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Page 52 · DO #455 · 204_Popenoe_Bx33FF25r
- Collection
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Wilson Popenoe (1892–1975) family papers
- Item/Folder
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The Citrus Fruits - Spanish & English manuscripts - chapter in outline for proposed book with Herbert Wolfe, n.d.
- Digital Object
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DO #455,
page 52
- Collection-level dates
- 1882–1975
Page transcription
13.
Nucellar Seedlings
There is a characteristic of the orange and other citrus fruits (with exception of the pummelo or shaddock, rarely grown in tropical America) which is of great horticultural importance. This is the production of what are technically known as nucellar seedlings. It is due to this phenomenon that seedling orange trees may be much alike, not only in growth and productivity, but also in fruit characters. Oranges harvested from a hundred - or a thousand- trees in any particular region may be just about as uniform in character as those from an equal number of grafted Valencias.
Nucellar embryos arise in the following manner; after the flower has been pollinated and fertilization has taken place in the ovule, buds develop from the tissues surrounding the embryo sac - the nucellus. Since these are not the result of fertilization, but are in reality parts of the mother plant, they reproduce the characteristics of the latter just as is the case when buds or scions are used in grafting. Several of these nucellar buds may develop in a single seed. They commonly crowd out the embryo which has resulted from fertilization - the embryo which would develop into a tree not exactly like its parent. Seedling variation is familiar to those who have planted avocado seeds, or those of many other fruits which have been improved through selection or mutation.
Of course, an occasional fertilized embryo does develop into a tree, and of course trees from nucellar seedlings may give rise to new horticultural varieties through mutation.