Estimation of genetic correlation and heritability of characteristics of Haloxylon persicum Bge. in the seed orchard of the Yazd Province, Iran

The aim of this study was to estimate the genetic parameters of Haloxylon persicum Bge., based on a progeny test in seed orchards of Yazd province using the REML method. For this purpose, 60 trees with good appearance, optimum quality, the relative balance between crown and trunk, resistant to pests and diseases, and with high germination seeds were selected among the Haloxylon persicum stands in different habitats of Yazd province. After seed planting and seedling production, they were transplanted into the field by preserving the tree and planted on rows with 6 m intervals. The final traits for genetic evaluation of genotypes were continuously recorded during 5 years of project implementation in three times. The studied traits consisted mainly of vegetative traits such as height, crown spreading, trunk diameter, number of branches, freshness, seed production and contamination of powder and psyllium. The results showed the highest genetic correlations between trunk and crown diameter and height and contamination with powder. The results also indicated a high environmental correlation between those traits. However, environmental correlations were estimated to be lower than genetic correlations, which indicated a greater genetic contribution to diversity among the trees. Estimation of heritability of traits also showed that the highest heritability was related to the height and diameter of the crown and the least to powder contamination. Moreover, freshness were estimated to be 0.619, 0.616, 0.509, 0.335, 0.170, and 0.20, respectively.