Turkish red pine (Pinus brutia ten.) seed characteristics of some seed stands and seed orchards of the same origin in the mediterranean breeding zone

In this study, the morphological and physiological characteristics of seeds obtained from different seed stands (SS) and seed orchards (SO) located within the Mediterranean Tree breeding Zone were comparatively evaluated for the Turkish Red Pine (Pinus brutia Ten.) species. Seed material derived from ten different seed sources distributed across the Mediterranean-Low, Mediterranean-Mid, and Mediterranean-High subzones was analyzed. The investigatedmtraits included 1000-seed weight, moisture content, seed diameter and length, as well as germination percentage (GP) and germination speed (GS). According to breeding zones, 1000-seed weight ranged from 38.2 to 53.8 g, moisture content from 6.42% to 8.68%, seed diameter from 3.31 to 4.50 mm. and seed length from 6.75 to 7.79 mm. Both GP and GS varied significantly among zones and seed sources. The highest GP was recorded in TM-28 located in the Mediterranean-High subzone (70.5%), while the highest GS was obtained from TB-18 within the same zone (38.0%). Comparisons with ORTOHUM harvest-year data indicated that, despite some inter-annual differences, the general ranking of morphological and germination traits remained largely consistent. Overall findings demonstrated pronounced variation in seed morphological and physiological traits across breeding zones. Several seed sources from the Mediterranean-Mid and Mediterranean-High subzones exhibited superior germination capacity and more favorable morphological attributes. The study highlights that seed quality in Turkish red pine is jointly shaped by genetic structure and zone-specific environmental conditions. Therefore, breeding and seed production programs should consider not only adaptive performance but also seed morphology, germination capacity, and physiological robustness as key quality criteria. Furthermore, ensuring long-term sustainability of seed sources requires regular field-level performance monitoring, renewal- and improvement-oriented interventions in low-productivity stands and orchards, and scientifically based selection of new seed orchard sites with regard to soil and microclimatic characteristics.