快好知 kuaihz


microspore造句
31. The microspore mother cells in plants exposed to low temperature develop numerous vacuoles and thus show thin cytoplasm. Plasmolysis and accumulation of lipid easily occur in these cells. 32. Low temperature and mannitol pretreatment favor the maintaining of microspore activity. 33. At the stage of microspore, the tapetal cells evidently degenerated, and starches in parenchyma around vascular bundle became large. 34. The microspore mother cells give rise to isobilateral tetrads by meiosis. Cytokinesis is successive. The mature pollen grains are 2-celled and are shed singly. 35. Potassium antimonate was used to locate calcium in the fertile and sterile anther of a thermo-sensitive genie male-sterile rice at microspore mother cell meiosis stage and at early microspore stage. 36. The stasis phenomenon of gynoecium development occurred in floral organogenesis of Reineckia and the abortion of microspore and ovule may be the important causes of its low seed bearing ratio. 37. Disintegration of cytoplasm at stage of central nucleus microspore .22. 38. The microspore culture technology has been widely applied in Brassica species nowadays. 39. At anaphase of mitosis, the organelles in microspore cytoplasm are concentrated in the future vegetative cell pole. 40. A row of microspore mother cells develop directly from the primary sporogenous cells. 41. After microspore mitosis, bicellular pollen contained a large vegetative cell and a small generative cell, and then the big vacuole disappeared. 42. The endogenous hormonal ratio was interdependent to the microspore abortion of radish. 43. However, the tapetal cells of sterile anther did not synthesis lipid material during microspore aborting. 44. Appropriate pretreatments are necessary conditions on promoting microspore embryogenesis in wheat (Triticum aestivum L. ). 45. The nucleus in shrinking cytoplasm of microspore mother cell enters into telophase .17. 46. Cytokinesis is of the simultaneous type and microspore tetrads are mainly tetrahedral. 47. When microspore mother cell preparing meiosis, abundant calcium precipitates appeared in cytoplasm of tapetal cells and microspore mother cells, and in callus wall surrounding the cells. 48. Some abnormal division had been observed at microspore mother cell meiosis stage, e. g. chromosome pairing abnormally, aberrant dyad formation and asynchronous dyad division. 49. The primary sporogenous cells functioned directly as microspore mother cells and were arranged in a single row in a microsporangium. 50. It is suggested that the microspore abortion in male-sterile anther would he attributed to premature degeneration of middle layer and tapetum. 51. Complete disintegration of cytoplasm of crescent or irregular shape of microspore .25. 52. Objective: The aim of this work is to probe into micro - morphological character of microspore of Selaginella and their significance in Taxonomy. 53. Crescent or irregular shape of microspore at stage of central nucleus .24. 54. Through ultra-structure observation, it is found that the microspore of Jin A began to abort at the stage of sporogenous cell division. 55. Cell layers of powder chamber wall and middle-level were increased, tapetum cells were hypertrophied and sporogenous cells or microspore mother cells were disaggregated. 56. In the process of litchi flower differentiation, the microspore abortion induced by external ethylene starts from the transition period(from sporogenous cells to microsporocytes).