Impact of Seawater Salinity on Ultrastructure of Chloroplasts and Oleosomes in Relation to Fat Metabolism in Flag Leaf of Two Wheat Cultivars During Grain-filling

2015 ◽  
Vol 04 (01) ◽  
Author(s):  
Heshmat Soliman Aldesuquy
Keyword(s):  
Flag Leaf ◽  
Fat Metabolism ◽  
Grain Filling ◽  
Wheat Cultivars ◽  
Seawater Salinity

Gas exchange rates and nitrogen concentrations in two winter wheat cultivars during the grain-filling period

1980 ◽  
Vol 58 (19) ◽  
pp. 2110-2116 ◽  
Author(s):  
W. N. Migus ◽  
L. A. Hunt
Keyword(s):  
Winter Wheat ◽  
Flag Leaf ◽  
Grain Filling ◽  
Wheat Cultivars ◽  
N Concentration ◽  
Nitrogen Concentrations ◽  
Winter Wheat Cultivars ◽  
N Treatment ◽  
Grain Filling Period ◽  
Rate Of Decline

CO2 exchange (CER) and transpiration (TR) rates of flag leaves, penultimate leaves, and the ear of two winter wheat cultivars (cv. Fredrick and cv. Bezostaya-1), were measured at intervals during the life of the flag leaf. These were grown at two levels of nitrogen (N), 105 and 210 mg L−1, supplied from the double ridge stage of apical development. Nitrogen concentrations and dry weights of the flag and penultimate leaves, and of various other plant parts, were also measured.CER of main culm flag leaves of both cultivars declined more slowly from ear emergence to approximately 2.5 weeks postanthesis than either before or after this period. Similarly, the CER pattern of main culm penultimate leaves of Fredrick showed a plateau during this same period. By contrast, CER of the penultimate leaves of Bezostaya declined more uniformly overtime. CER of illuminated ears declined steadily from anthesis, whereas CER in the dark decreased to a maximum negative value approximately 2 weeks postanthesis. Nitrogen treatment had little effect on these CER patterns, with the exception of Bezostaya penultimate leaves, in which the rate of decline was slower for the higher N treatment.Nitrogen concentrations of the flag and penultimate leaves, and in the nongrain ear component, decreased steadily during the grain-filling period for both cultivars and N treatments. Leaf N concentration also decreased during the preanthesis period in Fredrick at both N treatments, and in Bezostaya at the lower N treatment. The time – course of N concentration in the leaves was not closely mirrored by CER, indicating that factors other than the N concentration of the leaves were important in determining the pattern of CER.TR of the flag and penultimate leaves declined from full flag leaf expansion until anthesis and then rose during a 2- to 2.5-week-postanthesis period for both cultivars and N treatments, with the exception of Bezostaya at the lower N treatment. The increase in TR during the filling period suggests that the reduced rate of decline in CER at that time may have resulted, at least partly, because a reduction in gas phase resistance offset an increase in residual resistance.

POTENTIAL NET PHOTOSYNTHESIS IN FLAG LEAVES OF SEVERELY DROUGHT-STRESSED WHEAT CULTIVARS AND ITS RELATIONSHIP TO GRAIN YIELD

1974 ◽  
Vol 54 (4) ◽  
pp. 811-815 ◽  
Author(s):  
R. KAUL
Keyword(s):  
Desiccation Tolerance ◽  
Flag Leaf ◽  
Assimilation Efficiency ◽  
Relative Yield ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Wheat Cultivars ◽  
Water Deficits ◽  
Flag Leaves

Six wheat cultivars grown in the field in 1973 showed continuously increasing water deficits which attained severe levels by the end of the season. The relative yield performance of five Triticum aestivum L. cultivars was predictable from the integrated net photosynthetic potential of their flag leaves. Grain productivity of a T. durum L. cultivar, Pelissier, was uniformly underestimated, likely because of poor desiccation tolerance of its flag leaf. It is suggested that Pelissier depended on the longevity of its heavily awned spike for additional grain filling. Results show that photosynthetic desiccation tolerance in severely stressed flag leaves of Pitic 62 ranks above that of Manitou, Cypress, and particularly Selkirk and Pelissier. Glenlea was comparable to Manitou and Cypress in flag leaf assimilation efficiency when subjected to early drought hardening, but exhibited less efficiency when subjected to water deficits late in development.

The contribution of stem reserves to grain development in a range of wheat cultivars of different height

1971 ◽  
Vol 22 (6) ◽  
pp. 851 ◽  
Author(s):  
HM Rawson ◽  
LT Evans
Keyword(s):  
Flag Leaf ◽  
Dry Weight ◽  
Grain Filling ◽  
Gas Analysis ◽  
High Yield ◽  
Initial Growth ◽  
Wheat Cultivars ◽  
Stem Height ◽  
Grain Yields ◽  
Stem Reserves

Six wheat cultivars with more than a twofold range in stem height and weight were grown at 21/16°C in 16-hr days of high light intensity. Changes with time in photosynthesis, respiration, dry weight, and the distribution of 14C fed to the flag leaf or ear of the main stem were followed in all cultivars. The effects on grain yields, stem weights, and 14C distribution of prevention of photosynthesis by the ears or by the rest of the plant during grain filling were also examined. Substantial losses of dry weight from the stem occurred during the most rapid period of grain filling, but stem weights then rose again in most cultivars. About one-third of the early loss in stem weight of control plants was due to stem respiration, the remainder to mobilization, but cultivars differed in these proportions, the respiration rate of stems per unit dry weight being higher in the shorter cultivars. The assimilates mobilized from the stems were equivalent to 2.7–12.2% of final grain weight in control ears. Mobilization increased when photosynthesis was reduced, particularly that from the lower internodes, which indicated that grain yields in the control plants were not limited by lack of assimilate. Balance sheets derived from gas analysis measurements supported this conclusion. The amount of material lost from the stems of plants in all the conditions employed, measured as dry weight or as 14C, was unrelated to stem height. Tall cultivars were no more dependent than short ones on stem reserves, and no more able to draw on reserves for grain filling in conditions limiting photosynthesis. Nor was there evidence that stem growth in tall cultivars was more likely to compete with grain growth. The cultivars differed more than threefold in the rate of ear filling. High growth rate per ear was associated with high yield and grain number per ear and with slow initial growth of the grains.

scholarly journals Growth and physiological performance responses to drought stress under non-flooded rice cultivation with straw mulching

2010 ◽  
Vol 56 (No. 2) ◽  
pp. 51-59 ◽  
Author(s):  
J. Qin ◽  
X. Wang ◽  
F. Hu ◽  
H. Li
Keyword(s):  
Flag Leaf ◽  
Early Period ◽  
Grain Filling ◽  
Antioxidant Enzyme Activity ◽  
Straw Mulching ◽  
Flooded Rice ◽  
Significant Difference ◽  
Rice Yields ◽  
Change Tendency ◽  
Soil Moisture Status

A field experiment was performed to investigate the growth performance and the growth stage-dependent changes in activities of antioxidative enzymes and concentration of malondialdehyde (MDA) in leaves of rice subjected to treatment with (NF-M) or without straw mulching (NF-WM) under non-flooded conditions compared with continuously flooded treatment (CF). Compared with the NF-WM treatment, mulch application significantly increased the flag leaf area per plant before heading, tillers number and plant height at the early period of tillering stage. There was no significant difference between the yield of the NF-WM and CF treatment. However, the yield of NF-WM treatment was significantly lower than CF and NF-M treatments. Significantly higher activities of peroxidase (POD) and catalase (CAT) but lower concentration of superoxide dismutase (SOD) and malondialdehyde (MDA) were observed in straw mulching treatment than in treatment without mulching at elongation, heading and grain filling stages. The change tendency of antioxidant enzyme activity and MDA level was in line both with soil moisture status and rice yields of different treatments.

Variation in harvest index of modern spring barley, oat and wheat cultivars adapted to northern growing conditions

2007 ◽  
Vol 146 (1) ◽  
pp. 35-47 ◽  
Author(s):  
P. PELTONEN-SAINIO ◽  
S. MUURINEN ◽  
A. RAJALA ◽  
L. JAUHIAINEN
Keyword(s):  
Grain Yield ◽  
Harvest Index ◽  
Stand Structure ◽  
Spring Barley ◽  
Principal Component ◽  
Grain Filling ◽  
Wheat Cultivars ◽  
Cereal Species ◽  
Growing Conditions ◽  
Cereal Cultivars

SUMMARYIncreased harvest index (HI) has been one of the principal factors contributing to genetic yield improvements in spring barley (Hordeum vulgare L.), oat (Avena sativa L.) and wheat (Triticum aestivum L.) cultivars. Although high HI demonstrates high-yielding ability when cultivars are compared, it can also indicate challenges to yield formation when comparisons are made across differing growing conditions. The present study was designed to investigate variation in HI among modern cereal cultivars relative to that brought about by a northern environment, to assess whether HI still explains the majority of the differences in grain yield when only modern cereal cultivars are compared, and to monitor key traits contributing to HI. Stability of HI was also investigated with reference to the role of tillers. Twelve experiments (3 years, two locations, two nitrogen fertilizer regimes) were carried out in southern Finland to evaluate 12 two-row spring barley, 10 six-row barley, 10 oat and 11 wheat cultivars. In addition to HI, days to heading and maturity, length of grain filling period, grain yield, test weight and 13 traits characterizing plant stand structure were measured and analysed with principal component analysis (PCA) to detect traits associated with HI and those contributing to stability of HI. Although only modern cereals were studied, differences among cultivars were significant both in mean HI and stability of HI, and HI was associated with short plant stature in all modern cereal species. Also, single grain weight was associated with HI in all species. Differences between, but not within, species in HI were partly attributable to differences in tiller performance. Grain yield was associated closely with HI except in two-row barley. It may be possible to further increase HI of wheat, as it still was relatively low. High HI did, however, not indicate the degree of success in yield determination when environments are compared.

scholarly journals Grain filling parameters in high-yielding ns wheat cultivars

2008 ◽  
pp. 53-58
Author(s):  
Milka Brdar ◽  
Marija Kraljevic-Balalic ◽  
Borislav Kobiljski
Keyword(s):  
Multivariate Analysis ◽  
Nonlinear Regression ◽  
Environmental Conditions ◽  
Dry Weight ◽  
Grain Filling ◽  
Grain Weight ◽  
Cultivar Differences ◽  
Wheat Cultivars ◽  
Estimated Parameters ◽  
Grain Filling Duration

Grain yield of wheat is dependent on grain weight, which is the result of grain filling duration and rate. The study was undertaken to examine the relation between grain weight and rate and duration of grain filling in five high-yielding NS wheat cultivars. Stepwise multivariate analysis of nonlinear regression estimated grain filling parameters was used to examine cultivar differences in grain filling. On the basis of three-year average, the highest grain dry weight had cultivar Renesansa, and the lightest grains were measured for cultivar Evropa 90. Stepwise multivariate analysis indicated that all three nonlinear regression estimated parameters (grain weight, rate and duration of grain filling) were equally important in characterizing the grain filling curves of the cultivars studied, although sequence of their significance varied in different years, which is probably caused by different environmental conditions in three years of experiment.

scholarly journals Effect of Heat Stress on Inter-relationship of Physiological and Biochemical Traits with Grain Yield in Wheat (Triticum aestivum L.)

2020 ◽  
pp. 19-29
Author(s):  
Amrita Kumari ◽  
R. D. Ranjan ◽  
Chandan Roy ◽  
Awadesh Kumar Pal ◽  
S. Kumar
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Flag Leaf ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Seedling Stage ◽  
Biochemical Traits ◽  
Highly Correlated ◽  
Complex Phenomena ◽  
Physiological And Biochemical

Heat stress, particularly the stress appears at the time of flowering to grain filling stages causing severe yield loss in wheat. Heat tolerance is complex phenomena that include adjustment in morphological, physiological and biochemical traits of the crop. Present investigation was carried out to understand the effect of terminal heat stress on different traits of wheat. The experiment was conducted in three dates of sowing as timely sown, late sown and very late sown to expose the crop to heat stress at later stages of the crop growth. Significant genetic variations for all the traits evaluated under three conditions indicated the presence of variability for the traits. Trait association analysis revealed that flag leaf chlorophyll content and MSI at seedling stage; MDA at reproductive stage had direct relationship with grain yield. While under very late sown condition MDA and RWC at seedling stages were found to be highly correlated with grain yield. It indicates that MDA, RWC at seedling stage and days to booting, days to milking plays important role in very late sown condition that can be used as selection criteria in breeding programme.

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