Successful creation of seedless (sterile) leucaena germplasm developed from interspecific hybridisation for use as forage

Authors

Daniel Real, Department of Primary Industries and Regional Development, South Perth, WA, AustraliaFollow
Clinton K. Revell Dr, DPIRD, Department of Primary Industries and Regional DevelopmentFollow
Yong Han, Department of Primary Industries and Regional Development, Western AustraliaFollow
Chengdao Li, Murdoch UniversityFollow
Marieclaire Castello, Department of Primary Industries and Regional Development, South Perth, WA, AustraliaFollow
C. D. Bailey, New Mexico State University

Document Type

Article

Publication Date

12-1-2022

Journal Title

Crop and Pasture Science

ISSN

1836-0947

Keywords

breeding, flow cytometry, flowering, legume, molecular markers, seed production, sterility, triploids

Disciplines

Agricultural Science | Agriculture | Agronomy and Crop Sciences | Plant Breeding and Genetics

Abstract

Context: The legume shrub/tree leucaena (Leucaena leucocephala (Lam.) de Wit.) is highly regarded as a cattle fodder, although it is considered an environmental weed in many parts of Australia.

Aims: We investigated the feasibility of developing a forage variety of triploid leucaena through interspecific hybridisation that is sterile (without seeds) as a strategy to mitigate its weed risk.

Methods: A conventional breeding strategy was used to create triploid hybrids from hand-crosses between tetraploid and diploid species of leucaena. Molecular markers were developed to confirm successful crosses and flow cytometry was used to confirm the ploidy level. The plants are being evaluated for flowering behaviour, seed and herbage production across two environmentally diverse sites at Carnarvon and Kununurra in northern Western Australia.

Key results: During 2018/19 and 2019/20, 2260 crosses between 45 different combinations of diploid females by tetraploid males and their reciprocals have created over 3000 putative triploid hybrid plants. This is the first time that triploids have successfully been created in Australia and 10 new parental combinations were created as a world-first.

Conclusions: A cohort of sterile triploid plants has been identified and selections will be made based on their edible biomass productivity, insect tolerance, capacity for regrowth after cutting, nutritive value and plant chemistry (including anti-methanogenic responses). A sterile leucaena variety will have application not only in Australian grazing systems but also in other tropical regions of the world.

Implications: A cost-effective technology for mass vegetative propagation of leucaena will be required for commercialisation of a sterile variety.

Recommended Citation

Real D., Revell C., Han Y., Li C., Castello M., Bailey C. D. (2023) Successful creation of seedless (sterile) leucaena germplasm developed from interspecific hybridisation for use as forage. Crop & Pasture Science 74, 783-796. https://doi.org/10.1071/CP22281