Pedigree analysis of pre-breeding efforts in Trifolium spp. germplasm in New Zealand

Abstract

Background Prebreeding in plants is the activity designed to identify useful characteristics from wild germplasm and its integration in breeding programs. Prebreeding aims to introduce new variation into the populations of a species of interest. Pedigree analysis is a valuable tool for evaluation of variation in genebanks where pedigree maps are used to visualize and describe population structure and variation within these populations. Margot Forde Germplasm Centre (MFGC) is New Zealand’s national forage genebank and holds a collection of ~ 75 species of the genus Trifolium, of which only a dozen have been taken through prebreeding programs. The main objective of this study was to construct pedigree maps and analyse patterns of relatedness for seven minor Trifolium species accessions contained at the MFGC. These species are Trifolium ambiguum, Trifolium arvense, Trifolium dubium, Trifolium hybridum, Trifolium medium, Trifolium subterraneum and the Trifolium repens x Trifolium occidentale interspecific hybrids. We present a history of Trifolium spp. prebreeding in New Zealand and inform breeders of possible alternative forage species to use. Results Pedigree data from accessions introduced between 1950 and 2016 were used and filtered based on breeding activity. Kinship levels among Trifolium spp. remained below 8% and no inbreeding was found. Influential ancestors that contributed largely to populations structure were identified. The Australian cultivar ‘Monaro’ had a strong influence over the whole population of accessions in T. ambiguum. T. subterraneum and T. repens x T. occidentale had the largest number of generations (3). T. ambiguum and T. medium had the highest cumulative kinship across the decades. Conclusions We conclude that there are high levels of diversity in the seven Trifolium spp. studied. However, collection and prebreeding efforts must be strengthened to maximize utilization and bring useful genetic variation.

Perspectives on the Combined Effects of Ocimum basilicum and Trifolium pratense Extracts in Terms of Phytochemical Profile and Pharmacological Effects

“…Ocimum species have been shown to have multiple therapeutic effects in the area of respiratory diseases, wound treatment, bacterial or fungal infections, headaches, and gastrointestinal disorders. Meanwhile, Trifolium species have been demonstrated to present multiple therapeutic effects in the field of respiratory diseases, wound treatment, bacterial or fungal infections, gastrointestinal disorders, menstrual pain, anticancer, antidiabetic, tuberculosis, to mention only a few [ 5 , 7 , 18 ]. So, there are some common therapeutic activities, but also some distinct therapeutic effects of the two species as presented in Figure 1 .…”

“…Ocimum and Trifolium species are plants that have also not been valued in the past, but there is an increase interest in these two plants species in recent years [ 4 , 5 ]. Ocimum species is characterized by an abundance of compounds such as phenolic acids, but also volatile oils, and Trifolium species have been shown to be rich in biologically active compounds such as isoflavones [ 6 , 7 ].…”

Prospects for Trifolium Improvement Through Germplasm Characterisation and Pre-breeding in New Zealand and Beyond

“…Many Trifolium species are underutilised, or their use is not yet considered economically viable in agricultural systems ( Maxted and Bennett, 2001 ). The importance of the minor species within the Trifolium genus is, however, recognised for: (i) growth in adverse conditions; (ii) research to improve the major species; or (iii) hybridisation with major Trifolium species ( Morris and Greene, 2001 ; Ellison et al, 2006 ; Williams, 2014 ; Egan et al, 2020 ).…”

“…Relish was developed on the basis of the initial screening of wild germplasm at the MFGC. However, overall, there is a low utilisation of germplasm in New Zealand Trifolium breeding programmes ( Egan et al, 2019a , b , 2020 ).…”

“…The information obtained from pedigree maps and analysis enables faster and more efficient breeding decisions ( Holland et al, 2003 ). Pedigree analysis on white clover ( Egan et al, 2019a ), red clover ( Egan et al, 2019b ), and minor Trifolium species ( Egan et al, 2020 ) germplasm collections in New Zealand have been performed. High diversity was found within all collections.…”