scholarly journals The Early Stages of Grain Development in Wheat: Response to Water Stress in a Single Variety

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.

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.


Author(s):  
Aradhana Phukan ◽  
P. K. Barua ◽  
D. Sarma ◽  
S. D. Deka

Two CMS lines, IR 58025A and IR 68888A along with their maintainers and two fertility restorers, LuitR and IR 36R, were evaluated for flower and plant characters during early ahu (February-June) and kharif (July-November) seasons. IR 58025A showed longer stigmata and styles, and higher spikelet Length/Breadth (L/B) ratio while IR 68888A showed broader stigmata and wider glume opening angle in both the seasons. IR 68888A also exhibited higher pollen sterility during early ahu. IR 36R was characterized with broad anthers. LuitR showed longer and broader anthers with more pollen than others. Plant height, flag leaf length, flag leaf width and area were higher in IR 36R. Panicle exsertion was complete in pollen parents whereas it was 78-80% in CMS lines. The widest flag leaf angle was found in IR 58025B during early Ahu and in IR 36R during kharif. Kharif season was more favourable for growth of the plants with higher seed set percentage while floral traits of the CMS lines were better expressed in early Ahu. Manipulation of the seeding sequence of the parental lines in early Ahu is warranted for better seed set provided the seed crop escapes heavy premonsoon showers during reproductive stage. IR 68888A/LuitR was a good combination for pollen dispersal and seed setting.


2019 ◽  
Vol 157 (04) ◽  
pp. 283-299 ◽  
Author(s):  
C. Malumpong ◽  
S. Cheabu ◽  
C. Mongkolsiriwatana ◽  
W. Detpittayanan ◽  
A. Vanavichit

AbstractThe reproductive stage of rice is the most sensitive to heat stress, which can lead to spikelet sterility. Thus, heat-tolerant and heat-susceptible genotypes were used to investigate their differences in terms of phenotypic responses and expression changes of Hsf genes at the pre-flowering stage under heat stress. Results clearly showed that panicles had the highest temperature compared with other plant parts under both natural and heated conditions. However, the temperatures of tolerant and susceptible genotypes were not significantly different. In terms of spikelet fertility, the tolerant lines M9962 and M7988 had high seed set because their anther dehiscence, pollen viability and pollen germination were only slightly affected. In contrast, the susceptible line Sinlek showed severe effects at all steps of fertilization, and the pollen viability of M7766 was slightly affected under heat stress but was more affected in terms of anther dehiscence and pollen germination. Both susceptible lines showed dramatically decreased seed set. In addition, the expression of six HsfA genes in the flag leaves and spikelets at the R2 stage of plants under heat stress showed different responses. Notably, expression of the HsfA2a gene was predominantly upregulated in the flag leaf and spikelets under heat stress in M9962. Therefore, it can be concluded that heat stress has severe effects on the stamen, and that different genotypes have different susceptibilities to heat stress.


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.


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.


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


1960 ◽  
Vol 13 (4) ◽  
pp. 429 ◽  
Author(s):  
LT Evans

Plants of Lolium temulentum, raised in short days, were given an inductive treatment by exposure of one leaf blade to a 32-hr period of continuous illumination. Then either the leaf exposed to this one long light period or varying areas of lower leaves which were simultaneously in short-day conditions were removed at intervals after the long-day exposure. The longer the long-day leaves remained on the plants, the greater was the proportion of plants which initiated inflorescences and the greater the rate of development of their inflorescences. This was so even when short-day leaves were present above the long-day ones. The longer the short-day leaves remained, and the greater their area, the lower was the proportion of plants which initiated inflorescences.


2017 ◽  
Vol 50 (1) ◽  
pp. 31-45
Author(s):  
M. Abo-Youssef ◽  
A. El Sabagh ◽  
G. Abo-Gendy ◽  
A. Mohamed

Abstract The purpose of this study was to identify the optimum levels of gibberellic acid and suitable row ratio for maximization the seed yield of hybrid rice. An experiment was conducted at the experimental farm of Rice Research and Training Center, Egypt, during 2013 and 2014 growing seasons. The material under this study included the parental lines of IR69625A (Female lines) and Giza 179 R (Restorer line) to produce F0 hybrid seeds. A split-plot design with three replications was used. The main plot was row ratio (2R:8A, 2R:10A and 2R:12A) and sub plots was the doses of gibberellic acid (g/ha) (control, 300, 350, 400). The results indicated that, Application of GA3 and row ratio had significant effect on different traits of seed yield and hybrid seed production. The highest values of flag leaf area, panicle length, seed set, panicle weight, panicle exsertion and seed yield were acheived by using 2R: 8A row ratio and was observed the lowest values were obtained at the 2:12 row ratio. Acoording to gibberellic acid application, the highest values for panicle length (cm), seed set (%), panicle weight (g), panicle exertion (%), harvest index and seed yield were recorded by using 400 g /ha gibberellic acid. Accordingly, the highest net economic return from seed yield was obtained with the treatment combination of 400 g/ha GA3 x 2:8 (R: A) row ratio.


2012 ◽  
Vol 15 (2) ◽  
pp. 92-99 ◽  
Author(s):  
Chuan Yan ◽  
Heyun Chen ◽  
Tianyun Fan ◽  
Yifeng Huang ◽  
Shouwu Yu ◽  
...  

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