IDENTIFICATION OF 4 PRIMARY TRISOMICS OF SOYBEAN BY PACHYTENE CHROMOSOME ANALYSIS

By using pachytene chromosome analysis four of the possible 20 primary trisomics (2n = 41) of soybean [Glycine max (L.) Merr.] were identified for the first time. Association of the extra chromosome in a trivalent configuration, chromosome length, and euchromatin and heterochromatin distribution helped the cytological identification of primary simple trisomic types. Primary simple trisomic types A, C, D, and S carry chromosome 5, 1, 4, and 13, respectively.