Morphological Development and Secretion Activity of Glandular Trichomes in Oriental Tobacco

The morphology development and secretion activity of glandular trichomes in oriental tobacco were investigated by paraffin section, optical microscope and scanning electron microscope, respectively. The results showed that both primary long and short trichomes originated from the first and second leaf primordium at 100-200μm, while the initial trichome cells generally developed into long trichomes. The differentiation cells bulging from protoderm developed into long or short trichomes through different morphogenesis evolved. The secretion of long trichomes grandually strengthened in the ver-matured leaves, and came to climax with lots of gummy exudate overflowed from gland cells when the leaves were proper mature. However, the secretion of some trichomes delayed, entering the climax during curing of the leaves. The gummy exudate was hardly observed in the short trichomes during the growth, mature, curing and aging of the leaves.