Pollination Study of Mandarins and the Effect on Seediness and Fruit Size: Implications for Seedless Mandarin Production

Abstract

A pollination study was conducted using `Nules', `Fina Sodea', `Marisol', `Fina' Clementine, `Afourer', `Tahoe Gold', and `Gold Nugget' mandarin. The fruit sets from selfing of `Fina', `Marisol', `Fina Sodea', `Nules' Clementines and `Afourer' mandarin were very low or near 0. The open pollinated Clementines had very low fruit set and there were very few seeds per fruit. Fruit set was highest (20% to 40%) in cross-pollination between two Clementines, `Nules' and `Fina Sodea', and `Afourer' mandarin and their reciprocal crosses. There were averaged 23 to 32 seeds per fruit in Clementines × `Afourer' mandarin crosses and averaged 5 to 12 seeds per fruit in `Afourer' mandarin × Clementines crosses. Compatibility among Clementine mandarins and `Afourer' mandarin is very high and caution should be taken to properly isolate these two types of mandarins when planting to produce seedless fruit. The diploid `Nules' Clementine × triploid `Tahoe Gold' mandarin gave 14% and 17% fruit sets in 2002 and 2003, with an average 2 seeds and 9 seeds per fruit in 2002 and 2003, respectively. Caution should also be taken when planting triploid seedless `Tahoe Gold' mandarin near diploid `Nules' Clementine to avoid seeds. The compatibilities and seediness between diploid mandarin cultivars and new seedless triploid mandarin cultivars need to be tested to ensure the pollen of the new triploid cultivars will not cause seeds in the existing diploid cultivars.