Callose content of cals5 pollen tubes. Aniline blue staining (a-h,j,l,n,p) and differential interference contrast optics (i,k,m,o) of sections of tetrad stage anthers (a-d), self-pollinated pistils (e-h), pollen tubes germinated on an excised stigma and elongating in vitro (i-l), in vitro germinated pollen tubes; arrowheads, callose plugs (m-p). Wild-type (a,e,i,j,m,n), cals5-3 (b,f,k,l,o,p), cals5-4 (c,g), and cals5-5 (d,h). Wild type (upper) and cals5-3 (lower) pollen tubes stained with anti-β-1,3 glucan primary and FITC secondary antibodies (q), cellulose staining with calcofluor white (r), and pectin staining with Alcian blue 8GX (s). Bars, 10 μm (a-d, m-s); 100 μm (e-l).