Moisture Sensitivity of Cotton Pollen
Production of cotton (Gossypium hirsutum L.) hybrids is commonly preceded by removing anthers from recipient flowers or interrupting the functioning of the anthers before dehiscence. This study describes the development of an emasculation protocol that did not require removal of the anthers, did not result in female sterility, and maintained fruit retention. Cotton flowers were saturated with water at different times throughout the day. Water sprayed into the flower after the pollen dehisced resulted in the osmotic disruption of the pollen grains and prevented self-pollination of the cotton flowers. Morphological analysis of isolated pollen grains before and after water treatment showed the exudation of pollen cytoplasm into the surrounding water medium within seconds of the water treatment. The water treatment resulted in the loss of fruiting bodies. Hand pollination of water-emasculated flowers produced seed numbers equivalent to self-pollinated controls. To quantify the level of self-pollination following water emasculation, ‘Gregg 65’ cotton (glandless, recessive trait) was water-emasculated, the stigma allowed to dry, and the flower pollinated with pollen from ‘Paymaster HS-26’ cotton (glanded, dominant trait). Evaluation of 66 flowers revealed that 100% of the seedlings obtained from these crosses had the glanded phenotype, thereby showing that no self-pollination had occurred. In conclusion, this study demonstrates the use of water as an effective emasculation tool for hybrid cotton production that does not result in female sterility and maintains fruit retention and seed set following subsequent pollination with pollen from another flower.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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