Development of sparse-seeded mutant kinnow (Citrus reticulata Blanco) through budwood irradiation

Abstract

Kinnow is the major fruit of Pakistan and has a high export potential due to its excellent fruit and juice quality. However, high number of seeds (25 ± 5) per fruit is limiting its export on a large scale. Benefiting from the induced mutations for selectivity, especially in the vegetatively propagated fruit crops like citrus, induced mutation for seedlessness in Kinnow with gamma irradiation of dormant bud which was attempted at the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad. Dormant bud irradiation-cum-grafting technique was employed, using the Citrus jambhiri rootstock for propagation of the scion. A sparse seeded (5 ± 3 seeds/fruit) mutant was evolved from an exposure dose of 20 Gy. The mutant was put to the conventional propagation up to mV₅, for confirmation of the continuity of the mutation. The sparse seeded mutation was found to be a solid and stable one. The quality parameters in fruit and juice of the mutant were comparable with its parent.

Key words: Kinnow, seedlessness, dormant bud, gamma irradiation, mutant kinnow.