Production and evaluation of gynogenic leek (Allium ampeloprasum L.) plants

Abstract

A detailed study was conducted to assess the effects of 12 different induction media on the gynogenesis response of four open-pollinated (OP) leek (Allium ampeloprasum L.) genotypes. Gynogenic plant production was induced in 11 of 12 induction media. However, leek genotypes showed substantial differences in their responses to the induction media. Two MS-, two B5-, and one BDS-based media supplemented with auxin- and cytokinin-type plant growth regulators and high concentrations of sucrose (75 or 100 g l -1 ) provided gynogenic regenerants from all four leek genotypes included in the study. The highest gynogenic plantlet production (4.87 %) was obtained from the buds of an OP selection line (TU) cultured on B5 medium containing 2 mg l -1 dichlorophenoxyacetic acid (2,4-D), 2 mg l -1 6-benzylaminopurine, and 75 g l -1 sucrose. Culture of ~23,000 flower buds in 12 media provided 133 (0.58 %) green gynogenic plants. Flow cytometric analysis of the gynogenic plants showed that the majority (~62 %) of the recovered plants were diploid (1n = 2x) and about one-third was tetraploid (2n = 4x). Acclimated gynogenic plants obtained from the four donor genotypes were grown throughout spring and summer seasons in the greenhouse for morphological evaluations. Diploid gynogenic leek plants were substantially smaller in size (thinner and shorter pseudo-stems) when compared with tetraploid gynogenic and somatic plants. The results of this study show that sufficient numbers of diploid and tetraploid gynogenic leek plants can be produced for use in genetics studies and breeding programs for the improvement of new leek varieties with enhanced agronomical traits. © 2016, Springer Science+Business Media Dordrecht.