EFFECT OF ROOTSTOCK ON THE GROWTH, PHOTOSYNTHETIC CAPACITY AND OSMOTIC ADJUSTMENT OF EGGPLANT SEEDLINGS UNDER CHILLING STRESS AND RECOVERY

Abstract

Increasing evidences have shown that grafting can confer enhanced the resistance of many plant species to various biotic and abiotic stresses, but there is little information about the effects of grafting on the growth of eggplant plants under cold stress conditions. In this study, the eggplant (Jiza long eggplant) seedlings were grafted onto ‘Hiranasu’ and ‘Taibyo’ rootstocks, treated with low temperature (10/5ºC, day/night), and then recovered under normal conditions (25/18ºC, day/night). Meanwhile, we compared analysis of several physiological parameters among the non-grafted and two kinds of grafted plants. Our data revealed that cold stress resulted in a remarkable decrease in photosynthetic parameters of two kinds of grafted seedlings (‘Taibyo’and ‘Hiranasu’ as rootstocks) and non-grafted seedlings. However, the reduction in photosynthetic parameters was observed lower in the grafted plants with the cold-tolerant rootstocks (‘Hiranasu’) than those with the cold-sensitive rootstocks (‘Taibyo’). It was observed that these parameters were recovered more rapidly in the grafted plants with ‘Hiranasu’ rootstocks under normal conditions. Therefore, it can be concluded that grafting promotes the growth of eggplant seedlings with increased photosynthetic efficiency under cold stress and recovery as compared to nongrafted plants. Moreover, the grafted plants with the cold-tolerant rootstocks displayed better growth traits under cold stress.