Preliminary studies on microsporogenesis in Prunus salicina Lindl.
In most areas of cultivation, the productivity of Japanese plum (Prunus salicina Lindl.) and related hybrids is inconsistent and dependent on artificial pollination to overcome the low fecundity rate. Anomalous development during microsporogenesis in P. salicina can generate malformed and non-viable male gametes, hence causing fecundity problems. The objective of this work was to study the process of microsporogenesis in eight different P. salicina genotypes by applying optical and fluorescence microscopy and histological assays. Results obtained showed a normal pattern of microspore development, with mature pollen grains in some accessions. Nevertheless, other genotypes exhibited different anomalies, such as a lack of cytokinesis in the tetrad phase, the development of dyads, and the presence of very vacuolised tapetal cells followed by their degeneration within the tapetal cell wall. All the aberrant features could be associated with male sterility in the genotypes studied. A high correlation existed between the irregular development of microspores and the low viability of pollen grains.