Plantbreeding at Svalöf - continued...

Such register numbers always remained the same in contrast to the parcel numbers, which changed annually as the plants were moved from one parcel to the other to avoid the leaching of the soil and the production of high or low yields by coincidental circumstances. Register numbers thus designated pedigrees as stable, and effectively immutable units circulating within the well-developed system of fields and parcels on Svalöv and its subsidiary experimental stations (Nilsson 1893). They were 'elementary species', 'independent, systematic units', as Nilsson would designate them in an article summarising his views on plant breeding in 1907. In a sense, that is, they were atoms of the taxonomic discourse, and correspondingly, as species and varieties in systematic botany, they received immutable names in form of their register numbers. The breeder could only chose among them, a slow and continuous transition from one to the other, as presupposed by mass selection, had to appear as impossible (Nilsson 1907). Plant breeding, in the words of Nilsson, had become a 'lottery', and chances in that lottery could only be raised by cultivating the highest number of isolated types (Nilsson 1892, 131).

It was in this context of systematic collection and record keeping that Herman Nilsson-Ehle (1873 - 1949), a young plant physiologist from the University of Lund who had become research assistant at Svalöv in 1900, started to perform Mendelian experiments. One of these experiments began in 1903 with an artificial crossing – artificial in as much as oats is a species subject to obligatory self-fertilization – of two pedigrees of oats, which had been cultivated at Svalöv for a long time already and carried the register numbers 0353 and 0462, later changed to 0668. A field book entry for pedigree 0462 from the year 1903 contained, as all field book entries did as a rule, the following information: the year of the entry in the upper left hand corner; the number of the parcel from which the seeds were derived in the previous year in the upper right hand corner; the parcel number and the register number, followed by a detailed botanical description of the plants on the parcel; further information on steps in the development and cultivation of the plant; and finally, the number of the parcel on which seeds from these plants were sown out in the following year 1904. Each field book entry, which as a rule occupied a single page of the field book only, thus represented the plants grown on one parcel as a distinct unit in terms of botanical character, development, cultivation, and descent.