CROSS-POLLINATION RESPONSE IN 'ARBEQUINA' OLIVE
Cross-pollination response in olive varies according to the genotype, environment and management. The index of self-incompatibility (ISI) measures such cross-pollination response in terms of fruit set. Here, we present the comparison of ISI values of Arbequina trees located in two different sites (Tabernas and La Cañada de San Urbano, Almería, Spain) and years (2002 and 2003). The results show that cross-pollination response differed extraordinarily depending on the site and the year. ISI in La Cañada was 0.03, while in Tabernas, ISI was 1.51 (year 2002) and 0.69 (year 2003) which allows classifying Arbequina either as totally self-incompatible (La Cañada) or as self-compatible (Tabernas). No clear relation could be established among ISI values and parameters linked to flowering intensity and quality. At this regard, flowering levels measured by the number of inflorescences per node and quality estimated by the percentage of fertile inflorescence did not differ among locations and years. Nonetheless, Arbequina trees located in La Cañada de San Urbano (ISI=0.03) produced more flowers per panicle (p=0.05) and presented a lower percentage of hermaphrodite flowers (p=0.06); both parameters were negatively related (r=-0.73, p<0.01). Cross-pollination response of individual Arbequina trees was positively related to the number of flowers per inflorescence fitting an exponential curve (r2=0.37, p<0.05). The results confirm that cross-pollination response in olive is extremely variable even for a single genotype and suggest that this variability is linked to flower fertility.
González, M. and Cuevas, J. (2012). CROSS-POLLINATION RESPONSE IN 'ARBEQUINA' OLIVE. Acta Hortic. 949, 99-104
Olea europaea, self-incompatibility index, flowering levels, flower quality, fruit set