Understorey (FP19)

The Understorey project is focused on the development and commercialisation of messina (Melilotus siculus).  Earlier research conducted by the former CRC Salinity identified messina as an outstanding annual pasture legume for areas affected by dryland salinity and waterlogging in southern Australia.  Messina’s tolerance to the combined stresses of salinity and waterlogging easily surpasses that of all other pasture legumes.

Development of messina has been hampered by nodulation failure in the years after establishment. Therefore, research has centred on the collection and evaluation of strains of rhizobia; with the aim of identifying a persistent strain that can effectively nodulate regenerating messina plants in saline environments.  In 2010 the Understorey team were sufficiently confident that they had overcome this problem and commenced evaluating messina germplasm to enable cultivar selection.

Objective:

• Overcome the symbiotic constraints to the evaluation and development of commercial Melilotus siculus cultivars.

Activities

Five rhizobia nurseries, four in South Australia and one in Western Australia, have been assessed for  nodulation and growth on regenerating messina stands.  From over 100 strains of rhizobia evaluated, nine have been selected to form an elite cohort for further evaluation.  Selection was based on superior performance compared to the commercial AM medic strain.

The elite cohort is being tested for effectiveness with messina in the glasshouse.  In 2010 the elite strains were also sown in four field trials, two in South Australia and two in Western Australia.  Messina plants inoculated with these strains will be assessed for nodulation and growth.  The Understorey team is confident that a strain of rhizobia for messina will be recommended for commercialisation by June 2012.

In addition to the identification of a suitable strain of rhizobia the Understorey team has started evaluating messina germplasm with the aim of cultivar selection. Five messina germplasm field trials, three in South Australia and two in Western Australia, were established in 2010.  The trials consist of 21 accessions of messina and three commercial controls: Frontier balansa clover, Scimitar burr medic and Jota Melilotus albus.  Of the 21 accessions, eight are being evaluated for the first time. These accessions were sourced from Bunbury (WA) (one accession), Spain (four accessions) and Israel (three accessions). The new accessions greatly increase the robustness of the germplasm cohort and the commercialisation potential of messina. Opportunistic sowing of messina has occurred in both SA and WA, increasing the knowledge on soil adaptation, rainfall requirements, seed production and harvestability of this new saltland pasture legume.  A seed increase program of messina germplasm has also been initiated and basic morphological assessments will be undertaken.

For more information, email Amanda Bonython.