Genetic and Phenotypic Parameters for Growth Traits of Widdringtonia whytei-Rendle Translocation Provenance Trials in Malawi

Abstract

Prediction of genetic potential and response to selection in breeding needs knowledge of genetic parameters for important selection traits. This study aimed to estimate genetic and phenotypic parameters for growth traits (diameter at breast height (DBH) and total height) of Widdringtonia whytei (Mulanje cedar) grown in Malawi. Data on growth traits were collected from five provenance trial sites at the age of 5. The results portrayed that there were significant (P<0.05) differences in genetic and phenotypic parameters among sites. Dedza and Luwawa sites had a higher genetic control for both DBH (h2=0.382 and 0.354) and height (h2=0.354 and 0.329), respectively. Correspondingly, Dedza and Luwawa sites registered a higher Additive Genetic Coefficient of Variation percent (AGCV%) for both DBH (62.3% and 69.8%) and height (96.2% and 53.5%), respectively. Likewise, Dedza and Luwawa sites recorded higher genetic gain for both DBH (0.165 and 0.118) and height (0.127 and 0.121), respectively. The genetic and phenotypic correlations between DBH and height parameters were significantly favourable and high; ranging from 0.664 to 0.917 and from 0.635 to 0.914, respectively. This warrants simultaneous improvement of DBH and height traits. These estimated parameters shall live to guide the establishment and refinement of the W. whytei breeding programme in Malawi.