The tube protrudes from a pore in the EXINE and grows down through the stigma, style and ovary of the CARPEL , entering the ovule usually by the micropyle. The pollen grains are termed microgameteophytes, and consist of a sporopollenin coating which serves to protect the gameteophytes as they are transported from the stamens (male) or male cone to the pistil (female) or … Other articles where Pollen tube is discussed: angiosperm: Pollination: The pollen tube ultimately enters an ovule through the micropyle and penetrates one of the sterile cells on either side of the egg (synergids). pollen tube a slender structure produced from a POLLEN GRAIN after POLLINATION . Meaning of pollen tube. Section of grain, showing tube. See Fig. pollen tube: Fig. Pollen tubes can reach great lengths, as in corn, where the corn silk consists… • POLLEN TUBE (noun) The noun POLLEN TUBE has 1 sense: 1. Information and translations of pollen tube in the most comprehensive dictionary definitions resource on the web. It penetrates the style and conveys the male gametes to the ovule. Examples of how to use “pollen tube” in a sentence from the Cambridge Dictionary Labs Pollen Tube Length The time for pollen germination and subsequent pollen tube extension required to reach the ovary is measured in hours for soybean and groundnut to days in tree species such as apple (Kakani et al., 2005). ‘Guidance of the pollen tube down the style involves mechanical, chemical and physical cues that are not yet fully understood.’ A hollow tube which develops from a pollen grain when deposited on the stigma of a flower. Pollen Definition. Pollen germination typically takes up < 8% of the duration of the progamic phase, whereas the period of pollen tube growth determines > 92% of its duration (Williams, 2012b). These synergids begin to degenerate immediately after pollination. What does pollen tube mean? Dictionary entry overview: What does pollen tube mean? 255 Pollen tube . (botany) a slender tubular outgrowth from a pollen grain when deposited on the stigma for a flower; it penetrates the style and conveys the male gametes to the ovule Familiarity information: POLLEN TUBE used as a noun is very rare. Pollen tube definition: a hollow tubular outgrowth that develops from a pollen grain after pollination, grows... | Meaning, pronunciation, translations and examples Pollen tubes deliver sperm after navigation through flower tissue in response to __ and ___ cues 2.genetic analyses have shown that female ___ and surrounding diploid tissues are essential for guiding pollen tubes to ovules. 1. Definition of pollen tube in the Definitions.net dictionary. Pollen refers to the powdery product synthesized by seed plants responsible for the production of the male gametes of the plant (shown below).. There is evidence that pollen grains are preset to harness biomechanical forces for pollen tube emergence; dead pollen grains are able to hydrate to the same extent as living grains, swell, alter apertural coverings, and even germinate short tubes before the tubes … 255 .