Generation of Large Numbers of Independently Transformed Fertile Barley Plants

Abstract

A rapid, efficient, and reproducible system to generate large numbers of independently transformed, self-fertile, transgenic barley (Hordeum vurgare 1.) plants is described. lmmature zygotic embryos, young callus, and microspore-derived embryos were bombarded with a plasmid containing bar and uidA either alone or in combination with another plasmid containing a barley yellow The ability to transform plants through recombinant technologies has been of great value in exploring fundamental questions and enabling crop improvement. Recently, due to prolonged effort and substantial resources, the generation of stable transformants and fertile transgenic plants has been achieved in the cereals rice (Toriyama et al., 1988;

Genotypic differences in callus induction and plant regeneration from mature embryos of barley (Hordeum vulgare L.)

“…To date, Golden Promise has been well-known for its high tissue culture ability, and hence this genotype has been widely used in barley tissue transformation (Wan and Lemaux, 1994;Tingay et al, 1997;Holme et al, 2006;Kumlehn et al, 2006). In the current study, several genotypes were explored to establish callus induction and plantlet regeneration system.…”

“…Therefore, the application of genetic engineering has been restricted to only a few barley germplasms that possess high tissue culture capability; the so-called model cultivars mostly contain a low agronomic value. Most culture systems for callus formation and plant regeneration were developed for model barley varieties such as Golden Promise (Wan and Lemaux, 1994;Tingay et al, 1997;Holme et al, 2006;Kumlehn et al, 2006). It is imperative, therefore, to explore and establish regeneration systems for more elite barley genotypes that contain not only high tissue culture potential but also reasonable agronomic traits.…”

Expression of drought tolerance in transgenic cotton

“…The previous studies revealed consistent Mendelian ratios for single gene inheritance in certain crops like, alfalfa 25 , rice 26 , maize 27 , cotton [28][29][30][31] , and in cow pea 32 . However, in many cases, instead of Mendelian segregation, the complicated segregation profiles for the genes have also been reported [33][34][35][36][37][38] . Nevertheless, in the present study, Mendelian ratio of single gene inheritance was followed.…”

Improved Callus Quality and Prolonged Regenerability in Model and Recalcitrant Barley (Hordeum vulgare L.) Cultivars.

“…The practical utility of stable transformation technologies is largely dependent on having efficient methods to generate large numbers of fertile green plants from in vitro-cultured materials of commercially important germplasm. A successful, high-frequency barley transformation procedure was reported [1]; however, the protocol was developed for the amenable variety, Golden Promise (GP) and has been limited in its applicability to commercially important cultivars. This limitation is due in part to the gradual loss over time of embryogenic capacity and regenerability of callus tissue and to an increase in albino plants during the prolonged culturing periods needed for selection of transformed tissue.…”

“…Based on the results from these studies, it seemed likely that the appropriate use of phytohormones could prolong regenerability and reduce albinism during in vitro culture. The experiments reported here were designed to optimize in vitro culture conditions for an amenable cultivar used frequently for transformation, GP [1,4,8,9], and another commercial cultivar, Galena (GL), recalcitrant to published transformation methods. This optimization was accomplished by altering the combinations and levels of auxins and cytokinins during induction and maintenance of callus from IEs and observing the effects of these changes on callusinduction frequency, growth rate, quality, long-term regenerability and albinism of the tissue.…”