Responses to phosphorus among wheat genotypes

2015 ◽  
Vol 66 (5) ◽  
pp. 430 ◽  
Author(s):  
Glenn McDonald ◽  
William Bovill ◽  
Julian Taylor ◽  
Robert Wheeler

Phosphorus (P) recovery and P-use efficiency (PUE) by wheat are low, and genetic improvement in PUE is a potential means of improving the effectiveness of P in farming systems. We examined variation in response to P in wheat to identify genotypes that showed consistent responsiveness to P fertiliser in the field and which may be the target of future studies, and examined differences in P uptake and partitioning. The response to P was studied among a diverse set of bread wheat germplasm at three sites in South Australia between 2009 and 2012. Up to 53 varieties and breeding lines were grown at two rates of P, 0 kg/ha and 30 kg/ha. Grain yield at 0 kg P/ha and response to P varied independently among genotypes. There were large effects of site and season on the response to P, but some genotypes showed consistently low and others high response to P. Analysis of a subset of lines revealed large responses in vegetative growth to P but the response diminished as crops matured, and variation in early vegetative growth was unrelated to the responses in biomass at maturity or grain yield. Genotypic variation in grain yield was more strongly related to variation in P utilisation efficiency than to variation in P uptake among wheat genotypes, which was associated with differences in P harvest index (PHI). Although breeding has improved yield, there has been no significant genetic gain in total P uptake; rather, improvements in PUE have been associated with an increase in P utilisation efficiency and PHI.

2018 ◽  
Vol 69 (6) ◽  
pp. 574
Author(s):  
G. K. McDonald ◽  
J. D. Taylor ◽  
X. Gong ◽  
W. Bovill

Genetic improvement in phosphorus (P) use efficiency (i.e. the ratio of biomass or yield at nil P to that at a given rate of application) is an important goal to improve P recovery and P efficiency of farming systems. Experiments were conducted at three sites in South Australia between 2009 and 2011 to characterise genetic variation in yield with no applied P and in the response to P fertiliser among a diverse range of barley (Hordeum vulgare L.) genotypes. In each experiment, 39–54 genotypes were grown at 0 or 30 kg P/ha. Responses to P were measured near the beginning of stem elongation by using normalised difference vegetation index (NDVI) and by harvesting the grain. Rhizosheath size was also measured on seedlings. Consistent differences in growth and yield at 0 kg P/ha were measured among the genotypes. By contrast, there were large environmental effects on responses to P, but some genotypes showed consistent responses. Measurements of growth, yield and P uptake on a subset of genotypes showed that most of the variation in biomass and yield could be attributed to variation in P-uptake efficiency (net total P uptake per unit available P) rather than to P-utilisation efficiency (biomass or yield per unit total P uptake). The size of the rhizosheath made a small contribution to variation in NDVI but not grain yield, suggesting that rhizosheath size may be of some benefit to early growth but that this does not persist through to yield. Genetic correlations between NDVI and yield were often weak but were generally positive at 0 kg P/ha. Correlations between responses in NDVI and responses in grain yield were low and often negative. The study identified several barley genotypes that showed consistent differences in yield at low P and responses to P; however, selection for P efficiency based solely on responses in vegetative growth may not be appropriate. Variation in P uptake appeared to be more important than P-utilisation efficiency for P efficiency in barley.


2008 ◽  
Vol 59 (2) ◽  
pp. 167 ◽  
Author(s):  
Tatjana Balint ◽  
Zdenko Rengel ◽  
David Allen

Eighty-four canola genotypes, including current commercial Australian genotypes, some older Australian genotypes, new breeding lines, and several genotypes from China, were screened for nitrogen and sulfur efficiency in the early growth stage. Plants were grown in a glasshouse using virgin brown Lancelin soil (Uc4.22) supplied with basal nutrients. The treatments were: (i) adequate nitrogen and sulfur, (ii) low nitrogen, and (iii) low sulfur. Canola shoots were harvested at 38 days after sowing when growth reduction and the nitrogen and sulfur deficiency symptoms were evident in most genotypes. The nitrogen or sulfur efficiency in canola genotypes was evaluated on the basis of: (1) growth at low nitrogen or sulfur supply, (2) growth at low relative to adequate nitrogen and sulfur supply, and (3) nitrogen or sulfur utilisation efficiency expressed as shoot dry weight per unit of nitrogen or sulfur content in shoots. Genotypic variation in growth and nitrogen or sulfur efficiency in canola germplasm was significant. Two genotypes (Chikuzen and 46C74) were ranked efficient and 2 inefficient (CBWA-005 and Beacon) in uptake and utilisation of nitrogen under all 3 criteria. In terms of sulfur efficiency, genotype Argentina was ranked efficient, whereas CBWA-003 and IB 1363 were classified inefficient under all 3 criteria. Two canola genotypes (Surpass 600 and 46C74) were both nitrogen- and sulfur-efficient in terms of relative growth at low v. adequate nutrition; their use in the breeding programs could be considered.


2010 ◽  
Vol 61 (11) ◽  
pp. 892 ◽  
Author(s):  
S. G. L. Kleemann ◽  
G. S. Gill

A 3-year field study was undertaken to investigate the effect of row spacing on vegetative growth, grain yield and water-use efficiency of wheat. All 3 years of the study experienced 21–51% below-average rainfall for the growing season. Widening row spacing led to reduced biomass and tillers on per plant basis which could be related to the reduction in light interception by the wheat canopy in the wide rows which in turn could have reduced assimilate production. Reduction in vegetative growth in 54-cm rows translated into a significant reduction in grain yield which was strongly associated (r2 = 0.71) with the loss of spike density. The pattern of crop water use (evapotranspiration, ET) during the growing season was very similar for the three row-spacing treatments. However, there was some evidence for slightly lower ET (~5%) in 54-cm rows in two growing seasons. More importantly, there was no evidence for increased ET during the post-anthesis phase in wide rows as has been speculated by some researchers. Over the 3 years of the study, grain yield declined by 5–8% as row spacing increased from 18 to 36 cm and by a further 12–20% as row spacing increased from 36 to 54 cm. There was a consistent decline in water-use efficiency for grain (WUEG) with increasing row spacing over the 3 years. WUEG declined by 6–11% as crop spacing increased from 18 to 36 cm and declined further by 12–15% as row spacing increased to 54 cm. Lower light interception at wider row spacing could have reduced assimilate production by wheat as well as increased soil evaporation due to lower shading of the soil surface in more open canopies. Growers adopting wider row spacing on these relatively heavy textured soils are likely to experience some reduction in grain yield and WUEG. However, some growers may be prepared to accept a small yield penalty from intermediate row spacing as a trade-off for increased stubble retention and soil health.


2003 ◽  
Vol 54 (5) ◽  
pp. 445 ◽  
Author(s):  
C. Tang ◽  
M. Nuruzzaman ◽  
Z. Rengel

A soil-based screening method was used to test tolerance of wheat genotypes to acidity. Plants were grown for 6 days in an acid soil with the pH adjusted to 3.9–5.8. The number and length of roots were measured. To validate the method, 12 wheat cultivars of known acidity tolerance and one acid-sensitive barley cultivar were grown on an acid soil in the field with or without amelioration of subsoil acidity. The relative yields of these wheat genotypes on the soil with subsoil acidity ranged from 50 to 89% of yields on soil without subsoil acidity, and were correlated with root growth parameters obtained in the glasshouse. The best correlation was obtained between relative yields in the field (y) and root length per plant (x) at pH 3.9 in the glasshouse (y = –43 + 52*log x, r = 0.95) or root length per plant at pH 3.9 as a percentage of root length at pH 4.8 (y = 1.2 + 46*log x, r = 0.94). Following validation of the glasshouse screening method in the field, 115 wheat genotypes, including cultivars and breeding lines, were screened in the glasshouse. A substantial genotypic variation in acidity tolerance was found, with root length per plant at pH 3.9 ranging from 66 to > 350 mm. Many Western Australian breeding lines displayed better tolerance than existing tolerant wheat cultivars. The screening system can be instrumental in breeding wheat for increased tolerance to acid soils.


2014 ◽  
Vol 41 (6) ◽  
pp. 568 ◽  
Author(s):  
Eisrat Jahan ◽  
Jeffrey S. Amthor ◽  
Graham D. Farquhar ◽  
Richard Trethowan ◽  
Margaret M. Barbour

CO2 diffusion from substomatal intercellular cavities to sites of carboxylation in chloroplasts (mesophyll conductance; gm) limits photosynthetic rate and influences leaf intrinsic water-use efficiency (A/gsw). We investigated genotypic variability of gm and effects of gm on A/gsw among eleven wheat (Triticum aestivum L.) genotypes under light-saturated conditions and at either 2 or 21% O2. Significant variation in gm and A/gsw was found between genotypes at both O2 concentrations, but there was no significant effect of O2 concentration on gm. Further, gm was correlated with photosynthetic rate among the 11 genotypes, but was unrelated to stomatal conductance. The effect of leaf age differed between genotypes, with gm being lower in older leaves for one genotype but not another. This study demonstrates a high level of variation in gm between wheat genotypes; 0.5 to 1.0 μmol m−2 s−1 bar−1. Further, leaf age effects indicate that great care must be taken to choose suitable leaves in studies of genotypic variation in gm and water-use efficiency.


2011 ◽  
Vol 91 (4) ◽  
pp. 663-667 ◽  
Author(s):  
Anne Kirk ◽  
Martin Entz ◽  
Stephen Fox ◽  
Mario Tenuta

Kirk, A. P., Entz, M. H., Fox, S. L. and Tenuta, M. 2011. Mycorrhizal colonization, P uptake and yield of older and modern wheats under organic management. Can. J. Plant Sci. 91: 663–667. Arbuscular mycorrhizal fungi (AMF) are important for plant nutrient uptake, and mycorrhizal dependence varies between wheat genotypes. Cultivar selection under fertilized conditions may have reduced mycorrhizal associations in modern cultivars. This study investigated AMF colonization, tissue P and grain yield of five modern (post 1990) and five older (pre 1970) spring wheat cultivars over 4 site-years in Manitoba. Older cultivars actually had significantly lower AMF colonization and grain yield than modern cultivars, but no tissue P concentration differences were observed. The two highest yielding lines were released after 2004, and one of these (FBC Dylan) was selected for suitability in organic farming systems.


2017 ◽  
Vol 155 (9) ◽  
pp. 1407-1423 ◽  
Author(s):  
E. MANSOUR ◽  
A. M. A. MERWAD ◽  
M. A. T. YASIN ◽  
M. I. E. ABDUL-HAMID ◽  
E. E. A. EL-SOBKY ◽  
...  

SUMMARYAgricultural practices are likely to lower nitrogen (N) fertilization inputs for economic and ecological limitation reasons. The objective of the current study was to assess genotypic variation in nitrogen use efficiency (NUE) and related parameters of spring wheat (Triticum aestivumL.) as well as the relative grain yield performance under sandy soil conditions. A sub-set of 16 spring wheat genotypes was studied over 2 years at five N levels (0, 70, 140, 210 and 280 kg N/ha). Results indicated significant differences among genotypes and N levels for grain yield and yield components as well as NUE. Genotypes with high NUE exhibited higher plant biomass, grain and straw N concentration and grain yield than those with medium and low NUE. Utilization efficiency (grain-NUtE) was more important than uptake efficiency (total NUpE) in association with grain yield. Nitrogen supply was found to have a substantial effect on genotype; Line 6052 as well as Shandawel 1, Gemmiza 10, Gemmiza 12, Line 6078 and Line 6083 showed higher net assimilation rate, more productive tillers, increased number of spikes per unit area and grains per spike, extensive N concentration in grain and straw, heavier grains, higher biological yield and consequently maximized grain yield. The relative importance of NUE-associated parameters such as nitrogen agronomic efficiency, nitrogen physiological efficiency and apparent nitrogen recovery as potential targets in breeding programmes for increased NUE genotypes is also mentioned.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1295 ◽  
Author(s):  
Diego Rubiales ◽  
Amero A. Emeran ◽  
Fernando Flores

Grass pea (Lathyrus sativus) is an annual legume crop widely cultivated in South Asia and Sub-Saharan Africa, but in regression in Mediterranean region. Its rusticity and nutritious value is calling back attention for its reintroduction into Mediterranean rain-fed farming systems. We studied the adaptation of a range of breeding lines in multi-environment field testing in Spain and Egypt, showing wide variation for grain yield. Broomrape (Orobanche crenata) infection appeared as the major limiting factor in both countries. Level of broomrape infection was highly influenced by environmental conditions, being favored by moderate temperatures at crop flowering and rain and humidity after flowering. The additive main effects and multiplicative interaction (AMMI) analysis was applied to understand the interaction between genotype (G) and environment (E) on grain yield and on broomrape infection. AMMI analyses revealed significant G and E effects as well as G*E interaction with respect to both traits. The AMMI analysis of variance (ANOVA) revealed that both, yield and broomrape infection were dominated by the environment main effect. AMMI1 biplot for grain yield revealed Ls10 and Ls11 as the accession with highest yields, closely followed by Ls16, Ls18 and Ls19. However, these accessions showed also lower stability, being particularly adapted to Delta Nile conditions. On the contrary, accessions Ls12 and Ls14 were more adapted to rain fed Spanish conditions. Accessions Ls7, Ls1 and Ls3 were the most stable over environments for grain yield.


2011 ◽  
Vol 62 (1) ◽  
pp. 58 ◽  
Author(s):  
T. M. McBeath ◽  
M. J. McLaughlin ◽  
S. R. Noack

It is important to apply phosphorus (P) to the soil at the beginning of the crop growth cycle to provide essential P for early growth and to replace P exported in previous crops. With low rates of P added at sowing there may be sufficient P supply to grow crops to tillering, but in seasons of increased yield potential a top-up application of P may be required. Foliar P can be applied directly to the plant when required and in some cases have been shown to provide benefits for increasing P-use efficiency and the P concentration in grain. Wheat (Triticuum aestivum cv. Frame) was grown in two soils of marginal P status with soil moisture maintained at 80% of field capacity. Seven foliar P treatments labelled with 33P as a tracer were applied at Zadoks growth stage 39, at 1.65 kg P/ha with 120 L water/ha equivalent. Grain, chaff and shoots were harvested to measure yield and then digested to measure P concentrations and 33P activities. There was no crop response to top-up soil or foliar P on one soil, but on the other soil, foliar phosphoric acid plus adjuvant gave a 25% wheat grain yield response. The use of the tracing technique enabled measurement of the portioning of foliar P fertiliser between stem, chaff and grain. The most responsive treatment had the greatest amount of grain P uptake and the greatest partitioning of the foliar P fertiliser to grain.


2011 ◽  
Vol 62 (6) ◽  
pp. 504 ◽  
Author(s):  
R. F. Wang ◽  
D. G. An ◽  
C. S. Hu ◽  
L. H. Li ◽  
Y. M. Zhang ◽  
...  

Wheat (Triticum aestivum L.) cultivars with improved nitrogen-use efficiency (NUE) under low and medium N conditions will help to minimise production costs and nitrate-N contamination. The study was conducted to determine the NUE diversities of winter wheat genotypes, and to evaluate the possible physiological mechanisms contributing to these differences. A set of 12 winter wheat genotypes, including S4185 as control genotype, were grown at high N (applied with 180 kg N/ha as urea) and low N (with no N fertiliser, N-deficient) plots in 2005–06 and 2007–08 growing seasons (i.e. four environments). ANOVA showed significant differences among genotypes for all traits measured. Among genotypes, XJ19-1 had significantly higher NUE and N uptake efficiency (NUpE) than S4185 at the two N levels in the 2 years (P < 0.05). KN9204 had significantly higher NUE in the four environments and higher NUpE in three out of four environments than S4185 (P < 0.05). WR9603 and XJ138-1 had higher NUE and NUpE than S4185 in two or three out of four environments (P < 0.05). XJ19-1, KN9204, WR9603 and XJ138-1 also showed higher grain yield (GY) and aboveground dry matter (DM) than S4185 in at least two environments (P < 0.05). KN9204 were 45.7 and 23.1% higher in root dry weight (RDW) of the top 40-cm soil profile compared with J411 at high N and low N plots, respectively (P < 0.05). In addition, there was a highly positive correlation between RDW and grain N yield (GNY) of KN9204 and J411 (P < 0.01). Closely positive correlation between NUE and GY, DM, GNY and NUpE at both N levels in the 2 years (P < 0.01), and between N utilisation efficiency (NUtE) and NUE only at high N plot (P < 0.05) were found. Our results indicated that NUpE was the important factor of NUE under low N conditions, and both NUpE and NUtE were the most important NUE components under high N conditions.


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