Kakizaki: Sterility in Chinese Cabbage 



375 



POLLINATION IN PE-TSAI CABBAGE 



Figure 20. On the left (i) are the pods obtained from eleven flowers treated with 

 pollen from the same flower. Next (2) is the single pod obtained when six flowers 

 were treated with pollen from another flower on the same branch. At (3) are shown 

 the pods obtained from fifteen flowers treated with pollen from another branch of the 

 same plant; while on the right are the seven pods obtained by cross-pollination of seven 

 flowers with another iplant of the same variety. To self-pollination pc-tsai cabbage flowers 

 yielded only about five per cent of perfect pods, whereas ninety-six per cent were obtained 

 by cross-pollination. Apparently there is considerable variation in the extent of self- 

 sterility in different plants, and by selection it may be possible to develop strains that 

 will be nearly one hundred iper cent self-fertile. 



Discussion 



Results of the experiment are show^n 

 in the accompanying table. 



The flowers pollinated with their 

 own pollen (b), those pollinated with 

 that from different flowers in the same 

 inflorescence (c), and those pollinated 

 with pollen from different inflores- 

 cences the same plant (d) gave ap- 

 proximately similar results. About 30 

 per cent of the flowers treated pro- 

 duced normal pods, 20 per cent pro- 



duced imperfect pods, while 50 per 

 cent were entirely sterile, and failed to 

 develop at all. Consequently, it may. 

 be said that in Pe-tsai, different modes 

 of pollination have no effect on fer- 

 tility, when the pollen used is from 

 the same plant. 



Flowers pollinated with pollen from 

 different plants (e) exhibited a very 

 high degree of fertility — 96 per cent 

 of the pods being normal — which may 

 be regarded as very near the actual 



