Methodological aspects and impact on grain weight of source reduction through shade meshes during grain filling of bread wheat

2020 ◽  
Vol 71 (8) ◽  
pp. 739
Author(s):  
Maria L. Maydup ◽  
Mariana Antonietta ◽  
Nicolás Rouillet ◽  
Maria G. Cano ◽  
Juan J. Guiamet ◽  
...  
Keyword(s):  
Bread Wheat ◽  
Photosynthetic Activity ◽  
Light Attenuation ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Grain Weight ◽  
Light Transmittance ◽  
Source Reduction ◽  
Grain Filling Period ◽  
Days After Anthesis

In crop studies, shading is a common approach for reducing source activity (i.e. assimilates produced by photosynthesis); however, if source reduction is not directly proportional to the degree of light attenuation, estimations could be flawed. We analysed the effects of shading at three levels on light transmittance, air and canopy temperatures, and actual photosynthetic activity at different times of day, and on grain weight in a modern genotype of bread wheat (Triticum aestivum L.). The treatments were imposed 10 days after anthesis and comprised three levels of shading with meshes: 80%, 50% and 10% transmittance during midday. The decrease in midday photosynthetic activity (electron transport rate, ETR; and CO2 assimilation, An) in the shading treatments compared with control plants did not fit a 1:1 relationship with light transmittance of the meshes; for example, the reduction in ETR and An was <50% under the mesh with 50% light transmittance. The decrease in light transmittance and photosynthesis caused by the meshes was higher during the morning and afternoon than midday. In the grain-filling period, midday ETR showed a progressive, age-dependent decrease in control plants compared with shading treatments. Initial differences in photosynthetic activity between treatments were attenuated throughout the grain-filling period. The diurnal course of air temperature showed a progressive decrease from control to shade treatments, mainly during midday. This pattern was confirmed by infrared thermometry of canopy temperature, with severe shade showing the lowest temperature. Greenness measurements at 19 days after anthesis showed delayed senescence in shaded plants, possibly due to the decrease in temperature under shade. Grain weight per ear was reduced in shading treatments (mainly with 50% and 10% light transmittance). The decrease in grain weight per ear plotted against the decrease in photosynthesis (evaluated through ETR or An) did not fit a 1:1 relationship. This could be explained in part by an observed increase in dry matter retranslocation from the stem. In summary, estimations of source reduction on the basis of light attenuation could be biased, because the photosynthesis decrease is less than proportional, and photosynthesis differences are attenuated throughout grain filling.

Control of Grain Yield by Sink Capacity and Assimilate Supply in Various Rice (Oryza sativa) cultivars

1991 ◽  
Vol 27 (2) ◽  
pp. 127-135 ◽  
Author(s):  
S. Fukai ◽  
L. Li ◽  
P. T. Vizmonte ◽  
K. S. Fischer
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Grain Filling ◽  
Grain Weight ◽  
Rice Cultivars ◽  
Sink Capacity ◽  
Single Grain ◽  
Grain Filling Period

SummaryThe objective of this study was to identify whether grain yield in four contrasting rice cultivars is limited by supply of assimilate to fill the grains or by sink capacity to accept the assimilate. Grain yield was limited mostly by sink capacity, with little variation in single grain weight among cultivars, but an old cultivar showed some ability to adjust single grain weight. Sink capacity was very sensitive to variation in assimilate supply immediately after anthesis. Reduction in assimilate supply in the anthesis to early grain filling period reduced filled grain percentage and grain yield, particularly in high yielding cultivars with a large number of grains per panicle.

Source - sink effects on grain weight of bread wheat, durum wheat, and triticale at different locations

2006 ◽  
Vol 57 (2) ◽  
pp. 227 ◽  
Author(s):  
Daniel F. Calderini ◽  
M. P. Reynolds ◽  
G. A. Slafer
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Bread Wheat ◽  
Grain Filling ◽  
Grain Weight ◽  
The Other ◽  
Field Conditions ◽  
Breeding Strategies ◽  
Source Sink ◽  
Source Limitation

Source limitation during grain filling is important for both management and breeding strategies of grain crops. There is little information on the sensitivity of grain weight of temperate cereals to variations in source–sink ratios, and no studies are available on the comparative behaviour of temperate cereals growing together in the same experiment. The objective of the current study was to evaluate, under field conditions, the response of grain weight to different source–sink ratios during grain filling in high-yielding cultivars of bread wheat, durum wheat, and triticale at 2 contrasting locations. Two experiments were carried out at C. Obregon and El Batan in Mexico. In each location, 6 genotypes (2 bread wheat, 2 durum wheat, 2 triticale) were evaluated. A week after anthesis, 2 source–sink (control and halved spikes) treatments were imposed. Location and genotype significantly (P < 0.01) affected grain yield and components. Significant grain weight increases (P < 0.05) were found only in 2 cases in El Batan. The highest response of 17% was found in triticale, with less than 10% in most of the other genotypes. The effect of genotype and location is discussed.

scholarly journals Estimation of heterosis for grain yield and yield attributes in bread wheat genotypes utilizing line x tester analysis (Triticum aestivum L. em. Thell)

2021 ◽  
pp. 85-95
Author(s):  
Amitava Roy ◽  
Anil Kumar ◽  
Karthick Babu S ◽  
Simran Sisodiya ◽  
Anu Singh
Keyword(s):  
Grain Yield ◽  
Bread Wheat ◽  
Block Design ◽  
Triticum Aestivum L ◽  
Grain Weight ◽  
F1 Hybrids ◽  
Research Centre ◽  
Rabi Season ◽  
Yield Attributes ◽  
Randomized Block Design

Eleven genotypes of bread wheat were crossed with three testers in the rabi season of 2018-19 inline x tester mating fashion to obtain 33 F1 hybrids, which were evaluated with parents and two standard checks of wheat viz., UP 2855 and HD 2967. The experiment was laid out in randomized block design with three replications at Norman E. Borlaug Crop Research Centre, G.B. Pant University of Agriculture and Technology, Pantnagar in the rabi season 2019-20. Observations were recorded on various qualitative and quantitative characters including grain yield. The results obtained revealed significant differences among all the genotypes, indicating the presence of aconsiderable amount of genetic variability. The cross combinations SOKOLL x HI 1621, followed by QBP 12-11 x HI 1621, NAC/TH.AC//3*PVN/3/MIRLO/BUC/4/ 2*PASTOR/5/… x HD 3237 were observed to be the better heterotic F1s in terms of grain yield. The hybrid QLD 75 x HI 1621 was identified as the best heterotic combination for grain weight per spike and harvest index. Whereas, for grains per spike F1, NW 6036 x HI 1621, for 1000 grain weight F1, SOKOLL x HD3237, for spike length F1, NAC/TH.AC//3*PVN/3/ MIRLO/BUC/4/2*PASTOR/5/… x HD 3237, for peduncle length F1, VORB/4/D67.2/PARANA 66.270 x HI 1621 and for days to 75% heading and days to maturity F1, PRL/2*PASTOR*2//FH6-1-7/3/KINGBIRD#1//… x PBW 725 were observed to be the better heterotic combinations. The crosses with higher heterotic values may provide an opportunity for isolation of desirable purelines in advanced generations.

scholarly journals Earliness, spike productivity and protein content in European winter wheat landraces and obsolete cultivars

2011 ◽  
Vol 49 (No. 2) ◽  
pp. 67-74 ◽  
Author(s):  
L. Dotlačil ◽  
J. Hermuth ◽  
Z. Stehno
Keyword(s):  
Winter Wheat ◽  
Protein Content ◽  
Crude Protein ◽  
Grain Filling ◽  
Grain Weight ◽  
Crude Protein Content ◽  
European Winter Wheat ◽  
Wheat Landraces ◽  
Grain Filling Period ◽  
Obsolete Cultivars

European winter wheat landraces and obsolete cultivars (121 accessions in set I&nbsp;and 101 accessions in set II) with modern check cultivars were evaluated in three-year field trials. Increased spike productivity in modern cultivars could be attributed mainly to increased number of grains in spikelet and increased HI, whereas TGW has marginal effect. Old cultivars had on average by 2&ndash;3% higher crude protein content in grain than modern ones. Among selected 10 characters, relatively wide diversity (C.V. 11&ndash;20%) has been estimated in spike length and characters of spike productivity (except of grain weight with C.V. close to 9%). It was difficult to distinguish the cultivars according to the country of origin, however, earliness and lower spike productivity seems to be characteristic for South-East origin whereas cultivars from North-West Europe showed opposite characters. Correlation analyses showed close relations between earliness in heading and in maturity and negative relation between late heading and grain filling period, which was positively correlated with TGW and&nbsp;HI (r = 0.26 to 0.38). Number of grains in spikelets was highly correlated with spike productivity and HI (r = 0.62 to 0.69) whereas relations between these two characters and TGW were lower (r = 0.20 to 0.51). Spike productivity characters, except of TGW, are in negative correlation with crude protein content in grain (r = &ndash;0.34 to &ndash;0.50). Regression analyses confirmed that main determining character for the spike productivity is number of kernels in spikelet (about 40% of variation) while effects of TGW are about half-size. Crude protein content was positively affected by plant height (15&ndash;30% of variation) impact of grain weight per spike was lower (14&ndash;17% of variation) and negative. Potentially valuable donors of earliness and longer grain filling period were identified for further studies and/or utilization in breeding programs. As especially valuable character can be considered very high crude protein content (around 18% in cvs Berg-land, Ukrajinka, Sippbachzeller, Innichen Nr. 25001 and Barbu du Finistre). High crude protein content combined with relatively good spike productivity and/or long grain filling period or earliness was found in cvs Visperterminen 640 E, Hatvan, Szekacz 1242, Berchtesgardener Vogel, Ble du Lot and Barbu du Finistere.

TEMPERATURE AND PHOTOPERIOD RESPONSES OF EARLY-MATURING SORGHUM HYBRIDS

1977 ◽  
Vol 57 (3) ◽  
pp. 757-761 ◽  
Author(s):  
YILMA KEBEDE ◽  
D. J. HUME
Keyword(s):  
Grain Filling ◽  
Grain Weight ◽  
Temperature Regimes ◽  
Early Maturing ◽  
Number Of Leaves ◽  
Grain Filling Period ◽  
Shoot Weight ◽  
Type Of Behavior ◽  
Sorghum Bicolor L ◽  
Weight Number

This study was designed to assess the response of three early-maturing sorghum (Sorghum bicolor L. Moench) hybrids, Pride P130, X4043, and X3160, to different day and night temperature regimes and photoperiods under controlled environment conditions. Day/night temperatures were 25/20, 30/20, 35/20, 30/15, 30/25 C with a 12-h photoperiod and 30/20 with a 16-h photoperiod. Data on days to bloom, plant height, number of leaves, number of panicles per plant, duration of grain filling, grain weight, shoot weight and harvest index were obtained. Largest grain weights were obtained at 25/20 C. Grain weight, number of panicles, and grain-filling period were reduced markedly by 5 C increments in day temperature. X4043 and X3160 bloomed soonest at 30/20 C. P130 bloomed and matured in fewer days than the other hybrids at all temperatures. The response of the hybrids to a 16-h photoperiod indicated that they all had a long-day type of behavior at the temperature regime tested.

Water Relations of the Developing Wheat Grain

1980 ◽  
Vol 7 (5) ◽  
pp. 519 ◽  
Author(s):  
EWR Barlow ◽  
JW Lee ◽  
R Munns ◽  
MG Smart
Keyword(s):  
Water Deficit ◽  
Flag Leaf ◽  
Maximum Level ◽  
Grain Filling ◽  
Controlled Environment ◽  
Wheat Grain ◽  
Grain Filling Period ◽  
Pigment Strand ◽  
Days After Anthesis ◽  
Wheat Spike

The physiological and anatomical mechanisms underlying the reduced sensitivity of wheat grain growth to water deficits in the post anthesis period have been investigated. The water potential (Ψ) and water content of the developing wheat grain and of other tissues within the wheat spike and flag leaf were compared under controlled environment and field conditions. In the 14 days following anthesis when the amount of water in each grain was increasing, the Ψ gradient between the grain and the rest of the plant was most pronounced. This Ψ gradient disappeared when the water per grain reached its maximum level (15 days after anthesis). The apparent turgor potential (P) of the wheat grain was very small (less than 0.2 MPa) throughout the grain filling period. When water was withheld 10 and 20 days after anthesis, the grain Ψ changed little despite a large decrease in the Ψ of the glumes, rachis and flag leaf. Grain Ψ showed the same independence during a diurnal cycle of water deficit. The independence of grain Ψ under water deficit conditions may be related initially to the xylem discontinuity in the floral axis and, in longer-term water stress situations, to the deposition of lipid in the pigment strand of the grain itself.

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