Grafting for Sustainable Growth Performance of Melon (Cucumis melo) Under Salt Stressed Hydroponic Condition
The aim of the present study was to find out whether grafting could improve salinity tolerance of melon plants, and whether possible induction of tolerance to salinity was linked with the defense of the photosynthetic apparatus. The climate chamber experiment was carried out to determine main stem length, leaf chlorophyll index (SPAD), fresh weight of shoot and root, and root length. Under climate chamber conditions, two melon cultivars [galia type Citirex F1) and standard type (Kirkagac Manisa Altinbas)] were grafted onto two different commercial Cucurbita maxima x C. moschata hybrid rootstocks (Kardosa and Nun 9075) and grown in 8 L pots filled continuously with aerated nutrient solution under two different salt levels (1 and 8 dS/m) with three replications. The results indicated that grafted and un-grafted plants were significantly (P<0.001) affected by different salt levels. Grafted plants had better growth performance than un-grafted plants under both control and saline conditions. The SPAD value of the un-grafted plants significantly decreased as salinity stress increased, while root fresh weight of the grafted plants significantly increased under salinity stress. Under saline conditions the highest shoot fresh weight, and SPAD value were recorded in graft combination Nun 9075/ Citirex. These results suggest that the use of salt tolerant Cucurbita maxima x C. moschata hybrid rootstocks can improve crop performance in melon under salt stress, whereas the appropriate scion/ rootstock combinations under saline conditions will be investigated for fruit yield and quality parameters in further studies.
Keywords: Commercial rootstock, salinity tolerance, nutrient solution, grafting, melon