Morphochronological variations in the genus Posidonia

1997 ◽  
Vol 48 (5) ◽  
pp. 421 ◽  
Author(s):  
G. Pergent ◽  
C. Pergent-Martini ◽  
M. Cambridge
Keyword(s):  
Primary Production ◽  
Western Australia ◽  
Leaf Blade ◽  
Leaf Sheath ◽  
Growth Rings ◽  
New Techniques ◽  
Seagrass Meadows ◽  
Foliar Tissue ◽  
Tissue Production

Morphochronological variations have been observed in five marine phanerogams of the genus Posidonia in the two regions where they occur (Mediterranean and Western Australia). The occurrence of these variations, which is comparable to that of growth rings in trees (studied in dendrochronology), has provided a basis for developing new techniques for the investigation of characteristics of these underwater seagrass meadows (e.g. primary production). The development of lepidochronology in the assessment of primary production has the advantage of being rapid and allowing the determination of the total foliar tissue production (leaf blade and leaf sheath) including that of species for which no data were hitherto available.

The Genesis of Arbitration in Western Australia

1986 ◽  
Vol 28 (4) ◽  
pp. 545-563 ◽  
Author(s):  
Norman F. Duffy
Keyword(s):  
Western Australia ◽  
The Political ◽  
Trade Union Movement ◽  
Union Movement ◽  
Early Experiences ◽  
Compulsory Arbitration ◽  
Industrial Disputes ◽  
Political Scene ◽  
Conditions Of Employment

The use of compulsory arbitration for the determination of the conditions of employment has a long history in Australia. This paper covers the events leading up to the introduction of legislation for conciliation and for the compulsory arbitration of industrial disputes in Western Australia. After two bruising strikes and the experience of successful voluntary arbitration, the union movement came to the view that compulsory arbitration would be to their advantage. The development of political links between the unions and some members of the Legislative Assembly, coupled with certain fortuitous circumstances in the Parliament, resulted in arbitration legislation being passed in 1900—despite the dominance of the political scene by conservative forces and the opposition of the employers. Early experiences with the legislation showed that conciliation was not successful when arbitration was readily available and that the Act was not the answer to all the problems of the trade union movement.

Phomopsis oryzae-sativae. [Descriptions of Fungi and Bacteria].

1980 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
Geographical Distribution ◽  
Leaf Blade ◽  
Leaf Sheath ◽  
Advanced Stage ◽  
Collar Rot ◽  
Oryza Saliva ◽  
Water Splash

Abstract A description is provided for Phomopsis oryzae-sativae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Oryza saliva. DISEASE: Collar rot of rice, appearing at the end of tillering stage. Visible symptoms are small dark brown lesions at the base of the auricle of the topmost fully expanded leaf. These lesions enlarge to cover the whole auricle and in the advanced stage lesions extend to the adjacent parts of the leaf sheath and leaf blade. Within 14 days the blade joint at the top of leaf sheath turns dark brown and then rots, causing the leaf blade to drop off (Kanjanasoon, 1962). GEOGRAPHICAL DISTRIBUTION: Asia (Thailand). TRANSMISSION: No studies reported. Conidia presumably dispersed by water splash.

Seagrass Ecosystems of Andaman and Nicobar Islands: Status and Future Perspective

2020 ◽  
Vol 7 (4) ◽  
pp. 169-174
Author(s):  
Chatragadda Ramesh ◽  
Raju Mohanraju
Keyword(s):  
Water Quality ◽  
Primary Production ◽  
Environmental Changes ◽  
Future Perspective ◽  
Marine Biodiversity ◽  
Seagrass Beds ◽  
Seagrass Meadows ◽  
Seagrass Ecosystem ◽  
Seagrass Ecosystems ◽  
Nicobar Islands

Seagrasses are unique marine flowering plants that play an important ecological role by yielding primary production and carbon sequestration to the marine environment. Seagrass ecosystems are rich in organic matter, supporting the growth of bio-medically important epi and endophytic microorganisms and harbor rich marine biodiversity. They are an essential food source for endangered Andaman state animal Dugongs. Seagrasses are very sensitive to water quality changes, and therefore they serve as ecological bio-indicators for environmental changes. The benthic components in and around the seagrass beds support a significant food chain for other Micro and organisms apart from fishery resources. The epiphytic bacterial communities of the leaf blades support the sustenance against the diseases. Recent reports have shown that the loss of seagrass beds in tropical and temperate regions emphasizes the depletion of these resources, and proper management of seagrass is urgent. The decline of seagrass will impact primary production, biodiversity, and adjacent ecosystems, such as reefs. Therefore, restoring the seagrass meadows could be possible with effective implementing management programs, including seagrass meadows in marine protected areas, restoration projects, seagrass transplantation, implementation of legislative rules, monitoring coastal water quality and human activities in the coastal zone. Lacunas on the seagrass ecosystem management in Andaman & Nicobar Islands are addressed.

Rumen degradation of straw 4. Selection and degradation of morphological components of barley straw by sheep

1988 ◽  
Vol 47 (1) ◽  
pp. 105-110 ◽  
Author(s):  
P. K. Bhargava ◽  
E. R. Ørskov ◽  
T. K. Walli
Keyword(s):  
Leaf Blade ◽  
Dry Matter ◽  
Leaf Sheath ◽  
Practical Significance ◽  
Barley Straw ◽  
Rumen Degradation ◽  
Whole Plant ◽  
Ad Libitum ◽  
The Mathematical Model ◽  
Selection Of

AbstractExperiments were made to study the proportion, chemical composition, and rumen degradability of the morphological components of barley straw (Corgi variety) and to study the selection of these components by sheep. The proportions in the harvested straw dry matter (DM) as leaf blade, leaf sheath, stem and chaff were 128, 314, 500 and 58 g/kg DM, respectively. The different components of straw on analysis proved to have very different concentrations of nitrogen and neutral-detergent cellulase digestibility. The leaf blades had the highest and the stems the lowest values. The degradabilities of DM in the components and in the whole straw were determined by measuring DM loss from samples incubated in nylon bags for various periods in the rumen of sheep. Responses were measured using the mathematical model p = a+b (1–e−ct) where p is DM loss, (a+b) potential degradability, c the rate constant of DM loss and t is the time of incubation. DM losses decreased in the order leaf blades > leaf sheath > whole plant > chaff > stems. Leaf blades also had the highest potential degradability and rate of degradation.In another trial, five sheep were offered unchopped barley straw ad libitum. There were five treatment periods in which sheep were allowed to leave uneaten proportionately 0·2, 0·3, 0·4, 0·5 and 0·7 of the straw on offer for assessing the animal's selection of the morphological components of that straw. The amount of leaf blade in the material consumed increased in largely a linear (P < 0·01) fashion with the amount of excess allowance. The proportion of stem eaten varied conversely. The selection of leaf sheath was less apparent. Little stem was consumed until the proportion of leaf blade in the food available decreased below proportionately 0·4. The practical significance of the study is discussed.

The Progress of Research on Soil Heavy Metals

2012 ◽  
Vol 455-456 ◽  
pp. 1285-1288
Author(s):  
Yin Ye ◽  
Zhen Yang ◽  
Xiao Peng Dang ◽  
Zi Huai Liu
Keyword(s):  
Heavy Metals ◽  
Total Mass ◽  
Research Progress ◽  
New Techniques ◽  
Soil Heavy Metals ◽  
Methods Of Determination ◽  
Morphology Analysis ◽  
Weak Points

Recently, with the developing of new techniques, more new techniques has been used in the area of soil heavy metals monitoring. This paper reviewed the methods utilized in determination of total mass and morphology analysis of soil heavy metals, summarized the current research progress on soil heavy metals and pointed out the weak points of recent works. The article also forecasted the developing tendency of the methods of determination of total mass and morphology analysis of soil heavy metals.

scholarly journals Distinctness of 110 rice (Oryza sativa L.) varieties of Bangladesh through morphological traits

2014 ◽  
Vol 12 (1) ◽  
pp. 29-36
Author(s):  
MS Rahman ◽  
MKH Sohag ◽  
L Rahman
Keyword(s):  
Morphological Traits ◽  
Leaf Blade ◽  
Oryza Sativa L ◽  
Flag Leaf ◽  
Leaf Sheath ◽  
Seed Colour ◽  
Rice Varieties ◽  
Nodal Root ◽  
Two Hybrid ◽  
Research Institute

A total of 110 rice varieties of which 108 local (From Bangladesh Rice Research Institute) and two hybrid varieties (From ACI Ltd. Bangladesh) were used to identify the morphological traits during July, 2008 to June, 2009. These varieties represented four types viz. T. Aman (n=92), B. Aman (n=15), Boro (n=2) and Jhum accession (n=1) as described by Bangladesh Rice Research Institute’s literature. Though all these materials were varied ecotypically but grown in one (T. Aman) season. Irrespective of groups of all, 90 varieties were appeared distinctly morphologically from others due to seed colour; stigma colour; anthocyanin colouration of leaf sheath, nodes and lemma:palea, presence of awn and nodal root. Among 90 distinct varieties 19 were distinctly different from others by four traits, nine by three traits, 24 by two traits and 38 varieties by only single trait. The rest 20 varieties were distinguished flag leaf: attitude of the leaf blade. This was done to assess the quality traits of distinctness as major concern and was noninfluenced by the environment. DOI: http://dx.doi.org/10.3329/jbau.v12i1.21236 J. Bangladesh Agril. Univ. 12(1): 29-36, June 2014

Effects of simulated acid rain on the growth of five Brazilian tree species and anatomy of the most sensitive species (Joannesia princeps)

2005 ◽  
Vol 53 (8) ◽  
pp. 789 ◽  
Author(s):  
Luzimar Campos da Silva ◽  
Aristéa Alves Azevedo ◽  
Eldo Antônio Monteiro da Silva ◽  
Marco Antonio Oliva
Keyword(s):  
Acid Rain ◽  
Tree Species ◽  
Leaf Blade ◽  
Woody Species ◽  
Leaf Damage ◽  
Growth Responses ◽  
Foliar Injury ◽  
Sensitive Species ◽  
Abaxial Epidermis

Seedlings and young saplings of some woody species were exposed to simulated low-pH acid rain, in order to develop a response screening for tropical tree species by determination of the symptoms of foliar injury and growth responses, as well as to identify anatomical alterations in the leaf blade of the most sensitive species. Gallesia integrifolia (Spreng.) Harms, Genipa americana L., Joannesia princeps Vell., Mimosa artemisiana Heringer & Paula and Spondias dulcis Forst.f. were exposed daily to 20 min of acid rain, pH 3.0, for 10 consecutive days. The degree of leaf damage and the anatomical alterations observed were efficient parameters to determine the sensitivity to acid rain. At the end of the experiment J. princeps was the most sensitive species as determined by foliar injury and seedling growth. The degree of leaf damage was similar among the seedlings, except in S. dulcis, which showed reduced percentage of foliar injury. Necrotic and chlorotic spots on the leaf blade occurred. In the most sensitive species, J. princeps, necrotic blade tissues showed accumulation of phenolic compounds, hypertrophy and collapsed cells. Most of the structural alterations were observed in the adaxial epidermis, the palisade parenchyma and spongy parenchyma and the abaxial epidermis. Long-term experiments with seedlings of S. dulcis and saplings of G. integrifolia are suggested, to characterise the response of these species that presented fewer symptoms but whose growth was affected under acid rain.

scholarly journals Transcriptomic Analysis of Leaf Sheath Maturation in Maize

2019 ◽  
Vol 20 (10) ◽  
pp. 2472 ◽  
Author(s):  
Lei Dong ◽  
Lei Qin ◽  
Xiuru Dai ◽  
Zehong Ding ◽  
Ran Bi ◽  
...  
Keyword(s):  
Leaf Blade ◽  
Crop Yields ◽  
Transcriptional Profiling ◽  
Homeobox Gene ◽  
Lignin Biosynthesis ◽  
Gene Families ◽  
Longitudinal Axis ◽  
Leaf Sheath ◽  
Morphological Development ◽  
Maize Leaf

The morphological development of the leaf greatly influences plant architecture and crop yields. The maize leaf is composed of a leaf blade, ligule and sheath. Although extensive transcriptional profiling of the tissues along the longitudinal axis of the developing maize leaf blade has been conducted, little is known about the transcriptional dynamics in sheath tissues, which play important roles in supporting the leaf blade. Using a comprehensive transcriptome dataset, we demonstrated that the leaf sheath transcriptome dynamically changes during maturation, with the construction of basic cellular structures at the earliest stages of sheath maturation with a transition to cell wall biosynthesis and modifications. The transcriptome again changes with photosynthesis and lignin biosynthesis at the last stage of sheath tissue maturation. The different tissues of the maize leaf are highly specialized in their biological functions and we identified 15 genes expressed at significantly higher levels in the leaf sheath compared with their expression in the leaf blade, including the BOP2 homologs GRMZM2G026556 and GRMZM2G022606, DOGT1 (GRMZM2G403740) and transcription factors from the B3 domain, C2H2 zinc finger and homeobox gene families, implicating these genes in sheath maturation and organ specialization.

Guihaia heterosquama, a new species of coryphoid palm (Arecaceae) from Chongqing, China

Phytotaxa ◽  
2019 ◽  
Vol 405 (5) ◽  
pp. 248-254
Author(s):  
XIANYUAN LI ◽  
HUI PENG ◽  
XI HE ◽  
ZHINENG LI ◽  
DI WU
Keyword(s):  
New Species ◽  
Leaf Blade ◽  
Male Flower ◽  
Leaf Sheath ◽  
Flower Structure ◽  
A New Species

Guihaia heterosquama X. Y. Li, a new species from Chongqing, China, is described and illustrated. Guihaia heterosquama is similar to G. grossifibrosa and G. argyrata both in the shape of the leaf blade and flower structure, but it can be easily distinguished by its leaf scales, leaf sheath fibers and hastula. Notably, Guihaia heterosquama differs from all the reported species of Guihaia by the presence of a distinct pistillode in the male flower.

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