Table II.

Assessment of pollen vacuolar phenotype by Neutral Red staining

The effect of fab1a-1 and fab1b-1 mutant alleles on the morphology of vacuoles in pollen collected from freshly dehisced anthers was assessed by staining with Neutral Red as described in “Materials and Methods.” Pollen scored as “normal” contained numerous small vacuoles (Fig. 4E), whereas grains scored as “abnormal” typically contained fewer irregularly sized large vacuoles (Fig. 4, F–I) or were collapsed. “Unstained” pollen grains lacked cytoplasm and were frequently collapsed. Actual numbers of grains scored are indicated in parentheses.

Genotype	Normal Pollen	Abnormal Pollen	Unstained Pollen
	%	%	%
Wild type	98 (191)	1.5 (3)	0.5 (1)
fab1a-1/+;fab1b-1/fab1b-1	55.4 (210)	30.1 (114)	14.5 (55)
fab1a-1/fab1a-1;fab1b-1/+	48.1 (140)	19.6 (57)	32.3 (94)