Variation in Endosperm Characteristics and Nitrogen Content in Six Wheat Lines

1982 ◽  
Vol 9 (5) ◽  
pp. 539 ◽  
Author(s):  
RM Gleadow ◽  
MJ Dalling ◽  
GM Halloran

Grain growth was studied in six wheat lines which represented a wide range of mature grain weights (18-56 mg). Endosperm cell number, measured by counting nuclei, was positively related to final grain weight, apparently by allowing a higher rate of grain growth. Those wheat lines with fewer endosperm cells also tended to have smaller cells. As a consequence, large grains contained larger numbers of starch granules per endosperm and per cell. The time after anthesis at which nitrogen in the flag leaves began to decline varied between wheat lines and appeared to be related to both the pattern of nitrogen storage in the grain and the duration of grain growth. However, once initiated, the rate of flag-leaf senescence exhibited similar kinetics in all wheat lines.

2020 ◽  
Vol 73 (2) ◽  
pp. 9131-9141
Author(s):  
Zine El Abidine Fellahi ◽  
Abderrahmane Hannachi ◽  
Hamenna Bouzerzour

This study aimed at evaluating the expected gains from selection obtained based upon direct, indirect, and index-based selection in a set of 599 bread wheat lines. The experiment was carried out at the experimental field of INRAA institute, Setif research unit (Algeria), in a Federer augmented block design including three controls. A wide range of genetic variability was observed among lines for the eleven traits assessed. The results indicated that index-based selection and selection based on grain yield expressed higher expected genetic gain than direct and indirect mono-trait-based selection. The best 15 selected lines exhibited higher grain yield than the control varieties, and they were clustered in three groups that contrasted mainly for the flag-leaf area, thousand-kernel weight, biomass, and harvest index. The index-based selection appears as a useful tool for the rapid selection of early filial generations, enriching selected breeding materials with desirable alleles and reducing the number of years required to combine these traits in elite varieties.


2018 ◽  
Vol 28 (2) ◽  
pp. 32-44
Author(s):  
M. L. Pathak ◽  
B. B. Shrestha ◽  
L. Joshi ◽  
X. F. Gao ◽  
P. K. Jha

A wide range of habitat conditions including elevation determine adaptative variation in a species. The study was carried out to investigate the anatomical variation of two common species of Rhododendron (R. anthopogon and R. lepidotum) growing between 3200 and 4700 m asl in Gokyo valley of Sagarmatha National Park, Khumbu, eastern Nepal. Seven anatomical characters viz. pore area (PA), pore density (PD), vessel element length (VEL), fiber tracheid length (FL), ray density (RD), uniseriate ray height (URH) and uniseriate ray cell number (URCN) of twenty-three samples for two species (12 samples of R. anthopogon and 11 of R. lepidotum) were studied by making permanent slides of transverse, tangential longitudinal and radial longitudinal stem sections. In R. anthopogon, out of three non- anatomical characters (plant height, soil nitrogen and leaf nitrogen) the nitrogen content in leaf increased with increasing elevation. However, the plant height and nitrogen content in soil did not vary significantly with elevation. Out of the seven wood anatomical characters three characters such as PA, VEL and FL decreased with increasing elevation. The other four characters, PD, RD, URH and URCN did not vary significantly with elevation. In R. lepidotum, plant height decreased with increasing elevation and nitrogen content of soil and leaf increased with elevation. The PD, PA, VEL and FL decreased along the elevation gradient. However, RD, URH and URCN did not vary significantly with elevation. These variations in the anatomical features of both species have been attributed to the adaptative strategies of the plant in the hostile environment at high elevation.


2013 ◽  
Vol 39 (6) ◽  
pp. 1096 ◽  
Author(s):  
Dong-Qing YANG ◽  
Zhen-Lin WANG ◽  
Yan-Ping YIN ◽  
Ying-Li NI ◽  
Wei-Bing YANG ◽  
...  

Author(s):  
Xiaoping Huang ◽  
Hongyu Zhang ◽  
Qiang Wang ◽  
Rong Guo ◽  
Lingxia Wei ◽  
...  

Abstract Key message This study showed the systematic identification of long non-coding RNAs (lncRNAs) involving in flag leaf senescence of rice, providing the possible lncRNA-mRNA regulatory relationships and lncRNA-miRNA-mRNA ceRNA networks during leaf senescence. Abstract LncRNAs have been reported to play crucial roles in diverse biological processes. However, no systematic identification of lncRNAs associated with leaf senescence in plants has been studied. In this study, a genome-wide high throughput sequencing analysis was performed using rice flag leaves developing from normal to senescence. A total of 3953 lncRNAs and 38757 mRNAs were identified, of which 343 lncRNAs and 9412 mRNAs were differentially expressed. Through weighted gene co-expression network analysis (WGCNA), 22 continuously down-expressed lncRNAs targeting 812 co-expressed mRNAs and 48 continuously up-expressed lncRNAs targeting 1209 co-expressed mRNAs were considered to be significantly associated with flag leaf senescence. Gene Ontology results suggested that the senescence-associated lncRNAs targeted mRNAs involving in many biological processes, including transcription, hormone response, oxidation–reduction process and substance metabolism. Additionally, 43 senescence-associated lncRNAs were predicted to target 111 co-expressed transcription factors. Interestingly, 8 down-expressed lncRNAs and 29 up-expressed lncRNAs were found to separately target 12 and 20 well-studied senescence-associated genes (SAGs). Furthermore, analysis on the competing endogenous RNA (CeRNA) network revealed that 6 down-expressed lncRNAs possibly regulated 51 co-expressed mRNAs through 15 miRNAs, and 14 up-expressed lncRNAs possibly regulated 117 co-expressed mRNAs through 21 miRNAs. Importantly, by expression validation, a conserved miR164-NAC regulatory pathway was found to be possibly involved in leaf senescence, where lncRNA MSTRG.62092.1 may serve as a ceRNA binding with miR164a and miR164e to regulate three transcription factors. And two key lncRNAs MSTRG.31014.21 and MSTRG.31014.36 also could regulate the abscisic-acid biosynthetic gene BGIOSGA025169 (OsNCED4) and BGIOSGA016313 (NAC family) through osa-miR5809. The possible regulation networks of lncRNAs involving in leaf senescence were discussed, and several candidate lncRNAs were recommended for prior transgenic analysis. These findings will extend the understanding on the regulatory roles of lncRNAs in leaf senescence, and lay a foundation for functional research on candidate lncRNAs.


1990 ◽  
Vol 70 (2) ◽  
pp. 581-589 ◽  
Author(s):  
T. A. McALLISTER ◽  
K.-J. CHENG ◽  
L. M. RODE ◽  
J. G. BUCHANAN-SMITH

This study was conducted to determine the effect of formaldehyde treatment of barley on the rate of microbial starch digestion. Ground barley was left untreated (UB) or treated with 0.5% formaldehyde (TB) and incubated in vials with an inoculum consisting of a homogenate of rumen contents and Bryant's anaerobic media (1:1). Separate vials were analyzed for starch, ammonia, pH and volatile fatty acids (VFA) after 0, 4, 8, 12, 18, 24, 36 and 48 h. The digestion of starch was lower (P < 0.05) in TB than in UB between 4 and 24 h. Accumulation of NH3 was lower and pH was higher in TB vials (P < 0.05) than in UB vials. VFA production and fermentation efficiency were lower (P < 0.05) in TB than in UB. Formaldehyde treatment of barley reduced (P < 0.05) the production of propionate and enhanced (P < 0.05) the production of butyrate in comparison with UB. Examination by scanning electron microscopy (SEM) showed that the initial colonization of TB was inhibited in comparison with that of UB. The distinct shape of the endosperm cells of TB (12 h) were readily recognizable, but the endosperm cells of UB (12 h) were not readily distinguishable. SEM of TB (24 h) showed that the protein matrix of the endosperm cell is resistant to microbial digestion. The formaldehyde-induced reduction in starch digestion appears to result from the protein matrix inhibiting the access of bacteria to underlying starch granules. Key words: Starch, rumen bacteria, formaldehyde, barley


1986 ◽  
Vol 66 (3) ◽  
pp. 503-508 ◽  
Author(s):  
I. Ma. Martin del Molino ◽  
M. Ulloa ◽  
R. Martinez-Carrasco ◽  
P. Perez

Author(s):  
Andréia de L. Moreno ◽  
Jorge F. Kusdra ◽  
Angelita A. C. Picazevicz

ABSTRACT Rhizobacteria have a wide range of plant growth-promoting mechanisms of action, making them an alternative and/or complementary biological input for chemical fertilizers. In this respect, the present study aimed to assess growth and nitrogen accumulation in maize plants as a function of Azospirillum brasilense, Bacillus subtilis, zinc and nitrogen application at sowing. The experiment with the ‘AL Bandeirante’ maize variety was conducted in a greenhouse, using a completely randomized design. The treatments were arranged in a 2 x 2 x 2 x 2 factorial scheme, with six repetitions, considering the presence and absence of Azospirillum brasilense (5 g kg-1), Bacillus subtilis (5 mL kg-1) and zinc (20 g kg-1) in the seeds and addition or not of nitrogen (30 kg ha-1) to the soil. The variables assessed were plant height, stem diameter, leaf, stem, shoot, root and total dry weight, and shoot nitrogen content. Nitrogen fertilization in the absence of zinc increased shoot and total dry weight as well as shoot nitrogen content. Zinc applied to the seeds improved the total and stem dry weight of maize plants in the absence of Bacillus subtilis. Inoculation with Azospirillum brasilense and Bacillus subtilis increased the stem diameter and shoot nitrogen content of maize plants when nitrogen fertilization was not performed at sowing. There was no isolated or interaction effect between factors for plant height and root dry weight.


2021 ◽  
Author(s):  
Yu Zhang ◽  
Yanyun Li ◽  
Yuanyuan Zhang ◽  
Zeyu Zhang ◽  
Deyu Zhang ◽  
...  

Flag leaf senescence is an important biological process that drives the remobilization of nutrients to the growing organs of rice. Leaf senescence is controlled by genetic information via gene expression and epigenetic modification, but the precise mechanism is as of yet unclear. Here, we analyzed genome-wide acetylated lysine residue 9 of histone H3 (H3K9ac) enrichment by chromatin immunoprecipitation-sequencing (ChIP-seq) and examined its association with transcriptomes by RNA-seq during flag leaf aging in rice (Oryza sativa). We found that genome-wide H3K9 acetylation levels increased with age-dependent senescence in rice flag leaf, and there was a positive correlation between the density and breadth of H3K9ac and gene expression and transcript elongation. A set of 1,249 up-regulated, differentially expressed genes (DEGs) and 996 down-regulated DEGs showing a strong relationship between temporal changes in gene expression and gain/loss of H3K9ac was observed during rice flag leaf aging. We produced a landscape of H3K9 acetylation- modified gene expression targets that includes known senescence-associated genes, metabolism-related genes, as well as miRNA biosynthesis- related genes. Our findings reveal a complex regulatory network of metabolism- and senescence-related pathways mediated by H3K9ac and also elucidate patterns of H3K9ac-mediated regulation of gene expression during flag leaf aging in rice.


2020 ◽  
Vol 493 (2) ◽  
pp. 2490-2505 ◽  
Author(s):  
Dian P Triani ◽  
Manodeep Sinha ◽  
Darren J Croton ◽  
Camilla Pacifici ◽  
Eli Dwek

ABSTRACT We study the dust evolution in galaxies by implementing a detailed dust prescription in the SAGE semi-analytical model (SAM) for galaxy formation. The new model, called Dusty SAGE, follows the condensation of dust in the ejecta of Type II supernovae and asymptotic giant branch stars, grain growth in the dense molecular clouds, destruction by supernovae shocks, and the removal of dust from the interstellar medium (ISM) by star formation, reheating, inflows, and outflows. Our model successfully reproduces the observed dust mass function at redshift z = 0 and the observed scaling relations for dust across a wide range of redshifts. We find that the dust mass content in the present Universe is mainly produced via grain growth in the ISM. By contrast, in the early Universe, the primary production mechanism for dust is the condensation in stellar ejecta. The shift of the significant production channel for dust characterizes the scaling relations of dust-to-gas (DTG) and dust-to-metal (DTM) ratios. In galaxies where the grain growth dominates, we find positive correlations for DTG and DTM ratios with both metallicity and stellar mass. On the other hand, in galaxies where dust is produced primarily via condensation, we find negative or no correlation for DTM and DTG ratios with either metallicity or stellar mass. In agreement with observation showing that the circumgalactic medium contains more dust than the ISM, our model also shows the same trend for z &lt; 4. Our SAM is publicly available at https://github.com/dptriani/dusty-sage.


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