Genetic Variability in West Timor Landrace Maize Populations

Abstract

Genetic variability information, which is a heritable difference among maize cultivars, is important to a long-term plant breeding program. In the last decade a number of researchers have studied the correlation between phenotypic and genetic variability in maize by using Deoxyribonucleic Acid (DNA) markers. Maize landraces as maize cultivars grown ‘on farm’ by farmers who reproduce their seed every year, and they can be distinguished by specific traits, so maize landraces are composed of widely variable populations, where the variation can be seen between and within populations. Five white maize landrace seed samples were obtained from five farmers in each of three villages, Nunmafo, Amol and Ajaobaki; five yellow landrace maize seed samples were obtained from five farmers in Nunmafo village only; while the five certified improved open pollinated varieties (Lamuru, Piet kuning, Bisma, Harapan, Kalingga) were obtained from the Indonesia Cereal Research Institute (ICRI) Maros. The banding patterns of the samples’ fingerprint were evaluated in the scoring range of 50-700bp fragment weight using fragment size standard ladder (Figure 6.3). Image data was viewed on the computer screen and saved in the SAGA computer program. The gel images were scored manually in Excel 2010 program for presence (score 1) or absence (score 0) of bands, and the binary data used for further analysis. The results of this study for AFLP analysis of West Timor maize landrace populations from three villages and varieties have confirmed that there are extensivegenetic variations within West Timor yellow and white maize landrace populations and varieties. There were two clusters of genetic variation among all samples. The first cluster was a general West Timor maize landrace population, with more than 80% similarity among individuals, and the second cluster was amuch more diverse grouping with less than 80% similarity. It suggests that even though a high molecular diversity had been found among West Timor maize landrace populations most maize genotypes belong to a West Timor maize landrace cluster. In addition the analysis indicated not only significant difference between maize landraces and maize varieties but also maize landraces from the three villages were genetically significantly different from each other. The molecular marker characterization of West Timor maize landrace populations will be a key step for obtaining an improved understanding of the population so they can be managed carefully for the future. Moreover, due to the genetic diversity captured within local landraces, farmers have the opportunity to perform the phenotypic selections based on plant type and seed yield which are likely to give them significant genetic gain in yield in subsequent seasons. Plant breeders have the additional opportunity of applying molecular marker techniques to assist selection.