scholarly journals Unveiling the Actual Functions of Awns in Grasses: From Yield Potential to Quality Traits

2020 ◽  
Vol 21 (20) ◽  
pp. 7593
Author(s):  
Fabrice Ntakirutimana ◽  
Wengang Xie
Keyword(s):  
Grain Yield ◽  
Morphological Characteristics ◽  
Grain Filling ◽  
Yield Potential ◽  
Grass Species ◽  
Genetic Associations ◽  
Potential Yield ◽  
Yield And Quality ◽  
Advance Research ◽  
Favorable Conditions

Awns, which are either bristles or hair-like outgrowths of lemmas in the florets, are one of the typical morphological characteristics of grass species. These stiff structures contribute to grain dispersal and burial and fend off animal predators. However, their phenotypic and genetic associations with traits deciding potential yield and quality are not fully understood. Awns appear to improve photosynthesis, provide assimilates for grain filling, thus contributing to the final grain yield, especially under temperature- and water-stress conditions. Long awns, however, represent a competing sink with developing kernels for photosynthates, which can reduce grain yield under favorable conditions. In addition, long awns can hamper postharvest handling, storage, and processing activities. Overall, little is known about the elusive role of awns, thus, this review summarizes what is known about the effect of awns on grain yield and biomass yield, grain nutritional value, and forage-quality attributes. The influence of awns on the agronomic performance of grasses seems to be associated with environmental and genetic factors and varies in different stages of plant development. The contribution of awns to yield traits and quality features previously documented in major cereal crops, such as rice, barley, and wheat, emphasizes that awns can be targeted for yield and quality improvement and may advance research aimed at identifying the phenotypic effects of morphological traits in grasses.

scholarly journals Genetic Yield Gains and Changes in Morphophysiological-Related Traits of Winter Wheat in Southern Chilean High-Yielding Environments

2022 ◽  
Vol 12 ◽  
Author(s):  
Alejandro del Pozo ◽  
Claudio Jobet ◽  
Iván Matus ◽  
Ana María Méndez-Espinoza ◽  
Miguel Garriga ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Vegetation Indices ◽  
Grain Filling ◽  
Climatic Conditions ◽  
Yield Potential ◽  
Soil Conditions ◽  
Genetic Progress ◽  
Potential Yield ◽  
Stay Green

Both the temperate-humid zone and the southern part of the Mediterranean climate region of Chile are characterized by high wheat productivity. Study objectives were to analyze the yield potential, yield progress, and genetic progress of the winter bread wheat (Triticum aestivum L.) cultivars and changes in agronomic and morphophysiological traits during the past 60 years. Thus, two field experiments: (a) yield potential and (b) yield genetic progress trials were conducted in high-yielding environments of central-southern Chile during the 2018/2019 and 2019/2020 seasons. In addition, yield progress was analyzed using yield historical data of a high-yielding environment from 1957 to 2017. Potential yield trials showed that, at the most favorable sites, grain yield reached ∼20.46 Mg ha–1. The prolonged growing and grain filling period, mild temperatures in December-January, ample water availability, and favorable soil conditions explain this high-potential yield. Yield progress analysis indicated that average grain yield increased from 2.70 Mg ha–1 in 1959 to 12.90 Mg ha–1 in 2017, with a 128.8 kg ha–1 per-year increase due to favorable soil and climatic conditions. For genetic progress trials, genetic gain in grain yield from 1965 to 2019 was 70.20 kg ha–1 (0.49%) per year, representing around 55% of the yield progress. Results revealed that the genetic gains in grain yield were related to increases in biomass partitioning toward reproductive organs, without significant increases in Shoot DW production. In addition, reducing trends in the NDVI, the fraction of intercepted PAR, the intercepted PAR (form emergence to heading), and the RGB-derived vegetation indices with the year of cultivar release were detected. These decreases could be due to the erectophile leaf habit, which enhanced photosynthetic activity, and thus grain yield increased. Also, senescence of bottom canopy leaves (starting from booting) could be involved by decreasing the ability of spectral and RGB-derived vegetation indices to capture the characteristics of green biomass after the booting stage. Contrary, a positive correlation was detected for intercepted PAR from heading to maturity, which could be due to a stay-green mechanism, supported by the trend of positive correlations of Chlorophyll content with the year of cultivar release.

Grain nitrogen concentration differences among three sorghum hybrids with similar grain yield

1999 ◽  
Vol 50 (2) ◽  
pp. 137 ◽  
Author(s):  
A. Kamoshita ◽  
M. Cooper ◽  
R. C. Muchow ◽  
S. Fukai
Keyword(s):  
Grain Yield ◽  
Nitrogen Concentration ◽  
N Uptake ◽  
Grain Filling ◽  
Yield Potential ◽  
Yield Reduction ◽  
N Availability ◽  
N Accumulation ◽  
N Concentration ◽  
Grain Nitrogen

The differences in grain nitrogen (N) concentration among 3 sorghum (Sorghum bicolor (L.) Moench) hybrids with similar grain yield were examined under N-limiting conditions in relation to the availability of assimilate and N to grain. Several manipulation treatments [N fertiliser application, lower leaves shading, thinning (reduced plant population), whole canopy shading, canopy opening, spikelet removal] were imposed to alter the relative N and assimilate availability to grain under full irrigation supply. Grain N concentration increased by either increased grain N availability or yield reduction while maintaining N uptake. Grain N concentration, however, did not decrease in the treatments where relative abundance of N compared with assimilate was intended to be reduced. The minimum levels of grain N concentration differed from 0.95% (ATx623/RTx430) to 1.14% (DK55plus) in these treatments. Regardless of the extent of variation in assimilate and N supply to grain, the ranking of hybrids on grain N concentration was consistent across the manipulation treatments. For the 3 hybrids examined, higher grain N concentration was associated with higher N uptake during grain filling and, to a lesser extent, with higher N mobilisation. Hybrids with larger grain N accumulation had a larger number of grains. There was no tradeoff between grain N concentration and yield, suggesting that grain protein concentration can be improved without sacrificing yield potential.

scholarly journals Performance of Sorghum Recombinant Inbred Lines (RIL) developed for rain-fed areas of Sudan

2015 ◽  
Vol 60 (4) ◽  
pp. 395-406
Author(s):  
El Hassan ◽  
Yasir Gamar ◽  
Ibrahim Elzein ◽  
Asma Ali ◽  
Tareg Ahmed
Keyword(s):  
Grain Yield ◽  
Grain Quality ◽  
Recombinant Inbred Lines ◽  
Block Design ◽  
Inbred Lines ◽  
Yield Potential ◽  
High Yield ◽  
Growth Stages ◽  
Potential Yield ◽  
Wide Range

Sorghum (Sorghum bicolor (L) Moench) is the most widely produced and consumed cereal crop in Sudan. However, productivity is low since the crop is produced in favorable and unfavorable environments where the crop suffers from drought stresses at different growth stages. In the present study, six sorghum inbred lines developed by local breeding program and two commercial checks were evaluated for grain yield potential, yield stability, some important agronomic characters and grain quality properties. Series variety trials were conducted at Elobeid and Suki, Damazin areas of Sudan, during three consecutive rainy seasons. The selected locations represent low, medium and high rainfall areas of Sudan. The trial was laid out in a randomized complete block design. The results revealed that mean squares of genotypes, seasons, locations, location x season, location x genotypes, season x genotypes and season x location x genotype interactions were highly significant (P=0.01) for grain yield. The sorghum genotypes Edo 34-23-4, Edo 26-18 and Edo 16-dwarf produced substantially higher grain yields than commercial checks and the trial mean. Their percentage yield increase ranged from 5% to 75% over commercial checks. The stability analysis revealed that the above mentioned Edo-genotypes had high yield potentials and were stable across a wide range of agricultural conditions. Moreover, the same Edo-lines showed early maturing compared to selected commercial checks and also the Edo-lines possessed good food grains and were market preferred and acceptable for making quality kisra (fermented sorghum pancake-like flatbread). The Edo developed lines also possess the acceptable grain quality in addition to moderate physical grain characteristics such as protein content, fat acidity and moisture content.

Source - sink balance and manipulating sink - source relations of wheat indicate that the yield potential of wheat is sink-limited in high-rainfall zones

2010 ◽  
Vol 61 (10) ◽  
pp. 852 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Grain Yield ◽  
Western Australia ◽  
Unit Area ◽  
Grain Filling ◽  
Yield Potential ◽  
Limiting Factor ◽  
Wheat Cultivars ◽  
High Rainfall ◽  
Sink Size ◽  
Source Sink

Grain yield depends on the number of grains per unit area (sink) and the availability of assimilates (source) to fill these grains. The aim of the current work was to determine whether wheat yield in the high-rainfall zone of south-western Australia is limited in current cultivars by the size of the sink or by the assimilates available for grain filling. Three wheat cultivars (Calingiri, Chara and Wyalkatchem) and two breeding lines (HRZ216 and HRZ203) were grown in four replicates in the field from 2005 to 2007. Dry matter and water soluble carbohydrates (WSC) at anthesis and maturity were measured and used to determine the source and sink balance of the crop. In 2007, three further treatments were applied to manipulate the sink–source relationships: (i) spikelets were removed on main stems to increase the source : sink ratio; (ii) incoming solar radiation was reduced by 40% by shading after anthesis to reduce the availability of assimilates to grains; and (iii) supplemental irrigation was used to maintain the capacity for photosynthesis by an improved water supply during grain filling. The source–sink balance of the crops showed that the potential source was 25% greater than the actual grain yield in average and above-average seasons (2005 and 2007), suggesting that sink size, represented by the number of grain per unit area, was a limiting factor to yield potential. However, the source may have become a limiting factor in a drought season (2006). The grain yield increased with increased number of grains/m2 and kernel weight remained relatively stable even when grain number increased from 7000 to 16 000 per m2. The removal of half of the spikelets on the main stem did not increase kernel mass of the remaining grains and an additional 33 mm of irrigation water did not increase grain yield, but significantly (P < 0.05) increased WSC left in stems and leaf sheaths at maturity. Shading after anthesis did not significantly reduce grain yield of the current cultivars Calingiri and Wyalkatchem, but it reduced grain yield by 23–25% (P < 0.05) in Chara and HRZ203. The source–sink balance over three seasons and three independent experiments in 2007 suggested that the yield of the current wheat cultivars is more sink- than source-limited and that breeding wheat with a larger sink size than in the current cultivars may lift the yield potential of wheat in the high-rainfall zone of south-western Australia.

scholarly journals UNDERSTANDING PLANT DENSITY EFFECTS ON MAIZE GROWTH AND DEVELOPMENT: AN IMPORTANT ISSUE TO MAXIMIZE GRAIN YIELD

2001 ◽  
Vol 31 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Luís Sangoi
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Plant Traits ◽  
Yield Potential ◽  
Grass Species ◽  
Carbon And Nitrogen ◽  
Plant Densities ◽  
Female Flowering ◽  
Number Of Individuals ◽  
Maturity Rating

Maize is the agronomic grass species that is most sensitive to variations in plant density. For each production system, there is a population that maximizes grain yield. This article presents an overview of the factors that affect optimum plant population, emphasizingthe effects of dense stands on ear development and discussing important changes in plant traits that have contributed to increase the tolerance of modern hybrids to high plant densities. Population for maize maximum economic grain yield varies from 30,000 to over 90,000pl.ha-1, depending on water availability, soil fertility, maturity rating, planting date and row spacing. When the number of individuals per area is increased beyond the optimum plant density, there is a series of consequences that are detrimental to ear ontogeny and result in barrenness. First, ear differentiation is delayed in relation to tassel differentiation. Later-initiated earshoots have a reduced growth rate, resulting in fewer spikelet primordia transformed into functional florets by the time of flowering. Functional florets extrude silks slowly, decreasing the number of fertilized spikelets due to the lack of synchrony between anthesis and silking. Limitations in carbon and nitrogen supply to the ear stimulate young kernel abortion immediately after fertilization. Availability of earlier hybrids, with shorter plant height, lower leaf number, upright leaves, smaller tassels and better synchrony between male and female flowering time has enhanced the ability of maize to face high plant populations without showing excessive barrenness. Improved endurance in high stands has allowed maize to intercept and use solar radiation more efficiently, contributing to the remarkable increase in grain yield potential experienced by this crop.

Effects of Heat Stress at Different Grain-Filling Phases on the Grain Yield and Quality of Waxy Maize

2014 ◽  
Vol 91 (2) ◽  
pp. 189-194 ◽  
Author(s):  
Dalei Lu ◽  
Xuli Sun ◽  
Fabao Yan ◽  
Xin Wang ◽  
Renchao Xu ◽  
...  
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Grain Filling ◽  
Waxy Maize ◽  
Yield And Quality ◽  
Grain Yield And Quality

scholarly journals Effects of drought stress on growth, grain filling duration, yield and quality attributes of barley (Hordeum vulgare L.)

2018 ◽  
Vol 47 (3) ◽  
pp. 421-428 ◽  
Author(s):  
Fahad Alghabari ◽  
Muhammad Zahid Ihsan
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Biomass Accumulation ◽  
Field Capacity ◽  
Grain Filling ◽  
Quality Attributes ◽  
Fresh Biomass ◽  
Yield And Quality ◽  
Dry Biomass ◽  
Grain Filling Duration

A pot experiment was conducted to investigate the effect of drought stress at start of anthesis (applied by adjusting the field capacities at 100, 50 and 30%) on barley growth, grain filling duration, grain shape, yield and quality attributes. The effect of drought stress was more prominent on plant fresh biomass accumulation, grain yield and grain filling duration. However, it produced non-significant effect on total number of tillers and grain protein contents. With the increasing intensity of drought stress, barley growth and yield traits significantly diminished. Water stress gradually shortened the plant height and biomass accumulation but the difference was more prominent in fresh biomass accumulation (– 45%) over dry biomass accumulation. The field capacity of 30% caused 29 - 41% reduction in leaf chlorophyll content and 10 - 27% in grain quality traits. Root fresh and dry biomass accumulation decreased by drought stress while root length increased. Drought stress produced uneven grain size that resulted in lower grain yield (42%) specially at 30% field capacity. This reduction in yield was also due to the decreased grain filling duration (38 d) at 30% field capacity as compared to 100% field capacity. So, it may be concluded that drought stress affected barley yield through impaired grain development and grain filling duration. The results of present study are satisfactory and needed further exploration about the physiological mechanism and management strategies to overcome drought stress related yield losses in barley crop.

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