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Forage plant breeding aims to deliver cultivars that increase on-farm productivity through improved seasonal and annual yield, persistence of yield in perennials, and nutritive and feeding value. Breeding is generally undertaken in highly controlled field trials with individual plants or rows. However, the correlation of trait values between spaced plant trials and sward plots of forages is often low and non-significant. Heritability of traits, a measure of likely gains that can be achieved from plant breeding, can be moderate to high for many traits. The upper level of genetic gains in forage yield measured in small plot trials ranges between 6% and 15% per decade depending on species, indicating significant and lasting improvements have been achieved. Results from some farmlet scale grazing trials measuring animal performance support this but some others, particularly with dairy cows, fail to show advantage to improved cultivars. Factors contributing to this include aspects of systems management, systems trial design, and/or breeding objectives and evaluation systems; occurrence of environmental stresses; insufficient statistical power; and scaling interactions that restrict or dilute trait expression. Several factors are identified that should be considered as evaluation systems evolve in response to the changing economic, climatic, and regulatory forces affecting grassland farming. [ABSTRACT FROM AUTHOR]

Pastoral agriculture underpins the New Zealand economy. Its success in generating export income is due to a mild and moist temperate climate, productive soils, innovative farmers supported by an effective research and development system, and an energy efficient production system based on year-round grazing. However, pastoral agriculture is entirely reliant on introduced pasture and forage species and their ability to withstand both endemic and introduced pasture pests. Critical to this is the mutualistic relationship between ryegrass and Epichloë fungal endophytes which provide a range of secondary metabolites that deter herbivory by both ruminants and insect pests. The challenge has been to identify and commercialise Epichloë strains which while providing protection against insect pests, ensuring ryegrass persistence, do not cause animal health and welfare issues. The critical role that Epichloë fungal endophytes play in maintaining pasture persistence and as a result the pastoral economy of New Zealand will be reviewed. [ABSTRACT FROM AUTHOR]

Food and feed has been produced from genetically modified (GM) crops for 25 years. It is timely to review whether this technology has globally delivered the expected benefits and whether the ongoing debate on risks is justified. Expected benefits associated with GM include increased crop yields, reduced pesticide and insecticide use, reduced carbon dioxide emissions, improved soil structure, improved crop nutritive quality/value, and decreased costs of production. Concerns focus on food safety linked to toxicity and allergenicity, environmental risks associated with potential chances of gene flow, adverse effects on non-target organisms, evolution of resistance in weeds and insects, and genetic perturbations resulting in unintended compounds, new diseases, or antibiotic resistance. This review focusing on benefits and risks of GM crops concludes that they are a valuable option for delivering improved economic and environmental outcomes by providing solutions for many of the challenges facing mankind. GM technologies like many non-GM technologies can bring risks, but these can and have been monitored and quantified, allowing decisions balancing commercial, societal and environmental benefits against measurable risks. While 'checks' and 'balances' are required, regulatory schemes must focus on balancing risks and benefits and not on 'checks' alone which is the case for many countries. [ABSTRACT FROM AUTHOR]

Perennial ryegrass (Lolium perenne L.) remains the predominant grazed grass in New Zealand’s pastoral agriculture. Brought in from Europe in the early nineteenth century, locally adapted populations or ecotypes developed in a number of regions. Government plant breeders, employed to provide elite cultivars for farmer use as a public good, exploited an ecotype from the Hawke’s Bay region to produce ‘Grasslands Ruanui’. In the1950s Trevor Ellett, a dairy farmer in Mangere, Auckland noted that Grasslands Ruanui did not persist as well as ryegrass sown with seed harvested from 40 to 60 year old paddocks on his own farm. This ecotype, referred to as Mangere ryegrass, has since become the basis of many ryegrass cultivars bred by both government and commercial plant breeders over the past 50 years. This review documents how Mangere ryegrass became an important part of ryegrass cultivar development, the part it played in commercial plant breeders becoming involved in cultivar development, and coincidently in the discovery that the Epichloë fungal endophyte is crucial for perennial ryegrass persistence under drought, heat and insect pressure. [ABSTRACT FROM AUTHOR]

In identifying endophytes for use in pastures in New Zealand there have been two strategies used, either exclusion of ergopeptine and lolitrem alkaloids or, retaining some ergopeptine expression to enhance the stability of natural defences against invertebrate pests. Both have their strengths and weaknesses. It is a matter of balancing these to ensure the end-user has access to a product that satisfies their needs – a persistent pasture with low to nil animal toxicity in terms of animal production and welfare. The range and intensity of ergot alkaloids in grazed pasture on both pasture and ruminants is reviewed, with emphasis on New Zealand. Ergot alkaloids associated with pasture are produced by associations between certain Epichloë endophyte strains and temperate grasses. Ergot alkaloids have been shown to improve persistence of pasture through providing resistance/deterrence to insect pests as well as deterring grazing animals. However, ergovaline is toxic to grazing animals. Some commercially available ryegrass-endophyte associations can produce ergovaline concentrations close to those found in associations between ryegrass and the standard endophyte. It is feasible to eliminate ergot alkaloids from pasture grasses in New Zealand as endophyte strains are commercially available that do not express ergovaline and yet still provide excellent pest resistance. [ABSTRACT FROM AUTHOR]

Science ensures that explanations and predictions about the biological and physical worlds are verifiable, while also providing an approach that enables improved understanding to develop and be permanently recorded. There are several terms in common usage that describe the approaches used in scientific research, but at the extremes, words such as ‘reductionism’ and ‘holism’ are now frequently encountered. While singular reductionism can result in key relationships and linkages being missed, holism appears to ignore the need to identify how confounding factors can affect the quality of understanding derived from complex systems. Here we suggest that science is not a simple dichotomy of reductionism versus holism. Instead, it comprises a more fluid and complex mission. However, within multidisciplinary agricultural and horticultural science one regularly finds words like ‘systems’, ‘integration’, and ‘unifying’. Reductionist science is certainly part of the pursuit of holistic solutions to problems, not least in transdisciplinary research. [ABSTRACT FROM AUTHOR]

Condensed tannins (CT) are highly desirable in forage as they sequester dietary protein and reduce bloat and methane emissions in ruminants. However, the widely used forage legume white clover ( Trifolium repens ) only produces CTs in flowers and trichomes and at levels too low to achieve therapeutic effects. Genetic transformation with transcription factor Ta-MYB14-1 from Trifolium arvense was effective in inducing CTs to 0.6% of leaf dry matter. CT synthesis has been elevated further by crossing the primary white clover transgenic line with wild type genotypes producing the related phenylpropanoids, anthocyanins. CT levels in leaves were highest under the anthocyanin leaf marks associated with the "red midrib" trait; however, there was no evidence for CT accumulation in leaf sections with the "red V" anthocyanin marking. Ta-MYB14-1 was stably inherited in two generations of crosses, and T2 progeny produced up to 3.6-fold higher CTs than the T0 parent. The profile of small CT oligomers such as dimers and trimers was consistent in T0, T1, T2, and BC2 progeny and consisted predominantly of prodelphinidins (PD), with lesser amounts of procyanidins (PC) and mixed PC:PD oligomers.