Characteristics Of Pollen Germination, Tube Growth And The Expression Of Style S Gene In Pyrus Pyrifolia

Plant self-incompatibility is the comprehensive behavior of pollen and pistil interaction, a theory mode for research on information transmission among cells and gene expression controlling. It has been the research focus of plant physiology and molecular biology for a long time. Based on the previous studies, we used pear cultivars 'Housui' (genotype is S₃S₅), 'Kikusui' (S₂S₄), 'Kohsui' (S₄S₅), 'Atago'(S₂S₅) and 'Gold-Nijisseiki' (S₂S₄) as materials('Kohsui' and'Atago'used for testing the specificity of the antibody). Factors affecting pollen germination and tube growth in vitro were investigated. Pollen germination, tube growth state in vivo and fruit set under self-pollination and cross-pollination at different floral stage was observed. S-RNase was localized with indirect immunofluorescence method and quantified by isoelectric focusing polyacrylamide gel electrophresis(IEF-PAGE) and indirect immunofluorescence method. Finally, the way of S-RNase uptake by pollen tubes under self-pollination and cross-pollination was tested by immunogold labeling technique. The main results are summarized as follows:1. Pear pollen germination and tube growth in vitro were affected by many factors. 1) Pollen germination and tube growth were promoted by the components tested and pH at certain value. 0.01%H₃BO₃, 0.03% Ca (NO3)₂ · 4H₂O, 15% polyethylene glycol 4000(PEG-4000), 5% D-Fructose (or 5% Sorbitol,10% sucrose), pH 6.5, were best for pollen germination and tube growth. 2) For gibberellic acid (GA3), triacontanol (TRIA), indole actic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4-D), the most suitable concentrations that stimulated pollen germination and tube growth were 50³00mg/L, 3¹00mg/L, 5²5 mg/L and 5¹0 mg/L, respectively. Naphthylacetic acid (NAA) inhibited pollen germination and tube growth. The inhibitory effect became stronger with its increasing concentration. Paclobutrazol ( PP₃₃₃) and abscisic acid (ABA) had some inhibitory effect on pollen germination. Although they had some stimulating effect on tube growth at lower concentrations, at higher concentrations they still inhibited tube growth. The best...