14 research outputs found
Genetic basis for variation in wheat grain yield in response to varying nitrogen application
Nitrogen (N) is a major nutrient needed to attain optimal grain yield (GY) in all environments. Nitrogen fertilisers represent a significant production cost, in both monetary and environmental terms. Developing genotypes capable of taking up N early during development while limiting biomass production after establishment and showing high N-use efficiency (NUE) would be economically beneficial. Genetic variation in NUE has been shown previously. Here we describe the genetic characterisation of NUE and identify genetic loci underlying N response under different N fertiliser regimes in a bread wheat population of doubled-haploid lines derived from a cross between two Australian genotypes (RAC875 Ă Kukri) bred for a similar production environment. NUE field trials were carried out at four sites in South Australia and two in Western Australia across three seasons. There was genotype-by-environment- by-treatment interaction across the sites and also good transgressive segregation for yield under different N supply in the population. We detected some significant Quantitative Trait Loci (QTL) associated with NUE and N response at different rates of N application across the sites and years. It was also possible to identify lines showing positive N response based on the rankings of their Best Linear Unbiased Predictions (BLUPs) within a trial. Dissecting the complexity of the N effect on yield through QTL analysis is a key step towards elucidating the molecular and physiological basis of NUE in wheat.Saba Mahjourimajd, Julian Taylor, Beata Sznajder, Andy Timmins, Fahimeh Shahinnia, Zed Rengel, Hossein Khabaz-Saberi, Haydn Kuchel, Mamoru Okamoto, Peter Langridg
Crop Updates 2005 - Cereals
This session covers thirty six papers from different authors:
WHEAT AGRONOMY
1. Optimum sowing time of new wheat varieties in Western Australia, Darshan Sharma, Brenda Shackley, Mohammad Amjad, Christine M. Zaicou-Kunesch and Wal Anderson, Department of Agriculture
2. Wheat varieties updated in âFlowering Calculatorâ: A model predicting flowering time, B. Shackley, D. Tennant, D. Sharma and C.M. Zaicou-Kunesch, Department of Agriculture
3. Plant populations for wheat varieties, Christine M. Zaicou-Kunesch, Wal Anderson, Darshan Sharma, Brenda Shackley and Mohammad Amjad, Department of Agriculture
4. New wheat cultivars response to fertiliser nitrogen in four major agricultural regions of Western Australia, Mohammad Amjad, Wal Anderson, Brenda Shackley, Darshan Sharma and Christine Zaicou-Kunesch, Department of Agriculture
5. Agronomic package for EGA Eagle Rock, Steve Penny, Department of Agriculture
6. Field evaluation of eastern and western wheats in large-scale farmerâs trials, Mohammad Amjad, Ben Curtis and Veronika Reck, Department of Agriculture
7. New wheat varieties for a changing environment, Richard Richards, CSIRO Plant Industry; Canberra
8. Farmers can profitably minimise exposure to frost! Garren Knell, Steve Curtin and David Sermon, ConsultAg
9. National Variety Trials, Alan Bedggood, Australian Crops Accreditation System; Horsham
10. Preharvest-sprouting tolerance of wheat in the field, T.B. Biddulph1, T.L. Setter2, J.A. Plummer1 and D.J. Mares3; 1Plant Biology; FNAS, University of Western Australia; 2Department of Agriculture, 3School of Agriculture and Wine, University of Adelaide
11. Waterlogging induces high concentration of Mn and Al in wheat genotypes in acidic soils, H. Khabaz-Saberi, T. Setter, I. Waters and G. McDonald, Department of Agriculture
12. Agronomic responses of new wheat varieties in the Northern Agricultural Region, Christine M. Zaicou-Kunesch and Wal Anderson, Department of Agriculture
13. Agronomic responses of new wheat varieties in the Central Agricultural Region of WA, Darshan Sharma, Steve Penny and Wal Anderson, Department of Agriculture
14. EGA Eagle Rock tolerance to metribuzin and its mixtures, Harmohinder Dhammu, David Nicholson and Chris Roberts, Department of Agriculture
15. Herbicide tolerance of new bread wheats, Harmohinder Dhammu1 and David Nicholson2, Department of Agriculture
NUTRITION
16. The impact of fertiliser placement, timing and rates on nitrogen-use efficiency, Stephen Loss, CSBP Ltd
17. Cereals deficient in potassium are most susceptible to some leaf diseases, Ross Brennan and Kith Jayasena, Department of Agriculture
18. Responses of cereal yields to potassium fertiliser type, placement and timing, Eddy Pol, CSBP Limited
19. Sulphate of Potash, the potash of choice at seeding, Simon Teakle, United Farmers Co-operative
20. Essential disease management for successful barley production, K. Jayasena, R. Loughman, C. Beard, B. Paynter, K. Tanaka, G. Poulish and A. Smith, Department of Agriculture
21. Genotypic differences in potassium efficiency of wheat, Paul Damon and Zed Rengel, Faculty of Natural and Agricultural Sciences, University of Western Australia
22. Genotypic differences in potassium efficiency of barley, Paul Damon and Zed Rengel, Faculty of Natural and Agricultural Sciences, University of Western Australia
23. Investigating timing of nitrogen application in wheat, Darshan Sharma and Lionel Martin, Department of Agriculture, and Muresk Institute of Agriculture, Curtin University of Technology
24. Nutrient timing requirements for increased crop yields in the high rainfall cropping zone, Narelle Hill, Ron McTaggart, Dr Wal Anderson and Ray Tugwell, Department of Agriculture
DISEASES
25. Integrate strategies to manage stripe rust risk, Geoff Thomas, Robert Loughman, Ciara Beard, Kith Jayasena and Manisha Shankar, Department of Agriculture
26. Effect of primary inoculum level of stripe rust on variety response in wheat, Manisha Shankar, John Majewski and Robert Loughman, Department of Agriculture
27. Disease resistance update for wheat varieties in WA, M. Shankar, J.M. Majewski, D. Foster, H. Golzar, J. Piotrowski and R. Loughman, Department of Agriculture
28. Big droplets for wheat fungicides, Rob Grima, Agronomist, Elders
29. On farm research to investigate fungicide applications to minimise leaf disease impacts in wheat, Jeff Russell and Angie Roe, Department of Agriculture, and Farm Focus Consultants
PESTS
30. Rotations for nematode management, Vivien A. Vanstone, Sean J. Kelly, Helen F. Hunter and Mena C. Gilchrist, Department of Agriculture
31. Investigation into the adaqyacy of sealed farm silos in Western Australia to control phosphine-resistant Rhyzopertha dominica, C.R. Newman, Department of Agriculture
32.Insect contamination of cereal grain at harvest, Svetlana Micic and Phil Michael, Department of Agriculture
33. Phosure â Extending the life of phosphine, Gabrielle Coupland and Ern Kostas, Co-operative Bulk Handling
SOIL
34. Optimum combinations of ripping depth and tine spacing for increasing wheat yield, Mohammed Hamza and Wal Anderson, Department of Agriculture
35. Hardpan penetration ability of wheat roots, Tina Botwright Acuña and Len Wade, School of Plant Biology, University of Western Australia
MARKETS
36. Latin America: An emerging agricultural powerhouse, Ingrid Richardson, Food and Agribusiness Research, Rabobank; Sydne
Genetic markers for manganese efficiency in durum wheat
Manganese (Mn) deficiency is a major constraint of alkaline soils around the world, particularly for cultivation of durum wheat, which is more intolerant of low Mn levels than either common wheat or barley. Genetic variation for Mn efficiency exists in the current germplasm of durum wheat. Several restriction fragment length polymorphisms (RFLPs) previously shown to be linked to the Mel1 locus for Mn efficiency on chromosome 4HS of barley were tested on 88 selected Fâ plants of the durum cross, âStojocri 2â (Mn efficient) x âHazarâ (Mn inefficient). The Mel1-linked RFLP marker Xcdo583a was closely linked to the trait and explained over 42% of the total variation for Mn efficiency in the âStojocri 2â/âHazarâ Fâ progeny. This marker has the potential to provide a valuable tool for the marker-assisted selection of Mn-efficient durum progeny derived from crosses with `Stojocri 2â.H. Khabaz-Saberi, R. D. Graham, M. A. Pallotta, A. J. Rathjen and K. J. William
Quantification of the confounding effect of seed manganese content in screening for manganese efficiency in durum wheat (Triticum turgidum L. var. durum)
Whether due to the genotype or the environment of the mother plant, the nutrient content of seeds vary over a wide range; the amount of the nutrient contributes greatly to seedling vigor, especially on deficient soils and may result in major differences in grain yield. This effect has important implications for breeding programs. This paper examines the impact of seed manganese (Mn) on screening of durum wheats for tolerance to Mn-deficient soils. Seed stocks with a range of Mn contents (0.4-2.4 ÎŒg seedâ»Âč) were produced, and the effect on expression of Mn efficiency measured as either relative yield or shoot Mn content for two durum wheat (Triticum turgidum L. var. durum) genotypes differing in Mn efficiency. Both genotypes responded to seed Mn content in terms of enhanced root and shoot growth; there was no genotype by seed Mn interaction, so Mn provided in seed was utilized additively by both Mn-efficient and Mn-inefficient genotypes. Manganese efficiency, measured as relative yield, was a function of seed Mn content and varied from 40 to 70% in Hazar and 58 to 90% in Stojocri 2, in the same assay using seed of variable Mn content. From the response curves of yield vs. soil Mn added, the Mn required for 90% relative yield was determined for each level of seed Mn content. Seed Mn was regressed against the soil added Mn needed to obtain 90% of maximal growth at each level of seed Mn content (a total of 8 levels) for each of two genotypes. There was an inverse linear relationship between the amount of soil Mn and seed Mn needed for each genotype. Using the Mn-efficient genotype with high seed Mn content, the soil Mn needed to obtain 90% growth was nil, while inefficient genotypes with low Mn content required 75 mg Mn kgâ»Âč soil to produce the same relative yield. This relationship can be used to adjust the levels of soil applied Mn to be used in a pot bioassay when seeds have a certain Mn content, so as to maintain the screening at an optimal overall level of Mn stress.H. KhabazâSaberi, R.D. Graham, J.S. Ascher & A.J. Rathje
Review of wheat improvement for waterlogging tolerance in Australia and India: The importance of anaerobiosis and element/microelement toxicities associated with different soils
No abstract availabl
Review of wheat improvement for waterlogging tolerance in Australia and India: the importance of anaerobiosis and element toxicities associated with different soils
Background and Aims The lack of knowledge about key traits in field environments is a major constraint to germplasm improvement and crop management because waterlogging-prone environments are highly diverse and complex, and the mechanisms of tolerance to waterlogging include a large range of traits. A model is proposed that waterlogging tolerance is a product of tolerance to anaerobiosis and high microelement concentrations. This is further evaluated with the aim of prioritizing traits required for waterlogging tolerance of wheat in the field.
Methods Waterlogging tolerance mechanisms of wheat are evaluated in a range of diverse environments through a review of past research in Australia and India; this includes selected soils and plant data, including plant growth under waterlogged and drained conditions in different environments. Measurements focus on changes in redox potential and concentrations of diverse elements in soils and plants during waterlogging.
Key Results (a) Waterlogging tolerance of wheat in one location often does not relate to another, and (b) element toxicities are often a major constraint in waterlogged environments. Important element toxicities in different soils during waterlogging include Mn, Fe, Na, Al and B. This is the first time that Al and B toxicities have been indicated for wheat in waterlogged soils in India. These results support and extend the well-known interactions of salinity/Na and waterlogging/hypoxia tolerance.
Conclusions Diverse element toxicities (or deficiencies) that are exacerbated during waterlogging are proposed as a major reason why waterlogging tolerance at one site is often not replicated at another. Recommendations for germplasm improvement for waterlogging tolerance include use of inductively coupled plasma analyses of soils and plants