科研之友
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摘要
Inorganic nitrate (NO3 (-)) and ammonium (NH4 (+)) are the two major components in nitrogen (N) nutrition of typical tissue culture growth media, and the total amounts and ratios influence both shoot induction and differentiation. This study was designed to determine the optimal N requirements and interactions of NH4 (+) x NO3 (-) to complete the optimization of a pear shoot culture medium. Pyrus communis 'Horner 51' and 'OH x F 87', P. cordata, P. pyrifolia 'Sion Szu Mi', and P. ussuriensis 'Hang Pa Li' from the pear germplasm collection of the US Department of Agriculture, National Clonal Germplasm Repository-Corvallis (NCGR) were evaluated. Response surface design was used to create and analyze treatment combinations of NH4 (+), K+, and NO3 (-). Cultures were evaluated for overall quality, shoot length, multiplication, leaf color and size, leaf spotting and necrosis, and callus production. Significant improvement was observed in multiplication and length for most genotypes. Reduced callus amounts were seen in two genotypes, and greener leaves were also seen in two genotypes. Each species had a distinct response, and the N form could be manipulated to produce longer shoots, more shoots, or less callus. For the best-quality shoots, both P. communis cultivars required high NO3 (-) and low to moderate NH4 (+), P. cordata quality was best with high NO3 (-) and NH4 (+), P. pyrifolia 'Sion Szu Mi' quality improved with moderate NO3 (-) and high NH4 (+), and P. ussuriensis 'Hang Pa Li' required low NO3 (-) and high NH4 (+). This study illustrates that optimizing the N components of a growth medium is very important when working with diverse plant germplasm.
- 出版日期2015-2
