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

Abstract

Double haploid (DH) breeding helps shorten the breeding cycle and fastens the release of homozygous inbred lines with superior and desirable traits. In vitro microspore culture is the fastest approach for producing haploid plantlets. The critical parameter for the success of 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 is essential. In the present investigation, we developed the easiest and most 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 the late uninucleate to the early binucleate stage are optimal for the induction of androgenesis in a 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 4.8 mm in Bomby, an average anther length of 2.75 mm in Orobelle, and 2.71 mm in Bomby, and corolla was slightly longer than that of the calyx in both the hybrids. Anthers had no purple pigmentation in Orobelle and slight /no pigmentation at the top of the anther sac end in Bomby.