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. The aim of the present study is to examine chromosome variation of female, male, and monoecious nutmeg plants.
The study was started in August 1995 and lasted to September 1996- Microscopic preparation for observation were done in the Central Laboratory of Biological Sciences and photographs were taken in the IUC-Bioteclmology Laboratory of Gadjah Mada University.
New lateral roots of known sex type female, male, and monoecious of nutmeg plants (Myristica succedanea) of PTP XVIII central of Java were induced by putting compost within their rhizosphere. Root tips were collected, fixed in a 1:3 mixture of propionic acid and 95% ethanol, macerated in enzymatic mixture of 0,5% cellulase and 0,5% macerozyme, and finally stained with 45% lacto-propionic-orcein.
The records that collected included number, absolute length, relative length, and shape of the chromosomes. Absolute and relative length of individual chromosome was compared using analysis of variance followed by a LSD test.
The results revealed that the three plant sex groups had similar chromosome number (2n = 34), but did differ either in length (absolute or relative) for some number of chromosomes. Three chromosome formula i.e. 2m + 2sm + 30t, 3m + Ism + 30t, 2m + Ism + 31t for female, male, and monoecious plant respectively was proposed. Chromosome no.1 and 5 might be used to distinguish the female plant from the others as they were submetacentric and telocentric in female plants while the reversal was true in the other two groups. The monoecious plant would be identified from chromosome no_ 2 and 3 as they were metacentric and submetacentric compared to the reversal for the other groups. The absolute and relative length of chromosome no. 30 and 31 of the three sex groups were different to each other. For practical purposes, as identifying female plant is of considerable importance and larger chromosome size is of practical convenience, chromosome no.1 may be used as the sole key for sex determination.
Keywords: nutmeg -- sex determination -- karyotip
