The mature anthers in large flower buds of Periploca graceae L. ( Periplocaceae ) were examined cytologically. It was seen that pollen was retained in permanent tetrads. Pollen tetrads were usually observed as isobilateral, rarely as linear. It was also observed that pollen tetrads germinated within the anther loculi. Most of the pollen tetrads were well stained and the germination rate was 90 %. In in situ germinated pollen tetrads, 1-4 pollen tubes were observed. During germination of pollen tetrads, the behavior of the nuclei was normal. At the early stage of pollen tube formation, a vegetative nucleus and two sperm cells were seen within the Pollen tubes. Pollen tubes were usually normal but rarely some abnormalities such as wall thickening, tube tip branching and extreme callose increase were also observed.
DANE, FERUZAN (2000) "In Situ Germination of Pollen Tetrads in Periplocagraceae L. (Periplocaceae)," Turkish Journal of Biology: Vol. 24: No. 2, Article 17. Available at: https://journals.tubitak.gov.tr/biology/vol24/iss2/17