HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Related articles in Crop Science Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Novák, K. Articles by Vondrys, J. Search for Related Content PubMed Articles by Novák, K. Articles by Vondrys, J. Agricola Articles by Novák, K. Articles by Vondrys, J. Related Collections Other Legumes Symbiosis Crop Genetics

GENOMICS, MOLECULAR GENETICS & BIOTECHNOLOGY

Development of an Asymbiotic Reference Line for Pea cv. Bohatr by De Novo Mutagenesis

Karel Novák^a,*, Martin lajs^b, Eva Biedermannová^b and Josef Vondrys^b

^a Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeská l083, 142 20 Prague 4, Czech Republic
^b Univ. of South Bohemia, Studentská 13, 370 05 eské Budjovice, Czech Republic

^* Corresponding author (novak{at}biomed.cas.cz)

Comparison of asymbiotic and symbiotic pairs of lines (difference technique) is a reliable and accessible method for determining the contribution of symbiotic nitrogen fixation to the yield of legume crops. To obtain an isogenic reference line for a commercial pea (Pisum sativum L.) a mutagenesis program was initiated with cv. Bohatr. Ethyl methanesulfonate (EMS) treatment of large seeds was optimized in a closed system to scale-up the process and to improve safety. The 18-h exposure of non-presoaked seeds to 0.15% (w/w) EMS solution resulted in 30% field emergence in the M₁ generation and in 1.04% of chlorophyll mutants and 3.64% of mutants classified as symbiotic in the M₂. However, only 48.4% of the growth chamber-detected and 21.6% of the field-detected presumable symbiotic mutants were found to be stable genetic deviations in the M₃ to M₅. Twenty-two preliminary characterized stable mutants comprised one nonnodulating, one with reduced nodulation, one with markedly delayed nodulation, and 19 lines with affected nodule development and function. Further evaluation under controlled conditions and in field trials identified the nonfixing line Budfix2 as a suitable reference line for field estimates of symbiotic nitrogen fixation. This line was shown to be physiologically equivalent to the original cultivar when grown under asymbiotic conditions, i.e., when the symbiotic fault was compensated for by exogenous mineral nitrogen. The availability of Budfix2 allows for direct application of the difference method in the particular pea cultivar Bohatr, as well as in further varieties after trait introgression. The additional symbiotic mutants generated in the course of the search for a reference line are expected to enhance the variability available for the genetic dissection of rhizobial nodulation.

Abbreviations: DM, dry mass • EMS, ethyl methanesulfonate • FM, fresh mass • SNA, specific nitrogenase activity • TNA, total nitrogenase activity

Related articles in Crop Science:

THIS ISSUE IN CROP SCIENCE

Crop Science 2005 45: x. [Full Text]