Studies of the inheritance of morphological traits contribute to the understanding of peanut genetics. Investigations of the fertility and cytogenetics of interspecific progenies between Arachis hypogaea and wild Arachis species have provided invaluable information on the phylogenetic relationships within the genus Arachis and on the amphidiploid nature of peanut. However, the inheritance of morphological traits using interspecific progenies has not been elucidated to date. The objective of this study was to identify and to analyze genetic factors controlling growth habit, stem color, root nodulation, and leaflet size in peanut. F1 and F2 progenies were obtained from diallel crosses between A. hypogaea cvs. Argentine and T2442, and A. monticola. Fz progenies and parents were grown at the Tidewater Agricultural Experiment Station in 1985. F1 plants were grown in the greenhouse in 1986. Five, six, and seven phenotypic classes, respectively, were assigned to characterize growth habit, stem color, and leaflet size. Root nodulation was indirectly determined through leaf color. Chi-squares were computed to test homogeneity of reciprocal crosses and genetic ratios for growth habit, stem color, and root nodulation. Leaflet size distributions were analyzed graphically and independence of inheritance was tested among all traits studied. Analysis of results indicates that: 1) growth habit may be determined by four genes having two types of isoalleles, 2) the relationship between and within these four genes may be essentially additive, 3) all loci may not contribute with the same weight to growth habit phenotype, 4) purple and green pigmentations may be determined by two distinctive sets of epistatic genes, 5) the two genes responsible for green pigmentation may be duplicate, 6) more than two types of alleles may have been involved for one or more loci responsible for stem color, 7) root nodulation may be determined by three independent non-duplicate genes, 8) leaflet size may be quasi-quantitatively determined in peanut, 9) extranuclear factors may interact additively and/or epistaticly with nuclear factors determining growth habit, stem color, and leaflet size, 10) the relatively high number of segregating loci observed for all the traits studied may have resulted from the use of A. monticola as one of the parents, and 11) extranuclear factors may induce or modify relationships between traits when they interfere with nuclear genes determining these traits. / M.S.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/90969 |
| Date | January 1987 |
| Creators | Essomba, Nehru Bengono |
| Contributors | Agronomy |
| Publisher | Virginia Polytechnic Institute and State University |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Thesis, Text |
| Format | xi, 70 leaves, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 17391728 |
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