Agronomy and Crop Sciences Commons^™

Advances In Breeding Apomictic Brachiaria In Tropical America, J W. Miles, C B. Do Valle

IGC Proceedings (1997-2023)

Prior to 1988 Brachiaria improvement was based exclusively on the collection, introduction, and evaluation of natural germplasm from Africa. Breeding programs in Brachiaria have been possible only in the past 10 years with the creation of a sexual, tetraploid B. ruziziensis cross-compatible with B. decumbens and B. brizantha. Applied Brachiaria breeding projects are underway both in Colombia (International Center for Tropical Agriculture, CIAT) and Brazil (National Centre for Beef Cattle Research - Brazilian Corporation for Agricultural Research, CNPGC/EMBRAPA). These seek to combine the broad edaphic adaptation and other desirable agronomic attributes of B. decumbens cv. Basilisk with spittlebug resistance. An …

Assessment Of Grazing Procedures In The Evaluation Of Plant Breeding Material, D Real, I L. Gordon, J Hodgson

IGC Proceedings (1997-2023)

Four stocking densities (2, 3, 5 and 9 sheep/18 m2 for one hour) and two times of grazing (morning or evening) were imposed on a spaced plant nursery of nine red clover (Trifolium pratense L.) populations of varying growth habit, in order to optimize measurement of sheep grazing preference. Plant height, spread and leafiness were measured before and after each of three grazings. Sheep preference was viewed multivariately, using combined measurements of these plant characteristics. MANOVA revealed that the effect of stocking density was significant (P-0.05), but that of time of grazing was not. The plant, population and overall …

Fitness Of Apomictic And Sexual Buffelgrass Germplasm, M A. Hussey, Yue-Wen Wang, B L. Burson

IGC Proceedings (1997-2023)

Breeding apomictic grasses is based on either the direct selection of apomictic landraces or the hybridization of sexual and apomictic types and selection of apomictic F1 hybrids. Little is known about the potential of sexual hybrids as cultivars in apomictic species. To determine if method of reproduction (MOR) was related to plant vigor, parental, S1, and F1 hybrids of buffelgrass differing in method of reproduction (apomictic or sexual) were established in a common garden in 1994 and 1995. In both years severe inbreeding depression was observed in the S1 progeny as they were shorter, produced less biomass, and had low …

Differential Energy Allocation Among 15 New Guineagrass (Panicum Maximum Jacq.) Hybrids, J A. Usberti Jr, R Usberti, R S. Paterniani

IGC Proceedings (1997-2023)

The main aim of this research work was to determine trends of energy allocation among newly developed guineagrass (Panicum maximum Jacq) hybrids, ranging from very-early to late-flowering genotypes. Besides the flowering cycle, eight phenological and two seed quality traits were scored in a greenhouse randomized complete block experiment including plant height (PH), reproductive tiller number/overall tiller number (RTN/OTN), panicle number/reproductive tiller (PN/RT), leaf length (LL), leaf width (LW), panicle length (PL), fresh weight (FW), dry weight (DW), number of seeds/gram (NS/G) and seed sample physical purity (SPP). Very-early and early-flowering hybrids consistently showed the highest correlations values between flowering …

Breeding Reed Canarygrass As An Energy Or Fibre Crop By Using Local Collected Wild Populations, E Lindvall

IGC Proceedings (1997-2023)

Reed canarygrass (Phalaris arundinacea L.) has become interesting as an industrial crop in Sweden. The grass can be used as biofuel or fibre raw material for pulp production. New varieties have to be developed, with a quality different from forage varieties. High stem/ leaf-ratio, low content of ash and elements like silica, potassium and chlorine are important breeding goals. A Swedish project, aiming to evaluate local reed canarygrass populations, shows that there is some variation in these morphological and chemical characters which can be utilised in a breeding program.

Research Programme To Improve The Utilization Of Home-Grown Forages In The Netherlands, A.M. Van Vuuren, A H. Bosma, G J. Kaspers, J.J. M.H. Ketelaars, E.N. Van Loo, H J.P. Marvin, H Valk, G.W.J. Van De Ven

IGC Proceedings (1997-2023)

In The Netherlands a research programme has been initiated by the Ministry of Agriculture, Nature Management and Fisheries to increase the proportion of high-quality home-grown forage in rations for dairy cows. This should result in a more sustainable dairy husbandry by improving the efficiency of utilization of nitrogen and phosphorus from home-grown forages (mainly grass and maize) on farm level. Research disciplines involved are plant breeding, forage harvesting and conservation and nutrition.

Prospects For Improving Alfalfa Yield Using Genomic- And Phenomic-Based Breeding, M. W. Francis, D. Pap, A. Krill-Brown, E. C. Brummer

IGC Proceedings (1997-2023)

Alfalfa (Medicago sativa L.) is a perennial outcrossing legume that is cultivated as an important forage crop in many parts of the world. Yield is the most important trait for profitable alfalfa production, yet over the last 30 years yield improvement in California has stagnated. Current breeding methods focus on recurrent phenotypic selection; however, alternatives incorporating genomic- and phenomic-based information may enhance genetic gain and help to address the lack of yield improvement. Here we attempt to increase the yield potential of alfalfa using genomic selection (GS) in combination with high throughput phenotyping (HTP). A total of 193 families …

Annual Clovers Around The World: Current Status And Future Prospects, P. G. H. Nichols, G. R. Smith, D. J. Moot, Serkan Ates, Claudio Porqueddu, Esteban F. Rios, Mounir Louhaichi, Alejandro Del Pozo, N. Kotze, Alan W. Humphries, K. Ghamkhar, M. H. Ryan

IGC Proceedings (1997-2023)

This paper reviews the distribution and importance of annual clover (Trifolium) species for pasture and fodder production systems globally. Of the 158 recorded annual Trifolium species, 65.2% are endemic to the Mediterranean basin and surrounding areas, 14.6% to sub-Saharan Africa, 17.7% to the United States of America and 2.5% to Chile. Fourteen species have been commercialised, while other endemic and naturalised annual clovers are also utilised. Key species for self-regenerating pastures include T. subterraneum, T. michelianum and T. respinatum var. resupinatum, while major dual-purpose grazing and fodder species include T. incarnatum, T. vesiculosum, T. alexandrinum and T. …

New Zealand Pastoral Systems: A Current Perspective, F. R. Duder, R. B. Green, W. D. Catto, D. R. Woodfield, B. R. Guy

IGC Proceedings (1997-2023)

New Zealand's diverse grassland resource of 13.5 M ha of permanent pasture, tussock or alpine grasslands underpin an intensive pastoral industry worth NZ$13 billion in 2004. The pastoral industry involves 37,000 farmers and a service industry of about 215,000 persons. It produces 27 M prime export lambs and 180,000 t of predominantly crossbred wool from 40 M ewes; 13 B litres of milk from 5.2 M dairy cattle; 800,000 t of beef from 4.7 M beef cattle and 33,000 t of venison from 2 M deer. Pastures and forage crops, mostly non- irrigated, are grazed 'in situ' by animals through …

Selection For Tillering In Lolium Multiflorum L. In Texas Usa, L. R. Nelson, G. W. Evers, M. J. Parsons

IGC Proceedings (1997-2023)

Annual ryegrass is an important cool season forage in Texas and across the southern USA with approximately 2 million ha planted annually. Early tillering will enhance the leaf area index and the amount of photosynthesis which will improve seedling vigor and early forage production. The objective of this study was to determine if it was possible to select for early tiller (shoot) production in a diploid and tetraploid annual ryegrass breeding population. We expect early tiller production would be correlated with improved early season forage production with annual ryegrass.

Critical Analysis Of Tropical Forage Breeding In Brazil, J. A. Usberti Jr., P. B. Alcantara

IGC Proceedings (1997-2023)

Forage grasses account for 90% of the Brazilian forage seed market while the genera Brachiaria, Panicum and others are responsible for 85, 10 and 5% of the traded grass seeds, respectively. Most of the forage grass and legume cultivars available for sowing in Brazil were selected in germplasm banks during the last 20 years, while few of them were derived from artificial crossings, followed by selection for desirable forage traits. The selection of new genetic materials in germplasm banks (exploitation of naturally-occurring genetic variability) is still feasible but the chances of success are decreasing through time. From now on, …

Genomic Selection For Yield And Seed Composition Stability In An Applied Soybean Breeding Program, Benjamin Harms

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Stability traits are of primary importance in plant breeding to ensure consistency in phenotype across a range of environments. However, selection efficiency and accuracy for stability traits can be hindered due to the requirement of obtaining phenotype data across multiple years and environments for proper stability analysis. Genomic selection is a method that allows prediction of a phenotype prior to observation in the field using genome-wide marker data and phenotype data from a training population. To assess prediction of stability traits, two elite-yielding soybean populations developed three years apart in the same breeding program were used. The individuals in each …

Concurrent Selection For Low Coumarin And Multi-Stemmed Crowns In Annual Sweetclover, Gerald R. Smith, G. W. Evers

IGC Proceedings (1997-2023)

Annual sweetclover (Melilotus alba Desr) is a reseeding, drought tolerant forage legume that is well adapted to the alkaline and neutral soils of the US Southern Great Plains. Coumarin is a phytochemical found in sweetclover that is a precursor to dicoumarol, which causes a toxic bleeding disease in cattle. The inheritance of low coumarin in sweetclover is determined by a single gene (Goplen et al., 1957), but current low coumarin cultivars are all biennial, northern types. The ability of annual sweetclover to develop a multi-stemmed crown, similar to alfalfa (Medicago sativa L.), is also under genetic control …

Aluminum Tolerance In The Model Legume Medicago Truncatula, M. K. Sledge, B. Narasimhamoorthy, P. Pechter, J. H. Bouton

IGC Proceedings (1997-2023)

Aluminum (Al) is the most abundant metal found in the earth's crust, comprising up to 7% of its mass. At low pH, Al becomes soluble and available to plants, resulting in inhibition of root elongation and reduced plant growth. Aluminum toxicity associated with acid soils has been a major obstacle in alfalfa (Medicago sativa) production. The objective of this study is to identify genes that are differentially expressed under normal and Al stress conditions in the model legume M. truncatula, with the long term goal of using these genes to improve cultivated alfalfa.

Leaves Of High Yielding Perennial Ryegrass Contain Less Aggregated Rubisco Than S23, A. Kingston-Smith, P. W. Wilkins

IGC Proceedings (1997-2023)

Breeding diploid perennial ryegrass for improved dry matter yield under nitrogen-limiting conditions has reduced the nitrogen (N) concentration of the herbage (Wilkins et al., 2003). Reduced N concentration in the ruminant diet is one potential way to reduce losses of N to the environment by reducing the amount of N that animals excrete. The underlying physiological basis of this increased N-use efficiency in ryegrass was investigated.

Morphological Characteristic To Discriminate Festulolium Hybrids (Festuca Pratensis × Lolium Perenne), Mariusz Kulik, Z. Zwierzykowski, W. Jokś

IGC Proceedings (1997-2023)

Environmental change and uncertainty is likely to pose new challenges in plant breeders. Recently attention has focused on the crossing of Lolium and Festuca species to obtain hybrids exhibiting many desirable traits of both parents. Key objectives of such programs are to combine the persistency, winter hardiness and drought tolerance of fescues with the high herbage yields and quality of ryegrasses (Zwierzykowski, Naganowska, 1994). One of the hybrids with great practical significance is a F. pratensis × L. perenne hybrid [Festulolium loliaceum (Huds.) P.V. Fourn]. Many morphological traits of Festulolium hybrids demonstrate intermediate character, however, in relation to inflorescence …

Variability In Quantity And Composition Of Water Soluble Carbohydrates Among Irish Accessions And European Varieties Of Perennial Ryegrass, S. Mcgrath, S. Barth, A. Frohlich, M. Francioso, S. A. Lamorte, T. R. Hodkinson

IGC Proceedings (1997-2023)

The objective of this study was to identify perennial ryegrass accessions displaying high fructose and glucose contents and an improved ratio between fructose and glucose fractions across different time points throughout the year. Fructose and glucose are the main constituents of the water soluble carbohydrate (WSC) fraction in perennial ryegrass. For animal nutrition the amount of WSC is crucial as it is the primary energy source available to metabolise the intake of plant protein. The ratio between fructose and glucose fractions is important since fructosan chains, which are an excellent energy source for ruminants, are built from fructose. Furthermore the …

Breeding Of Cms-F1-Hybrids In Lolium Perenne With Improved Nitrogen Use Efficiency, W. Luesink, B. Ingwersen, L. Wolters, J. De Riek

IGC Proceedings (1997-2023)

The environmental pollution by nitrogen losses from dairy farms can be reduced by improving the nitrogen use efficiency (NUE) of grass varieties. The main goal is to develop varieties with a better nitrogen utilisation. These low input varieties can produce acceptable yields at a low level of N-fertilisation. High input varieties express their high yield potential only at high N-supply. These varieties are less preferable, because N- losses increase at higher levels of nitrogen application. The breeding of CMS-F1-Hybrids can be a successful strategy for developing varieties with a higher NUE. In F1-Hybrid varieties higher heterosis effects can be achieved …

Application Of Molecular Technologies In Forage Plant Breeding, K. F. Smith, J. W. Forster, M. P. Dobrowolski, N. O. I. Cogan, N. R. Bannan, E. Van Zijll De Jong, M Emmerling, G. C. Spangenberg

IGC Proceedings (1997-2023)

Key points

1. A range of molecular breeding technologies have been developed for forage plant species including both transgenic and non-transgenic methodologies.
2. The application of these technologies has the potential to greatly increase the range of genetic variation that is available for incorporation into breeding programs and subsequent delivery to producers in the form of improved germplasm.
3. Further developments in detailing the phenotypic effect of genes and alleles both through research in target species and through inference from results from model species will further refine the delivery of new forage cultivars.

Leaves Of High Yielding Perennial Ryegrass Contain Less Aggregated Rubisco Than S23, A. Kingston-Smith, P. W. Wilkins

IGC Proceedings (1997-2023)

Breeding diploid perennial ryegrass for improved dry matter yield under nitrogen-limiting conditions has reduced the nitrogen (N) concentration of the herbage (Wilkins et al., 2003). Reduced N concentration in the ruminant diet is one potential way to reduce losses of N to the environment by reducing the amount of N that animals excrete. The underlying physiological basis of this increased N-use efficiency in ryegrass was investigated.

Variability In Quantity And Composition Of Water Soluble Carbohydrates Among Irish Accessions And European Varieties Of Perennial Ryegrass, S. Mcgrath, S. Barth, A. Frohlich, M. Francioso, S. A. Lamorte, T. R. Hodkinson

IGC Proceedings (1997-2023)

The objective of this study was to identify perennial ryegrass accessions displaying high fructose and glucose contents and an improved ratio between fructose and glucose fractions across different time points throughout the year. Fructose and glucose are the main constituents of the water soluble carbohydrate (WSC) fraction in perennial ryegrass. For animal nutrition the amount of WSC is crucial as it is the primary energy source available to metabolise the intake of plant protein. The ratio between fructose and glucose fractions is important since fructosan chains, which are an excellent energy source for ruminants, are built from fructose. Furthermore the …

Soybean Response To Water: Trait Identification And Prediction, Shawn Jenkins

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The rising demand for soybean [Glycine Max (L.) Merrill] taken in consideration with current climatic trends accentuates the importance of improving soybean seed yield response per unit water (WP). To further our understanding of the quantitative WP trait, a multi-omic approach was implemented for improved trait identification and predictive modeling opportunities. Through the evaluation of two recombinant inbred line populations jointly totaling 439 lines subjected to contrasting irrigation treatments, informative agronomic, phenomic, and genomic associations were identified. Across both populations, relationships were identified between lodging at maturity (r = -0.58, H = 0.86), canopy to air temperature differential …

Wheat Height Estimation Using Lidar In Comparison To Ultrasonic Sensor And Uas, Wenan Yuan, Jiating Li, Madhav Bhatta, Yeyin Shi, P. Stephen Baenziger, Yufeng Ge

Department of Agronomy and Horticulture: Faculty Publications

As one of the key crop traits, plant height is traditionally evaluated manually, which can be slow, laborious and prone to error. Rapid development of remote and proximal sensing technologies in recent years allows plant height to be estimated in more objective and efficient fashions, while research regarding direct comparisons between different height measurement methods seems to be lagging. In this study, a ground-based multi-sensor phenotyping system equipped with ultrasonic sensors and light detection and ranging (LiDAR) was developed. Canopy heights of 100 wheat plots were estimated five times during a season by the ground phenotyping system and an unmanned …

Selection For Silage Yield And Composition Did Not Affect Genomic Diversity Within The Wisconsin Quality Synthetic Maize Population, Aaron Lorenz, Timothy M. Beissinger, Renato Rodrigues Silva, Natalia De Leon

Department of Agronomy and Horticulture: Faculty Publications

Maize silage is forage of high quality and yield, and represents the second most important use of maize in the United States. The Wisconsin Quality Synthetic (WQS) maize population has undergone five cycles of recurrent selection for silage yield and composition, resulting in a genetically improved population. The application of high-density molecular markers allows breeders and geneticists to identify important loci through association analysis and selection mapping, as well as to monitor changes in the distribution of genetic diversity across the genome. The objectives of this study were to identify loci controlling variation for maize silage traits through association analysis …

Resource Allocation For Maximizing Prediction Accuracy And Genetic Gain Of Genomic Selection In Plant Breeding: A Simulation Experiment, Aaron Lorenz

Department of Agronomy and Horticulture: Faculty Publications

Allocating resources between population size and replication affects both genetic gain through phenotypic selection and quantitative trait loci detection power and effect estimation accuracy for marker-assisted selection (MAS). It is well known that because alleles are replicated across individuals in quantitative trait loci mapping and MAS, more resources should be allocated to increasing population size compared with phenotypic selection. Genomic selection is a form of MAS using all marker information simultaneously to predict individual genetic values for complex traits and has widely been found superior to MAS. No studies have explicitly investigated how resource allocation decisions affect success of genomic …

Crop Updates 2003 - Cereals, Graham Crosbie, Robert Loughman, Collin Wellings, Greg Shea, Simon Mckirdy, Neil C. Turner, Brenda Shackley, Wal Anderson, Darshan Sharma, Mohammad Amjad, Steve Penny Jr, Melanie Kupsch, Anne Smith, Veronika Reck, Pam Burgess, Glenda Smith, Elizabeth Tierney, Peter Burges, Moin Salam, Megan Collins, Art Diggle, Blakely Paynter, Roslyn Jetter, Kevin Young, Jocelyn Ball, Natasha Littlewood, Lucy Anderton, Irene Waters, Tim Setter, Jeff Russell, Reg Lance, Chengdao Li, Sue Broughton, Michael Jones, Grace Zawko, Keith Gregg, Stephen Loss, Frank Ripper, Ryan Guthrie, Daniel Bell, Patrick Gethin, Narelle Hill, Laurence Caeslake, Vivien Vanstone, Sean Kelly, Helen Hunter, Christopher R. Newman

Crop Updates

This session covers twenty one papers from different authors:

PLENARY

1. Recognising and responding to new market opportunities in the grains industry, Graham Crosbie, Manager, Grain Products Research, Crop Breeding, Plant Industries, Department of Agriculture

2. Stripe rust – where to now for the WA wheat industry? Robert Loughman¹, Colin Wellings² and Greg Shea¹¹Department of Agriculture, ²University of Sydney Plant Breeding Institute, Cobbitty (on secondment from NSW Agriculture)

3. Benefits of a Grains Biosecurity Plan, Dr Simon McKirdy, Plant Health Australia, Mr Greg Shea, Department of Agriculture

4. Can we improve …

Canola : Golden Oil For Farmers And Consumers, Paul Carmody

Journal of the Department of Agriculture, Western Australia, Series 4

It is feasible that canola could become Western Australia's fourth largest crop after wheat, barley and lupins by the turn of the century.

Without the stigma attached to its parent crop, rapeseed, canola has also become one of the most successful international agricultural product launches, proving itself not only a useful cropping alternative but a healthy oil for consumers. State Oilseeds Adviser PAUL CARMODY sets the scene.

Fast Tracking Barley Varieties Using Anther Culture, Sue Broughton, Penny Priest

Journal of the Department of Agriculture, Western Australia, Series 4

Breeding new varieties of barley or other cereal crops usually takes between 12 and 15 years. five years of that time may be needed to stabalise the new varieties so that they breed trueto type, but anther culture can reduce this delay to only eight months. This technology will allow the Department of Agriculture's barley breeding programme to respond more rapidly to changes in goals set by industry and to meet market demands.

The Art And Science Of Plant Breeding, John Sylvester Gladstones

Journal of the Department of Agriculture, Western Australia, Series 4

The first part of this article described the evolution of crop varieties and their improvement by simple selection. This part discusses cross-breeding and the other techniques which underly most modern plant breeding programmes.

The purpose cf crossing is to generate new combinations of varietal characteristics. It does not create anything basically new. All the genetic "ingredients" of a new variety must be present in one or other of the parents.