Table Of ContentsNext Page

Identification of novel germplasm to develop new tall fescue cultivars for Australia

M.Z.Z. Jahufer and K.F.M. Reed

Agriculture Victoria, Pastoral and Veterinary Institute, Private Bag 105, Hamilton, Vic.

ABSTRACT

Seasonal dry matter (DM) production during the 4th year of growth of 36 tall fescue germplasm accessions, collected from Morocco, Tunisia, and Sardinia, and 6 commercial cultivars, was used to identify superior accessions. There was significant genotypic variation among the germplasm accessions and cultivars for each season, and across all seasons. Pattern analysis indicated the presence of autumn, winter, spring and summer active groups. Accession 45, collected from Sardinia, had the highest spring and summer DM production compared to all other entries.

KEY WORDS

Breeding, endophytes, seasonal yield, pattern analysis.

INTRODUCTION

The potential of tall fescue (Festuca arundinacea Schreb.) has not been fully utilised in Australia. Limitations such as poor seedling vigour, poor winter production, and low palatability impede the use of tall fescue in Australia. Overcoming these limitations by developing new tall fescue cultivars for Australian environments will increase adoption by farmers. An important phase within the National Tall Fescue Breeding Program, based at the Agriculture Victoria Pastoral and Veterinary Institute, Hamilton, is the evaluation of new germplasm with the objective of identifying accessions with superior agronomic and seasonal dry matter production characteristics. This paper reports on the identification of superior tall fescue germplasm based on seasonal DM production.

MATERIALS AND METHODS

In 1995 a set of 36 germplasm accessions collected from Morocco, Tunisia, and Sardinia, were planted in the field together with 6 commercial tall fescue cultivars (Advance, AU Triumph, Cajun, Demeter, Dovey and Melik). The experiment was conducted at the Agriculture Victoria, Pastoral and Veterinary Institute, Hamilton (37o 49’ S, 142o 04’ E, and altitude 200 m). The mean annual rainfall at Hamilton is 688 mm. The soil type at the experimental site has a duplex profile with a clay-loam surface derived from basalt. The experimental layout was a randomised complete block design consisting of 2 x 1m plots, with 4 replicates. The accessions and cultivars were rotationally grazed with sheep. Close grazing was achieved by a high rate of stocking. Seasonal DM production during the 4th year of the experiment was measured using a 1m x 0.5 m quadrat. The herbage samples were dried for 24 hours at 80oC before determining the weight of DM. The data were analysed using the Residual Maximum Likelihood (REML) method (2) and analysis of variance, using Genstat 5.41. Best Linear Unbiased Predictor (BLUP) values (4) were also estimated. Cluster (3) and principal component (1) analyses were used to summarise the data.

RESULTS AND DISCUSSION

Seasonal DM production during the 4th year of the experiment indicated significant (P<0.05) genotypic variation among the germplasm accessions and cultivars in autumn 1998, winter 1998, spring 1998, and summer 1999 (Table 1).

Table 1. Genotypic variation (σg) for seasonal dry matter (DM) production among tall fescue germplasm accessions and commercial cultivars, and seasonal ranges.

There were also significant (P<0.001) differences among the accessions and cultivars for mean DM production across all 4 seasons (Table 2). Pattern analysis indicated the presence of five distinct accession/cultivar groups (Figure 1). Autumn, winter, spring and summer active groups were identified. The group that showed superior spring/summer DM production consisted of 3 germplasm accessions. Accession 45, collected from Sardinia, had the highest spring/summer DM production in comparison to all the other accessions and cultivars. This accession also exhibited a soft leaf texture (data not shown). However, immediate incorporation of accession 45 into the breeding program will be unlikely due to the presence of endophyte (Neotyphodium coenophialum Morgan-Jones and Gams). It has therefore been decided to; a) cross accession 45 with other superior non-endophytic germplasm - seed will not be harvested from accession 45, b) maintain seed of this accession at room temperature over the next 24 months in order to reduce endophyte viability, with a view to subsequently compare performance with and without endophyte.

Table 2. Analysis of variance for dry matter production of the tall fescue germplasm accessions and commercial cultivars across four seasons. R, replicates; S, seasons; G, accessions/cultivars; G.S, genotype-by-season interaction.

Figure 1. Bi-plot from principal component analysis showing 5 accession groups (indicated by different symbols) based on seasonal DM production. Directional vectors indicate the seasons. Accession 45 and cultivars, Ad- Advance, AU-AU Triumph, De- Demeter and Ms- Melik selection, are shown.

REFERENCES

1. Gabriel, K.R. 1971. Biometrica 58, 453-467.

2. Harville, D.H. 1977. J. Amr. Stat. Ass. 72, 320-340.

3. Watson, S.L., DeLacy, I.H., Podlich, D.W. and Basford, K.E. 1995. Centre of statistics research report.

4. (The University of Queensland, Australia).

5. White, T.L. and Hodge, G.R. 1989. In: Forestry Sciences 33, (Kluwer Academic Publishers, Boston).

ACKNOWLEDGEMENTS

The authors thank Mr. Harry Armstrong and Mr. Darren Pickett for their help in maintaining the trial.

Top Of PageNext Page

...

Search Site