Taste Il. Chromosome numbers of D. candida cultivars, 
No. of cells during microsporogenesis with Voucher 
Cultivar n=10 n=11 n=12 n=18 collection* 
*Buyés’ l Q 137 3 1117, 1266 
‘Ocre’ - 5 57 - 1267 
*Biangan’® l 3 43 - 1431 
*Amaron’ - _ 29 1 564 
‘Quinde’ l l 30 - 1304, 1483 
*Munchira’ 1 8 46 l 1268 
‘Culebra’ - 6 122 5 1112, 1400 
* On deposit at the Economic Herbarium of Oakes Ames, Harvard Univer- 
sity, and the United States National Herbarium. 
Anaphase bridges 
In four cultivars of D. candida, the frequency of ana- 
phase [ bridges in pollen mother cells was recorded. ‘The 
formation of the anaphase bridge leads to uneven distri- 
0 
sy 
QO 
? 
a b 
Figure 1. Chromosomes of D. candida ‘Culebra’. (a) Metaphase I 
(=< 500). (b) Anaphase II bridges ( * 2000). 
bution of chromosomal material between the first division 
meiotic products and to consequent imbalance in the four 
resulting microspores. ‘Table I1] summarizes the data 
and includes frequencies of pollen abortion from ‘Table 
LV for comparison. 
In ‘Ocre’, no pollen mother cells were seen with more 
than one anaphase I bridge. *‘Buyés” plants showed 
PMC’s with one to four bridges, while in ‘Culebra’ 
there were up to nine bridges between first division 
nuclei. Figure 1b, illustrates an occurrence of anaphase 
