Improving the Utilisation of Germplasm of \u3cem\u3eTrifolium Spumosum\u3c/em\u3e L. By the Development of a Core Collection Using Ecogeographical and Molecular Techniques

A core collection is a sub-set encompassing more than 70% of the variability of all accessions held in a collection (Brown 1995), the development of one for Trifolium spumosum (bladder clover) could assist in future development of the cultivar within southern Australia. The aim of this work is to develop a core collection of Trifolium spumosum as a model for other pasture legume species using molecular and ecogeographical data

Improving the Utilisation of Germplasm of \u3cem\u3eTrifolium Spumosum\u3c/em\u3e L. By the Development of a Core Collection Using Ecogeographical and Molecular Techniques

A core collection is a sub-set encompassing more than 70% of the variability of all accessions held in a collection (Brown, 1995). The development of one for Trifolium spumosum (bladder clover) could assist in future development of the cultivar within southern Australia. The aim of this work is to develop a core collection of Trifolium spumosum as a model for other pasture legume species using molecular and ecogeographical data

Prospects for Trifolium improvement through germplasm characterisation and pre-breeding in New Zealand and beyond

Trifolium is the most used pastoral legume genus in temperate grassland systems, and a common feature in meadows and open space areas in cities and parks. Breeding of Trifolium spp. for pastoral production has been going on for over a century. However, the breeding targets have changed over the decades in response to different environmental and production pressures. Relatively small gains have been made in Trifolium breeding progress. Trifolium breeding programmes aim to maintain a broad genetic base to maximise variation. New Zealand is a global hub in Trifolium breeding, utilising exotic germplasm imported by the Margot Forde Germplasm Centre. This paper describes the history of Trifolium breeding in New Zealand as well as the role and past successes of utilising genebanks in forage breeding. The impact of germplasm characterisation and evaluation in breeding programmes is also discussed. The history and challenges of Trifolium breeding and its effect on genetic gain can be used to inform future pre-breeding decisions in this genus, as well as being a model for other forage legumes

Annual Clovers Around the World: Current Status and Future Prospects

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. respinatum var. majus. Less important commercial species include T. hirtum, T. squarrosum, T. nigrescens and T. cherleri. Australian scientists have also recently domesticated T. glanduliferum, T. spumosum, T. purpureum and T. dasyurum. The areas sown to annual clovers may increase in future years, due to increasing nitrogen (N) fertiliser costs, environmental concerns with N runoff. Climate change brings new challenges and opportunities for annual clovers. The forage plant genetic resource centres will be crucial for developing new adapted cultivars

Mobilizing Crop Biodiversity

Over the past 70 years, the world has witnessed extraordinary growth in crop productivity, 1 enabled by a suite of technological advances, including higher yielding crop varieties, improved farm management, synthetic agrochemicals, and agricultural mechanization. While this “Green Revolution” intensified crop production, and is credited with reducing famine and malnutrition, its benefits were accompanied by several undesirable collateral effects (Pingali, 2012). These include a narrowing of agricultural biodiversity, stemming from increased monoculture and greater reliance on a smaller number of crops and crop varieties for the majority of our calories. This reduction in diversity has created vulnerabilities to pest and disease epidemics, climate variation, and ultimately to human health (Harlan, 1972). The value of crop diversity has long been recognized (Vavilov, 1992). A global system of genebanks (e.g.www.genebanks.org/genebanks/) was established in the 1970s to preserve the abundant genetic variation found in traditional “landrace” varieties of crops and in crop wild relatives (Harlan, 1972). While preserving crop variation is a critical first step, the time has come to make use of this variation to breed more resilient crops. The DivSeek International Network (https://divseekintl.org/) is a scientific, not-for profit organization that aims to accelerate such effort

Pasture biomass estimation using an image processing approach to LiDAR data processing

Our aim in this project was to develop a tool for measuring ryegrass morphological data larger phenomics for grass breeding project. Specifically, we used a LiDAR (Light Detection and ranging) based tool to accurately estimate ryegrass biomass by scanning from a mobile platform. While high-throughput phenotyping platforms are available for arable crops and tree type plants, to our knowledge, no such platforms exist for ryegrass. The unit is designed to scan individual ryegrass segments or plots planted in rows and separated from each other with buffer zones of bare soil. The unit must be able to continuously scan as it drives along the rows and automatically detect plot boundaries so that data collected from multiple segments can be separated from each other and collated in a biomass report. Our approach is to use a high-speed, high-resolution LiDAR to collect a dense 3D-point cloud of the grass from a top-down perspective. As the unit moves over the grass the LiDAR pointing straight down collects data and builds a 3D model of the ryegrass canopy. By projecting this 3D model of the grass canopy to a 2D plane we create an image similar to a relief map that we process using image processing techniques to segment individual grass plots from each other and to build an accurate convex hull around each grass plot. This convex hull represents the volume of the ryegrass plot based on the point cloud data and is the basis of our biomass estimation. We tested our method at two different sites. The first site contained irrigated ryegrass planted as individual segments of 30 rows, each comprising of 30 segments. We scanned all segments at 3 different events over a period of two weeks during a period of intense growth. This experiment showed a consistent growth trend over all the segments scanned and showed that our estimated biomass correlated well with the real growth. Our second experiment was a dryland trial (not irrigated) at a site that consisted of 5 rows of 16 segments each and one row of 18 segments. We scanned 3 times a week over a period of two months to monitor growth at a finer granularity than our previous experiment. Results from this scan again showed a consistent growth trend for most segments but also highlighted some interesting growth trends from those segments that did not follow a trend that we expected

Hotspots and gaps in the world collection of subterranean clover (Trifolium subterraneum L.)

Subterranean clover (Trifolium subterraneum L.) is the most important annual pasture legume in the winter-dominant rainfall areas of Southern Australia. Systematic germplasm collections of subterranean clover from its centre of origin have been made since the 1950s, particularly by Australian scientists, in order to broaden the genetic base of the species. The present study reports on a meta-analysis of the distribution of the world collection of subterranean clovers and their relationships to eco-geographic variables of the collection sites in their native habitat. Diversity hotspots (areas rich in number of accessions and containing a high diversity of sub-species) and also gaps (areas with particular traits un- or under-represented in collections) were identified. This was achieved using a stratified data system to evaluate eco-geographical and agro-morphological data which incorporated three tiers of information for the subterranean clover collection: (1) information from each collection site, including ecological data; (2) information on the phenotypic diversity within each collection site; and (3) plant agro-morphological data from each sample grown under controlled conditions. Correlations were found between some eco-geographic conditions and agronomic performance. These included correlations between latitude and flowering time, mean temperature in winter and winter productivity and precipitation in summer and seed dormancy. The present study concluded that subterranean clover versatility is greater than suggested in the past. The results of the current analysis provide a guide for future collecting missions to specific regions towards areas of maximum diversity (hotspots) and unknown diversity (gaps)

Population structure, relatedness and inbreeding derived from pedigree data in a white clover germplasm collection

Presentation made by Lucy Egan at Canterbury Omics Symposium VI

Identification of founding accessions and patterns of relatedness and inbreeding derived from historical pedigree data in a white clover (Trifolium repens L.) and red clover (Trifolium pratense L.) germplasm collection in New Zealand

Presentation given at Plant Canada 2019