Chilling Requirements to Relieve Bud Dormancy in Black-fruited Aronia Taxonomic Groups Is Related to Ploidy and Geographic Origin

The genus Aronia Medik., also known as chokeberry, is a group of deciduous shrubs in the Rosaceae family, subtribe Malinae. two commonly accepted black-fruited species are black chokeberry [ melanocarpa (Michx.) Elliott] and aroniaberry mitschurinii (A.K. Skvortsov & Maitul)]. geographic range wild A. Great Lakes region northeastern United States, with southerly extension into higher elevations Appalachian Mountains. Wild found New England diploids, whereas plants throughout rest tetraploids. cultivated hybrid between × Sorbaronia fallax (C.K.Schneid.) C.K.Schneid. exists tetraploid. There currently limited diversity genotypes ornamental fruit industries, many current cultivars not adapted to southern States similar environs chilling break winter dormancy. goal this study was determine 1) requirements for ‘Viking’ 2) from different origins. Two experiments were conducted which subjected various accumulation treatments then moved greenhouse observation budbreak subsequent growth. Expt. 1 at University Maryland Wye, MD, focused solely on commercial cultivar ‘Viking’. Outdoor, ambient fall temperatures used achieve treatments. In 1, we determined optimal be greater than 900 h using single temperature model. 2 Connecticut genotypes, plus A fixed cold room 2, regions required 600 (single model), compared northern that more accumulation. Tetraploid bud, but diploid 1200 bud. confirmed 900-h requirement For both experiments, rate shoot growth positively correlated increasing amounts chilling.