominantly of heavily melanized, ovoid to fusiform cells with melanin-laden macrophages scattered among them. The BULT melanoma has been maintained in LT/Ch mice for approximately 5 years by periodic transplantation, at first subcutaneously on the flanks and, more recently, intramuscularly in the hind legs. The shift in transplantation site was made following a marked decline in the growth of subcutaneous grafts. The transplants have retained the uniform deep-black melanization and general histology of the primary melanoma. Numerous melanosomes at all stages of development are found within the melanoma cells. DOPA-positive cytoplasmic vesicles are abundant. Occasional autophagic vacuoles containing clusters of melanosomes are also present. A few metastases from the transplanted melanoma have been observed in lymph nodes and on one occasion in the lungs. When grown in vitro, BULT melanoma cells do not require special growth promoting agents (e.g., TPA; cAMP) in order to proliferate. The BULT melanoma differs in one or more respects from each of the other three transplantable spontaneous mouse melanomas widely used in cancer research. In addition, it arose in a strain of mice characterized by the spontaneous death of melanocytes while the latter are engaged in synthesizing eumelanin within hair follicles. Karyotypic analysis of cultured cells showed a modal chromosome number of 68 with a range of 58–72 chromosomes.     

桑蚕促前胸腺激素的作用与前胸腺分泌活动的某些特点

本工作以前胸腺的体外器官培养技术和蜕皮激素的放射免疫分析法(MH-RIA)相结合,研究了桑蚕(Bombyx mori)促前胸腺激素(PTTH)的作用与前胸腺分泌的某些特点。结果表明,被PTTH激活后的前胸腺,在一定的时相过程内合成并分泌脱皮甾类激素;前胸腺本体不积累蜕皮甾类激素;PTTH对前胸腺的作用是积累性的;五龄不同天数的前胸腺合成分泌脱皮甾类激素的能力不同,并有不同的剂量反应。     

Streptozotocin toxicity to cultured pancreatic islets of the Syrian hamster

Pancreatic islets of the Syrian golden hamster were maintained in culture for extended periods of time. Toxicity of streptozotocin in these cultures was evaluated by measurement of insulin secretion. Exposure of islets to 1 or 2 mM streptozotocin immediately following isolation resulted in a permanent and dose-related inhibition of insulin secretion. This was accompanied by islet disruption as observed by phase-contrast microscopy. Culture of islets for 24 hours before streptozotocin exposure afforded protection from toxicity. For example, exposure of freshly isolated islets to 2 mM streptozotocin resulted in complete destruction of beta cells, whereas islets similarly exposed after a 24 hr culture period continued to secrete insulin for many months. Islets maintained in culture for one week before exposure to 0.1–0.5 mM streptozotocin, however, became more sensitive than freshly isolated islets. Repeated weekly exposure of cultured islets to a non-toxic concentration (0.1 mM) resulted in sustained suppression of insulin secretion after 11 weeks.     

High cell density perfusion culture of hybridoma cells recycling high molecular weight components

We have developed a high cell density and high product concentration culture system recycling high molecular weight components. The production of monoclonal antibodies in high concentration was performed by this culture system with mouse human hybridoma H2 and V6 cells in serum-free defined media.The concentration of IgG after 48 days culture of H2 cells in ITES-eRDF reached 2 mg/ml and the purity of IgG in culture fluid was 61%. In addition, high molecular weight components in serum-free media, such as transferrin or BSA, could be reduced to 5% of the original concentration.