Production of viable male unreduced gametes in Brassica interspecific hybrids is genotype specific and stimulated by cold temperatures

Table 3 Unreduced and abnormal male gamete production in amphidiploid Brassica species estimated by sporad counts.

Species	Genotype	No. plants	Total no. sporads observed	Total no. of abnormal sporads observed	Abnormal male gamete production	No. dyads observed	2n male gamete production*
B. juncea	J1	4	1916	1	0.03%	1	0.03%
B. carinata	C1	3	900	0	0.00%	0	0.00%
B. carinata	C2	5	2322	3	0.16%	0	0.00%
B. napus	N1	3	903	3	0.25%	2	0.11%
B. napus	N2	3	1230	0	0.00%	0	0.00%
B. napus	N3	2	700	0	0.00%	0	0.00%
B. napus	N4	2	600	0	0.00%	0	0.00%
B. napus	N5	5	1504	1	0.03%	1	0.03%
	Total	27	10075	8	Av: 0.06%	4	Av: 0.02%

* 2n male gamete production was estimated by the formula (number of nuclei in dyads)/(number of nuclei in all other sporad types)*100.
Both dyads and giant sporads were assumed to produce unreduced (2n) male gametes, whereas monads, dyads, triads, pentads, hexads and heptads were assumed to produce abnormal male gametes.

ISSN: 1471-2229