Performance in vitro of fresh and stored plum (Prunus domestica L.) pollen

Abstract

In this study performance in vitro of fresh and pollen stored for three months at different constant temperatures were investigated in three plum cultivars (ʻValerijaʼ, ʻČačanska Lepoticaʼ, ʻValjevkaʼ). Pollen were collected from the flowers in late balloon phase and after drying stored for three months at four different constant temperatures (+4 °C, ‒20 °C, ‒80 °C, ‒196 °C). Pollen tube length was examined as well as the nuclear presence in pollen tube and its migration. In vitro pollen tube length was tested after a 24-hour germination period after which the pollen tube was stained with Hoechst 33258 to observe the nuclear presence within it. The longest average pollen tube length in all tested cultivars were observed with fresh pollen. With the pollen stored at low temperatures the longer pollen tube was obtain compared to pollen stored at +4 °C. In all cultivars mature pollen grains were in binucleate stage contained vegetative nucleus (VN) and generative nucleus (GN). Although at each storage temperature a higher percentage of GN was achieved in pollen tubes compared to fresh ones, nevertheless, regular movement of nuclei, primarily VN than GN or sperm nucleus (SN), was found in the highest percentage in all tested cultivars.

U ovom radu su ispitane performanse in vitro svežeg i polena čuvanog na različitim konstantnim temperaturana tokom tri meseca kod tri sorte šljive (ʻValerijaʼ, ʻČačanska Lepoticaʼ, ʻValjevkaʼ). Polen je sakupljan iz cvetova koji su bili u kasnoj balon fazi i nakon sušenja čuvan na četiri konstantne temperature (+4 °C, ‒20 °C, ‒80 °C, ‒196 °C). Ispitana je dužina polenovih cevčica, prisustvo i migracija jedara u njima. Dužina polenovih cevčica je određivana nakon inkubacionog perioda od 24h a zatim bojenje sa Hoechst 33258 da bi se uočilo prisustvo jedara u njima. Prosečno najduže polenove cevčice kod svih ispitivanih sorti utvrđene su kod svežeg polena. Kod polena čuvanog na niskim temperaturama prosečna dužina polenovih cevčica je bila veća nego kod polena čuvanog na +4 °C. Polen svih sorti u zrelom stanju je dvojedaran, sadrži vegetativno i generativno jedro. Iako je kod svih sorti nakon perioda čuvanja polena, uočen veći procenat prisustva genetativnog jedra u polenovim cevčicama, raspored jedara je bio regularan, prvo vegetativno, potom generativno ili spermatično jedro.