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【目的】通过对人工授粉后海岛棉受精过程进行切片观察,获得其受精过程的动态结构变化规律,为新疆海岛棉遗传育种提供支持。【方法】以新海35号为材料,采用人工授粉、石蜡法连续切片及苯胺蓝染色的方法,观察并拍摄授粉后花粉粒萌发、花粉管生长和双受精过程的显微结构变化。【结果】海岛棉具有胚珠倒生、双层珠被、厚珠心,蓼型成熟胚囊,受粉前反足细胞和部分珠心细胞已经开始解体;人工授粉后0.5~1h,花粉粒萌发形成花粉管;2~14 h,花粉管在花柱内向下生长;16~20 h,花粉管到达珠孔端;20~24 h,花粉管进入胚囊释放出精子和营养物质,一个精子靠近卵细胞并与之受精,24 h时另一个精子与极核受精;50 h时,初生胚乳核分裂成2个游离核;74 h,合子第一次分裂,游离核数量也明显增多。此外,传粉50 h,胚珠表皮细胞伸长生长,74 h,纤维明显伸长。【结论】海岛棉与陆地棉受精过程中的生物学特征基本相同,但海岛棉受精各阶段与陆地棉相比时间更长,受精过程较慢,74 h后仍未见胚的第2次分裂及进一步的分裂,有待进一步研究。
【Objective】 The objective of this study was to observe the dynamic changes of the process of fertilization of island cotton (Gossypium barbadense) after artificial pollination, and to provide support for the genetic breeding of Xinjiang island cotton. 【Method】 The changes of pollen germination, pollen tube growth and double fertilization after pollination were observed and photographed by artificial pollination, paraffin section serial sections and aniline blue staining. 【Result】 The results showed that the antispapter cells and part of pearl heart cells had begun to disintegrate in the island cotton with ovule formation, double layer beads, thick pearl kernel and Polygonum-type mature embryo sac. Pollen grains germinated after 0.5 ~ 1 h artificial pollination The pollen tube grew down in the style within 2 ~ 14 h. The pollen tube reached the end of the pore in 16 ~ 20 h. After 20 ~ 24 h, the pollen tube entered the embryo sac and released sperm and nutrients. After fertilization for 24 h, another spermatozoa and polar nucleus were fertilized. At 50 h, the primary endosperm nucleus split into two free nuclei. For the first time after 74 h, the number of free nuclei was significantly increased. In addition, 50 h after pollination, the ovule epidermal cells grew and grew 74 h with obvious fiber elongation. 【Conclusion】 The biological characteristics of sea-island cotton and Upland cotton during fertilization are basically the same. However, compared with Upland cotton, the stages of fertilization are longer, the fertilization process is slower, and the second division of embryo is still not seen after 74 h And further division, pending further study.