ISHS Acta Horticulturae 714: XXII International Eucarpia Symposium, Section Ornamentals, Breeding for Beauty
THERMOSENSITIVITY OF THE RESTORATION OF MALE FERTILITY AND GENOTYPIC DIFFERENCES IN THE FORMATION OF ABERRANT FILAMENTS AND PISTILS AMONG THREE MALE-STERILE CULTIVARS OF ASIATIC HYBRID LILY |
| Authors: | T. Sato, K. Miyoshi |
| Keywords: | Lilium sp., immature anther, antherless stamen, thermosensitive male-sterility, petaloid, split stigma |
| Abstract:
We examined the thermosensitivity of the restoration of stamens and genotypic differences in the formation of aberrant filaments and pistils in three male-sterile cultivars of Asiatic hybrid lily (Lilium sp.), namely, ‘Akita Petit Lemon’ (APL), ‘Akita Petit Gold’ (APG), and ‘Akita Petit Cream’ (APC). When cultivated in the traditional manner in early summer, APC had immature indehiscent anthers that contained no pollen grains, while the other two cultivars had antherless stamens. In a field trial of these cultivars, designed for harvesting of cut flowers in autumn, APC with intact anthers and APL and APG with immature anthers were unexpectedly observed in less than 1% of 400 plants in each case. Plants were then grown, from bulbs, under three temperature regimes in a set of growth cabinets, as follows: under high-temperature conditions (HT), at 32/25°C; under moderate-temperature conditions (MT), at 25/18°C; and under low-temperature conditions (LT), at 18/11°C. The restoration of stamens in APL, APG and APC was achieved under high-temperature conditions and the extent of restoration was dependent on temperature. The thermosensitivity of APL and APG with respect to the restoration of stamens was similar. Both cultivars had antherless stamens under LT and restored stamens with immature anthers under MT. Under HT, there was an obvious difference between these two cultivars. Both APL and APG developed intact anthers; however, those of APL contained viable pollen grains while those of APG did not. The thermosensitivity for restoration of stamens in APC was somewhat different from that in APL and APG. APC had immature anthers even under LT but it had intact anthers with viable pollen grains under both MT and HT. Homeotic changes in floral components, such as transformation of filaments into tepals in APL and APC and split stigmas in APL were observed. The possible role of temperature in the restoration of stamens and genotypic differences in terms of the formation of aberrant filaments and pistils are discussed. | |
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