ศึกษาการเข้ากันได้ของต้นตอยางพาราที่ทนทานต่อโรครากข้าวกับพันธุ์ RRIM 600

Abstract

Compatibility of the white root disease tolerant rootstocks of rubber clones with RRIM 600 was investigated. The objectives of this study were 1) to search for rubber rootstocks that exhibit high growth rate with a good root system and tolerance to white root disease, and 2) to determinate the interaction between rootstock and scion (RRIM 600). The experiments were conducted at the Faculty of Natural Resources, Prince of Songkla University, Songkhla Province. Seeds were collected from 5 local rubber clones. Seedlings from each clone were chosen and transferred to rhizoboxes (10x45x100 cm). All rootstocks were budded with RRIM 600. The experimental design was arranged as completely randomized designs (CRD) with 4 replications. It was found that clone#5 gave the highest values of the following characters: high root length density (1.26 cm/cm2), plant height (182.50 cm) and stem diameter (12.49 mm) with significant differences from other clones. Clone RRIM 600 had the highest root-shoot ratio (1.13). After 4 weeks of budding, the rootstock of the RRIM 600 clone and clone#4 exhibited 100% successful budding, whereas the other clones were 75% successful. The investigation of graft union development showed that callus tissues developed on the graft union after 5 days of budding. Graft union growth was almost fully developed on the wound areas and connected with the old tissues after 10 days of budding. Cambium bridge and new vascular tissues were connected with old cambium and vascular tissues of scion and rootstocks after 20 days of budding. The physiological responses of clone RRIM 600 as scion on the rootstock of local rubber clones after budding showed that average photosynthetic rate, stomatal conductance and transpiration rate were not significantly different among the treatments. However, leaf greenness values were significantly different when compared with the other clones. Clone#5 provided the highest leaf greenness value (56.52). It is suggested clone#5 is most suitable for use as a rootstock.