| 释义 |
Definition of pollen tube in English: pollen tubenoun Botany A hollow tube which develops from a pollen grain when deposited on the stigma of a flower. It penetrates the style and conveys the male gametes to the ovule. Example sentencesExamples - In only one pollination did a pollen tube appear to enter the ovary, but not the ovule.
- For example, low temperatures near flowering affect ovule development and pollen tube growth.
- In pre-zygotic mechanisms, the pollen tube may grow as far as the ovule but not penetrate it, or penetration may be achieved without fertilization.
- The grain is empty because the body cell and prothallial nuclei have moved out along the pollen tube towards the archegonia.
- Guidance of the pollen tube down the style involves mechanical, chemical and physical cues that are not yet fully understood.
Definition of pollen tube in US English: pollen tubenounˈpɑlən t(j)ub Botany A hollow tube which develops from a pollen grain when deposited on the stigma of a flower. It penetrates the style and conveys the male gametes to the ovule. Example sentencesExamples - The grain is empty because the body cell and prothallial nuclei have moved out along the pollen tube towards the archegonia.
- Guidance of the pollen tube down the style involves mechanical, chemical and physical cues that are not yet fully understood.
- For example, low temperatures near flowering affect ovule development and pollen tube growth.
- In only one pollination did a pollen tube appear to enter the ovary, but not the ovule.
- In pre-zygotic mechanisms, the pollen tube may grow as far as the ovule but not penetrate it, or penetration may be achieved without fertilization.
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