Sreening Male Sterility Germplasm And Its Mechanism In Chinese Jujube

Chinese jujube is the first characteristic dry fruit tree in our country. The blossom of Chinese jujube is so small that cumbered castration and hybridize very severely. So screening male sterile germplasm was one significative thing in Chinese jujube. But new male sterile material was identified from 219 Chinese jujube germplasms by the test of pollen vitality and number. The preliminary studies on male sterile mechanism of Chinese jujube including the changes of anther anatomic structure and isoenzyme including POD, COD, AMY during pollen development were achieved. The mostly results were as follows.1 Screening nature male sterile germplasmThere were six male sterile germplasms was identified from 219 Chinese jujube germplasms by the systemic observation of modality of flowerage organism, pollen number and pollen germination rate. They were JMS1, JMS2, JMS3, Liuyuezao, Shandonglizao and Suangedazao. JMS3 is an excellent new male sterile germplasm among these new male sterile cultivars. Because of the stability of male sterile trait at yellow bud times JMS1 was also a superior female parent germplasm, which held 100% seed pip and super tone.2 The influence of pollen number and pollen germination rateDifferent Chinese jujubes have different distinction on the pollen germination rate and the pollen number. The pollen number varied significantly among cultivars, for example Lajiaozao which from the Chinese jujube excellent germplasm garden of gardening institution in Shanxi province has the maximal pollen number, its pollen number can reach 55000 grain per single anther. But pollen number of the male sterile germplasm was zero. The change of pollen number in Dongzao different strains was from zero to 1444, and the change in Wuhezao was among 111 to 4111.There were apparent differences in pollen number per anther and pollen germination rate at different seasons. Because of the most flowering, pollen number and pollen germination, it was the optimum date for pollination and hybridization in the medium and later term of blooming. The pollen germination rate and the pollen number per anther had obvious directly connection which the increasing of pollen number result in the raise of the pollen germination rate at flourishing season. But the pollen number and pollen germination rate have no notable pertinence in all.The pollen number per anther also varied significantly among different region. Forinstance, the pollen number of Jinsixiaozao, Langjiayuanzao and Fengmiguan were reached 35000, 23000 and 11667 respectively in Taiyuan of Shanxi. But there were only 3333,667 and 833 in Taigu of Shanxi province.The pollen number of yellow buds in the crown of Lajiaozao had significantly changed among different positions of the tree. The most quantity of pollen number was appeared at the perennial branch and shadow part of tree. 3 Mechanism of male sterile in Chinese jujubeThe observation of organize paraffin slice showed that the microspore of the male sterile cultivars disappeared between the tetrad and single nucleus on the contrast of the male cultivars. The microspore came together and then disintegrated in the late of development, the anther of yellow bud was empty and shriveled, the pollen grain remained the damaged site only, or just leave over the vestiges of tapetum cell and microspore with dark colouration.Make use of the PAGE to analyze the isoenzyme of different size flower bud. There were overt discrepancy in the POD, COD, AMY among the male sterile cultivars and the male cultivars. But a characteristic strip with male sterile was no found.