PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Grafting is a safe agro-technique used to boost tolerance against biotic and abiotic stresses and increase crop yield and quality. This study was undertaken to control cucumber Fusarium wilt through grafting onto novel Cucurbit interspecific hybrids and assess their effect on nutrients, defense enzymes in cucumber, and root characteristics. Four crosses were done between two lines of each of Bottle Gourd (Lagenaria siceraria), Winter squash (Cucurbita maxima), Winter squash (C. moshata), and Wild cucumber (C. zambinus). The commercial hybrid rootstock Supper Shintosa was also considered. Results indicated that all hybrid rootstocks, except Bottle Gourd, exhibited a significant decrease in Fusarium wilt severity compared with non-grafted control. Plant height and shoot dry weight of grafted plant were higher than those of the nongrafted control with best results for grafting onto C. moshata. The macro (N, P, K, Ca, and Mg%) and micro (Fe and Zn ppm) nutrient contents in the leaf of grafted plants were more than those of the nongrafted control. The highest macro and micronutrient contents were observed due to grafting onto C. moshata followed by C. maxima. Grafting of cucumber onto resistant rootstocks exhibited a significant increase in activity of peroxidases and polyphenoloxidase enzymes. Furthermore, grafting onto all rootstocks, except C. zambinus, caused an increase in root diameter more than the nongrafted control. Grafted cucumber onto C. maxima rootstock showed the best values in terms of diameter of the root, thickness of the cortex, dimension of vascular bundle, mean diameter of the vessel, and the pith over the nongrafted control.