MEIOTIC CHROMOSOME BEHAVIOR IN SOME INTERGENERIC HYBRIDS OF THE VANDA ALLIANCE

Tanaka , R., and H. Kamemoto . (U. Hawaii, Honolulu.) Meiotic chromosome behavior in some intergeneric hybrids of the Vanda alliance. Amer. Jour. Bot. 48(7): 573–582. Illus. 1961.—Meiotic chromosome behavior of 11 groups of diploid intergeneric hybrids (2n=38) of the Vanda alliance was investigated. Vanda Miss Joaquim × Luisia teretifolia and Ascocentrum curvifolium × Vanda lamellata usually produced 19 bivalents at metaphase I, indicating good homology of the parental chromosomes. Vanda tricolor var. sanderae × Vandopsis lissochiloides, Vandopsis lissochiloides × Vanda sanderiana, Vandopsis lissochiloides × Vanda Tatzeri and Arachnis flos-aeris × Vandopsis lissochiloides showed fair homology of parental genomes with formation of 12–15 bivalents at metaphase I. Trichoglottis brachiata × Vanda sanderiana, Vanda tricolor var. purpurea × Phalaenopsis denevei, Vanda Tatzeri × Aerides lawrenceae, Renanthera monachica × Vanda luzonica, Renanthera storiei × Vanda Clara Shipman Fisher and Aerides lawrenceae × Saccolabium giganteum, formed an average of 2–7 bivalents, thereby indicating poor homology of parental genomes. The hybrids, Renanthera monachica × Phalaenopsis sanderiana and Arachnis hookeriana × Vanda suavis, lacked chromosome pairing. On the basis of chromosome affinity at meiosis, a cytotaxonomic scheme was developed for the several genera of the Vanda alliance studied. Cytotaxonomy, evolution and breeding behavior in the Vanda tribe were briefly discussed.