Genetic diversity of the chemical composition and pod production of Prosopis juliflora trees grown in Saudi Arabia

Abstract

This investigation was conducted to evaluate pod and chemical component traits and the genetic diversity of Prosopis juliflora genotypes at two locations. The selected locations were in the middle (Qassim region) and western (Jeddah region) areas, representing two agro-climatic zones of Saudi Arabia. The measured pod characteristics included production, weight, length, filling period, and chemical composition. A wide range of variations in pod yield and chemical traits were observed in the different agro-climatic regions. The results revealed that the mean values ranged from 9.5 kg tree−1 (Jeddah) to 14.2 kg tree−1 (Qassim) for pod yield, 3.1 g pod−1 (Qassim) to 3.7 g pod−1 (Jeddah) for pod weight, and 14.8 cm (Qassim) to 16.6 cm (Jiddah) for pod length. The results of genetic diversity indicated that Prosopis genotypes in each location were distributed in three different clusters in the two regions at 60 Euclidean distances. The principal component analysis (PCA) showed that the two components (PC1 and PC2) explained 25.03 % and 20.03 % of the overall variance, respectively, which is over 45 % of the variability. The heatmap revealed that genotypes Q20, Q21, and Q24 at the Qassim location and genotypes J1, J6, and J7 at the Jiddah location exhibited positive and significant correlations with pod yield. It can be concluded that superior Prosopis genotypes (Q20, Q21, Q24, J1, J6, and J7) were identified with good traits (pod yield, pod-filling period, and protein %) in each location and may be used in the future for the selection of elite genotypes.

Keywords

• Prosopis plant
• Pod production
• Chemical composition
• Genetic diversity
• Cluster analysis
• Heatmap