枳砧红绵蜜柚嫁接黄化苗的光合特性及其CgSGR基因克隆与表达分析

该研究以枳砧‘红绵蜜柚’(Hm/Pt)为试验材料,以枳砧‘琯溪蜜柚’(Gx/Pt)和香橙砧‘红绵蜜柚’(Hm/Cj)为对照,测定分析3种砧穗组合蜜柚的光合特性、叶绿素含量差异;利用RT-PCR技术克隆并分析滞绿基因(CgSGR)表达,为进一步研究枳砧‘红绵蜜柚’嫁接不亲和机理奠定基础。结果显示:(1)枳砧‘红绵蜜柚’嫁接苗净光合速率、气孔导度、蒸腾速率、叶肉羧化效率明显低于2个对照组合,且3种砧穗组合以上各指标的最大值均出现在嫁接后第98天。(2)3个嫁接组合的叶绿素含量变化趋势一致,但枳砧‘红绵蜜柚’在整个试验期间的叶绿素a、叶绿素b和总叶绿素显著低于2个对照组合。(3)成功克隆获得‘红绵蜜柚’滞绿蛋白SGR调控基因序列,命名为CgSGR(GenBank登录号:MF945620);CgSGR基因片段长度为816bp,序列编码一个含有271个氨基酸的蛋白质,分子量为30.62kD,属于稳定的碱性亲水性蛋白;SGR序列多重比对结果显示,‘红绵蜜柚’CgSGR序列与柑橘属柚、甜橙和克里曼丁橘之间一致性较高,其中‘红绵蜜柚’与柚无碱基差异,与甜橙在第33bp处有1个变异位点,与克里曼丁橘在33、52、118、159、622和765bp处有6个变异位点;系统进化树表明,CgSGR与柑橘属甜橙、克里曼丁橘的距离最近,与荔枝关系较近,与其它物种的关系较远。(4)实时荧光定量PCR结果表明,CgSGR基因在香橙砧‘红绵蜜柚’中的表达量总体均低于其他2个组合材料,而嫁接139d后,3个材料均随着植株黄化,CgSGR基因的表达水平均呈上升趋势,且枳砧‘红绵蜜柚’的CgSGR基因表达显著高于2个对照组合。(5)随着嫁接苗的生长发育,CgSGR的表达水平总体变化趋势与净光合速率、叶绿素的变化趋势相反。研究认为,枳砧‘红绵蜜柚’CgSGR基因的表达量在嫁接苗叶绿素降解过程中上调,其可能参与调控黄化幼苗的叶绿素降解。     

柚雌蕊不同部位抽提液对自交不亲和阻抑效果的研究

以‘土柚’（Citrus grandis ‘Tuyou’）作对照,采用荧光显微技术对‘琯溪蜜柚’（Citrus grandis‘Guanxi-miyou’）、‘度尾蜜柚’（Citrus grandis ‘Duweimiyou’）两个品种花粉在本品种和异品种雌蕊不同部位抽提液中花粉萌发和花粉管伸长状态进行了观察。结果表明：‘琯溪蜜柚’和‘度尾蜜柚’子房抽提液对自身花粉管伸长阻抑最明显,并产生严重的弯曲;柱头抽提液对自身花粉管伸长稍有影响,出现中度弯曲;花柱抽提液中自身花粉管伸长正常,仅有轻微弯曲。然而,对于异品种的花粉以及自交亲和的‘土柚’,其子房、花柱和柱头抽提液对花粉管伸长没有这种阻抑效应。     

一个柚新种质的亲缘关系鉴定

该研究以1个疑似柚新品种——‘迷你红柚’为实验材料,利用植物形态学观察、花粉电镜观察以及ISSR分子标记技术,以确定‘迷你红柚’与‘琯溪蜜柚’、‘邓肯葡萄柚’之间的关系。(1)从形态学观察可以看出:‘迷你红柚’果实的外形特征与‘邓肯葡萄柚’较相似,但与‘琯溪蜜柚’有较大的差别;而且‘迷你红柚’嫩叶的形态学特征与‘琯溪蜜柚’和‘邓肯葡萄柚’均有不同。(2)电镜观察发现:‘迷你红柚’花粉的萌发孔沟、花粉沟与‘琯溪蜜柚’和‘邓肯葡萄柚’相似,但花粉大小、外壁网眼与‘琯溪蜜柚’和‘邓肯葡萄柚’均有不同。(3)聚类分析结果表明,‘迷你红柚’和‘邓肯葡萄柚’遗传关系最近,但又有一定距离。研究认为,‘迷你红柚’不同于‘琯溪蜜柚’和‘邓肯葡萄柚’,极有可能是柚的一个新品种。     

柑桔接穗对砧木生长及若干生理生化特性的影响

以体细胞杂种红桔+枳、红桔+粗柠檬和有性杂种Troyer枳橙、Swingle枳柚以及枳作砧木的"国庆4号"温州蜜柑、脐橙(无枳砧)和不嫁接的砧木幼树为试材,通过两年盆栽试验研究接穗对砧木生长、根系活力和根系抗氧化酶活性的影响。结果表明,Swingle枳柚和红桔+粗柠檬的砧粗易受接穗影响,接穗显著地影响砧木根系体积。在一般情况下,同一种砧木嫁接后砧木根系活力、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性低于未嫁接砧木,或与其差异不显著;同时存在接穗促进根系过氧化氢酶(CAT)活性升高的现象。     

荔枝新品种‘贵妃红’和‘草莓荔’嫁接亲和性试验

以荔枝新品种‘贵妃红’和‘草莓荔’与10种砧木为试材,对各砧穗组合的嫁接成活率及嫁接苗田间生长指标进行测定及比较。结果表明,不同砧穗组合间嫁接成活率以及嫁接苗田间生长势存在明显差别,‘贵妃红’以钦州红荔、黑叶、禾荔为砧木的嫁接成活率分别达80.0%、78.0%和74.0%,‘草莓荔’以禾荔为砧木的嫁接成活率最高,达82.0%。综合其成活率及嫁接苗生长状况等指标,‘贵妃红’宜以黑叶、禾荔、钦州红荔、白腊为砧木进行嫁接,而‘草莓荔’宜以黑叶、禾荔、钦州红荔、镇奉为砧木进行嫁接。     

不同砧木对柑橘幼树生长和叶片糖含量的影响

以体细胞杂种红橘 枳和红橘 粗柠檬、有性杂种Troyer枳橙和Swingle枳柚、枳(对照)作砧木的‘国庆4号’温州蜜柑2a生嫁接苗为试材,通过盆栽试验研究了砧木对柑橘幼树生长和叶片糖含量的影响。结果表明,4种处理的生长势比对照旺盛;红橘 枳处理的花量极显著多于对照,其余3种砧木处理的则极显著少于对照。在光合色素含量上,Troyer枳橙处理最高,对照最低。不同砧木处理对叶片可溶性糖含量的年变化动态特征影响明显;不同砧木处理的叶片淀粉含量年变化动态特征相似。在不同时期,不同砧木处理对叶片可溶性糖和淀粉含量有明显的影响。初步评价了体细胞杂种红橘 枳和红橘 粗柠檬用作柑橘砧木的利用价值。     

不同苹果砧穗组合的生长及光合特性

以‘垂丝海棠’（Malus halliana）和‘平邑甜茶’（Malus hupehensis）为基砧,分别嫁接品种‘烟富6号’和‘长富2号’接穗,测定4种砧穗组合的嫁接亲和性、接穗生长量、光合与荧光参数及叶绿素含量（SPAD）,并用主成分分析法综合评价砧穗组合的优劣,探讨不同苹果砧穗组合嫁接苗的生长及光合特性,为西北盐碱地选择适宜的苹果砧木提供理论依据。结果表明：（1）4种砧穗组合中‘垂丝海棠/烟富6号’的上下口粗度比最接近1,嫁接亲和性最好。（2）整个生长期内,以‘垂丝海棠’为基砧的2个组合嫁接苗的生长量、净光合速率（P_n）、最大荧光（F_m）、PSⅡ最大光能转化率（F_v/F_m）均显著大于‘平邑甜茶’为基砧的组合,但其胞间CO₂浓度（C_i）及初始荧光（F₀）显著低于‘平邑甜茶’为基砧的组合;光化学猝灭系数（qP）在4种砧穗组合中无显著差异。（3）在8月份光照强度较高时,‘垂丝海棠/烟富6号’ 嫁接苗的气孔导度（G_s）高于其他砧穗组合;以‘垂丝海棠’为基砧的2个组合嫁接苗叶片的蒸腾速率（T_r）和相对叶绿素含量（SPAD）显著高于‘平邑甜茶’ 基砧组合。（4）根据主成分分析对各项指标进行综合评价,按照4个砧穗组合的综合得分由高到低依次为：‘垂丝海棠/烟富6号’、‘垂丝海棠/长富2号’、‘平邑甜茶/长富2号’、‘平邑甜茶/烟富6号’。研究发现,基砧‘垂丝海棠’的适应性优于‘平邑甜茶’,且‘垂丝海棠/烟富6号’砧穗组合的嫁接亲和性高,长势强,光合能力优,为甘肃中部地区适宜的砧穗组合。     

两类柑桔杂种砧木对脐橙(Citrus sinensis Osbeck)幼树生长和叶片糖营养含量年变化的影响

以体细胞杂种红桔＋枳和红桔＋粗柠檬、有性杂种Troyer枳橙和Swingle枳柚作砧木的耐湿脐橙(Citrus sinensis Osbeck)2年生嫁接苗为试材,通过盆栽试验研究了砧木对苗木生长和叶片糖营养含量年变化动态的影响。结果表明：红桔＋枳的生长势和花量明显地强于和大于其它砧木,红桔＋粗柠檬的生长和花量表现介于2种有性杂种之间。叶绿素a／b和类胡萝卜素含量在不同砧木间无显著差异,而不同砧木显著或极显著地影响叶绿素含量各指标。砧木影响叶片可溶性糖和淀粉含量年变化动态的基本特征。在休眠期,红桔＋枳的可溶性糖和淀粉含量都高于2种有性杂种砧木,而红桔＋粗柠檬则反之;在生长期,红桔＋粗柠檬的可溶性糖和淀粉含量表现出高于有性杂种砧木的趋势,而红桔＋枳则介于2种有性杂种砧木之间。同时还重点讨论了2种体细胞杂种砧木的利用价值。     

两类杂种砧木资源对柑橘幼树生长和叶片矿质营养含量的影响

以柑橘体细胞杂种砧木资源红橘 枳和红橘 粗柠檬、有性杂种砧木资源Troyer枳橙和Swingle枳柚、枳(对照)作砧木的‘国庆4号’温州蜜柑2年生嫁接苗为试验材料．通过盆栽试验研究了砧木对苗木生长和叶片矿质营养含量的影响。结果表明,4种处理生长势比对照旺盛;红橘 枳处理花量极显著地高于对照,其余3种处理则反之;处理基本上不影响叶片N、K、Ca、Mg和Mn含最年变化动态的特征。而明显影响P、Fe和Zn含量的年变化动态的特征;在各不同时期,不同处理对叶片各矿质营养含量有明显的影响。本文还重点讨论了2类杂种砧小资源的利用价值。     

两类柑橘杂种砧木对脐橙幼树生长及若干生理生化指标的影响

以体细胞杂种红橘+枳、红橘+粗柠檬和有性杂种Swingle枳柚、Troyer枳橙(对照)作砧木的脐橙幼树为试材,以盆栽试验研究砧木对幼树的影响。结果表明,体细胞杂种砧木处理和有性杂种Swingle枳柚的树体生长势总体上强于对照;叶片可溶性糖含量较高的是红橘+粗柠檬处理和对照;叶绿素含量最高的是红橘+粗柠檬处理。两年中叶片POD活性分别与当年树冠体积呈负相关。     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Analysis of twin of eyeless regulation during early embryogenesis in Drosophila melanogaster

The Drosophila Pax6 homolog twin of eyeless (toy) is so far the first zygotically expressed gene involved in eye morphogenesis in Drosophila. The study of its expression during embryogenesis is therefore informative of the initial events of eye development in Drosophila. We have analyzed how the initial expression domain of toy at cellular blastoderm is regulated. We show that the three maternal patterning systems active in the cephalic region (the anterior, terminal and dorsal-ventral systems) cooperate with zygotically activated gap genes to shape the initial expression domain of toy. Whereas Bicoid, Dorsal and Torso signaling synergistically act as activators, Hunchback, Knirps and Decapentaplegic act as repressors.     

Host plants of someRhinanthoideae (Scrophulariaceae) of eastern North America

Twenty three species in 11 genera were examined in the field to determine hosts. OnlyStriga asiatica andSeymeria cassioides have a narrow host range being restricted to grasses and pines, respectively. These are the only species which cause pronounced and sometimes serious host damage. The other species attach to a great diversity of hosts.     

Apoptotic Regulation of Caspase Activity

Intracellular cysteine aspartate-specific proteases (caspases) play both signaling and effector roles in realizing the program of cell death. Caspases function as proteolytic cascades unique for each cell type and signal triggering apoptosis. All parts of the proteolytic cascades are duplicated and controlled by feedback signals. Amplification cycles between pairs of caspases (the third and the sixth, the ninth and the third, the twelfth and the sixth, and others) help multiply the initial apoptotic signal. The presence of physiological inhibitors of apoptosis that directly interact with caspases creates a multilevel regulatory network of apoptosis in cell. The caspase proteolytic cascades are also regulated by sphingolipid secondary messengers, among them ceramide, sphingosine, and their phosphates. Moreover, an association of the caspase signaling with ubiquitin-dependent proteolysis is shown in cells. In particular, the use of extracellular activators and inhibitors of caspases allows irreversible activation of apoptosis in tumor cells or the prevention of apoptosis in cortical neurons under neurodegenerative diseases.     

广西青藓科分类学修订

通过对采自广西24个县(市)的1 147份青藓科植物标本的逐一鉴定及相关文献的查阅,确认有广西青藓科植物11属、44种,其中包括广西青藓科植物新记录属1属,即拟异叶藓属(Pseudokindbergia),新记录种7种,分别为匐枝青藓(Brachythecium procumbens)、阔叶尖喙藓(Oxyrrhynchium latifolium)、泛生尖喙藓(O. vagans)、拟异叶藓(Pseudokindbergia dumosa)、华东细喙藓(Rhynchostegiella sinensis)、长肋拟青藓(Sciurohypnum populeum)和弯叶拟青藓(S. reflexum)。该文提供了修订后的广西青藓科植物名录,并对其中的新记录属、种的主要形态学识别特征、生境和地理分布等进行了详细描述。     

The effect of cyanobacteria and azolla on the performance of rice under different levels of fertilizer nitrogen

Cyanobacteria and/or azolla were inoculated, with urea at 0, 72 or 144 kg N/ha, in plots in which azolla-free Indica rice var. IR 28 was grown. Productive tillers, yield and nitrogen contents of grain and straw positively responded to inoculation with cyanobacteria or azolla, even with fertilizer-N up to 144 kg N/ha. Inoculation improved colonization by cyanobacteria. Azolla were superior to the asymbiotic cyanobacteria in enhancing rice performance. Urea at a rate of 72 kg N/ha was found to support the best colonizations when applied with cyanobacteria or azolla or, to give maximum rice yields, both inoculants.     

Evaluation of antiprotozoal and antimycobacterial activities of the resin glycosides and the other metabolites of Scrophularia cryptophila

Resin glycosides are secondary metabolites exclusive to the convolvulaceous plants. In this study, crypthophilic acids A–C (1–3), the first resin glycosides occurring in another family (Scrophulariaceae), and the other constituents of Scrophularia cryptophila were examined for in vitro antiprotozoal and antimycobacterial potentials. Except for crypthophilic acid B (2), all tested compounds exhibited growth-inhibitory effect against Trypanosoma brucei rhodesiense, with l-tryptophan (6) and buddlejasaponin III (7) being the most potent ones (IC₅₀'s 4.1 and 9.7 μg/ml). In contrast, the activity towards Trypanosoma cruzi was poor, and only crypthophilic acid C (3), 6 and 7 were trypanocidal at concentrations above 40 μg/ml. With the exception of 2 and 6, all compounds were active against Leishmania donovani. Harpagide (4) and 3 emerged as the best leishmanicidal agents (IC₅₀'s 2.0 and 5.8 μg/ml). Only compounds 3, 6 and 7 showed antimalarial activity against Plasmodium falciparum with IC₅₀ values of 4.2, 16.6 and 22.4 μg/ml. Overall the best and broadest spectrum activity was presented by compounds 3 and 7, as they inhibited all four parasitic protozoa. None of the isolates had significant activity against Mycobacterium tuberculosis (MICs >100 μg/ml) or were toxic towards mammalian (L6) cells. This is the first report of antiprotozoal activity for natural resin glycosides, as well as for harpagide (4), acetylharpagide (5), tryptophan (6) and buddlejasaponin III (7).