关键词: 枣, 柱头, 形态特征, 可授性

Abstract: In order to improve the efficiency of cross breeding in Chinese jujube，the stigma morphology and receptivity at different development stages were observed by microscopy，and the pollen germination on stigma was observed regularly to detect the receptivity of stigma at different development stages. The results showed that the stigma of Ziziphus jujuba‘Zhongqiu Sucui’was dry stigma and bifid， and there was no mucus secretion on the surface. The mature stigma was covered with a layer of nearly circular papillary cells. The morphological characteristics of the Z. jujuba‘Zhongqiu Sucui’stigma exhibited a specific pattern as the opening of a single flower progressed. From the bud oblate stage to the early flowering stage，two styles were very close to one another，together as a cone shape. The space between the two styles began to increase from the sepal flattening stage and the styles started to grow towards two sides. At the petal flattening stage，the angle between the two styles exhibited a“V”shape，At the stamen flattening stage，the angle between the two styles exhibited a“Υ”shape，which lasted until the ovary enlargement stage. The bottom width and length of the style increased as the flowering process progressed. The stigma was flat at the bud oblate stage；from the bud fat stage to the petal flattening stage，the stigma had a pointed，round morphology. Its submicroscopic morphology showed that at that time，the stigmatic surface changed from being wrinkled to full-bodied，then to bulging outwards. At the stamen flattening and petal wilting stages，the stigma was curled outwards，bulging upwards，with a relatively large surface area. At the stamen wilting and ovary enlargement stages，the stigma shrank and dried up. From the floral bud oblate stage to the petal flattening stage，the colour of the Z. jujuba‘Zhongqiu Sucui’stigma was green，and then it began to lose its green colour. At the stamen flattening stage，the colour of the stigma was light yellowish-brown. At the petal wilting stage，the colour of the stigma was yellowish-brown，and it turned black at the stamen wilting and ovary enlargement stages. From the floral bud oblate stage to the stamen flattening stage，the colour of the stigma remained green，and therefore the slight differences in the green colour during each stage cannot be used to determine the level of stigma receptivity. However，it could be sure when the stigma began to lose its green colour，the stigma receptivity decreased. From the floral bud flattening stage to the ovary enlargement stage，the stigmatic papilla cells on the stigmatic surface at different flowering stages exhibited a changing pattern，first developing to maturity，then reaching the most active stage，followed by shrinking and becoming shrivelled，senesced，and degraded. As the stigmatic papilla cells developed towards maturity and reached physiological senescence，the stigma receptivity exhibited a changing pattern of“no receptivity-weak- strong-weak-no receptivity”. Stigma receptivity can be determined based on the developmental level of the stigmatic papillae on the stigmatic surface of the jujube flowers. The optimal stigma receptivity period of Z. jujuba‘Zhongqiu Sucui’lasted from the sepal flattening stage to the petal flattening stage，which lasted approximately 6–8 h.

Key words: Salvia splendens, cultivar, Ziziphus jujuba, stigma, morphological characteristics, receptivity