Changes in cellular and water soluble sugar contents during grain filling period in three parts of main culm of spring wheats.

The crop performance of semi-dwarf wheat cv. (Maris Hobbit) was compared with a standard-ht. cv. (Lely) at various levels of N supply. The grain yields of Maris Hobbit were considerably higher due to a higher number of grains and a heavier grain wt. Owing to the higher grain yield and a lower stem wt. the harvest index of Maris Hobbit was higher than that of Lely (0.47 and 0.40, resp.). The content of water-soluble carbohydrates in the stems of both cv. appeared to be very high until 3 wk after anthesis, despite the occurrence of low light intensities. Lely used more assimilates for structural stem material than did Maris Hobbit. Quantity and date of N application greatly affected grain number, but affected grain wt. to a lesser extent. Thus within each cv. grain number/m2 was the main determinant of grain yield. Late N dressings promoted photosynthetic production, grain wt. and CP content of the grain. The low CP contents of the grain were attributed to the low temp. during the grain-filling period. The distribution of N within the plant was only slightly influenced by N dressings and cv. differences. N harvest index ranged from 0.74 to 0.79. Grain N was derived from the vegetative organs (63-94%) and from uptake after anthesis (6-37%). The importance of carbohydrate and N economy for grain yield are discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Physiological Traits Determining Yield Tolerance of Wheat to Foliar Diseases

Phytopathology ◽

10.1094/phyto-07-16-0283-r ◽

2017 ◽

Vol 107 (12) ◽

pp. 1468-1478 ◽

Cited By ~ 3

Author(s):

F. van den Berg ◽

N. D. Paveley ◽

I. J. Bingham ◽

F. van den Bosch

Keyword(s):

Carbon Assimilation ◽

Grain Filling ◽

Specific Weight ◽

Water Soluble ◽

Strong Positive Correlation ◽

Area Index ◽

Disease Tolerance ◽

Wide Range ◽

Mechanistic Basis ◽

Grain Filling Period

Tolerance is defined as the ability of one cultivar to yield more than another cultivar under similar disease severity. If both cultivars suffer an equal loss in healthy (green) leaf area duration (HAD) over the grain filling period due to disease presence, then the yield loss per unit HAD loss is smaller for a more tolerant cultivar. Little is understood of what physiological and developmental traits of cultivars determine disease tolerance. In this study, we use a mathematical model of wheat to investigate the effect of a wide range of wheat phenotypes on tolerance. During the phase from stem extension to anthesis, the model calculates the assimilate source and sink potential, allowing for dynamic changes to the source–sink balance by partitioning assimilates between ear development and storage of water-soluble carbon (WSC) reserves, according to assimilate availability. To quantify tolerance, rates of epidemic progress were varied on each phenotype, leading to different levels of HAD loss during the postanthesis, grain-filling period. Model outputs show that the main determinant of tolerance is the total amount of assimilate produced per grain during the rapid grain-fill period, leading to a strong positive correlation between HAD per grain and tolerance. Reductions in traits that affect carbon assimilation rate and increases in traits that determine the amount of structural biomass in the plant increase disease tolerance through their associated reduction in number of grains per ear. Some of the most influential traits are the canopy green area index, carbon use efficiency, and leaf specific weight. Increased WSC accumulation can either increase or decrease tolerance. Furthermore, a cultivar is shown to be maximally tolerant when a crop is able to just fill its total sink size in the presence of disease. The model has identified influential functional traits and established that their associations with tolerance have a mechanistic basis.

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Evaluation of the Tolerance Ability of Wheat Genotypes to Drought Stress: Dissection through Culm-Reserves Contribution and Grain Filling Physiology

Agronomy ◽

10.3390/agronomy11061252 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1252

Author(s):

Md. Amirul Islam ◽

Rajib Kumar De ◽

Md. Alamgir Hossain ◽

Md. Sabibul Haque ◽

Md. Nesar Uddin ◽

...

Keyword(s):

Drought Stress ◽

Grain Yield ◽

Grain Filling ◽

Dry Mass ◽

Water Soluble ◽

Limiting Factors ◽

Soluble Carbohydrates ◽

Matter Production ◽

Grain Filling Period ◽

Ripe Stage

Drought stress is one of the limiting factors for grain filling and yield in wheat. The grain filling and determinants of individual grain weight depend on current assimilation and extent of remobilization of culm reserves to grains. A pot experiment was conducted with eight wheat cultivars at the Pot House to study the grain filling and the contributions of reserves in culm, including the sheath to grain yield under drought stress. Drought stress was enforced by restricting irrigation during the grain-filling period. The plants (tillers) were harvested at anthesis, milk-ripe, and maturity. The changes in dry weights of leaves, culm with sheath, spikes, and grains; and the contribution of culm reserves to grain yield were determined. Results revealed that drought stress considerably decreased the grain filling duration by 15–24% and grain yield by 11–34%. Further, drought-induced early leaf senescence and reduced total dry matter production indicate the minimum contribution of current assimilation to grain yield. The stress reduced the contribution of culm reserves, the water-soluble carbohydrates (WSCs), to the grains. The accumulation of culm WSCs reached peak at milk ripe stage in control, varied from 28.6 to 84 mg culm−1 and that significantly reduced in the range from 14.9 to 40.6 mg culm−1 in stressed plants. The residual culm WSCs in control and stressed plants varied from 1.23 to 8.12 and 1.00 to 3.40 mg g−1 culm dry mass, respectively. BARI Gom 24 exhibited a higher contribution of culm WSCs to grain yield under drought, while the lowest contribution was found in Kanchan. Considering culm reserves WSCs and their remobilization along with other studied traits, BARI Gom 24 showed greater drought tolerance and revealed potential to grow under water deficit conditions in comparison to other cultivars.

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Grain filling patterns of barley as affected by high temperature stress

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v15i2.35059 ◽

2017 ◽

Vol 15 (2) ◽

pp. 174-181

Author(s):

Md Rasel Rana ◽

Md Masudul Karim ◽

Md Juiceball Hassan ◽

Md Alamgir Hossain ◽

Md Ashraful Haque

Keyword(s):

Heat Stress ◽

Grain Yield ◽

Grain Filling ◽

High Temperature Stress ◽

Water Soluble ◽

Grain Weight ◽

Soluble Carbohydrates ◽

Barley Cultivars ◽

The Mean ◽

Grain Filling Period

Grain filling determines the grain weight, a major component of grain yield in cereals. Grain filling in barley depends on current assimilation and culm reserves (mainly water-soluble carbohydrates). Nowadays barley is facing heat stress problem which is mostly responsible to reduce the yield of barley. A field experiment was conducted at the Field Lab, Department of Crop Botany, BangladeshAgriculturalUniversity, Mymensingh during November 2015 to March 2016 to study the grain filling patterns and the contributions of culm reserves to grain yield under heat stress. The experiment consisted of two factors—barley cultivars and heat stress. The heat stress was imposed by late sowing. The tillers were sampled once a week during grain filling period to determine the changes in dry weights of different parts, viz., leaves, culm with sheath, spikes, and grains; and to examine the contribution of culm reserves to grain yield. The results in the experiment revealed that the grain yield was reduced by 22-28% due to the stress. The grain yield varied from 52 to 150 g m−2 with the mean of 102 g m−2 under control while it varied from 37 to 116 g m−2 with the mean of 75 g m−2 under heat stress. Among the cultivars studied BARI Barley5, BARI Barley2 and BARI Barley1, seemed as high yielders while BARI Barley3, BARI Barley4, BARI Barley6 as the low yielders under heat stress treatment. The reduction in grain yield was attributable mainly to lighter grain weight due to the stress. Heat stress drastically reduced the grain filling duration by 45–50%. However, the stress increased the grain filling rate by 6–53%. The amount of reserves remobilized to grain varied among the cultivars ranging from 4.8 to 12.77 mg spike−1 in control and from 1.73 to 6.25 mg spike−1 in stressed plants. The stressed barley plants exhibited lower accumulation of reserves in culm but they showed almost its complete remobilization to the grain. The contribution of culm reserves to grain yield varied from 1.13 to 19.52%, and 1.09 to 2.11% in control and in stressed plants, respectively. In conclusion, culm reserve is the important attributes in grain yield in Bangladeshi barley cultivars but the contribution remains almost unaffected due the post-anthesis heat stress.J. Bangladesh Agril. Univ. 15(2): 174-181, December 2017

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Stem carbohydrate dynamics during post anthesis period in diverse wheat genotypes under different environments

Plant Science Today ◽

10.14719/pst.2019.6.sp1.688 ◽

2019 ◽

Vol 6 (sp1) ◽

pp. 556-559

Author(s):

Vidisha Thakur ◽

Girish Chandra Pandey ◽

Jagadish Rane

Keyword(s):

Genetic Variation ◽

Grain Yield ◽

Grain Filling ◽

Water Soluble ◽

Soluble Carbohydrates ◽

Growth Stages ◽

Terminal Drought ◽

Grain Filling Period ◽

Terminal Drought Stress ◽

Carbohydrate Dynamics

The contribution of stem water soluble carbohydrates (SWSCs) to grain biomass of wheat ranges from 10 to 20% under irrigated condition and 40 to 60% under stresses such as terminal heat and drought. Genetic variation in SWSC and its mobilization can be useful to increase the grain yield of wheat under harsh environments. Hence, a set of 16 genotypes varying in spike morphology and grain yield was grown in field under timely sown, late sown and terminal drought stress conditions. The anthrone method was used to measure the SWSC concentration in the dried peduncle and penultimate internodes in three replicates at 3 growth stages starting from anthesis. The effect of delay in sowing and terminal drought on the SWSC concentration was significant from anthesis to 14 days after anthesis. Significant genetic variation was observed in the rate of post anthesis change in SWSC during the early grain filling period under the three conditions which partially contributed to the variation in grain yield per spike among the genotypes. Due to sterile florets and/or shorter grain filling duration, all the genotypes did not have a correlation between grain weight per spike and rate of decrease of SWSCs. Thus, our experiments reconfirm the significance of SWSC in present cultivars of wheat and also the scope for exploiting the genetic variation in this trait.

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BIPLOT ANALYSIS FOR IDENTIFICATION OF SUPERIOR GENOTYPES IN A RECOMBINANT INBRED POPULATION OF WHEAT UNDER RAINFED CONDITIONS

Journal of Experimental Biology and Agricultural Sciences ◽

10.18006/2021.9(5).598.609 ◽

2021 ◽

Vol 9 (5) ◽

pp. 598-609

Author(s):

Ashutosh Srivastava ◽

◽

Puja Srivastava ◽

R S Sarlach ◽

Mayank Anand Gururani ◽

...

Keyword(s):

Canopy Temperature ◽

Grain Filling ◽

Water Soluble ◽

Physiological Traits ◽

Soluble Carbohydrates ◽

Biplot Analysis ◽

Water Soluble Carbohydrates ◽

Grain Filling Period ◽

Peduncle Length ◽

Ideal Genotype

Physiological traits of wheat genotypes and their trait relation to drought conditions are important to identify the genotype in target environments. Thus, genotype selection should be based on multiple physiological traits in variable environments within the target region. This study was conducted at Punjab Agricultural University during rabi crop seasons 2012-13 and 2013-14 to study the recombinant inbred lines (RILs) of wheat genotypes derived from traditional landraces and modern cultivars (C518/2*PBW343) based on various morpho-physiological traits. A total of 175 RILs were selected for this study based on various tolerance indices. The genotype by trait (GT) biplot analysis was applied to data from seven high-yielding RILs grown under irrigated (E1) and rainfed environments (E2). The GGE biplot explained 100% of the total variation for chlorophyll content, grain filling period, peduncle length, water-soluble carbohydrates, grain number, grain yield, and 95.1% for canopy temperature, 94.9% for thousand-grain weight. GT-biplots indicated that the relationships among the studied traits were not consistent across environments, but they facilitated visual genotype comparisons and selection in each environment. RIL 84 and RIL108 were close to the average environment (ideal genotype) for all traits studied except chlorophyll content. A well-performing genotype with great environmental stability is called an "ideal genotype. Among all entries, these genotypes performed well. Therefore, among the traits studied, grain filling period, peduncle length, canopy temperature, water soluble carbohydrates, and 1000 grain weight contributed to grain yield under a stress environment. Furthermore, it may be used as a donor material in breeding programs and QTLs mapping.

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Screening of barley genotypes for drought tolerance based on culm reserves contribution to grain yield

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v16i1.36482 ◽

2018 ◽

Vol 16 (1) ◽

pp. 62-66

Author(s):

Md Masudul Karim ◽

Md Amirul Islam ◽

Md Rasel Rana ◽

Md Alamgir Hossain ◽

Md Abdul Kader

Keyword(s):

Drought Stress ◽

Grain Yield ◽

Grain Filling ◽

Water Soluble ◽

Grain Weight ◽

Soluble Carbohydrates ◽

Barley Cultivars ◽

Two Factors ◽

Grain Filling Period ◽

Ripe Stage

Grain filling determines the grain weight, a major component of grain yield in cereals. Grain filling in barley depends on current assimilation and culm reserves. A pot experiment was conducted at the Grilled House, Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during October 2015–May 2016 to study the grain filling patterns and the contributions of culm reserves to grain yield under drought stress. The experiment consisted of two factors—barley cultivars (six cultivars) and drought stress treatments (control and drought stress). Drought stress was imposed by limiting the irrigation during grain filling period. The tillers were sampled at anthesis, milk-ripe and maturity to determine the changes in dry weights of different parts, viz., leaf lamina, culm with sheath, spikes, and grains; and to examine the contribution of culm reserves to grain yield. The result in this experiment revealed that the grain yield was reduced by 5–25% due to drought stress. The reduction in grain yield was attributable to reduce number of grains per spike and lighter grain weight due to the stress. Drought stress drastically reduced the grain filling duration by about 30% and the stress induced early leaf senescence. Photosynthesis rate and leaf greenness were also reduced in stress. The stress altered the contribution of culm reserves, water soluble carbohydrates (WSCs) in culms to grains. At milk ripe stage, accumulation reached its peak. It accumulated 29.0 to 70.0 mg and from 15.8 to 40.6 mg culm−1 in control and stressed plants, respectively. The residual culm WSCs ranged from 3.5 to 11.2 mg and 1.0 to 3.5 mg culm−1 under control and stress conditions, respectively. The highest contribution of culm WSCs to grain yield was observed in BARI barley2 and the lowest was in BARI barley5 both in control and stress condition. Among the cultivars studied, BARI barley2 produced higher yield with the higher contribution of culm reserves to grain yield under the drought stress.J. Bangladesh Agril. Univ. 16(1): 62-66, April 2018

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