Analysis of self-fertility in transgenic apple lines transformed with an S-allele either in sense or antisense direction.

摘要

Apple trees are moderately to strongly self-incompatible. Because of this self-incompatibility, fruit production is dependent on the activity of insects, which is strongly influenced by weather conditions. Self-incompatibility therefore leads to irregular fruit production. To obtain self-fertile apple trees, plants from the strongly self-incompatible apple cv. Elstar were transformed with either a sense or antisense copy of one of the endogenous alleles of the S-gene which controls the self incompatibility reaction. In spring 1999 these transgenic trees were flowering. For each tree part of the flowers were self-pollinated and part were cross-pollinated with pollen of the cross-compatible apple cv. Delbard Jubile. Analysis of fruit and seed set revealed that in some lines the self incompatibility mechanism was switched off. Fruit and seed set after self-pollination in these lines were comparable to that obtained after cross-pollination. Fluorescence microscopy further confirmed that in these lines the incompatibility mechanism was switched off as pollen tubes were frequently observed in the ovules six days after self-pollination.