Association of Floral Bud and Anther Size with Microspore Developmental Stage in Campari Tomato

Abstract

Successful anther/microspore culture largely depends on the use of microspores at appropriate developmental stages at the time of culture, which can be specific for each plant species and genotype. This study was carried out to determine the correlation between morphological characteristics, namely floral bud (FB) length and width and anther length, and specific microspore developmental stages in Campari tomato. FBs ranging from 3.55 mm to 18.38 mm were collected, for which FB diameter and anther length were quantified. Furthermore, the developmental stage of microspores contained within these FBs were observed and recorded. The study revealed a strong positive correlation between each size parameters and the progression of microspore development. Moreover, the strongest correlation was observed between anther length and microspore development, indicating that this parameter was more suitable to predict the microspore developmental stage than the FB size parameters. The study also showed wide and overlapping ranges of FB lengths/diameters and anther lengths for specific microspore developmental stages. Subsequent histological observation revealed that this was the result of microspores at multiple developmental stages within a single anther. Moreover, microspores located in the middle of anthers were at a more advanced developmental stage compared to that of microspores at either anther extremity. The results of this study can be readily applied in the collection of Campari tomato FBs/anthers that harbor microspores at particular developmental stages for anther/microspore culture or for further tissue–specific developmental studies. Also, the technique described here can be applied for similar applications in other plant species and genotypes.