B.M. Reed, H. Aynalem
Improving the duration of cold storage of in vitro germplasm collections is important to safeguarding plant diversity available for plant breeding. In this study, we characterized the response of 12 diverse Humulus lupulus L. genotypes to the iron formulation used in the growth medium during storage. Treatments were standard MS iron alone (EDTA chelated) or with 100 or 200 mg/L sequestrene 138 iron (EDDTA chelated). In standard storage conditions, the average length of storage for hops on MS medium is 14.1 ± 3.5 months. Evaluation of 12 genotypes after 3, 6 and 9 months indicated that the plantlets grown with standard MS iron had generally higher condition ratings than those on sequestrene iron. Plants on either concentration of sequestrene iron declined at all rating periods and by 9 months all were near death. When all 12 genotypes were considered as a group, the growth-condition ratings for plantlets stored on MS iron were not significantly different from those on either sequestrene iron concentration due to the large amount of variation among the genotypes. Plants stored for 9 months on 1X sequestrene iron declined from mean ratings of 5 to ratings of 1.2 ± 1.1 and those on 2X declined to 0.8 ± 0.9 while plants on MS were rated 2.7 ± 1.5. Significant differences among treatments were noted for several genotypes. These results indicate that 4°C storage of in vitro hops germplasm should be on medium with the standard MS iron formulation.
Reed, B.M. and Aynalem, H. (2005). IRON FORMULATION AFFECTS IN VITRO COLD STORAGE OF HOP. Acta Hortic. 668, 257-262
DOI: 10.17660/ActaHortic.2005.668.33
EDTA, EDDTA, germplasm storage, Humulus lupulus L., sequestrene iron, tissue culture

Acta Horticulturae