Morphology-based diversity analysis of improved irrigated lowland rice (Oryza sativa L.) varieties in the Philippines
1995
De Leon, J.C. | Carpena, A.L. (Philippine Rice Research Inst., Maligaya, Munoz, Nueva Ecija (Philippines). Div. of Plant Breeding, Genetics and Biotechnology)
The extent of diversity/similarity among the 46 improved irrigated lowland rice cultivars developed by various research institutions located in the Philippines was assessed by calculating their genetic distances on the basis of 20 morphological and agronomic traits. The mean genetic distance for the 1035 possible pairings of the 46 cultivars was 5.9, a relatively much lower value than the maximum obtained of 15.0, suggesting a close morphological resemblance among many of these varieties. A cluster analysis of the standardized genetic distance matrix produced a phenogram depicting 80 percent varietal clustering at around 5.4 genetic distance value. Analysis of the materials by research institution showed that varieties developed by a national agency, which constitute only 20 percent of the materials studied, were the most diverse. A comparison of the results of the study and of one where diversity of the same materials was determined by pedigree analyses indicated that irrigated lowland rice varietal releases in the Philippines in general, resemble a common plant type because they share a common ancestry
显示更多 [+] 显示较少 [-]