Morphological markers to correlate bud and anther development with microsporogenesis and microgametogenesis in pepper (Capsicum annuum L.)

Abstract

The identification of microspores or pollen grains at particular developmental stages during microsporogenesis or microgamentogenesis is an important step for different basic and applied purposes. Among them, the most relevant example from a biotechnological perspective is the production of androgenic doubled haploids. For this and other techniques, precise, fast, easy and reliable criteria to identify flower buds carrying microspores or pollen at particular stages are essential. In anthocyanin-producing pepper types, the particularities of flower development allow for the identification of several morphological markers potentially useful as criteria for such an identification. In this work, our aim was to determine the easiest and more accurate criterion to correlate visible, measurable traits of bud and anther development with each of the individual stages of microsporogenesis and microgametogenesis. For this, we used three Spanish sweet pepper F1 hybrids (‘Herminio’, ‘Gacela’ and ‘Águila’). We analyzed and discussed the accuracy and practical usefulness of using anther length, bud length, anther purple pigmentation and the ratio between calyx length and bud length (calyx/bud ratio) as predictors of individual microspore/pollen developmental stages. According to our results, we propose a combination of calyx/bud ratio and anther pigmentation as an easy, fast and accurate criterion potentially applicable to anthocyanin-producing pepper cultivars to determine their particular markers.