Articles
THE EFFECT OF APPLE S-ALLELE COMPATIBILITY ON FRUIT SET LEVELS IN NON-OPTIMAL FERTILIZATION CONDITIONS
Article number
561_33
Pages
231 – 234
Language
English
Abstract
Apple (Malus domestica), like most Rosaceae fruit crops has a gametophytically determined self-incompatibility (SI) system.
SI prevents inbreeding and promotes outcrossing.
The outcome of pollination in SI plants is determined by a single polymorphic gene locus, called the S locus. If the pollen carries the same alleles as the pistil, SI will occur, whereas if one or both alleles are different, fertilization will occur.
Two of the commercial pollenizers of Topred in Israel are Golden Delicious and Jonathan. We determined the fertilization potency of Jonathan as pollenizer for Topred was significantly lower than that of Golden Delicious in the years 1997 and 1998 (non-optimal conditions for fertilization). PCR analysis of the S-alleles demonstrated that Jonathan and Topred share the allele, S9. PCR-S-allele analysis of Topred progeny seedlings revealed in the case of Jonathan only S7, the non shared allele, took part in fertilization, whereas both alleles of Golden Delicious (S2, S3) participated at equal rates.
Thus, the lower potency of Jonathan as a pollenizer of Topred could be related, at least in part, to semi-compatibility between the two cultivars.
Preliminary data from fully compatible pollenizers of Topred: Golden Delicious, Royal Gala, and Granny Smith, determined that in non-optimal conditions (1998) Royal Gala conferred significantly lower fruit-set to Topred than the other two pollenizers.
However, in 1999, when pollination and fertilization conditions were optimal, no significant differences in fruit-set of Topred were found with any of the fully compatible cultivars analyzed.
These findings emphasize that, under extreme conditions for apple cultivation fertilizer, potency should not be concluded experiments performed under optimal growing conditions, but rather should be evaluated specifically under the non-optimal or severe conditions.
SI prevents inbreeding and promotes outcrossing.
The outcome of pollination in SI plants is determined by a single polymorphic gene locus, called the S locus. If the pollen carries the same alleles as the pistil, SI will occur, whereas if one or both alleles are different, fertilization will occur.
Two of the commercial pollenizers of Topred in Israel are Golden Delicious and Jonathan. We determined the fertilization potency of Jonathan as pollenizer for Topred was significantly lower than that of Golden Delicious in the years 1997 and 1998 (non-optimal conditions for fertilization). PCR analysis of the S-alleles demonstrated that Jonathan and Topred share the allele, S9. PCR-S-allele analysis of Topred progeny seedlings revealed in the case of Jonathan only S7, the non shared allele, took part in fertilization, whereas both alleles of Golden Delicious (S2, S3) participated at equal rates.
Thus, the lower potency of Jonathan as a pollenizer of Topred could be related, at least in part, to semi-compatibility between the two cultivars.
Preliminary data from fully compatible pollenizers of Topred: Golden Delicious, Royal Gala, and Granny Smith, determined that in non-optimal conditions (1998) Royal Gala conferred significantly lower fruit-set to Topred than the other two pollenizers.
However, in 1999, when pollination and fertilization conditions were optimal, no significant differences in fruit-set of Topred were found with any of the fully compatible cultivars analyzed.
These findings emphasize that, under extreme conditions for apple cultivation fertilizer, potency should not be concluded experiments performed under optimal growing conditions, but rather should be evaluated specifically under the non-optimal or severe conditions.
Publication
Authors
M. Goldway, D. Schneider, H. Yehuda, A. Matityahu, D. Eisikowitch, R.A. Stern
Keywords
pollination, self-incompatibility, S-RNase, apple.
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