Low temperature storage and in vitro germination of cherimoya (Annona cherimola Mill.) pollen

Abstract

Due to the protogynous dichogamy of cherimoya and to the absence of proper pollinating vectors, hand-pollination with fresh pollen is a common practice for cherimoya commercial production. In order to optimize the process of hand-pollination, in this work we have studied the conservation of cherimoya pollen at –20, -80 and –196ºC for up to three months. In vitro pollen germination of fresh pollen was 57.1% and it was progressively reduced with conservation time at the three temperatures studied reaching a minimum after three months of storage of 10.4 %, 14.2% and 13.6% at –20, -80 and –196ºC, respectively. Differences in germination among temperatures were only significant during the first two weeks of storage. Field pollinations with pollen stored for up to three months at the three temperatures show no yield differences compared to pollinations performed with fresh pollen. The results indicate that pollen collected and stored at sub-zero temperatures at the beginning of the cherimoya blooming season can be used along the whole blooming season avoiding the need of collecting fresh pollen daily.