Relationship between meiotic instability and fertility in F2 generation Arabusta coffee plants

Abstract

Parental plants, an F1 interspecific hybrid and the F2 generation from Arabusta coffee plants were investigated for meiotic behavior and viability of pollen to understand part of their reproductive biology that affects their possible use in coffee breeding programs. Both parental plants (C. canephora var. Robusta 4x and C. arabica var. dihaploid Bourbon Vermelho) showed a meiosis diploid-like behavior, despite presenting a small percentage of irregularities, just as occurred for the F1 Arabusta hybrid. On the other hand, all F2 plants showed a higher frequency of anomalies that compromised pollen viability. The highest meiotic indices were registered for three analyzed plants of the F2 generation, and the pollen viability tests revealed the highest values for staining (PVS) and germination in vitro tests (PVG) for three others different F2 plants. The meiotic analysis and pollen viability tests may facilitate the selection of the best genetic resources, reducing the time needed for producing new hybrid cultivars. F2 plants which have high meiotic indices and/or high pollen fertility could be used as pollen donors in crossbreeding programs when there is interest in their functional or morphological characteristics. In contrast, the F2 plants that showed low pollen viability could be exploited as sterile male plants or discarded from a breeding program.