Numbers of Cuttings and Stamens Required

In experimental situations, the number of stamens to be scored is limited by the technical personnel and facilities available or by the number of stock plants. However, it is particularly important to collect all possible data from such expensive and nonrepeatable experiments as Biosatellite 11.(17,32-34,47,48) In that experiment, all of the stamen hairs from all of the flowers were scored. The number of flowers was limited by the relatively small sample size allowed (Fig. 5B) and the environmental stresses of the 2-day orbital flight. 

The number of stamen hairs scored and their resulting standard errors used to construct dose-response curves at intermediate dose levels (about 20-90 rads of X-rays or lesser doses of fast neutrons) led us to extrapolate that a dose of 0.25 rad of X-rays would require the scoring of nearly 1 

The left-hand scale on Fig. 6 shows total numbers of stamen hairs needed and total numbers of flowers (based on 300 hairs per flower). The right-hand scale gives the numbers of stamen hairs and flowers needed each day for a 5-day scoring period. Aberration frequency and X-ray dose are shown along the abscissa. 

It is usually desirable to determine the number of flowers or stamen hairs to be scored for each day rather than the total number, since it must be decided how much scoring can be undertaken each day. The experimenter, of course, must decide on the standard errors he is willing to 

For most radiations except those having an LET lower than X-rays, the numbers of stamen hairs scored usually can be less than the numbers indicated in Fig. 6 because of the relatively high RBE values expected from this species. 

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