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柿树减数分裂和小孢子形成过程的观察 总被引:5,自引:0,他引:5
研究了柿树品种“禅寺丸”(2n=6x=90)的减数分裂和小孢子形成过程。同源染色体配对和分离基本正常,中期Ⅰ构型为45Ⅱ,但出现似多价体(次级配对),观察发现了不减数分裂现象。不减数发生的第1次分裂,第2次分裂时可见2个n=90的子核。未减数子核在四分体期形成二分体,小孢子期形成大型花粉粒。观察结果提示了柿树多倍体由未减数配子受精产生的可能性。 相似文献
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秤锤树的核型研究及其减数分裂过程的观察 总被引:11,自引:1,他引:11
观察研究了秤锤树有丝分裂和减数分裂的细胞学特征。秤锤树核型为2n=2x=24=4m 7sm(2SAT) 1st,属于较为原始的2A型。有丝分裂间期核为复杂染色中心型,前期出现B染色体,中期染色体中等大小。减数分裂中期具12对正常的二价体,但后期I和后期Ⅱ均有染色体异常现象发生。统计断片、落后染色体和染色体桥出现的比例与花粉粒败育性比例比较一致,表明秤锤树的小孢子在发生和发育过程中较高频率的败育现象可能存存一常的细胞学原因. 相似文献
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以水稻(Oryza sativa)和银灰杨(Populus canescens)的小孢子母细胞为例,介绍2种不同胞质分裂类型的小孢子母细胞其细胞板的形成及细胞壁的变化,帮助广大师生进一步了解植物减数分裂的过程。 相似文献
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桔是我国长江以南各省广泛栽培的常绿小乔木或灌木。近几年已成了长江以北包括东北三省在内的花盆观赏植物。因此取材不受地域气候、季节限制。具体如下:当桔花吐蕾时,找一个晴朗天气的正中午取长约8mm 左右的花蕾,立即放入盛有1∶3的冰醋酸与纯乙醇中浸泡。大约7h 后就可以放在显微镜下观察减数分 相似文献
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利用整体压片法 ,对分别隶属于球角科和长角科的两种跳虫似微小球角 (Hypogastruraadex ilis (Stach ,196 4 ) )和曲毛裸长 (SinellacurvisetaBrook 1889)的染色体进行了首次观察。发现似微小球角单倍染色体数目n =7,雄性有 13条染色体 ,雌性有 14条 ,为XO型性别决定 ;曲毛裸长n =6 ,雄性 2n =11,雌性 2n =12 ,同样为XO型性别决定。还记述了雄性似微小球角的减数分裂过程 :在分裂前期 ,同源染色体进行配对 ;部分同源染色体发生交叉 ,部分仅末端相连 ;早后期Ⅰ ,当常染色体向两极移动时 ,性染色体仍滞后于赤道板中央。 相似文献
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NOBUHIKO SUZUKI 《Plant Species Biology》1994,9(1):31-35
Abstract To elucidate the effects of herbivory by chrysomelid beetles on Rumex japonicus, rosette leaves were clipped and the subsequent fruit production and root growth were observed. The increase of leaf biomass of some clipped plants was greater than that of control plants, although this varied among individual plants. The root growth of clipped plants was less than that of control plants. Fruit production increased with plant size, and there was no difference in fruit production between clipped and control plants. Reproductive allocation (fruit biomass, relative to fruit biomass plus root growth) increased with plant size; it was greater in clipped plants than in control ones. Based on these results, reproductive allocation strategy against herbivory was discussed. 相似文献
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Dae Sik Jang Jong Min Kim Junghyun Kim Jeong Lim Yoo Young Sook Kim Jin Sook Kim 《化学与生物多样性》2008,5(12):2718-2723
An anthraquinone, emodin ( 1 ), and five flavonoids, kaempferol‐3‐O‐β‐D ‐glucoside ( 2 ), quercetin ( 3 ), quercitrin ( 4 ), isoquercitrin ( 5 ), and (+)‐catechin ( 6 ), were isolated from an AcOEt‐soluble extract of the fruits of Rumex japonicus. Their structures were determined by spectroscopic data interpretation. All the isolates were evaluated for their potential to inhibit AGEs (advanced glycation end products) formation and AGEs cross‐linking, and to break already formed AGEs cross‐links. 相似文献
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Rumex acetosa is one of the few angiosperms that possesses sex chromosomes. The same types of abundant repetitive sequences cover both heterochromatic Y chromosomes present in males. The aim of this study was to investigate genetic variation in paternally inherited Y chromosomal DNA and in maternally inherited cpDNA, and to find out whether the examined genomic regions are suited to a phylogeographic study in R. acetosa. DNA sequence polymorphisms present in the 850-bp heterochromatic segment on the Y chromosomes were compared to variation in the 409-bp long chloroplast section (trnL- trnF spacer) in R. acetosa originating from several European locations and from the Altai mountains in Russia. A great amount of genetic variation was detected within the Y chromosomal region while only four chloroplast genotypes were detected. Although the chloroplast haplotypes possessed some geographic pattern, no clear phylogeographic pattern was detected based on the variable Y chromosomes. The mean Y chromosomal nucleotide diversity among all samples equaled 6.6 %, and the mean proportion of polymorphic sites per individual equaled 8.2 % among SNP sites and 1.7 % among all sites investigated. The high number of substitutions detected in the Y chromosomal DNA shows that this heterochromatic sequence has a high mutation rate. The diversity pattern indicates that gene flow via pollen is extensive and it blurs any geographical pattern in the Y chromosomal variation. The high number of repeats and uncertainty concerning the extent of recombination between the two Y chromosomes impair the usability of the Y chromosomal segment for phylogeographic or population genetic studies. 相似文献
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Leonurus japonicus Houtt. [L. heterophyllus Sweet, L. artemisia (Lour.) S. Y.
Hu] is one of the most important traditional Chinese medicines used as a remedy for gynaecological disease since ancient times. A cytological investigation on the species was carried out
and the materials for chromosomal examination were collected from 26 localities in 20 provinoes and autonomous regions of this country. The number of chromosomes in root tip cell of
the species was found to be 20 on the whole (Tab. 1:1), agreeing with those reported by Ma and
al.[2] and probably by Chuang and al.[3] as well.
The genus Leonurus L. is variable in its chromosomes with an aneuploidy of x=9, 10 and
12. The present authors would propose that the primitive basic number of chromosome in the
genus is 9, and thus both 10 and 12 are derived, for: (1) among the 9 species (including 1 subspecies) heretofore cytologically examined, x=9 occurring in 66.7%, x=10 occurring in 22.2%,
while x=12 occurring only in 11.1%; (2) in generaclosely related to the genus under consideration, such as Panzeria, Galeobdolon and Lamium x=9 being the sole basic number.
But L. japonicus exhibits a mixoploidy of 2n=20 (occurring at the rate of 53.30% of the
total amount of cells examined), 2n=18 (30.70%), and 2n=16 (15.99%) in our work. (Table
1). Since the original basic number of chromosome of the genus is 9 as proposed above, 2n=
20 would be considered as a derived one and the occurrence of 2n=18 probably suggests an
early evolutionary trend of 2n=18→20 of the pecies in question. 相似文献
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The incongruency of diurnally varying resources essential to plants may detrimentally affect plants early in their development as indicated by reduced water use efficiency and carbon gain. Typical diurnal patterns of light and CO(2) availability in a midsized temperate herbaceous or forest gap were simulated in specially designed growth chambers. A sinusoidally varying CO(2) treatment (400 ppm minimum, 800 ppm maximum) approximated the diurnal cycle of CO(2) at the soil surface, while a steady-state CO(2) treatment (600 ppm) with the same average CO(2 )concentration provided a control. Crossed with these two CO(2) treatments were two light regimes, one with 3 h of high light (850 μmol·m·s) in the morning (west side of a gap), and the other with 3 h of high light in the afternoon (east side). All treatments received baseline low light (55 μmol·m·s) for 14 h during the day. Rumex crispus was selected as a model species because of its rosette leaves, which grow close to the ground where diurnal CO(2 )variation is greatest. The relative timing of diurnal variations in light and CO(2) significantly affected seedling water use efficiency, carbon gain, and morphology. Total biomass, photosynthetic rates, daily integrated carbon, water use efficiency, and leaf area were enhanced by morning exposure to high light. Seedlings that were exposed to peak values of light and CO(2) incongruently, i.e., those plants receiving intense afternoon light with diurnally varying CO(2), were detrimentally affected relative to control plants receiving intense afternoon light with steady-state CO(2). The results of this experiment indicate that the incongruent availability of required resources-such as light and CO(2)-can detrimentally affect performance relative to when resources are congruent. These contrasting resource regimes can occur on the east and west side of gaps. 相似文献
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从毛脉酸模根(Rumex gmelini Turcz.)75%乙醇提取物中分离得到1个新色原酮苷和5个已知化合物,应用波谱学方法及文献对照分别鉴定为2,5-dimethyl-7-hydroxychromone-7-O-β-glucopyranoside (1),nepodin-8-O-β-D-glucopyranoside (2),10-hydroxyaloin A (3),10-hydroxyaloin B (4),5-methoxyl-1(3H)-benzofuranone-7-O-β-D-glucopyranoside (5),phenylethyl-O-α-L-arabinopyranosy-(1→6)-O-β-D-glucopyranoside (6). 其中化合物1为新化合物,3~6首次从酸模属中分离得到,化合物2首次从该植物中分离得到. 相似文献
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濒危植物矮沙冬青减数分裂期染色体行为的观察 总被引:8,自引:1,他引:8
用涂片法和酶解法,观察了濒危植物矮沙冬青的减数分裂过程。在减数分裂双线期末或终变期初,可以观察到9个二价体,在中期Ⅰ末至后期Ⅰ初,同源染色体基本排列在赤道板上,然后在纺锤丝的牵引下二价体的两条同源染色体分开,分别移向两极,每一极有9条染色体,从而确认该属植物的染色体基数为x=9。在矮沙冬青减数分裂过程中,没有发现染色体有异常行为,认为其小孢子形成过程正常。因此认为矮沙冬青濒危不是染色体行为异常和小孢子发育不正常而造成的。 相似文献
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Jouda Abidi Cristina Occhiuto Francesco Cimino Antonio Speciale Giuseppe Ruberto Laura Siracusa Mohamed Bouaziz Mahieddine Boumendjel Claudia Muscar Antonina Saija Mariateresa Cristani 《化学与生物多样性》2020,17(8)
The present study is aimed at the evaluation of the phytochemical profile and the biochemical properties of methanolic extracts obtained from different parts of Rumex algeriensis and Rumex tunetanus, two relict species limited to the North Africa. Phytochemical analyses of these extracts were performed using standard colorimetric procedures, HPLC‐DAD, and HPLC‐DAD‐ESI/MS, and their antioxidant/free radical scavenging capability was estimated through several in vitro cell‐free assays. Moreover, the anti‐inflammatory potential of these extracts was demonstrated in an in vitro model of acute intestinal inflammation using differentiated Caco‐2 cells. The results showed that all the extracts appeared endowed with excellent antioxidant/free radical scavenging properties. In particular, the extracts from both R. algeriensis and R. tunetanus flowers, and that from R. algeriensis stems were characterized by a remarkable SOD‐like and NO‐scavenging activity, as well as by the capability to protect albumin against HClO‐induced degradation. Furthermore, the extracts from flowers of both Rumex species, as well as R. algeriensis stems, showed an anti‐inflammatory effect in intestinal epithelial cells, as demonstrated by the inhibition of TNF‐α‐induced gene expression of IL‐6 and IL‐8. In conclusion, R. algeriensis and R. tunetanus have shown to be potential sources of bioactive products to be used in the prevention and treatment of pathologies related to oxidative stress and inflammation. 相似文献
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黄瓜花粉母细胞减数分裂过程中微核仁现象的研究 总被引:5,自引:0,他引:5
在黄瓜(Cucumis sativus L.)高代自交系花粉母细胞减数分裂过程中,首次观察到了微核仁现象。在被观察的430个花粉母细胞(PMCs)中,有279个含有微核仁,占64.9%。微核仁在PMCs中数目变化范围在1~7之间。从细线期到四分孢子期都可观察到微核仁,其数量和大小在分裂的不同时期有所差异,但在第一次和第二次减数分裂时期内的变化趋势相似。在微核仁的周期性变化过程中,染色体的行为正常,并没有发现染色体畸变或染色体桥等现象。将此高代自交材料与3个商品种对照,分别在不同的季节种植在不同的地点,证明微核仁仅在此高代自交系上发生,且不受栽培季节和环境的影响。 相似文献
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羊蹄植株的水培养以及对污水的净化作用研究 总被引:1,自引:0,他引:1
用武汉沙湖污水培养不同大小羊蹄植株,以观察羊蹄植株的生长状况,结果表明:湿生植物羊蹄完全可以悬浮生长于污水之中,且生长极好,当培养1d后可长大量新须根(0.3—0.5cm),培养到第12d可长须根23.5cm左右;测定其生物量时发现植株越大其生物量增加越大,但植株越小其净增加生物量越大(每克植物每天的增加量);当测定羊蹄对污水的蒸腾加蒸发量时,发现最大量达到420mL/d,12d总量达1820mL,由于羊蹄植株的作用使污水的透光率由96上升到99.1(自来水为100),即较浑浊的污水已变为几乎透明的清水,通过测定污水的污染指标发现,由于6号羊蹄植株的净化使污水COD由原来的49mg/L降为28mg/L、氨氮由原来的328mg/L降为82mg/L、磷由原来的2.931mg/L降为0.124mg/L,因此,本实验证明了羊蹄植株是治理污水的优良品种之一。
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