Morphological characterization of floral traits to predict ideal stage for haploid production in bell pepper

Abstract

Double haploid (DH) breeding not only helps in shortening the breeding cycle, also in fastening the release of homozygous inbred lines with superior and desirable traits. In vitro microspore culture is the fastest approach for the production of haploid plantlets. The key parameter for success of the haploid production in any crop species is the stage of microspore or pollens at the time of culture as it decides the fate of cultured anthers/pollens. Therefore an easy, precise, fast, and reliable criterion to identify flower buds carrying microspores or pollen at particular stages are essential. In the present investigation, we developed easiest and accurate criterion to correlate visible, measurable traits of bud and anther development with individual stages of microsporogenesis in two sweet pepper F1 hybrids (Orobelle and Bomby). Anthers containing microspores at late uninucleate to early binucleate stage are optimal for induction of androgenesis in wide range of crop species. Anther containing uninucleate pollens were observed in flower buds with an average size of 5.39 mm in Orobelle and 4.8mm in Bomby, average anther length of 2.75 mm in Orobelle and 2.71mm in Bomby and corolla was slightly longer than that of the calyx in both the hybrids. Anthers were without any purple pigmentation in Orobelle and slight/no pigmentation at the top of the anther sac end in Bomby.