Über den Einfluß der Auxine auf das Wurzelwachstum und über die chemische Natur des Auxins der Graskoleoptilen. 12. Mitteilung über pflanzliche Wachstumsstoffe.

Culture of Zygotic Embryos

“…Cultures of embryos preceded a long time before plant tissue culture. Tissue culture was definitely settled when two researchers Nobecourt and Gautheret, had the idea to supplement the medium with a hormone in 1937 [I, 2], but this addition had been delayed until Kogi et al in 1934 discovered this hormone: indole-3-acetic acid [3]. The early beginning of immature embryo culture (1904) can be easily explained since the culture of embryos was achieved with a hormone-free medium containing only nutrients [4].…”

Influence of Indole Acetic, Indole Butyric, and Naphthalene Acetic Acids on Roots of Lupinus Albus Seedlings

“…Inasmuch as these acids are not freely soluble in water, a weak solution of each was prepared by using a stock solution, 1: 1,000, dissolved in 95 per cent ethyl alcohol. This was first shown by Nielsen in 1930 and later by Kogl, Haagen-Smit, and Erxleben (1934), Hitchcock and Zimmerman (1936) and others. Only dilute solutions were required for this research 2 Obtained through the courtesy of Merck & Co. Rahway, New Jersey.…”

Influence of Indole Acetic, Indole Butyric, and Naphthalene Acetic Acids on Roots of Lupinus albus Seedlings

“…The second remarkable finding is the curious difference between the effect of growthstimulating chemicals and auxins on stems and their action on the growth of primary roots, for it has been asserted by most of those writing on this subject that while these chemicals promote the elongation of stems and shoots, they inhibit growth of primary roots. This was first shown by Nielsen in 1930 and later by Kogl, Haagen-Smit, and Erxleben (1934), Hitchcock and Zimmerman (1936) and others. This extraordinary finding has given rise to much speculation and consderable experimentation in an endeavor to elucidate the mechanism of plant-hormone action on the two different tissues.…”