Viabilidad de polen, densidad y tamaño de estomas en autotetraploides y diploides de physalis Ixocarpa

Abstract

In order to study the impact of autopolyploidy in pollen viability and in stomatal features of husk tomato (Physalis ixocarpa), pollen was analyzed as well as the size and number of stomata of five diploid populations and five colchicines-formed autotetraploids populations. All ten populations were established on open ground, under a randomized block design with four replications. For the study of pollen viability, pollen was collected and stained with acetocarmin 1[%]. Rounded and red colored pollen grains were considered viable and those constrained and undyed, non-viable. In addition, the stomatal density and index were assessed as well as the length and width of stomata occlusive cells on the adaxial and abaxial leaf surface. The diploids showed significantly higher values of pollen viability and stomatal density than those of autotetraploids (P = 0.05); however, the diploids had pollen grains and stomata significantly smaller than the autotetraploids. Therefore, the polyploidy did affect the viability of pollen, leading to the loss of fertility. However, this feature can be avoided by selecting plants with meiotic stability, to increase the fertility of the autotetraploids. Cell size increment shows that the autopolyploids have the potential to generate more vigorous plants, but with a decline in fertility; although fertility can be improved through several generations. This type of studies opens up the possibility of initiating new strategies for the improvement of husk tomato.