TABLE 1.

Male and female transmission of the stt1 mutation

	Seed phenotype after female transmission of the mutation				Seed genotype after male transmission of the mutation
	Mutant stt1/+ (♀) × wild type (♂)				Wild type (♀) × mutant stt1/+ (♂)
Cross no. (N)	Miniature (stt1) (%)	Normal (stt1) (%)	Normal (WT) (%)	Cross no. (N)	Heterozygous stt1/+ (%)	Homozygous WT (%)
1 (177)	4	15	81	1 (77)	0	100
2 (203)	29	3	68	2–13 (466)	0	100
3–27 (1127)	8	25a	67a

When stt1 is crossed as a heterozygous mutant female by a wild-type male <50% of the progeny are abnormal, demonstrating incomplete penetrance of the maternal effect phenotype. Transmission of the mutation through the pollen was not detected, suggesting stt1 is required for normal pollen development and/or function.

^aCalculations made on the basis of transmission of wx1 on T2-9d in repulsion to stt1.