Estudio citogenteico en Karwinskia humboldtiana (Rhamnaceae) del Valle de Actopan, Hidalgo

Abstract

CYTOGENETIC ANALYSIS WAS PERFORMED USING THE CHROMOSOME SPLASH TECHNIQUE IN ROOT CELLS OF TEN PLANTS OF KARWINSKIA HUMBOLDTIANA (RHAMNACEAE) FROM ACTOPAN VALLEY, STATE OF HIDALGO, MEXICO (20° 16' N AND 98°56'O). CYTOLOGICAL DATA FROM 443 NUCLEI SHOW A SOMATIC CHROMOSOME NUMBER OF 2N = 24 WITH ALOW PRESENCE FREQUENCY IN TETRAPLOID NUCLEI (1.8%). THE SOMATIC COMPLEMENT OF K. KUMBOLDTIANA INCLUDED ONLY META-AND SUBMETACENTRIC CHROMOSOMES. THE AVERAGE CHROMOSOME LENGTH RANGED FROM 0.88 TO 1.49 M AND THE ABSOLUTE CHROMOSOMAL LENGTH WAS 28.72 M PER NUCLEI. THE MITOTIC KARYOTYPE ESTABLISHED 8M 4SM, REPORTED FOR THE FIRST TIME FOR THIS GENUS WAS FAIRLY SYMMETRICAL (T.F.=40.0).