The present study deals with comparative evaluation of three different aquatic macrophytes, i.e. Myriophyllum spicatum, Sagittaria sagittifolia and Pistia stratiote planted at three different ...concentrations (1.0, 3.0 and 5.0 mg/L) of metals in laboratory experiment for Cd, Cu and Zn removal from aqueous solution. Result revealed high removal (>90%) of different metals during 15 days experiment. Highest removal was observed on 13th day of experiment, thereafter it decreased. Results revealed Pistia stratiote as the most efficient for the removal of selected heavy metal followed by Sagittaria sagittifolia and Myriophyllum spicatum. Selected plants can be used for large scale removal of Cd, Cu and Zn from waste water.
In this work, cobalt nanoparticles were syn- thesized by chemical reduction procedure. After the hydrophilic functionalization, Co/polypyrrole （PPy） nanocomposites were prepared by in situ ...polymerization of pyrrole in aqueous dispersion of Co nanoparticles. The Co/ PPy nanocomposites show good electromagnetic properties with both magnetic loss and dielectric loss to electromag- netic wave. The electromagnetic wave absorbing band- width （reflection loss 〈-10 dB） for Co/PPy （20 wt%） is above 5.5 GHz at a thickness of 2 mm, and with a maximum reflection loss （around -20.02 dB） at 14.77 GHz. This magnetic nanoparticles/conducting polymer nanocomposites are great potential candidates for electromagnetic wave absorbent, because of their wide-absorbing frequency, strong absorption, good compatibility, low density, and controllable absorbing properties.
A transcript repressor is responsible for the normal development of spikelet and floral organs in rice and can be used in breeding design to improve yield.
An understanding of flower and panicle ...development is crucial for improving yield and quality in majority of grass crops. In this study, we used mapping-based cloning to identify
MULTI
-
FLORET SPIKELET2
(
MFS2
), which encodes a MYB transcription factor and regulates flower and spikelet development in rice (
Oryza sativa
). In the
mfs2
mutant, specification of palea identity was severely disturbed and showed degradation or transformation into a lemma-like organ, and the number of all floral organs was increased to varying degrees. Due to the increase in the number of floral organs and development of extra transformed palea/marginal region of the palea-like organs, some
mfs2
spikelets had a tendency to produce two florets. These defects implied that the
mfs2
mutation caused abnormal specification of palea identity and partial loss of spikelet determination. We confirm that
MFS2
is a transcriptional repressor that shows strong repression activity by means of two typical ethylene-responsive element binding factor-associated amphiphilic motifs, one of which locates at the C terminus and is capable of interaction with three rice TOPLESS and TOPLESS-related proteins. The results indicate that
MFS2
acts as a repressor that regulates floral organ identities and spikelet meristem determinacy in rice by forming a repression complex with rice TOPLESS and TOPLESS-related proteins.
A stripe leaf mutant, temporarily designated
st(t), was discovered in the progeny of the
indica restorer Jinhui 10 treated with ethyl methane sulfonate (EMS). This mutant displayed the variegated ...leaves at three-leaf stage, and the variegation developed the white irregular stripe from elongation to maturity. Compared with the wild type, the mutant decreased the chlorophyll content and increased the carotenoid content significantly. Transmission electronic microscope (TEM) observation of cell structures indicated that there was no difference between the wild type and the green part of the mutant, and both of them developed normal chloroplast. In the white part of
st(t), cell development was abnormal including irregular stromal lamellae, aberrant thylakoids, and more osmiophilic granules. Genetic analysis suggested that the mutational character was controlled by a recessive nuclear gene. An F
2 population (1500 plants) derived from the cross between Xinong 1A and
st(t) was constructed to map this gene, and simple sequence repeats (SSRs) RM19745 and RM19762 on chromosome 6 were determined as the flanking markers for
St(t). The genetic distances between
St(t) and the 2 markers were 0.07 cM and 0.27 cM, respectively. Based on the genomic sequence map of 9311, the physical distance of
St(t) was estimated to be 345 kb. This result provides a basis for map-based cloning of
St(t) gene and molecular marker-assisted breeding.
利用EMS诱变育成优良籼型恢复系缙恢10号, 从其后代中鉴定出一个白色条斑花叶突变体
st(
t), 在三叶期开始表现白斑, 拔节期白斑变为不规则线状, 一直保持到成熟。突变体叶绿素含量明显下降, 类胡萝卜素含量显著升高。透射电镜观察表明, 突变体的绿色叶片部位与野生型相比, 在细胞结构上无明显差异, 叶绿体发育正常; 突变体的白化部位细胞结构异常, 质体内多含有积聚在一起的嗜锇小球, 不能发育出正常叶绿体所具有的类囊体和基质片层结构。遗传分析表明该性状受一对隐性核基因调控, 利用1500株西农1A/
st(
t)的F
2隐性定位群体, 最终把
St(
t)基因定位在第6染色体SSR标记RM19745和RM19762之间, 遗传距离分别为0.07 cM和0.27 cM, 根据9311基因组序列推测, 两标记之间的物理距离约为345 kb。这为
St(
t)基因的图位克隆和分子标记辅助育种奠定了基础。
Leaf is an important organ for photosynthesis. Moderate leaf rolling could facilitate structure improvement of plant population and enhance light-use efficiency, which is important in breeding for ...ideotype plants. A rolled leaf mutant temporarily named
rl12(t), was obtained from the rice (
Oryza sativa L.) restorer line Jinhui 10 treated with ethyl methyl sulphonate (EMS). In the mutant, the newly developing leaves of the mutant did not roll, the upper 1/3 section of mature leaves was curled, and the older mature leaves were rolled completely. The pigment contents of the mutant increased significantly. The cytoplasmic male sterile (CMS) line Xinong 1A with flat leaves was crossed with the
rl12(t) mutant to produce F
1 and F
2 populations. Genetic analysis indicated that the mutant was controlled by a single dominant gene. Gene
rl12(t) was finally located on chromosome 10 between
SWU-1 and
SWU-2 with the genetic distances of 1.5 and 0.2 cM, respectively. Because no genes for rolled leaf trait have been previously located on this chromosome,
RL12(t) should be a novel and unique dominant gene for rolled leaf.
叶片是水稻光合作用的重要器官, 适度卷曲有利于改善群体光照、提高光能利用率, 卷叶基因是培育理想株型的重要资源。本研究利用EMS诱变优良恢复系缙恢10号, 获得了一个水稻新型卷叶突变体, 该性状受一对显性基因控制, 表现为新叶不卷, 老叶全卷, 而成熟叶片叶上部约1/3卷曲、中下部正常, 叶绿素含量极显著高于对照, 暂被命名为
rl12(
t)。利用SSR标记将该基因定位于第10染色体SWU-1和SWU-2之间, 遗传距离分别是1.5 cM和0.2 cM。目前, 类似于
rl12(
t)卷叶突变体表型未见报道,
RL12(
t)是唯一一个在第10染色体被分子定位的显性卷叶主基因。
The spikelet is a unique structure of grass plants, and its development involved with complicated molecular regulation network. nsg (nonstop glumes) mutant affecting spikelet development was ...identified from EMS-treated Jinhui10 (Oryza sativa L. ssp. indica.). Mutant plants had normal glumes (inner rudimentary glume, empty glumes and lemma/palea) and pedicel at the early flowering stage, but had longer ones at later stage. An extra glume-like organ was found in 84 % of mutant individuals. The number of stamens decreased in most mutant individuals whereas three stigmas or two carpels were found in some mutant individuals. The mutant phenotype suggests that NSG is involved in the whole rice spikelet development. NSG was mapped to a 15 kb region on the chromosome 4. According to sequence analysis, a gene encoding a protein with C2H2 domain exhibited a 13 bp insertion, causing a frame shift in genomics DNA and cDNA in nsg. This gene was identified as the candidated gene of NSG. The mutation of NSG influenced the transcription level of some floral hometic genes. The expression of OsMADS4, OsMADS16, DL and OsMADS3 decreased distinctly, and OsMADS1 increased in nsg panicle, suggests that NSG affected spikelet development through influencing the expression of floral hometic genes.
PDF
