Desarrollo de un método eficiente para la germinación invitro de polen de sorgo

the in vitro germination of pollen in sorghum is useful on studies of viability, physiology, and genetic transformation of pollen. however, the reported media are low efficient. this research aims to develop an artificial medium and to determine the optimal conditions for pollen germination of sorghum. it was used a factorial arrangement of concentrations of sucrose, boric acid, and calcium nitrate; besides, it was evaluated the effect of ph, relative humidity, physical state of the media, and the floral developed stage on pollen collection. the optimal medium was done using 0.7 m of sucrose, 3.81 mm of calcium nitrate, 1.21 mm of boric acid, and 1% of agar with ph 6. the highest germination was obtained with pollen collected just after anthesis and relative humidity above to 70 %. the non germinated pollen grains was negatively correlated with relative humidity (-0.47, p>0.01). with the conditions described in this paper was obtained up to 51% of in vitro pollen germination in 14 varieties of sorghum. our findings indicate that for increasing in vitro germination is required an optimal formulation of the medium; besides, it is needed to control the relative humidity (above 70 %) and the stage of pollen collection (just after anthesis).