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|Title:||Efficient production of doubled haploid plants through antimicrotubule agent treatment of anther-derived maize callus and the RFLP analysis of the maize anther culture response|
|Doctoral Committee Chair(s):||Widholm, Jack M.|
|Department / Program:||Crop Sciences|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||Antimicrotubule agents, colchicine, amiprophos-methyl (APM), pronamide, oryzalin and trifluralin were used to induce chromosome doubling of maize anther-derived haploid callus before plant regeneration. Without treatment with these agents, all the plants regenerated from the callus were haploid. More than 50% of the plants regenerated from the callus treated with 0.625 or 1.25 uM colchicine for 1 to 3 days, 5 to 10 uM APM or 10 uM pronamide for 3 days were doubled haploids. These treatments had no effect in callus growth and plant regeneration. Oryzalin and trifluralin either severely inhibited the growth of regenerable callus or did not induce chromosome doubling effectively at lower concentrations. The results from field evaluation of the progeny of the doubled haploid plants from colchicine, APM and pronamide treatments suggest that no more than usual somaclonal variation was induced by these agents. Thus maize anther-derived haploid callus should be treated with these agents before plant regeneration in order to obtain a high frequency of doubled haploid plants.
RFLP analysis was performed with anther-derived callus lines from maize hybrids, H99 x Pa91 (HP), Pa91 x FR16 (PF) and H99 x FR16 (HF). Segregation of 58, 52 and 35 RFLP markers in 15 HP, 50 PF and 9 HF callus lines, respectively, was studied. The results indicate that 6 chromosomal regions on chromosomes 1, 2 (2 regions), 3, 6 and 8 may be associated with the formation of embryo-like structures (ELSs) (anther culture response) and regenerable callus from the ELSs (related to plant regeneration). The information from the RFLP analysis and the anther culture studies of these hybrids and their parental inbreds suggests that 2 regions at the long arm end of chromosome 2 and on the long arm of chromosome 8 should bear the genes associated with the ELS formation while further study is necessary to clarify whether the other regions are associated with ELS or regenerable callus formation or both.
This study also found that: (1) In some cases multiple ELSs can be formed from single microspores and the formation of multiple ELSs is under genetic control; (2) during maize anther culture spontaneous chromosome doubling occurs before or during microspore embryogenesis at a low frequency. The callus lines retain their ploidy levels once they are initiated.
|Rights Information:||Copyright 1992 Wan, Yuechun|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9215903|