Euploid Endosperm of Triploid × Diploid/tetraploid Crosses Results in Aneuploid Embryo Survival in Lilium

The main objective of the present study was to identify chromosome number variation in the progenies from triploid · diploid/tetraploid (3x · 2x/4x) crosses in Lilium to analyze the survival of aneuploid embryos from 3x · 2x/4x crosses and the potential significance of triploid for lily breeding. Two male-sterile autotriploid Asiatic lily cul- tivars were crossed with four diploid and/or two autotetraploid Asiatic cultivars. The results showed that the fruits of all triploid · diploid/tetraploid (3x · 2x/4x) crosses fully developed, and seedlings were obtained from the 3x · 2x/4x crosses, indicating that male- sterileautotriploidliliescanbeusedasfemaleparents.Chromosome preparationshowed that the progenies of the 3x · 2x/4x are predominantly aneuploid. Based on megaspo- rogenesis, we deduce that the endosperm of 3x ·2xis 7xand that of 3x ·4xis 8xinLilium and conclude that the aneuploid embryo survival of 3x · 2x/4x in Lilium is the result of the euploid endosperm. Lily is usually propagated by scaling or tissue culture; therefore, aneuploids obtained from triploid · diploid/tetraploid lilies would be a good source for cultivar breeding.

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