%0 Journal Article
%T Improved efficiency of doubled haploid generation in hexaploid triticale by in vitro chromosome doubling
%A Tobias W¨¹rschum
%A Matthew R Tucker
%A Jochen C Reif
%A Hans Maurer
%J BMC Plant Biology
%D 2012
%I BioMed Central
%R 10.1186/1471-2229-12-109
%X In this study we investigated the applicability of an in vitro approach for chromosome doubling based on microspore culture. Our results show a pronounced increase in the proportion of doubled haploid triticale plants compared to the spontaneous doubling rate, but also compared to the doubling obtained by the standard in vivo approach. In addition, the frequency of plants surviving from culture medium to maturity is also much higher for the in vitro approach. Colchicine concentrations of 1£¿mM for 24£¿h or 0.3£¿mM applied for 48 or 72£¿h during the first hours of microspore culture performed best.Our results suggest that for triticale, in vitro chromosome doubling is a promising alternative to the in vivo approach.Doubled haploid (DH) technology is a valuable tool in modern breeding programs since it allows for the production of completely homozygous lines within a few months and dramatically reduces the time required to establish new cultivars [1]. In addition, many genomic approaches such as association or QTL mapping benefit greatly from the use of DH populations [2-4]. DH plants are routinely generated in crops such as barley [5]. However, due to high costs and low efficiency, DH production is yet to be established in applied breeding programs for other cereals such as triticale. Of the different methods available for DH production, microspore embryogenesis (androgenesis) shows the greatest potential due to the abundance of microspores per spike and consequently the higher frequency of DH output as compared to other approaches such as wide crosses. Factors limiting the application of microspore culture at a commercial level include the rate of embryogenesis and regeneration, the frequency of albinism among regenerants and the frequency of chromosome doubling required to obtain fertile DH plants [6]. In barley, the rate of spontaneous chromosome doubling is high and ranges from 70-90£¿% [6]. By contrast, the rate of spontaneous doubled haploids reported for triticale
%U http://www.biomedcentral.com/1471-2229/12/109