scholarly journals The Velocity and Pattern of Assimilate Translocation in Wheat Plants During Grain Development

1965 ◽  
Vol 18 (2) ◽  
pp. 269 ◽  
Author(s):  
IF Wardlaw

The translocation of labelled assimilates from the flag leaf blade to the ear and other parts of the plant was followed in wheat, 15-20 days after anthesis. The velocity of assimilates moving through the top internode varied from 80 to 100 cm/hr and the velocity of movement down the leaf sheath was about half this value. Removing grains from the head reduced the velocity of the assimilates moving up the stem from the node and increased their downward velocity in the stem. How-ever, the rate of movement out of the leaf was unaffected by the removal of grains. With full grain development assimilates from the flag leaf moved directly from the node of insertion of the leaf up the stem to the ear. The results are discussed in relation to the vascular anatomy of wheat and the mechanism and factors controlling translocation.

2014 ◽  
Vol 12 (1) ◽  
pp. 29-36
Author(s):  
MS Rahman ◽  
MKH Sohag ◽  
L Rahman

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


1970 ◽  
Vol 23 (1) ◽  
pp. 19-30
Author(s):  
MM Islam ◽  
U Sarker ◽  
MG Rasul ◽  
MM Rahman

An experiment was conducted to study the heterosis of 27 F1 hybrids produced from nine CMS lines and three restorer lines of rice with their parental lines and BRRI Dhan29 as standard check for 17 yield and its contributing traits. Mid parent, better parent and standard heterosis of most of the crosses were significant for most of the characters studied either in positive or in negative direction. Desirable and significant mid parent and better parent heterosis was observed in 13 and seven cross combinations, respectively for grain yield and most of its related traits. Considering more than 20% mid parent and better parent heterosis for grain yield along with most of its related traits, nine and five cross combinations, respectively were identified as good heterotic combinations over mid parental and better parental value. On the basis of individual trait significant and desirable mid parent heterosis was observed in eight cross combinations for plant height, 12 for leaf blade length, nine for flag leaf blade length, 13 for flag leaf sheath length, eight for tillers per hill, eight for panicles per hill, 14 for days to 50% flowering, four for days to maturity, four for panicle length, 14 for panicle weight, nine for primary branches per panicle, 16 for secondary branches per panicle, six for filled grains per panicle, 15 for 1000 seed weight, 13 for grain yield per hill and 15 for harvest index. Significant and desirable better parent heterosis was observed in 12 cross combinations for plant height, 11 for leaf blade length, 5 for flag leaf blade length, nine for flag leaf sheath length, seven for tillers per hill, seven for panicles per hill, 25 for days to 50% flowering, one for days to 100% flowering, seven for days to maturity, three for panicle length, nine for panicle weight, five for primary branches per panicle, 12 for secondary branches per panicle, four for filled grains per panicle, nine for 1000 seed weight, seven for grain yield per hill and nine for harvest index. None of the crosses were identified as good heterotic over standard check for grain yield per hill but many good and desirable heterotic crosses were identified over standard check for most of the yield related characters. Twenty cross combinations were identified as heterotic over standard check due to desirable and significant standard heterosis for most of the yield related traits.   Keywords: Heterosis; rice; Oryza sativa; boro DOI: http://dx.doi.org/10.3329/bjpbg.v23i1.9314 BJPBG 2010; 23(1): 19-30


1971 ◽  
Vol 24 (4) ◽  
pp. 1047 ◽  
Author(s):  
IF Wardlaw

In wheat (Triticum ae8tivum cv. Gabo) a temporary water deficit in the first 7 days following anthesis significantly reduced the final grain weight per ear. A reduction in seed set in response to stress was associated with an initially greater rate of development of the remaining grains, with an enhanced rate of cell division in the endosperm. Relative turgidity measurements indicated that the stress applied did not significantly reduce grain water content, although the ear structure showed some water loss, and the stem and flag leaf blade were quite severely stressed. Th!' greater desiccation of the leaf and stem in comparison with the ear was reflected in the lower rate of photosynthesis of these organs under stress conditions.


1976 ◽  
Vol 12 (4) ◽  
pp. 411-415 ◽  
Author(s):  
A. Rehman Chowdhry ◽  
M. Saleem ◽  
Khurshid Alam

SUMMARYPhenotypic correlation coefficients of flag leaf blade length, breadth and sheath length with plant height, grain yield and its components were computed in four wheat varieties and their ten F2 crosses. Flag leaf sheath length was positively related to plant height, grain yield and its components in almost all the populations, but little or no such relation occurred with flag leaf blade length and breadth in most cases. The data suggested the possibility of selecting plants with longer flag leaf sheaths, with obvious yield advantage.


Author(s):  
E. Punithalingam

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.


2020 ◽  
Vol 21 (6) ◽  
pp. 2098 ◽  
Author(s):  
Dong Zhu ◽  
Gengrui Zhu ◽  
Zhen Zhang ◽  
Zhimin Wang ◽  
Xing Yan ◽  
...  

We present the first comprehensive proteome analysis of wheat flag leaves under water-deficit, high-nitrogen (N) fertilization, and combined treatments during grain development in the field. Physiological and agronomic trait analyses showed that leaf relative water content, total chlorophyll content, photosynthetic efficiency, and grain weight and yield were significantly reduced under water-deficit conditions, but dramatically enhanced under high-N fertilization and moderately promoted under the combined treatment. Two-dimensional electrophoresis detected 72 differentially accumulated protein (DAP) spots representing 65 unique proteins, primarily involved in photosynthesis, signal transduction, carbohydrate metabolism, redox homeostasis, stress defense, and energy metabolism. DAPs associated with photosynthesis and protein folding showed significant downregulation and upregulation in response to water-deficit and high-N treatments, respectively. The combined treatment caused a moderate upregulation of DAPs related to photosynthesis and energy and carbohydrate metabolism, suggesting that high-N fertilization can alleviate losses in yield caused by water-deficit conditions by enhancing leaf photosynthesis and grain storage compound synthesis.


1988 ◽  
Vol 47 (1) ◽  
pp. 105-110 ◽  
Author(s):  
P. K. Bhargava ◽  
E. R. Ørskov ◽  
T. K. Walli

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.


Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 99-102 ◽  
Author(s):  
Toshinobu Morikawa

Inheritance of the peroxidase isoenzymes of the flag leaf blade was examined by isoelectrofocusing in the hexaploid oats Avena byzantina cv. Kanota, Avena fatua ssp. compacta, and Avena sativa cv. Cherokee. Two independent peroxidase loci (Px0 and Px9) were detected in the F2 from the 'Kanota' × compacta cross. The Px0a derived from compacta expressed the highest peroxidase activity and was accompanied by a post-transcriptionally modified form or mozyme. A monosomic analysis of the Px0 and Px9 loci revealed that they were located on chromosomes 18 and 6, respectively. Phenotypic expression of the peroxidases varied in each genotye at the Px0 and Px9 loci. Phenotypes of the homozygote (Px0aPx0a) and the hemizygote (Px0a—) were similar to each other. The heterozygote (Px0aPx0b) had half the enzymatic activity of the others. Px9b of compacta was functional as a suppressor but that of 'Cherokee' was nonfunctional.Key words: monosomic analysis, peroxidase loci, isoenzyme, hexaploid oats.


1994 ◽  
Vol 21 (3) ◽  
pp. 255 ◽  
Author(s):  
IF Wardlaw ◽  
J Willenbrink

Wheat plants grown under non-stress conditions at a dayhight temperature of 18/13�C under glasshouse conditions from head emergence to maturity showed a maximum accumulation of water-soluble, non-structural carbohydrates 20-25 days after anthesis. This storage was largely as fructans with the timing and amount of storage and mobilisation varying between cultivars, although the maximum concentration (fructose equivalents per unit stem fresh weight) was similar in all cultivars. The main storage in the culm was located in the lower part of the peduncle enclosed by the flag leaf sheath, in the penultimate internode and for one cultivar also in the flag leaf sheath. 14CO2 pulse-chase studies showed that there was a considerable delay in the incorporation of flag leaf assimilates into stem fructans, a delay probably associated with transfer and metabolic processes in the stem itself. At anthesis, when soluble carbohydrates were rapidly accumulating in the culm, the level of activity of sucrose synthase (SS) in the penultimate internode was much greater than that of sucrose phosphate synthase (SPS). The activity of SS declined rapidly as active storage ceased. This pattern was the reverse of that found in the leaf where SPS, rather than SS, was initially high and declined towards maturity. These changes are discussed in relation to the possible role of sucrose synthesising enzymes, particularly SS, in the accumulation and mobilisation of stem reserves in wheat.


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