Intrapopulational chromosome number variation in Zephyranthes sylvatica Baker (Amaryllidaceae: Hippeastreae) from northeast Brazil.
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Zephyranthes Herb. is a taxonomically complex and cytologically variable group, withabout 65 species of Neotropical distribution. Chromosome number variability in 32 individuals of a Zephyranthes sylvaticapopulation from Northeast Brazil was investigated. Three cytotypes were found: 2n = 12 (one metacentric, four submetacentricand one acrocentric pairs), in 24 individuals; 2n = 12 + 1B, in five and three individuals with 2n = 18, a triploid cytotype.All diploid individuals showed chromosomes with polymorphism in pair one and two, while in triploids this polymorphismwas observed in all chromosome triplets, generally with two homomorphic chromosomes and a higher or lower heteromorphicchromosome. All individuals had reticulated interfasic nucleus and a slightly asymmetric chromosome complement, withone metacentric chromosome pair and the others more submetacentric to acrocentric. These data confirm the cytologicalvariability previously registered for the genus. Mechanisms involved in karyotypic evolution in this population are discussed.
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Zephyranthes sylvatica Baker, Comossomo, Variação, Triplóide, Lirio da Caatinga, Planta Ornamental, Melhoramento Genético Vegetal, Caatinga, Amaryllidaceae, Zephyranthes