- Stenospermocarpy
Stenospermocarpy is the biological mechanism that produces seedlessness in some fruits, notably many
table grapes . Normalpollination andfertilization are required to set fruit in stenospermocarpic fruits. The near seedless condition results from subsequent abortion of theembryo that began growing following fertilization. The remains of the undeveloped seed are visible in the fruit.The fruit of seedless grapes is smaller than normal because the seeds produce the
plant hormone gibberellin , which causes fruit enlargement. Most commercial seedless grapes are sprayed withgibberellin to increase the size of the fruit and also to make the fruit clusters less tightly packed. A new cultivar, 'Melissa', has naturally larger fruit so does not require gibberellin sprays. [Ramming, D.W. 1999. New grape trio. "Agricultural Research" 47(10): 23. [http://ars.usda.gov/is/pr/1999/990618.htm] ]Grape breeders have developed some new seedless grape
cultivar s by using the embryo rescue technique. [Wood, M. 1997. Mouth-watering new fruits "Agricultural Research" 45(8): 9-10. [http://ars.usda.gov/is/AR/archive/aug97/fruit.pdf] ] Before the tiny embryo aborts, it is removed from the developing fruit and grown intissue culture until it large enough to survive on its own. Embryo rescue allows the crossing of two seedless grape cultivars.eedless grape cultivars
Seedless grapes are divided into white, red and black types based roughly on fruit color. The most popular seedless grape is known in the United States as '
Thompson Seedless ', but was originally known as 'Sultana'. It is believed to be of ancient origin. It is considered a white grape, but is actually a pale green. Other white cultivars are 'Perlette', 'Menindee Seedless', 'Interlaken', 'Himrod', 'Romulanus', 'Lakemont', 'Fayez', and 'Remailey Seedless.' The most popular red seedless in the U.S. is 'Flame Seedless'. Other red cultivars are 'Crimson Seedless', 'Ruby Seedless', 'Suffolk Red', 'Saturn' and 'Pink Reliance'. Some black cultivars are 'Black Beauty', 'Black Monukka', 'Concord Seedless', 'Glenora' and 'Thomcord.'References
ee also
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Parthenocarpy
*Seedless fruit
*List of grape varieties External links
* [http://cahe.nmsu.edu/pubs/_h/H-311.pdf Herrera, E. 2002. Improving size and quality of seedless grapes. Guide H-311. New Mexico State University.]
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