Marker-free transgenic (MFT) near-isogenic introgression lines (NIILs) of 'golden' indica rice (cv. IR64) with accumulation of provitamin A in the endosperm tissue

We have developed near-isogenic introgression lines (NIILs) of an elite indica rice cultivar (IR64) with the genes for β-carotene biosynthesis from dihaploid (DH) derivatives of golden japonica rice (cv. T309). A careful analysis of the DH lines indicated the integration of the genes of interest [phytoene synthase ( psy ) and phytoene desaturase ( crtI )] and the selectable marker gene (hygromycin phosphotransferase, hph ) in two unlinked loci. During subsequent crossing, progenies could be obtained carrying only the locus with psy and crtI , which was segregated independently from the locus containing the hph gene during meiotic segregation. The NIILs (BC₂F₂) showed maximum similarity with the recurrent parent cultivar IR64. Further, progenies of two NIILs were devoid of any fragments beyond the left or right border, including the chloramphenicol acetyltransferase ( cat ) antibiotic resistance gene of the transformation vector. Spectrophotometric readings showed the accumulation of up to 1.06 µg total carotenoids, including β-carotene, in 1 g of the endosperm. The accumulation of β-carotene was also evident from the clearly visible yellow colour of the polished seeds.     

扁桃叶的化学成分研究

从芒果属植物扁桃(Mangifera persiciformis C.Y.Wu et T.L.Ming)叶乙醇提取物乙酸乙酯萃取部位中分离得到7个化合物,经波谱鉴定为没食子酸甲酯(1),没食子酸(2),3,4-二羟基苯甲酸(3),槲皮素(4),山奈酚-3-O-β-D-葡萄糖苷(5),槲皮素-3-O-β-D-葡萄糖苷(6)和芒果苷(7).其中化合物1、3、5、6为首次从该植物中分离得到.     

中国大戟科一新归化种——硬毛巴豆

首次报道了大戟科(Euphorbiaceae)巴豆属硬毛巴豆(Croton hirtus L'Hér.)在中国的归化新记录,并提供该种的特征描述和形态图。凭证标本保存于中国科学院华南植物园标本馆(IBSC)。     

垂花青兰花蜜腺的发育解剖学研究

垂花青兰（Dracocephalum nutans Linn.）花蜜腺分布于子房基部的花托上,盘状蜜腺的上部裂成三小一大的四枚裂片,基部在膨大的花托外环绕一圈。蜜腺组织由分泌表皮、产蜜组织和维管束三部分组成,是典型的结构蜜腺;组织化学染色显示淀粉粒动态明显,因此又属淀粉蜜腺。在发育的过程中细胞液泡化动态明显,且淀粉粒和蛋白质具有明显的消长变化,蜜汁通过气孔器和表皮细胞的角质层泌出。     

Purification and characterization of α-glucosidase in Apis cerana indica

Apis cerana indica foragers were used for the isolation of a full‐length α‐glucosidase cDNA, and for purification of the active nascent protein by low salt extraction of bee homogenates, ammonium sulphate precipitation and diethylaminoethyl‐cellulose and Superdex 200 chromatographies. The molecular mass of the purified protein was estimated by polyacrylamide gel electrophoresis resolution, and the pH, temperature, incubation, and substrate optima for enzymic activity were determined. Conformation of the purified enzyme as α‐glucosidase was performed by BLAST software homology comparisons between matrix assisted laser desorption ionization time of flight mass spectroscopy analysed partial tryptic peptide digests of the purified protein with the predicted amino acid sequences deduced from the α‐glucosidase cDNA sequence.     

油菜籽提取物清除活性氧作用研究

自由基是一种带有未成对电子的分子或离子,具有很高的反应活性,可对机体产生毒害,破坏生物大分子,影响细胞活性.如果自由基被中途清除,就可能中断此反应[1].科学研究表明,自由基与免疫、疾病、衰老等许多病理生理现象都有密切的关系.     

中国昆虫病原线虫一新纪录

采用分子生物学和形态学相结合的方法,对采自广东省翁源县的编号为GDa71的昆虫病原线虫进行分类鉴定.该线虫各虫期的主要形态特征、测量值以及基于ITS1和部分28S rDNA两段序列,分别构建系统进化树均显示它与印度异小杆线虫Heterorhabditis indica相似,是后者的一个品系,为中国新纪录.     

渗透胁迫对花生幼叶细胞性氧伤害的定量分析

在渗透胁迫条件下不同花生（Arachis hypogaea Linn．）品种的水势、质膜相对透性（RPMP）、超氧离子、丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性两两之间都呈显著相关。而花生各品种的过氧化氢酶活性、过氧化物酶活性、谷胱甘肽含量和抗坏血酸含量与水势、RPMP、超氧离子、MDA含量和SOD活性等指标之间相关程度波动较大。水势对RPMP、MDA含量、超氧离子和SOD活性的弹性系数处于负效应阶段。SOD活性对RPMP、MDA含量和超氧离了的弹性系数的效应处于递减阶段。超氧离了对RPMP和MDA含量的生系数的效应处于递减阶段。各指标的弹性系数和相应的边际量因花生品种的抗旱能力不同而异。     

蛇莓克隆构型对光照强度的可塑性反应

克隆植物构型的可塑性反应可能是它在资源斑块性状分布的环境中获取资源对策的重要方面,因而可能具有重要的生态学意义。在一田间实验中,匍匐茎草本蛇毒（Duchesnea indica Focke）经历了不同相对光照强度的处理,以研究光照强度对蛇莓克隆构型的影响。结果表明：随着相对光照强度的增加,间隔子的长度逐渐降低,分枝角度、分枝强度和分株密度呈二次曲线变化。结合植物对环境异质性的利用对策,对的揭示的蛇莓克隆构型可塑性进行了讨论。