Fig. 1. Photographs of the water treatment of cotton flowers showing (A) the use of a water bottle to fill an opening flower with water and (B) the covering of the stigma with a plastic bulb following the water treatment.
Fig. 2. Fluorescence micrographs showing the extent of pollen germination and tube growth on (A) control and (B) water-treated pistils. Arrows are provided to highlight representative pollen grains (A) with and (B) without pollen tube formation.
Fig. 3. Fluorescence micrographs showing the extent of pollen germination and tube growth on (A) control and (B) water-treated pistils. Pollen tube growth into the transport tissue of the pistil is shown in A while B shows that no pollen tube development was observed from the pollen grains of the water-treated flowers.
Fig. 4. Photomicrographs of cotton pollen (A) before and (B) after water treatment. Cotton pollen grains burst upon exposure to water, and the cytoplasmic contents stream out of the pollen grain into the surrounding water (B).
Fig. 5. Determination of the average number of seeds per boll observed for flowers treated with water at different times during the day. Treated flowers are compared with self-pollinated flowers (control). An average of 20 flowers were evaluated at each time point for the Paymaster HS26 variety. Means and standard errors are provided.
Fig. 6. Evaluation of the effect of the water treatment timing on stigma receptiveness to pollen. One-half of the water-treated flowers were pollinated at 1435 h, and the average number of seeds per boll were determined at boll maturity. Five flowers were evaluated per treatment at each time point. Means and standard errors are provided.
Fig. 7. Photographs of (A) Gregg 65 and (B) Paymaster HS-26 seedlings demonstrating the (A) absence and (B) presence of gossypol glands on the hypocotyls and cotyledons.
