Anther androgenesis in response to culture media and donor genotypes in brinjal (Solanum melongena L.)

Abstract

Androgenesis offers a rapid approach for the development of completely homozygous lines; however, its efficiency depends upon donor genotype and culture conditions. This study aimed to optimize the Androgenesis using different donor hybrids and Murashige and Skoog (MS) medium supplemented with different concentrations and combinations of growth regulators for callus induction and regeneration in brinjal. Among different media combinations, MS medium supplemented with 2 mg/l IAA and 0.5 mg/l Kinetin developed the highest and earliest calli (65.8% in 28.5 days). Among donor hybrids, SC-15-2 x MR-319 produced the maximum (73.4%) calli in 13.5 days. Following subcultures of induced calli, MS supplemented with 0.2 mg/l IAA and 4 mg/l Zeatin achieved the highest regeneration (19.5%) in 21.4 days. Among donors, SR-5 x SR-9322 revealed 15.5% calli regeneration in 21.7 days. This donor hybrid also demonstrated direct regeneration from cultured embryos in MS + 2 mg/l IAA + 0.5 mg/l Kinetin medium, which turned into shoots and developed roots upon sub-culturing. In addition, ½ MS added with 0.5 mg/l IBA induced rooting in 58.3% of rootless cut-shoots that were hardened to complete plants following in-vitro and ex-vitro methods for acclimatization. An SSR marker emf21M05 confirmed gametic origin of 20 regenerants. Cytological analysis of Metaphase-1 stages in dividing pollen mother cells of 24 regenerants categorized the plants into diploid (4), haploids (9), and doubled-haploids (11) for further crop improvement in brinjal.