|Author: ||M. Grilli Caiola|
|Keywords: ||apomixis, chromoplasts, Crocus sativus, hybridisation, pollination, saffron ancestors, sexual reproduction, vegetative multiplication|
Studies on saffron reproduction are recent and scarce compared to millenary experience of its cultivation and vegetative multiplication.
Sexual reproduction concerns numerous steps: micro- and mega-sporogenesis, gamete differentiation, pollen and pistil organization and compatibility, fertilization, embryo development, seed set and fruit development.
Reproductive research on saffron is difficult because the triploid genome of the plant and the still controversial opinion about where, when, how saffron originated.
Saffron cultivations from different countries do not show significant variations.
When nuclear DNA of Crocus sativus L. is compared to that of diploid allies species, it indicates that the most probable ancestor of saffron is C. cartwrightianus Herb., although C. thomasii Ten and C. pallasii Goldb. have been considered other possible parents of saffron.
Saffron is male sterile, self-incompatible and if crossed with pollen of C. cartwrightianus or C. thomasii it seed sets and matures capsules.
Self-incompatibility is not mediated by RNase, peroxidase or calcium.
Moreover, experiments on stigmatic and intraovarian pollination between C. sativus and C. cartwrightianus, C. thomasii or C. hadriaticus indicate that embryo development is not related to apomixis or somatic embryogenesis.
This has been verified both in vitro as well as in field.
So in spite of numerous informations until now available on saffron sexual reproduction, many more researches are necessary before of undertaking breeding programme with the aim of ameliorating yield and quality of saffron spice.
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