Effects of Different Concentration of Glucose in the Development of Pollen Tube Growth of Acapulco (Cassia lata)

Abstract

INTRODUCTION

The study was based on the economic importance of Acapulco (Cassia lata) to the market. The researchers studied how the pollen of Acapulco quickly germinates using different media. The molecular and physiological processes of sugar uptake and metabolism during pollen tube growth and plant fertilization was investigated. In-vitro germination assays showed that Acapulco pollen can germinate and grow not only in medium containing sucrose (Suc) as a carbon source, but also in medium containing the monosaccharides glucose (Glc). The concentrations used in the study were 0.25, 0.5, 0.75 and 1.0.

METHODS

Flowers with several mature anthers and has shedding pollen was collected. The point of a mounted needle was gently rubbed over the anthers for the pollen to fell on to the medium on each slide. Then a filter paper was placed in four petri dishes it was moistened with water. Afterward a drop of the medium was placed in the center of a slide. The pollen was transferred to the slide. The step was repeated to have two slides with pollen for each type of flower. The time when the pollen was added to the medium placed in the petri dishes was noted. A microscope with x100 magnification was used to observe the slides over the next 15 minutes for signs of pollen germination. When the pollen tubes have started to grow the length of four or five tubes were measured at three-minute intervals for about 1 hour. Graphs were drawn to show the growth of pollen tubes with time, compared with a graph of group results for each solution.

RESULTS

Substituting sucrose in the germination medium with monosaccharide glucose showed that: a.) after 1 hour of incubation differences were observed with regards to the quality and the growth rates of pollen in the four different media; and, b.) The following 2 hours, tube growth in glucose continued and spicules developed. This experiment showed that an external carbon source is essential in maintaining pollen tube growth. However, this assay could not discriminate whether monosaccharide, disaccharides, or both were actually imported into growing Acapulco pollen tubes.

DISCUSSIONS

Pollen tubes require high and rapid sugar uptake to support their growth. The pollen tubes were actually can easily be seen in the sucrose concentration, on the other hand, it can also be observed in glucose concentration. Series of the test was done after 3 hours of observation and afterward the pollen tube in Acapulco changes morphologically in 0.75 glucose concentration.