不同栽培方式对粳型巨胚稻产量性状相关性及通径分析

以西巨胚1号为试验材料,比较了淹水、旱种、垄畦3种不同栽培方式下的水稻产量性状,并对其进行了相关及通径分析。结果表明,垄畦栽培方式下,西巨胚1号产量比淹水栽培下增产24．33％,产量构成较合理,有效穗、穗粒数、结实率和千粒重都显著提高;旱种下产量各构成因素均有较大幅度下降,导致减产显著。有效穗、每穗粒数和结实率与产量均呈极显著正相关,千粒重和产量呈显著正相关,而有效穗数与每穗粒数、有效穗数与千粒重、每穗粒数与千粒重呈较弱的负相关,因此,生产上巨胚稻栽培建议采用垄畦栽培方式更有利于其产量形成,在制定巨胚稻高产栽培措施时,应加强稻田水分管理,在提高千粒重的同时,主攻并协调好有效穗数和每德粒数。     

Intrinsic forces alone are sufficient to cause closure of the neural tube in the chick

Summary An isolated neural plate or a postnodal piece of early chick embryos, when cultured under appropriate experimental conditions, can undergo morphogenetic movements and form tubular structures closely resembling neural tubes of early chick embryos.This work was supported by grants from the NIH (NS 23200 and NS 21730) and the Busch Fund of Rutgers University.     

The effect of 5-bromodeoxyuridine on mouse embryos during neurulation in vitro

Summary Mouse embryos explanted at various stages during neurulation were cultured for 20–28 h in the presence of 25–900 g/ml of 5-bromodeoxyuridine (BUdR). BUdR strongly inhibited closure of the cranial neural tube, which was found to be stage-dependent. When mouse embryos were exposed to BUdR after development of the concave curvature in the neuroepithelium of the midbrain to the upper hindbrain regions, they became insensitive to the drug-induced open cranial neural tube. Histological observations showed that BUdR interfered with interkinetic migration and cytokinesis of the neuroepithelial cells. These cellular abnormalities were not dependent on the morphological development of the cranial neural folds. The³H-BUdR experiment confirmed that the label was mostly incorporated into the DNA fraction.Acknowledgment. This work was supported by Grant-in-Aids for scientific research No. 557469 and 58480391 from the Ministry of Education, Japan.     

Sea urchin embryo as a model for analysis of the signaling pathways linking DNA damage checkpoint,DNA repair and apoptosis

DNA integrity checkpoint control was studied in the sea urchin early embryo. Treatment of the embryos with genotoxic agents such as methyl methanesulfonate (MMS) or bleomycin induced the activation of a cell cycle checkpoint as evidenced by the occurrence of a delay or an arrest in the division of the embryos and an inhibition of CDK1/cyclin B activating dephosphorylation. The genotoxic treatment was shown to induce DNA damage that depended on the genotoxic concentration and was correlated with the observed cell cycle delay. At low genotoxic concentrations, embryos were able to repair the DNA damage and recover from checkpoint arrest, whereas at high doses they underwent morphological and biochemical changes characteristic of apoptosis. Finally, extracts prepared from embryos were found to be capable of supporting DNA repair in vitro upon incubation with oligonucleotides mimicking damage. Taken together, our results demonstrate that sea urchin early embryos contain fully functional and activatable DNA damage checkpoints. Sea urchin embryos are discussed as a promising model to study the signaling pathways of cell cycle checkpoint, DNA repair and apoptosis, which upon deregulation play a significant role in the origin of cancer. Received 10 April 2007; accepted 23 April 2007     

Developmental control of heat shock and chaperone gene expression Hsp70 genes and heat shock factors during preimplantation phase of mouse development

Heat shock genes are found in all organisms, and synthesis of heat shock proteins is induced by various stressors in nearly all the cells forming these organisms. However, a particular situation is noticed for hsp70 genes in mouse embryos at the beginning of their development. First, spontaneous expression of hsp70 is observed at the onset of zygotic genome activity. Second, inducible expression is delayed until morula or early blastocyst stages. A better understanding of both these points depends on a more careful analysis of hsp70 expression in relation to their major regulators, the heat shock factors. In this review, we will see how the development of the preimplanta tion embryo highlights the complexity of heat shock gene regulation involving trans-cis interactions and the cellular and nuclear environment.     

鸡胚尿囊膜法评价板蓝根提取液抗H1N1流感病毒活性作用

 为探讨板蓝根药材、板蓝根颗粒提取液及板蓝根活性组分对流感病毒活性的影响作用,应用鸡胚尿囊膜法评价了板蓝根药材及板蓝根颗粒提取液对流感病毒的预防、治疗和病毒中和作用;评价了板蓝根活性组分对流感病毒的中和应用。研究结果表明,板蓝根药材、板蓝根颗粒提取液及板蓝根活性组分对流感病毒活性具有良好的抑制作用。板蓝根药材提取液对流感病毒具有预防和中和病毒的作用,板蓝根颗粒提取液和板蓝根活性组分具有中和流感病毒的作用。     

中华猕猴桃“红阳”花药和胚囊发育研究

采用石蜡切片技术对中华猕猴桃\"红阳\"(Actinidia chinensis cv.Hongyang)花药和胚囊的发育进行了观察研究.结果表明:中华猕猴桃\"红阳\"花药由4室构成,药室壁为4层结构;子房内有30~45个心室,每心室有11~45个胚珠,胚珠为倒生型,胚囊属于蓼型根据中华猕猴桃\"红阳\"胚囊形成的特点,可将猕猴桃胚囊发育过程分为5个时期,即孢原细胞形成期、大孢子母细胞形成期、功能大孢子形成期、胚囊有丝分裂期和胚囊成熟期.     

国产试剂配制的培养液对小鼠早期胚胎培养效果的研究

本实验用 Whitten 的小鼠早期胚胎培养法验证了国产试剂配制培养液对小鼠早期胚胎体外培养的效果。实验表明,在用国产试剂配制的小鼠早期胚胎培养液中,2—细胞胚胎能正常发育到囊胚阶段。     

濒危植物-半日花(Helianthemum songaricum)的双受精作用及胚和胚乳发育

运用石蜡切片法,对半日花Ｈ．ｓｏｎｇａｒｉｃｕｍ的受精过程,胚及胚乳发育进行了初步观察．受精前,一个助细胞解体,另一助细胞宿存．精核与极核的融合早于精核与卵的融合．受精极核不经过休眠过程,经多次分裂形成核型胚乳．胚乳游离核于球胚晚期开始细胞化．种子成熟后无胚乳．胚胎发育属柳叶菜型．胚柄由一纵列细胞组成并于球胚晚期开始退化．胚的发育经历球形原胚、心形胚、鱼雷形胚及成熟胚各时期．     

可可茶子叶培养中体细胞胚状体形成及植株再生

用含有０．５ｍｇＬ－１２,４－Ｄ或０．５ｍｇＬ－１２,４－Ｄ加２ｍｇＬ－１ＰＣＰＡ的ＳＨ培养基（含ρ（蔗糖）＝３％）培养可可茶的未成熟子叶,２周后即可从合子胚的下胚轴诱导出胚状体,５～７周后可以从子叶表皮直接诱导出胚状体．在含０．２ｍｇＬ－１２,４－Ｄ的培养基中,子叶外植体在培养４周内即能分化出胚状体且分化频率较高．培养１５周后把培养物转接至含２ｍｇＬ－１ＢＡ加上０．２ｍｇＬ－１ＩＢＡ的培养基中（含ρ（葡萄糖）＝２．５％）可以诱导出“种子状胚”、“芽状胚”和“杯状胚”,并可使“种子状胚”和“芽状胚”转化成苗．另外,还可诱导出丛芽并使丛芽转化成无根苗．若把“芽状胚”转移到含５ｍｇＬ－１ＧＡ－３和１ｍｇＬ－１ＩＡＡ的培养基中,“芽状胚”转化成无根苗的频率较高．