A Microscopic Study of Trichomes on Gynoecia of Normal and Tetraploid Clark Cultivars of Glycine Max and Seven Near‐Isogenic Lines

Abstract

The surfaces of gynoecia of Glycine max cultivars—normal Clark, a tetraploid Clark, and seven isolines—display variations in at least three types of trichomes. The normal Clark soybean gynoecium has at least three and possibly four types of trichomes: a two‐ to four‐celled, elongate, thick‐walled trichome (TWT), an elongate thin‐walled unicellular trichome (UCT), a secretory multicellular trichome (MCT), and an elongate thin‐walled bicellular trichome that we have interpreted as an immature TWT. All these types are present on the gynoecium by 1 d before anthesis. After fertilization, the UCT is rare, but the other types continue to initiate and develop on the young pod. During flowering, the UCT and the MCT are distributed along the ovary from the base of the gynoecium to the top of the ovary. The TWT forms primarily along the dorsal side of the style. The Clark tetraploid and the extra-dense, dense 1, dense 2, sharp hair tip, sparse, and puberulent isolines have all four types of trichomes on their gynoe...