  Federico M. Ribalta federico.ribalta@uwa.edu.au 1 Centre for Plant Genetics and Breeding, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia 2 School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS 7001, Australia 3 Agroécologie, AgroSup Dijon, INRA, Univ. Bourgogne Franche-Comté, 21000 Dijon, France Received: 19 April 2016 / Accepted: 19 August 2016 © Springer Science +Business Media Dordrecht 2016 Precocious foral initiation and identifcation of exact timing of embryo physiological maturity facilitate germination of immature seeds to truncate the lifecycle of pea Federico M. Ribalta · Maria Pazos-Navarro · Karen Nelson · Kylie Edwards John J. Ross · Richard G. Bennett · Christine Munday · William Erskine Sergio J. Ochatt · Janine S. Croser Plant Growth Regul DOI 10.1007/s10725-016-0211-x of recombinant inbred lines (RIL) and multi-parental advanced generation intercrosses (MAGIC) populations. Keywords Early foral onset · Embryo physiological maturity ·  L. · Precocious seed germination · Seed moisture content · Seed sucrose content Introduction The current extended generation cycle time is a serious impediment to progress in the genetic enhancement of pea (  L.). To improve pea cultivars, landraces or primitive forms are hybridised, elite individuals selected and genes fxed using pedigree, bulk, backcross or single seed descent (SSD) methods (Redden et al. 2005). Depend - ing on infrastructure resources, pea geneticists can achieve between one feld-based generation and three glasshouse- based generations per year. Pea and the other species lag behind cereals and oilseeds in the availability of time-saving technology such as doubled haploidy, which permits the development of homozygous individuals from gametes in a single generation (Maluszynski et al. 2003; Croser et al. 2006; Germanà 2011). Within this context, we set out to determine whether the generation cycle could be radically shortened in pea by understanding and then manipulating: (1) the physiology of fowering response, particularly in late and very late fower- ing genotypes, and (2) the precise time/developmental stage at which the embryo achieves germination competence with low external input. The literature provides compel- ling evidence to suggest combining in vivo growth condi- tions designed to trigger early fowering with technology to enable precocious germination of immature seed will enable Abstract We propose herein a novel single seed descent protocol that has application across a broad phenotypic range of pea genotypes. Manipulation of key in vivo grow- ing conditions, including light, photoperiod and tempera - ture, combined with precocious in vitro germination of the embryo at full physiological maturity substantially short- ened the pea lifecycle. We defne full embryo physiological maturity as the earliest point in seed development when precocious in vitro germination and robust seedling growth can be reliably achieved without supply of exogenous hor- mones. Under our optimised conditions for accelerated plant growth, embryo physiological maturity was attained at . 18 days after pollination, when seed moisture content was below 60 % and sucrose level under 100 mg g −1 DW. No delay penalty in terms of time to fowering and plant development was caused by the culture of immature seeds 18 days after pollination compared to the used of mature ones. Determining the role embryo maturity plays in the ftness of the germinated plant has facilitated the truncation of the lifecycle across pea genotypes. The accelerated sin - gle seed descent system proposed within this research will beneft complex genetic studies via the rapid development 1 3