Effects of Drought and High Temperature on Grain Growth in Wheat

1984 ◽  
Vol 11 (6) ◽  
pp. 553 ◽  
Author(s):  
ME Nicolas ◽  
RM Gleadow ◽  
MJ Dalling
Keyword(s):  
Cell Division ◽  
High Temperature ◽  
Cell Size ◽  
Dry Matter ◽  
Cell Number ◽  
Limiting Factor ◽  
Dry Matter Accumulation ◽  
Starch Granules ◽  
Maximum Cell ◽  
Effects Of Drought

The effects of two levels of temperature and of water supply on grain development of wheat (cv. Warigal) were studied by imposing treatments during the early or late period of cell division. High temperature (28°C day/20°C night) accelerated development of the grain. Dry matter accumulation and cell division proceeded at a higher rate but had a shorter duration in the high temperature treatments. Maximum cell number, final cell size and the number of large starch granules per cell were not significantly reduced by high temperature. Drought and drought × high temperature reduced the storage capacity of the grain, with a decrease in number of cells and starch granules in the endosperm. Cell size was also reduced when treatments were imposed late during cell division. Duration of dry matter accumulation and cell division was reduced in the drought and drought × high temperature treatments. The combined effects of drought and high temperature were much more severe than those of each separate treatment. The amount of sucrose per cell was similar in all treatments. It appears unlikely that the supply of sucrose to the endosperm cells is the main limiting factor of dry matter accumulation in both drought and high temperature treatments.

Effects of Water Deficit on Endosperm Starch Granules and on Grain Physiology of Wheat and Barley.

1982 ◽  
Vol 9 (4) ◽  
pp. 423 ◽  
Author(s):  
A Brooks ◽  
CF Jenner ◽  
D Aspinall
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Dry Matter ◽  
Amino Acid Content ◽  
Dry Weight ◽  
Cell Number ◽  
Dry Matter Accumulation ◽  
Starch Granules ◽  
Barley Grains ◽  
Endosperm Starch

Wheat (cv. Sun 9E) and barley (cv. Clipper) plants were subjected to water deficit after anthesis. In both species grain dry matter accumulation was initially unaffected by water deficit but terminated earlier in stressed plants than in controls. Water deficit did not affect endosperm cell number. In water stressed wheat plants the number of B-type starch granules per endosperm and the size of the largest A-type granules were significantly less than in control plants but A-type granule number was unaffected. Water potentials of wheat flag leaves and bracts were reduced by water deficit but this treatment did not affect grain water potential or osmotic potential during the first 29 days after anthesis. During these 29 days, neither grain nor bract water potential of barley was affected by stress and the water potential of bracts was relatively low even in control plants. Maturing grains eventually lost water and endosperm volume declined. This water loss occurred earlier in stressed plants. Stress significantly reduced the amount of sucrose per wheat grain but not the amount of sucrose per unit of grain dry matter or water content. In barley grains, stress did not reduce the relative or absolute sucrose contents. It was considered unlikely that the earlier cessation of grain growth on stressed plants was caused by insufficient assimilate. Although protein as a proportion of grain dry weight was higher in stressed plants than in controls, protein and amino acid content per grain were unaffected by water deficit.

scholarly journals Rootstock Effects on Growth, Cell Number, and Cell Size of `Gala' Apples

2004 ◽  
Vol 129 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Yahya K. Al-Hinai ◽  
Teryl R. Roper
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Agricultural Research ◽  
Fruit Size ◽  
Cell Number ◽  
Fruit Growth ◽  
Research Station ◽  
Full Bloom ◽  
Final Size ◽  
Load Effects

The effects of rootstock on growth of fruit cell number and size of `Gala' apple trees (Malus domestica Borkh) were investigated over three consecutive seasons (2000-02) growing on Malling 26 (M.26), Ottawa-3, Pajam-1, and Vineland (V)-605 rootstocks at the Peninsular Agricultural Research Station near Sturgeon Bay, WI. Fruit growth as a function of cell division and expansion was monitored from full bloom until harvest using scanning electron microscopy (SEM). Cell count and cell size measurements showed that rootstock had no affect on fruit growth and final size even when crop load effects were removed. Cell division ceased about 5 to 6 weeks after full bloom (WAFB) followed by cell expansion. Fruit size was positively correlated (r2 = 0.85) with cell size, suggesting that differences in fruit size were primarily a result of changes in cell size rather than cell number or intercellular space (IS).

Effects of Exposure of Wheat Ears to High Temperature on Dry Matter Accumulation and Carbohydrate Metabolism in the Grain of Two Cultivars. I. Immediate Responses

1991 ◽  
Vol 18 (2) ◽  
pp. 165 ◽  
Author(s):  
CF Jenner
Keyword(s):  
High Temperature ◽  
Sucrose Synthase ◽  
Dry Matter ◽  
Starch Synthesis ◽  
Grain Filling ◽  
Mass Action ◽  
Dry Matter Accumulation ◽  
Partial Explanation ◽  
Calculated Mass ◽  
Percentage Basis

Ears of wheat were exposed for up to 7 days during the grain-filling stage to high temperature (35�C day/25�C night) and metabolic responses in the grain were compared to those in ears maintained at lower temperatures (21�C day/16�C night). Two cultivars of wheat known to differ in their post-anthesis tolerance of high temperature were compared. Raising the temperature resulted in a small increase in the rate of dry matter accumulation: both cultivars responded similarly. Sucrose content of the endosperm was either not affected or increased by raising the temperature. Raising the temperature had differential effects on glucose and fructose content: fructose was substantially reduced while glucose was either unaffected or slightly increased. After raising the temperature the concentrations of all three hexose phosphates measured, glucose-6-phosphate (G-6-P), glucose-1-phosphate (G-1-P) and fructose-6-phosphate (F-6-P), were reduced similarly on a percentage basis and to about the same extent as fructose. The concentration of the sugar nucleotide (UDP-glucose) resulting from the breakdown of sucrose by sucrose synthase was also reduced at high temperature. Judging from calculated mass-action ratios, all three catalytic steps involved in the interconversion of the metabolites mentioned above were close to equilibrium, and only one mass action ratio (for sucrose synthase) was affected by heating: it was doubled. Although temperature clearly resulted in changes in the reaction catalysed by sucrose synthase, it was not clear how temperature had acted. Concentration of the precursor for starch synthesis (ADP-glucose) was slightly lower in both cultivars at the higher temperature. Taken together the responses could provide at least a partial explanation for the smallness of the increase in starch deposition with increase in temperature, but do not explain the different responses of these two cultivars to high temperature.

scholarly journals The Interactive Effects of Daytime High Temperature and Humidity on Growth and Endogenous Hormone Concentration of Tomato Seedlings

HortScience ◽  
2020 ◽  
Vol 55 (10) ◽  
pp. 1575-1583
Author(s):  
Yanjiao Zheng ◽  
Zaiqiang Yang ◽  
Chao Xu ◽  
Lin Wang ◽  
Haijing Huang ◽  
...  
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Dry Matter ◽  
Soluble Sugar ◽  
Dry Matter Accumulation ◽  
Tomato Seedling ◽  
Tomato Plants ◽  
Temperature Conditions ◽  
Temperature Environment ◽  
Tomato Growth

High temperature and high relative humidity (RH) are one of the most serious agricultural meteorological disasters that limit the production capacity of agricultural facilities. However, little information is available on the precise interaction between these factors on tomato growth. The objectives of this study were to determine the effect of high temperature under different RH levels on tomato growth and endogenous hormones and to determine the optimal RH for tomato seedling growth under high temperature environment. Two high temperature (38/18 °C, 41/18 °C) and three relative humidity (50 ± 5%, 70 ± 5%, 90 ± 5%) orthogonal experiments were conducted, with 28/18 °C, 50 ± 5% (CK) as control. The results showed that the dry matter accumulation of tomato plants under high temperature environment was significantly lower than that of CK. At 38 °C, the dry matter accumulation with 70% relative humidity was not significantly different from that of CK; at 41 °C, dry matter accumulation with 70% and 90% relative air humidity was significantly greater than that of 50%. The concentrations of soluble sugar and free amino acids in all organs in high temperature-treated plants were significantly higher than that in CK. As relative humidity increased, soluble sugar concentrations of each organ decreased, and the free amino acid concentrations increased. Cytokinin (ZT) and indole acetic acid (IAA) concentrations in tomato buds were significantly lower than in CK under high temperature conditions. The lower the RH, the lower the content of ZT and IAA. The gibberellin (GA3) and abscisic acid (ABA) concentrations were higher than in CK under high temperatures. GA3 concentrations decreased and ABA concentrations were augmented with increased humidity. The differences of tomato seedling growth indices and apical bud endogenous hormone concentrations between RHs under high temperature conditions were significant. Raising RH to 70% or higher under high temperature conditions could be beneficial to the growth of tomato plants. The results contribute to a better understanding of the interactions between microclimate parameters inside a Venlo-type glass greenhouse environment, in a specific climate condition, and their effects on the growth of tomato.

scholarly journals cMyc increases cell number through uncoupling of cell division from cell size in CHO cells

2009 ◽  
Vol 9 (1) ◽  
pp. 76 ◽  
Author(s):  
Darrin Kuystermans ◽  
Mohamed Al-Rubeai
Keyword(s):  
Cell Division ◽  
Cell Size ◽  
Cho Cells ◽  
Cell Number

Dry matter accumulation in potato clones under seasonal high temperature conditions in Pakistan

1992 ◽  
Vol 69 (10) ◽  
pp. 667-676 ◽  
Author(s):  
Nasrullah J. Malik ◽  
Robert B. Dwelle ◽  
Michael K. Thornton ◽  
Joseph J. Pavek
Keyword(s):  
High Temperature ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Temperature Conditions

scholarly journals THE RESULTS OF PRODUCTIVITY STUDY OF DIFFERENT SAMPLES OF ALFALFA CHANGEABLE (MEDICAGO VARIA MARTYN) IN THE CONDITIONS OF THE MIDDLE VOLGA REGION

2019 ◽  
Vol 4 (2) ◽  
pp. 34-41
Author(s):  
Ирина Володина ◽  
Irina Volodina
Keyword(s):  
Dry Matter ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Volga Region ◽  
Limiting Factor ◽  
Dry Matter Accumulation ◽  
Middle Volga Region ◽  
Economically Valuable Traits ◽  
Middle Volga ◽  
Seed Yields

The aim of the research was to increased fodder and seed productivity of variable alfalfa (Medicago varia Martin) in the middle Volga region. The results of the researches made during the period 2012-2014 for incorporated 13 vari-ety samples of alfalfa changeable in the nursery of competitive trials are provided. The most promising population demonstrated economically valuable traits in previous years, from various nurseries of the study were used. Popu-lation was created by the polikross. Weather conditions analysis of the region allows us to conclude that over the 2012-2014 they met the requirements needed for the studied culture, providing a sufficiently high potential of productivity, but the limiting factor for the formation of the vegetative mass of alfalfa is the level of moisture. The data on the possibility of obtaining seeds in the year of sowing in the climatic conditions of the Middle Volga region un-der the condition of early sowing (until 10-12 may) are confirmed. Seed yields in 2012 ranged from 24.7 to 47.8 g/m2. It was found that in different years of moisture supply, taking into regard the conditions of the region, all the studied samples form 2 full-fledged mowing per season. All studied samples can be characterized as highly pro-ductive by vegetative mass and seeds. The dry matter accumulation in the estimated samples in the first mowing of 2013 was 0.65-0.68 kg/m2, in the second – 0.38-0.86 kg/m2. In arid 2013, the highest yield of seeds was obtained 337.5-494.7 g/m2. In 2014, the yield of dry matter both mowing was approximately equivalent 0,56-0,79 kg/m2 and 0.54-0.97 kg/m2 respectively, the average for the samples is 0.66 kg/m2 in the first mowing and 0.67 kg/m2 in the second. The yield of seed populations in 2014 ranged from 22.9 to 55.8 g/m2. All studied samples can be charac-terized as highly productive for the accumulation of dry matter and seed yield.

scholarly journals Molecular Analysis of Fruit Size Regulation in Apple

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 868C-868
Author(s):  
Anish Malladi* ◽  
Peter Hirst
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Cell Size ◽  
Fruit Size ◽  
Cell Number ◽  
Size Analysis ◽  
Cell Cycle Gene ◽  
Cell Cycle Regulators ◽  
Size Regulation ◽  
Molecular Aspects

Fruit size is a commercially valuable trait. Although several factors are known to affect fruit size in apple, insights into the molecular aspects of its regulation are lacking. Our research aims to understand fruit size regulation using a combination of approaches. Analysis of a large fruited mutant of `Gala', `Grand Gala' (GG), showed that it was 40% heavier than `Gala' at harvest. Increase in size of GG fruit was caused by an increase in the cell size apparent at full bloom. Flow cytometry revealed the presence of multiple levels of ploidy (up to 16C) in GG during early fruit development. Increase in ploidy of GG is hypothesized to be due to endoreduplication, a process normally absent in apple. Endoreduplication is a modification of the cell cycle where DNA replication is not followed by cell division, resulting in increased DNA content accompanied by increased cell size. To understand if the cell cycle is altered in GG, four key cell cycle regulators, MdCDKA1, MdCDKB1, MdCYCB2 and MdCYCD3 have been partially cloned from apple using RT-PCR and RACE. As cell number at the end of the cell division phase is correlated with fruit size at harvest, expression analysis of these genes can provide valuable insights into their role in the regulation of cell number and fruit size. Analysis of cell cycle gene expression in GG may provide key insights into the altered molecular regulation that leads to endoreduplication in the mutant. Parallel approaches being employed to study whether environmental and cultural factors regulate fruit size through an influence on the cell cycle will also be discussed.

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