Triploids and Haploid Progenies Derived from Small Seeds of 'Banpeiyu', a Pummelo, Crossed with 'Ruby Red' Grapefruit.

Abstract

In order to establish a triploid grapefruit-like cultivar adaptable to the citrus area of Japan, 'Banpeiyu' (Citrus grandis Osbek) was crossed with 'Ruby Red' grapefruit (C. para-disi Macf.). Out of 2, 049 seeds, 82 were selected as small seeds. Among the seedlings obtained from the small seeds, one haploid, 18 diploids, and 51 triploids segregated. The haploid seedling has a dwarf growth habit with a roseate leaf type. When grafted onto trifoliate orange (Poncirus trifoliata Raf.) rootstock, however, it grew normally. The tri-ploids grew poorly immediately after germination, but after one year they grew as vigor-ously and as well as the diploid seedlings derived from the normal large seeds.