Natural Branching in Citrus Juice Vesicles

Abstract

Juice vesicles in several Citrus species and cultivars differentiate additional vesicle apex primordia. Four distinct types of juice vesicles were described and quantified in citrus fruits: solitary (single stalk/single vesicle body/single apex primordium), dual-tipped (single stalk/single vesicle body/dual apex primordia), multiple-tipped (single stalk/single vesicle body/multiple apex primordia) and branched (single-stalk/multiple vesicle bodies/multiple apex primordia). The type and frequency of branching varies considerably among species and within cultivars. Branching was found in grapefruit, mandarin, pummelo, and tangelo, but not in blood orange, citron, lemon, lime, navel orange, rough lemon, sour orange, sweet orange, Valencia orange, and several other species. ‘Kao Panne’ pummelo [Citrus maxima (J. Burman) Merrill] exhibited one of the highest rates of vesicle branching, with 72% of its vesicles exhibiting this condition. The average number of branching vesicles produced per stalk was 3.7 for this cultivar. The frequency of branching was below 50% in other branched groups (e.g., grapefruit, mandarin, and tangelo).