African Journal of
Plant Science

  • Abbreviation: Afr. J. Plant Sci.
  • Language: English
  • ISSN: 1996-0824
  • DOI: 10.5897/AJPS
  • Start Year: 2007
  • Published Articles: 718

Full Length Research Paper

Assessment of phenotypic diversity of macadamia (Macadamia spp) germplasm in Kenya using leaf and fruit morphology

Lucy Gitonga1, 2, Esther Kahangi2, Anne Muigai3, Kamau Ngamau2, Simon Gichuki4, Wilson Cheluget1 and Simon Wepukhulu1
  1Kenya Agricultural Research Institute, National Horticultural Research Center, P. O. box 01000- 220, Thika, Kenya. 2Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 00200-62000, Nairobi, Kenya. 3Department of Botany, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 00200-62000, Nairobi, Kenya. 4Kenya Agricultural Research Institute, Biotechnology Center, P. O. Box 00200-57811, Nairobi, Kenya.
Email: [email protected]

  •  Accepted: 16 September 2008
  •  Published: 30 September 2008

Abstract

The ability to identify genetic variation is indispensable to effective management and use of genetic resources. Morphological traits are among the earliest markers used in germplasm characterization and management. Leaf and fruit morphological characteristics were recorded for 23 cultivars of Macadamia using a sample of 30 for each trait and replicated three times. The analysis of variance revealed significant differences in leaf length, width, petiole length and leaf marginal serrations. Significant differences were also revealed in fruit cluster length, number of fruits per cluster, fruit length but not fruit width. Cluster analysis using R statistics grouped the accessions into three major clusters referring to the two cultivated Macadamia species; Macadamia integrifolia and Macadamia tetraphylladisplaying the highest dissimilarity, and the hybrids at the intermediate position. These markers are found to be reliable in distinguishing between the macadamia cultivars in Kenya. Among the markers, leaf petiole and marginal serrations are easily assessable and possible to use in distinguishing between the species.

 

Key words: Genetic diversity, macadamia germplasm, morphological markers, cluster analysis.