Relationship of cone and seed traits on progeny growth performance in Casuarina equisetifolia FORST. & FORST.f.

摘要

An experiment was carried out to elucidate the relationship of cone and seed traits on juvenile and adult growth of Casuarina equisetifolia. Cones and seeds were collected from 18 selected trees. Samples of 10 cones and 25 seeds were taken in 4 replications to measure 2D surface area, length, breadth, weight, roundness and aspect ratio. Five seedlings in 4 replications from each seedlot were planted in randomized block design at 2 m spacing. Progeny height and diameter were recorded at the juvenile(18 months after sowing, 18 MAS) and mature (60 months after sowing, 60 MAS) stages. Significance tests and estimations of variability, heritability and genetic advance were carried out. The seed and cone morphological characters were found to have higher heritability and genetic advance values than tree growth characters. Correlation of cone or seed traits on progeny growth characters and path analysis of seed traits on diameter at 60 MAS were carried out. The 100-seed weight was found to be significantly correlated consistently with progeny growth characters both at the juvenile and mature stages. Shape characters like roundness and aspect ratio also showed significant correlation on progeny growth. Juvenile-adult correlation was established with diameter growth of juvenile on both height and diameter growth at 60 MAS. Seed 2D surface area had high direct and indirect effects on diameter at 60 MAS. Identification of better seed sources or grading of seeds may be carried out based on seed weight and/or size and/or shape to get better progenies.