Quality Seed Production and Effective Marketing Systems for Development of Grasslands

Seed quality is defined as (i) maintaining genetic purity using seed certification principles (generation system; isolation; previous cropping history); (ii) achieving high levels of physical purity (especially low weed seed levels) by in field weed control and seed cleaning; (iii) achieving high levels of seed germination at harvest and maintaining germination through the seed supply chain. Seed production systems must not only produce high quality seed but also achieve economic seed yields. Seed crops have to be profitable (by being high yielding) to justify the investment of time and input costs to achieve quality. This in turn requires supporting research and extension to seed growers. Effective marketing requires a seed supply chain from the forage user back to seed producer i.e. it should be demand driven. Creating demand requires on farm trials and demonstrations to develop awareness and to move end-users away from commodity price-sensitive thinking. End users must understand the need for, and value of, paying a premium price for quality seed and for new cultivars that can add value to crops and livestock. Four seed supply chain models are discussed

Avanex\u3csup\u3eTM\u3c/sup\u3e Unique Endophyte Technology--Bird Deterrent Endophytic Grass for Amenity Turf and Airports

Bird strike is recognised throughout the civil and military aviation industries as a significant cost with more than $US 2 billion/year attributed to this problem globally. To manage this risk the aviation industries have in the past adopted many practices to frighten wildlife from airports rather than reducing the attractiveness of the area by grass habitat management. There has been little proven research on ground cover species evaluation using fungal endophyte to reduce wildlife. Our research has shown that the adoption of a specialist Neotyphodium fungal endophyte (strain AR601) placed in a turf type tall fescue cv. Jackal (Festuca arundinacea Schreb.), is reducing bird numbers and strike rates on the test airfields under study. In the recreational industry, large birds such as Canada geese (Branta canadensis), which forage on tender new shoots and stems, can cause severe damage to turf with the added issue of faecal contamination and associated heath issues. The inoculation of another specialist endophyte (strain AR95) into a turf type ryegrass (Lolium perenne L.) cv. Colosseum offers another tool to reduce this problem. This paper reviews the results from trials of these selected turf type grasses containing the unique fungal endophytes and shows effects on herbivorous, insectivorous and omnivorous birds that visit airfields and surrounding parklands for foraging. Specialty endophyte grasses may also have a place in the viticulture and horticulture industries to reduce the use of insecticides. Extracts and mulches offer a new opportunity to use grass endophyte associations

Effects of Storage Conditions on Endophyte and Seed Viability in Pasture Grasses

Several important temperate pasture grasses have co-evolved with mutualistic Epichloë fungal endophytes. These endophytes impart beneficial attributes to their host as they enhance the fitness of the grass when under biotic and abiotic stresses. The asexual species of these fungi (formerly classed as Neotyphodium) are obligate symbionts, and efficiently colonise newly formed tillers and infect seed by direct colonisation of the embryo. These endophytes are strictly seed transmitted. Survival of the fungus in this seed is therefore critical for the dissemination of endophyte-infected seed to grassland farmers. Longevity of endophyte in stored seed is primarily determined by the length of storage, temperature, and relative humidity as this is in equilibrium with seed moisture. Elevated temperature and relative humidity both reduce endophyte viability. The relative importance of each of these environmental parameters is unclear. Longevity may be further modified by grass species, cultivar, seed lot, and endophyte strain. Valuable seed requiring long term storage can utilise controlled storage facilities where temperature is preferably ≤ 5oC and relative humidity ≤ 30% (seed moisture \u3c 8%). For large quantities of commercial seed, moisture barrier packaging can be used

Control of tansy ragwort in western Oregon pastures with 2,4-D

Published January 1978. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo

Seed Transmission of Epichloë Endophytes in Lolium perenne Is Heavily Influenced by Host Genetics

Vertical transmission of symbiotic Epichloë endophytes from host grasses into progeny seed is the primary mechanism by which the next generation of plants is colonized. This process is often imperfect, resulting in endophyte-free seedlings which may have poor ecological fitness if the endophyte confers protective benefits to its host. In this study, we investigated the influence of host genetics and environment on the vertical transmission of Epichloë festucae var. lolii strain AR37 in the temperate forage grass Lolium perenne. The efficiency of AR37 transmission into the seed of over 500 plant genotypes from five genetically diverse breeding populations was determined. In Populations I–III, which had undergone previous selection for high seed infection by AR37, mean transmission was 88, 93, and 92%, respectively. However, in Populations IV and V, which had not undergone previous selection, mean transmission was 69 and 70%, respectively. The transmission values, together with single-nucleotide polymorphism data obtained using genotyping-by-sequencing for each host, was used to develop a genomic prediction model for AR37 seed transmission. The predictive ability of the model was estimated at r = 0.54. While host genotype contributed greatly to differences in AR37 seed transmission, undefined environmental variables also contributed significantly to seed transmission across different years and geographic locations. There was evidence for a small host genotype-by-environment effect; however this was less pronounced than genotype or environment alone. Analysis of endophyte infection levels in parent plants within Populations I and IV revealed a loss of endophyte infection over time in Population IV only. This population also had lower average tiller infection frequencies than Population I, suggesting that AR37 failed to colonize all the daughter tillers and therefore seeds. However, we also observed that infection of seed by AR37 may fail during or after initiation of floral development from plants where all tillers remained endophyte-infected over time. While the effects of environment and host genotype on fungal endophyte transmission have been evaluated previously, this is the first study that quantifies the relative impacts of host genetics and environment on endophyte vertical transmission

Identification of simple sequence repeat markers for sweetpotato weevil resistance

The development of sweetpotato [Ipomoea batatas (L.) Lam] germplasm with resistance to sweetpotato weevil (SPW) requires an understanding of the biochemical and genetic mechanisms of resistance to optimize crop resistance. The African sweetpotato landrace, ‘New Kawogo’, was reported to be moderately resistant to two species of SPW, Cylas puncticollis and Cylas brunneus. Resistance has been associated with the presence of hydroxycinnamic acids esters (HCAs), but the underlying genetic basis remains unknown. To determine the genetic basis of this resistance, a bi-parental sweetpotato population from a cross between the moderately resistant, white-fleshed ‘New Kawogo’ and the highly susceptible, orange-fleshed North American variety ‘Beauregard’ was evaluated for SPW resistance and genotyped with simple sequence repeat (SSR) markers to identify weevil resistance loci. SPW resistance was measured on the basis of field storage root SPW damage severity and total HCA ester concentrations. Moderate broad sense heritability (H2 = 0.49) was observed for weevil resistance in the population. Mean genotype SPW severity scores ranged from 1.0 to 9.0 and 25 progeny exhibited transgressive segregation for SPW resistance. Mean genotype total HCA ester concentrations were significantly different (P < 0.0001). A weak but significant correlation (r = 0.103, P = 0.015) was observed between total HCA ester concentration and SPW severity. A total of five and seven SSR markers were associated with field SPW severity and total HCA ester concentration, respectively. Markers IBS11, IbE5 and IbJ544b showed significant association with both field and HCA-based resistance, representing potential markers for the development of SPW resistant sweetpotato cultivars