Studies on Anatomy of Generative Organs of Pumpkin

Pumpkin was a kind of plant of Cucurbitaceae,annual trailing herb, had high nutritional with high economic vaule and was a favorite one of the main vegetables. In this paper, through the method of paraffin section, safranin-green staining, hematoxylin staining and fluorescence staining, the flower bud differentiation process, the development of micro-megaspore and famale-male gametophytes, pollination and fertilization, and the development of seed, which of the reproductive organs of pumpkin was observed. It also determined the mature pollen activity by TTC staining, observed by scanning electron microscopy appearance of the structure of pollen and pollen germination. This pumpkin cultivation techniques and provided the basis of genetic breeding. The main results are as follows:1. The order of pistillate, staminate flower differentiation and maturation are from the outside, and the order of staminate flower differentiation is flower bud undifferentiated, flower bud early differentiate, sepal primordial, corolla lobe primordial, stamen primordial. The two big and one small-three stamen primordial were generated in the development of staminate, but not the pistil; the development of pistil flower and stamen flower were similar and has digenetic phase. With the development of pistil , the stamen was degradation.2. The filament was short, the anthers had two pollen sacs and was S-shaped curve. Microspore mother cells was simultaneous cytokinesis. Tetrad was tetrahedral arrangement of the corpus callosum wall developed. Male gametophyte ware 2-celled. Mature pollen was large and numbers of apertures, a manhole cover; outer wall thickness, spiny outer surface of uniform glyph.3. The style of pumpkin was the solid style. The ovule was anatropous ovule, andmultiple ovules of per ovary. Mature ovule was componented of nucellus, integument, bead handles, combined point and composition of the nucellar beak. The megaspore had 3 consecutive mitosis, and the formed of eight-nucleate polygonum type embryo sac.4. The highest viability of pumpkin mature pollen was determined in 6:00 in the morning by TTC; the pollen tube bourgeoned by artificial pollination pollen after 1h; the pollen tube elongated 2h after pollination; a tube inserted entering the stigma after 4h, but less; a large number of pollen tubes inserted into the stigma pollination 8h growing rapidly, and reached the stigma of 1 / 2; pollination after 12h; a large number of pollen tubes reached the style of the 2 / 3; a large number of pollen tubes reached the style base pollination after 24h; a part of the pollen tubes reached the style base and fertilization.5. The pollen tubes can be observed after 2 days .The development of embryo was similar to most dicotyledons; endosperm was nuclear-type endosperm, and has endosperm haustoria. With the development of embryo, the endosperm was gradually absorbed. There was comparison both of normal and hull-less mutant seeds develop a five-zoned testa in 10 days post-anthesis. They have consistent differences between normal and hull-less mutant seeds in 15 days post-anthesis. The normal strain exhibited all five tissue layer. The cell layers of hypodermal increased and the color of that stained; the cell walls of sclerenchyma and parenchyma tissue were thickened , strained and positive for lignin, after which both became rigid. No consistent differences in the cell layers of hypodermal increased in the hull-less mutant seeds , the cell walls of sclerenchyma and parenchyma tissue were not thickened , the cell of tissue were collapsed and formed a clarity layer.