Genetic Similarity Indices for Ancestral Cotton Cultivars and their Impact on Genetic Diversity Estimates of Modern Cultivars

摘要: The accuracy of pedigree-derived genetic-distance estimates depends on the availability breeding records and validity a number assumptions. Pedigree analysis for cotton (Gossypium hirsutum L.) indicates wide genetic base, which conflicts with other types distance indicating narrow base. objectives this study were to determine similarity indices from agronomic morphological traits ancestral cultivars their impact coefficient parentage (CP) recent cultivars. Twelve two grown at three locations (Clayton, NC; Florence, SC; Stoneville, MS) during 1995 evaluated fiber properties. Multivariate properties was used create (s). There little agreement between CP s. Several developed earliest (pre-1800) introductions into USA very similar most (post-1900) Mexico. This suggested that all original Mexican genetically similar. Changing assumptions in pedigree assume related by average s among (s = 0.38) decreased level diversity frequently modern 0.16 0.46 but had effect relative ranking occurred because effects possible erroneous distant generations became diluted. high degree suggests have overestimated today's not relationships.