|
生长素与乙烯对兰花授粉后花发育的调节作用 |
| |
ing et al. 1993). In many flowers, such as petunia and carnation, perianth senescence is preceded by an increase in ethylene production. Inhibitors of ethylene biosynthesis can prevent pol-lination-induced perianth senescence, indicating that perianth senescence is regulated by ethylene (Hoekstra and Weges 1986,Pech et al. 1987, Wang and Woodson 1989). In addition, analysis of senescence-related gene expression in carnation flowers has demonstrated that continued perception of ethylene is required for the expression of these genes in the petals (Lawton et al. 1990).
After pollination, perianth senescence is followed by ovary development. Based on the fact that both pollen extracts and auxin can induce ovary development, it is generally accepted that there is some substance in the pollen, probably auxin, which is responsible for ovary development (Gustafson 1937). At later stages, ovary development is regulated by its own supply of auxin (Crane 1969). Other studies have shown that ethylene accelerates ovary growth by promoting cell expansion (Burg and Burg 1966, Nichols 1971,1976).
Although many studies have been carried out on pollination-induced ethylene production in flowers, little is known about the role of ethylene in the processes involved in the development of the male gametophyte (pollen germination and tube growth) during pollination. Some experiments have shown that pollen germination and/or tube growth in vitro are promoted by exogenous ethylene (Search and Stanley 1968, Buchanan and Briggs 1969). However, other results do not support the supposition that ethylene plays a role in the regulation of pollen germination and pollen tube growth (Sfakiotakis et al. 1972, Hoekstra and Van Roekel 1988).
In orchid flowers, pollination-induced changes include perianth wilting, stigma swelling and closure, and ovary development (Arditti and Knauft 1969, Arditti and Flick 1976, O'Neill et al. 1993, Zhang and O'Neill 1993). Pollination induces t上一页 [1] [2] [3] 下一页
上一个医学论文： 超干红花种子抗老化作用及其机理
下一个医学论文： 羧甲基壳聚糖对玉米籽粒氮代谢关键酶和种子贮藏蛋白含量的影响
|
|
|
|
|
|
|
您现在的位置： 绿色健康网 >> 医学论文 >> 基础医学论文 >> 正文