Overcoming Self-incompatibility And Cross-incompatibility By Laser And High-voltage Electrostatic Field

Incompatible cultivars of Brassica oleracea var. acephala and Eustoma grandiflorum. and cullivars of Brassica nigra and Brassica campestris were used in this experiment. The pollens of each plant were treated by laser and high-voltage electrostatic field for overcoming their self-incompatibility and cross- incompatibility. The biological effect of laser and high-voltage electrostatic field on the treated pollens was studied further by analyzing the surface structure, proteinase activity and germination on the stigma In addition, expression difference of SLG and SRK genes and spectrum difference of protein of stigma after pollination of the treated pollen were analyzed by Northern blotting and protein 2-D electrophoresis. The mechanism involved in the effect of laser and high-voltage electrostatic field on reproductive process was discussed. The results are as follows.1. At an appropriate dosage of laser and high-voltage electrostatic field, the germination rate of pollen in Brassica oleracea var. acephala and Eustoma grandiflorum was increased, the self-compatibility index and the number of seeds were increased, and the growth vigor of seedlings from self-fertilized seeds was improved remarkably to produce a higher plant weight in the field. 2. The surface structure of the pollen treated by laser and high-voltage electrostatic field was observed by an electronmicroscope. The sculpturing pattern of the treated pollen was damaged so that some reticulate structures were disordered and the space encircled by reticulate ridges enlarged. Pollen tube primordium became longer than that of the untreated control. The concentration of water-soluble protein, activity of a-amylase and total activity of amylases in mature anthers inclusive of pollens were increased.3. After self-pollinated by the treated pollen, stigma tissues were sampled at regular intervals. RNA was extracted from the tissue and the expression of SLG and SRK genes was examined by Northern blotting. The expression of SLG and SRK genes from the treated materials was not distinctly different from that of control 8 hours after pollination. The expression of SLG and SRKgenes from the laser-treated materials was lower than that of control 24 hours after pollination, bul their expression from materials treated by high-voltage electrostatic field was not apparently different from that of control.4. The protein points, on 2-D electrophoresis, from unpollinated stigma, were more obvious than those from pollinated ones. Some protein points from the pollinated stigma near the alkali end disappeared and some proteins with low molecular weight became less apparent. Difference of such specific protein points between treated materials and controls occurred 8 and 24 hours after pollination.