Production of haploid and doubled haploid plants of Allium tuncelianum (Kollman)Özhatay, Matthew and Siraneci via in vitro gynogenesis

Allium tuncelianum (Kollman)Özhatay, Matthew and ?iraneci forms a single-cloved edible white bulb with a mild garlic (A. sativum)odor and taste. Its ability to form seeds makes it suitable for genetic improvement via classical and modern approaches. A detailed study was carried out to determine the gynogenic and somatic plant regeneration potential of two A. tuncelianum accessions (AT1 and AT2). Unopened flower buds of A. tuncelianum accessions were cultured in various BDS (Dunstan and Short, Physiol Plant 41:70-72, 1977)and MS (Murashige and Skoog, Plant Physiol 15:473-497, 1962)-based induction media. Accessions showed slight differences in their responses to gynogenesis and somatic shoot induction cultures. Gynogenic plantlets were obtained in six induction media (T2, T3, T6, T9, T12, and T15). Three of these (T2, T3, and T9)did not contain plant growth regulators (PGRs). Seventeen (0.09 percent)gynogenic plantlets were obtained from approximately 20,000 AT1 and AT2 flower buds used in gynogenesis induction experiments. The highest gynogenic plantlet production frequency (0.34 percent)in AT1 was achieved with buds cultured in T12 [MS-based medium with 1.0 mg L?1 ?-naphthalene acetic acid, 8.0 mg L?1 isopentenyl adenine, and 100.0 g L?1 sucrose]. Flower buds of AT2 showed the best gynogenic response (0.44 percent)in T2 (PGR-free BDS-based medium with 50.0 g l?1 sucrose). Somatic regeneration was observed in six media (T5, T6, T11, T12, T14, and T15)containing at least 50.0 g L?1 sucrose and auxin- and cytokinin-type PGRs. Two hundred and thirty-three (1.18 percent)somatic plantlets were obtained from the cultured flower buds of AT1 and AT2. The highest somatic plantlet production frequencies for AT1 (4.44 percent)and AT2 (3.89 percent)were obtained from flower buds cultured in T5 [BDS-based medium with 2.0 mg L?1 2,4-dichlorophenoxyacetic acid, 2.0 mg L?1 6-benzylaminopurine, and 50.0 g L?1 sucrose]. Three induction media (T6, T12, and T15)provided both gynogenic and somatic regeneration in A. tuncelianum. Eight of 17 (46.06 percent)gynogenic plantlets and 33 of 233 (14.16 percent)somatic plantlets continued to grow, resulting in healthy plants with green leaves and well-established root systems. The remaining gynogenic plantlets had abnormal development. Flow cytometric analysis of the well-developed gynogenic plants showed that two were haploid (25 percent), four were diploid (50 percent), and two were mixoploid (25 percent)containing both haploid and diploid cells. The nine abnormal gynogenic plantlets were diploid. Results obtained from this study suggest that doubled haploid technology can be used in the production of homozygous A. tuncelianum inbred lines in breeding programs