Grain weight in wheat cultivars released from 1920 to 1990 as affected by post-anthesis defoliation

1997 ◽  
Vol 128 (3) ◽  
pp. 273-281 ◽  
Author(s):  
B. C. KRUK ◽  
D. F. CALDERINI ◽  
G. A. SLAFER
Keyword(s):  
Grain Yield ◽  
Plant Breeding ◽  
Field Experiments ◽  
Wheat Breeding ◽  
Grain Weight ◽  
Yield Potential ◽  
Sink Strength ◽  
Wheat Cultivars ◽  
The Difference ◽  
Source Sink

Although it has been generally recognized that the difference in yield potential amongst wheat cultivars released in different eras is related to differences in their reproductive sink strength, there have been few investigations about changes in source–sink ratios as a consequence of wheat breeding. In the present study, two field experiments, in which plots were fertilized and irrigated and lodging and diseases were prevented, were carried out with seven cultivars (including a commercial hybrid) representing different periods of plant breeding in Argentina from 1920 to 1990. The cultivars were defoliated during post-anthesis to analyse the response of grain weight at particular positions within the spike (which have intrinsic differences in potential size).Individual grain weight was virtually unaffected by defoliation in the old cultivars, but modern cultivars exhibited a significant reduction in individual grain weight for several positions within the spike, although this reduction was small (c. 15%) and many grains were unaffected. In addition, no relationship was found between individual grain weight in the controls and its reduction due to defoliation.We concluded that if the source–sink ratio is further reduced, the grain yield of modern wheats will be simultaneously limited by the source and the sink. Future breeding should therefore attempt to improve simultaneously both sink and source strengths.

Contribution of Stem Dry Matter to Grain Yield in Wheat Cultivars

1991 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
PC Pheloung ◽  
KHM Siddique
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Yield Potential ◽  
Percentage Reduction ◽  
Wheat Cultivars ◽  
Activity Increase ◽  
Structural Carbohydrate ◽  
Days After Anthesis

Field experiments were conducted in the eastern wheat belt of Western Australia in a dry year with and without irrigation (1987) and in a wet year (1988), comparing three cultivars of wheat differing in height and yield potential. The aim of the study was to determine the contribution of remobilisable stem dry matter to grain dry matter under different water regimes in old and modern wheats. Stem non-structural carbohydrate was labelled with 14C 1 day after anthesis and the activity and weight of this pool and the grain was measured at 2, 18 and 58 days after anthesis. Gutha and Kulin, modern tall and semi-dwarf cultivars respectively, yielded higher than Gamenya, a tall older cultivar in all conditions, but the percentage reduction in yield under water stress was greater for the modern cultivars (41, 34 and 23%). In the grain of Gamenya, the increase in 14C activity after the initial labelling was highest under water stress. Generally, loss of 14C activity from the non-structural stem dry matter was less than the increase in grain activity under water stress but similar to or greater than grain activity increase under well watered conditions. Averaged over environments and cultivars, non-structural dry matter stored in the stem contributed at least 20% of the grain dry matter.

scholarly journals Estimating Organ Contribution to Grain Filling and Potential for Source Upregulation in Wheat Cultivars with a Contrasting Source–Sink Balance

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1527
Author(s):  
Carolina Rivera-Amado ◽  
Gemma Molero ◽  
Eliseo Trujillo-Negrellos ◽  
Matthew Reynolds ◽  
John Foulkes
Keyword(s):  
Grain Growth ◽  
Photosynthetic Rate ◽  
Grain Filling ◽  
Leaf Sheath ◽  
Grain Weight ◽  
Yield Potential ◽  
Wheat Cultivars ◽  
Sink Limitation ◽  
Source Sink ◽  
Source And Sink

Grain filling may be limited by the joint source and sink capacity in modern wheat cultivars, indicating a need to research the co-limitation of yield by both photosynthesis and the number and potential size of grains. The extent to which the post-anthesis source may be limiting final grain size can be estimated by partial degraining of spikes, while defoliation and shading treatments can be useful to estimate if any excess photosynthetic capacity exists. In the current study, degraining was applied to a set of 26 elite spring wheat cultivars from the International Maize and Wheat Improvement Center (CIMMYT)’s core germplasm (CIMCOG) panel, while lamina defoliation and shading through stem-and-leaf-sheath covering treatments were applied to a subset of the same cultivars. Responses to source treatments in grain weight, pre-anthesis reserve contribution to grain weight, dry-matter translocation efficiency, and flag-leaf and spike photosynthetic rate were measured and compared to an unmanipulated control treatment. Grain weight responses to degraining among cultivars ranged from no response to increases of 28%, suggesting a range of responses from sink limitation, to probable source and sink co-limitation of grain growth. Grain weight’s response to degraining increased linearly with the years of cultivar release from 1966 to 2009, indicating that the current highest yield potential CIMMYT spring wheats have a co-limitation of grain growth by source and sink. This may have been due to an increase in grain sink strength with years of cultivar release with no commensurate increase in post-anthesis source capacity. The relatively low decreases in grain weight with defoliation compared to decreases in light interception by defoliation indicated that sink limitation was still likely predominating in the cultivars with co-limitation. The stem-and-leaf-sheath covering treatment decreased grain weight by nearly 10%, indicating that stem-and-leafsheath photosynthesis plays a key role in grain growth during grain filling. In addition, pre-anthesis reserve contribution to grain weight was increased by ca. 50% in response to lamina defoliation. Our results showed that increasing the post-anthesis source capacity, through increases in stem-and-leaf-sheath photosynthetic rate during grain filling and pre-anthesis reserve contribution to grain weight, is an important objective in enhancing yield potential in wheat through maintaining a source–sink balance.

Enhancement of dwarf wheat germplasm with high-yield potential derived from induced mutagenesis

2016 ◽  
Vol 16 (1) ◽  
pp. 74-81 ◽  
Author(s):  
Hongchun Xiong ◽  
Huijun Guo ◽  
Yongdun Xie ◽  
Linshu Zhao ◽  
Jiayu Gu ◽  
...  
Keyword(s):  
Yield Components ◽  
Field Experiments ◽  
Wheat Breeding ◽  
Grain Weight ◽  
Yield Potential ◽  
High Yield ◽  
Dwarfing Genes ◽  
Biosynthetic Genes ◽  
Specific Pcr ◽  
1000 Grain Weight

AbstractThe dwarfing wheat (Triticum aestivum L.) breeding has promoted a dramatic increase in yields. Since the utilized dwarfing genes in wheat are very limited, identification of novel dwarfing genes is necessary for improving the genetic diversity of wheat. In this study, more than 300 dwarfing wheat lines from induced mutation were screened by kompetitive allele-specific PCR and gibberellin (GA) treatment. The 17.49% of Rht-D1b and 1.37% of Rht-B1b dwarfing mutants were identified in this mutant group. Additionally, Rht-D1b mutants showed more effective in reduction of plant height and higher 1000-grain weight comparing with that of Rht-B1b mutants. By combing with comparison of yield components and expression profile of GA biosynthetic genes with wild-type, the GA-responsive mutant dm15 without directly involvement in GA metabolism, significantly increased 1000-grain weight but no change of other yield components in two locations of field experiments. Meanwhile, another elite mutant dm11 with change of GA biosynthetic genes expression was also identified. These mutants will be promising candidates for dwarfing wheat breeding.

scholarly journals EFFECT OF REGULATION OF SOURCE-SINK RELATIONSHIP ON GRAIN YIELD AND ITS COMPONENT OF DIFFERENT BREAD WHEAT CULTIVARS

2016 ◽  
Vol 47 (2) ◽  
Author(s):  
Jaddoa & Kadom
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Bread Wheat ◽  
Flag Leaf ◽  
Grain Weight ◽  
Abu Ghraib ◽  
Research Station ◽  
Wheat Cultivars ◽  
Source Sink ◽  
1000 Grain Weight

A field trial was conducted at Abu-Ghraib Research Station-Agricultural Research Directorate-Ministry of Agriculture during the growing seasons of 2012-2013 and 2013-2014. The objective was to investigate the effect of source-sink Regulation on grain yield  and its companents of five bread wheat cultivars (Triticum aestivum L.). Randomized complete block design with the arrangement of split-plots with three replicates was used. Bread wheat cultivars (Bohooth-22, IPA 99, Abu-Ghraib-3,Al-Fath and Al-Rasheed) occupied the main plots while treatments of source-sink relationship regulation occupied the sub-plots. They included eight treatments: Con. control (Con.), S1 (removal of lamina of the flag leaf of main stem), S2 (removal of laminas of the leaf  beneath the flag leaf), S3 (removal of both lamina of the leaf  and the leaf under flag leaf), S4 (removal of upper third spikelets),S5 (removal of median third spikelets), S6 (removal of lower third spikelets) and S7 (removal all spikelets from one side of spike) . Characteristics of plant height, flag leaf area, spike length, no of spikelet per spike, spike weight, and grain yield and its components were measured and estimated. Results of the present study indicated the followings:  Cultivar (Bohooth-22) gave the highest 1000 grain weight (35.70 and 35.31 g) the highest grain yield (5.467 and 5.148 t.ha-1) in both seasons, respectively compared with Abu-Ghraib3 and Al-Rasheed cultivars which gave lowest grain yield (4.918,4.364, 4.239 and 4.352 t.ha-1) in both seasons, respectively and then less 1000 grain weight (30.15, 32.66, 32.61 and 32.77 g), in both seasons, respectively. Treatment (Con.) i.e no modification of source-sink relationship gave the highest grain yield (5.93 and 5.66 t.ha-1) in both seasons, respectively. Treatments of regulation source (S1 and S3)gave grain yield (4.909, 4.698, 4.621and 4.356 t.ha-1), respectively while (S5) treatment gave the lowest grain yield (4.203 t.ha-1) in the first season and (4.061 t.ha-1) in the second season. This indicates that sink regulation treatment was the most influencial in reducing grain yield than the source regulation treatment, especially, treatment (S5) in both seasons where the  median third of spikelets had been removed due to the reduction of spike growth rate (3.18 and 2.49 g.day-1) in both seasons compared with the (Con) treatment which gave the highest values of spike growth rate (3.91 and 3.12 g.day-1) in both seasons, respectively which resulted in the reduction of dry matter translocation in the (S5) treatment (1.87 and 1.74 g.day -1) and consequently in the reduction of 1000 grain weight (30.09 and 31.199) compared with (34.99 and 37.12 g) in the (Con.) treatment in both seasons, respectively.

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 Effect of Source–Sink Ratio Manipulation on Growth, Flowering, and Yield Potential of Soybean

Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 926
Author(s):  
Heba M. Ibrahim ◽  
Basharat Ali ◽  
Ali El-Keblawy ◽  
Taoufik Ksiksi ◽  
Mohamed A. El-Esawi ◽  
...  
Keyword(s):  
Plant Growth ◽  
Field Experiments ◽  
Main Stem ◽  
Yield Potential ◽  
Sink Strength ◽  
Open Flower ◽  
Stay Green ◽  
Trade Offs ◽  
Physiological Capacity ◽  
Source Sink

Trade-offs between growth and reproduction in soybean require resource availability manipulations. Decapitation and reducing sink strength through deflowering can affect the source–sink ratio that affects plant growth, development, and yield. The current study assesses the effect of decapitation (Decap) and removal of the two lowest racemes (R2LR) and their combination on growth, flowering, and yield capacity of soybean through controlling the source–sink ratio and inducing the “stay-green” phenotype. Two field experiments were conducted during 2018 and 2019 in the Agronomy Farm located at Mansoura University, Egypt. Decapitation was done at the V4 stage (35 days after sowing, DAS), during which four nodes on the main stem had fully developed leaves beginning with the unifoliolate nodes, whereas R2LR was performed at the R2 stage (50 DAS), during which the plants had one open flower at one of the two uppermost nodes on the main stem. Results indicated that Decap, R2LR, and their combination significantly increased seed yield per plant through increasing plant growth and flowering and improving biochemical attributes. The combination between Decap and R2LR was generally more effective in positively modulating plant vegetative, reproductive, and physiological capacity than either Decap or R2LR alone. Moreover, the number of branches as well as pods/plant and IAA content responded positively to Decap, whereas net assimilation rate, seed growth rate, number of flowers/node, and cytokinins content responded positively to R2LR. Decap and R2LR were interpreted in light of their effects on inducing the “stay-green” phenotype and altering the source–sink ratio. Based on the findings, it can be concluded that concealing the apical dominance in conjunction with reducing the sink strength through guided raceme removal would be beneficial for the reproductive potential in soybean.

scholarly journals Comparative study on yield and yield attributes of hybrid, inbred, and NPT rice genotypes in a tropical irrigated ecosystem

1970 ◽  
Vol 35 (2) ◽  
pp. 343-353 ◽  
Author(s):  
M Sirajul Islam ◽  
Shaobing Peng ◽  
Romeo M Visperas ◽  
M Sultan Uddin Bhuiya ◽  
SM Altaf Hossain ◽  
...  
Keyword(s):  
Grain Yield ◽  
Hybrid Rice ◽  
Grain Weight ◽  
Yield Potential ◽  
High Yield ◽  
Wet Season ◽  
Yield Attributes ◽  
Rice Genotypes ◽  
The Difference ◽  
1000 Grain Weight

Yield potential of 16 rice genotypes including 12 hybrids, 3 inbreds, and I new plant type (NPT), were studied at the International Rice Research Institute farm under optimum crop management to achieve maximum attainable yields during the wet season (WS) of 2004 and dry season (DS) of 2005. Yield and yield components were determined at maturity. 1R76712H produced the highest grain yield (7.7 t/ha) followed by 1R75217H and Magat (7.6 t/ha) in WS; in DS, 1R79118H produced the highest grain yield (9.17 t/ha) followed by 1R73855H (8.9 t/ha) and SL-8H (8.8 t/ha. The high yield of hybrid rice was due to high harvest index (0.50). Hybrid produced significantly higher productivity (80.2 kg/ha/day) than inbred in DS, but the difference was not significant in WS. Hybrid produced higher spikelets/panicle and 1000-grain weight than inbred rice. Spikelet filling percent was higher in inbred than hybrid rice. The NPT rice genotype had the lowest spikelet filling percent, but the highest 1000-grain weight across the season. Keywords: Yield; yield attributes; hybrid and inbred rice genotypes. DOI: 10.3329/bjar.v35i2.5897Bangladesh J. Agril. Res. 35(2) : 343-353, June 2010

scholarly journals Early generation selection strategy for yield and yield components in white oat

2005 ◽  
Vol 62 (4) ◽  
pp. 357-365 ◽  
Author(s):  
Giovani Benin ◽  
Fernando Irajá Félix de Carvalho ◽  
Antônio Costa de Oliveira ◽  
Claudir Lorencetti ◽  
Igor Pires Valério ◽  
...  
Keyword(s):  
Grain Yield ◽  
Indirect Selection ◽  
Grain Weight ◽  
Yield Potential ◽  
High Yield ◽  
Direct Selection ◽  
Selection Strategy ◽  
Breeding Method ◽  
Growing Seasons ◽  
Selection For

Several studies have searched for higher efficiency on plant selection in generations bearing high frequency of heterozygotes. This work aims to compare the response of direct selection for grain yield, indirect selection through average grain weight and combined selection for higher yield potential and average grain weight of oat plants (Avena sativa L.), using the honeycomb breeding method. These strategies were applied in the growing seasons of 2001 and 2002 in F3 and F4 populations, respectively, in the crosses UPF 18 CTC 5, OR 2 <FONT FACE=Symbol>´</FONT> UPF 7 and OR 2 <FONT FACE=Symbol>´</FONT> UPF 18. The ten best genetic combinations obtained for each cross and selection strategy were evaluated in greenhouse yield trials. Selection of plants with higher yield and average grain weight might be performed on early generations with high levels of heterozygosis. The direct selection for grain yield and indirect selection for average grain weight enabled to increase the average of characters under selection. However, genotypes obtained through direct selection presented lower average grain weight and those obtained through the indirect selection presented lower yield potential. Selection strategies must be run simultaneously to combine in only one genotype high yield potential and large grain weight, enabling maximum genetic gain for both characters.

scholarly journals Residual Effect of Poultry Manure and Mineral N Application on Maize Production under Wheat-Maize Cropping System

2017 ◽  
Vol 5 (9) ◽  
pp. 1061
Author(s):  
Syed Azam Shah ◽  
Wisal Mohammad ◽  
Haroon Haroon ◽  
Adnan Anwar Khan
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Poultry Manure ◽  
Residual Effect ◽  
Grain Weight ◽  
Organic N ◽  
Wheat Crop ◽  
Silty Clay ◽  
Mineral N ◽  
1000 Grain Weight

The study was designed to asses the residual effect of organic N (Poultry Manure) and mineral N on maize crop in field experiments carried out on silty clay loam soil at NIFA, Tarnab, Peshawar, Khyber Pakhtunkhwa (KP) Pakistan during 2014-15. Combined dose of N from both sources were 120 kg ha-1 applied to wheat crop alone and in different combination making six treatments. Maize variety (Azam) was sown in Randomized complete block (RCB) design with four replications. Agronomic data, grains ear-1, 1000 grain weight, biomass grain yield data, N-uptake in maize grain and straw were recorded. Results showed that maximum grain ear−1, 1000 grain weight, biomass and grain yield was obtained from treatment where 25% N applied from poultry manure + 75% from mineral N source applied to previous wheat crop. Agronomic efficiency and nitrogen use efficiency were also found maximum in treatment where 75% poultry manure + 25% mineral N was applied. It was concluded from the study that residual effect of organic manure with mineral N in different ratios enhances crop productivity and soil fertility.

scholarly journals Host-pathogen interaction between spring wheat and Septoria nodorum with reference to resistance breeding

1985 ◽  
Vol 57 (1) ◽  
pp. 1-66
Author(s):  
Reijo Karjalainen
Keyword(s):  
Grain Yield ◽  
Spring Wheat ◽  
Wheat Breeding ◽  
Grain Weight ◽  
Septoria Nodorum ◽  
Spore Concentration ◽  
Screening Techniques ◽  
Host Pathogen Interaction ◽  
Host Pathogen ◽  
1000 Grain Weight

Host-pathogen interaction between spring wheat and Septoria nodorum Berk. with applications for wheat breeding were studied. Ultrastructure of interactions was studied using electron microscopic techniques. Following inoculation, conidia of S. nodorum germinate, form appressoria anda penetration peg which directly penetrates through the cell walls. It is suggested that most penetration attempts fail because of cellular defence reactions, formation of papillae and cell wall alterations. Inoculation with low spore concentration reduced grain yield of Hankkija’s Taava cultivar by 10 % and 1000-grain weight by 14 %. Inoculation with high spore concentration on large plots of Tähti cultivar reduced grain yield by 32 % and 1000-grain weight by 18 %. Inoculation with high spore concentration on normal breeding plots of Tähti cultivar reduced grain yield by 35 % and 1000-grain weight by 21 % and the grain yield of Kadett cultivar by 27 % and 1000-grain weight by 20 %. Inheritance studies on F2 progenies of spring wheat crosses involving susceptible and moderately or highly resistant parents suggest that heredity component of symptom expression is moderate level and breeding success depends mainly on efficient screening techniques. Resistance was associated with tallness in crosses, and cultivar trials suggest that resistance is positively associated with late maturation time. Field screening techniques based on small plots and artificial inoculation showed that the most resistant entries were wild Triticum species and late and tall cultivars. Seedling plant tests based on attached seedling leaves and detached leaves revealed easily the most resistant and most susceptible cultivars. The overall correlation between seedling tests and field tests was quite high. The results are discussed in relation to wheat breeding strategies for resistance to S. nodorum.

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